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clang-p2996/llvm/test/Transforms/SimpleLoopUnswitch/nontrivial-unswitch.ll
Chandler Carruth 1652996fd6 [PM/LoopUnswitch] Teach the new unswitch to handle nontrivial 
unswitching of switches.

This works much like trivial unswitching of switches in that it reliably
moves the switch out of the loop. Here we potentially clone the entire
loop into each successor of the switch and re-point the cases at these
clones.

Due to the complexity of actually doing nontrivial unswitching, this
patch doesn't create a dedicated routine for handling switches -- it
would duplicate far too much code. Instead, it generalizes the existing
routine to handle both branches and switches as it largely reduces to
looping in a few places instead of doing something once. This actually
improves the results in some cases with branches due to being much more
careful about how dead regions of code are managed. With branches,
because exactly one clone is created and there are exactly two edges
considered, somewhat sloppy handling of the dead regions of code was
sufficient in most cases. But with switches, there are much more
complicated patterns of dead code and so I've had to move to a more
robust model generally. We still do as much pruning of the dead code
early as possible because that allows us to avoid even cloning the code.

This also surfaced another problem with nontrivial unswitching before
which is that we weren't as precise in reconstructing loops as we could
have been. This seems to have been mostly harmless, but resulted in
pointless LCSSA PHI nodes and other unnecessary cruft. With switches, we
have to get this *right*, and everything benefits from it.

While the testing may seem a bit light here because we only have two
real cases with actual switches, they do a surprisingly good job of
exercising numerous edge cases. Also, because we share the logic with
branches, most of the changes in this patch are reasonably well covered
by existing tests.

The new unswitch now has all of the same fundamental power as the old
one with the exception of the single unsound case of *partial* switch
unswitching -- that really is just loop specialization and not
unswitching at all. It doesn't fit into the canonicalization model in
any way. We can add a loop specialization pass that runs late based on
profile data if important test cases ever come up here.

Differential Revision: https://reviews.llvm.org/D47683

llvm-svn: 335553
2018-06-25 23:32:54 +00:00

2964 lines
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; RUN: opt -passes='loop(unswitch),verify<loops>' -enable-nontrivial-unswitch -S < %s | FileCheck %s
; RUN: opt -simple-loop-unswitch -enable-nontrivial-unswitch -S < %s | FileCheck %s
declare void @a()
declare void @b()
declare void @c()
declare void @d()
declare void @sink1(i32)
declare void @sink2(i32)
; Negative test: we cannot unswitch convergent calls.
define void @test_no_unswitch_convergent(i1* %ptr, i1 %cond) {
; CHECK-LABEL: @test_no_unswitch_convergent(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br label %loop_begin
;
; We shouldn't have unswitched into any other block either.
; CHECK-NOT: br i1 %cond
loop_begin:
br i1 %cond, label %loop_a, label %loop_b
; CHECK: loop_begin:
; CHECK-NEXT: br i1 %cond, label %loop_a, label %loop_b
loop_a:
call void @a() convergent
br label %loop_latch
loop_b:
call void @b()
br label %loop_latch
loop_latch:
%v = load i1, i1* %ptr
br i1 %v, label %loop_begin, label %loop_exit
loop_exit:
ret void
}
; Negative test: we cannot unswitch noduplicate calls.
define void @test_no_unswitch_noduplicate(i1* %ptr, i1 %cond) {
; CHECK-LABEL: @test_no_unswitch_noduplicate(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br label %loop_begin
;
; We shouldn't have unswitched into any other block either.
; CHECK-NOT: br i1 %cond
loop_begin:
br i1 %cond, label %loop_a, label %loop_b
; CHECK: loop_begin:
; CHECK-NEXT: br i1 %cond, label %loop_a, label %loop_b
loop_a:
call void @a() noduplicate
br label %loop_latch
loop_b:
call void @b()
br label %loop_latch
loop_latch:
%v = load i1, i1* %ptr
br i1 %v, label %loop_begin, label %loop_exit
loop_exit:
ret void
}
declare i32 @__CxxFrameHandler3(...)
; Negative test: we cannot unswitch when tokens are used across blocks as we
; might introduce PHIs.
define void @test_no_unswitch_cross_block_token(i1* %ptr, i1 %cond) nounwind personality i32 (...)* @__CxxFrameHandler3 {
; CHECK-LABEL: @test_no_unswitch_cross_block_token(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br label %loop_begin
;
; We shouldn't have unswitched into any other block either.
; CHECK-NOT: br i1 %cond
loop_begin:
br i1 %cond, label %loop_a, label %loop_b
; CHECK: loop_begin:
; CHECK-NEXT: br i1 %cond, label %loop_a, label %loop_b
loop_a:
call void @a()
br label %loop_cont
loop_b:
call void @b()
br label %loop_cont
loop_cont:
invoke void @a()
to label %loop_latch unwind label %loop_catch
loop_latch:
br label %loop_begin
loop_catch:
%catch = catchswitch within none [label %loop_catch_latch, label %loop_exit] unwind to caller
loop_catch_latch:
%catchpad_latch = catchpad within %catch []
catchret from %catchpad_latch to label %loop_begin
loop_exit:
%catchpad_exit = catchpad within %catch []
catchret from %catchpad_exit to label %exit
exit:
ret void
}
; Non-trivial loop unswitching where there are two distinct trivial conditions
; to unswitch within the loop.
define i32 @test1(i1* %ptr, i1 %cond1, i1 %cond2) {
; CHECK-LABEL: @test1(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 %cond1, label %entry.split.us, label %entry.split
loop_begin:
br i1 %cond1, label %loop_a, label %loop_b
loop_a:
call void @a()
br label %latch
; The 'loop_a' unswitched loop.
;
; CHECK: entry.split.us:
; CHECK-NEXT: br label %loop_begin.us
;
; CHECK: loop_begin.us:
; CHECK-NEXT: br label %loop_a.us
;
; CHECK: loop_a.us:
; CHECK-NEXT: call void @a()
; CHECK-NEXT: br label %latch.us
;
; CHECK: latch.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_begin.us, label %loop_exit.split.us
;
; CHECK: loop_exit.split.us:
; CHECK-NEXT: br label %loop_exit
loop_b:
br i1 %cond2, label %loop_b_a, label %loop_b_b
; The second unswitched condition.
;
; CHECK: entry.split:
; CHECK-NEXT: br i1 %cond2, label %entry.split.split.us, label %entry.split.split
loop_b_a:
call void @b()
br label %latch
; The 'loop_b_a' unswitched loop.
;
; CHECK: entry.split.split.us:
; CHECK-NEXT: br label %loop_begin.us1
;
; CHECK: loop_begin.us1:
; CHECK-NEXT: br label %loop_b.us
;
; CHECK: loop_b.us:
; CHECK-NEXT: br label %loop_b_a.us
;
; CHECK: loop_b_a.us:
; CHECK-NEXT: call void @b()
; CHECK-NEXT: br label %latch.us2
;
; CHECK: latch.us2:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_begin.us1, label %loop_exit.split.split.us
;
; CHECK: loop_exit.split.split.us:
; CHECK-NEXT: br label %loop_exit.split
loop_b_b:
call void @c()
br label %latch
; The 'loop_b_b' unswitched loop.
;
; CHECK: entry.split.split:
; CHECK-NEXT: br label %loop_begin
;
; CHECK: loop_begin:
; CHECK-NEXT: br label %loop_b
;
; CHECK: loop_b:
; CHECK-NEXT: br label %loop_b_b
;
; CHECK: loop_b_b:
; CHECK-NEXT: call void @c()
; CHECK-NEXT: br label %latch
;
; CHECK: latch:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_begin, label %loop_exit.split.split
;
; CHECK: loop_exit.split.split:
; CHECK-NEXT: br label %loop_exit.split
latch:
%v = load i1, i1* %ptr
br i1 %v, label %loop_begin, label %loop_exit
loop_exit:
ret i32 0
; CHECK: loop_exit.split:
; CHECK-NEXT: br label %loop_exit
;
; CHECK: loop_exit:
; CHECK-NEXT: ret
}
define i32 @test2(i1* %ptr, i1 %cond1, i32* %a.ptr, i32* %b.ptr, i32* %c.ptr) {
; CHECK-LABEL: @test2(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 %cond1, label %entry.split.us, label %entry.split
loop_begin:
%v = load i1, i1* %ptr
br i1 %cond1, label %loop_a, label %loop_b
loop_a:
%a = load i32, i32* %a.ptr
%ac = load i32, i32* %c.ptr
br i1 %v, label %loop_begin, label %loop_exit
; The 'loop_a' unswitched loop.
;
; CHECK: entry.split.us:
; CHECK-NEXT: br label %loop_begin.us
;
; CHECK: loop_begin.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br label %loop_a.us
;
; CHECK: loop_a.us:
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: %[[AC:.*]] = load i32, i32* %c.ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_begin.backedge.us, label %loop_exit.split.us
;
; CHECK: loop_exit.split.us:
; CHECK-NEXT: %[[A_LCSSA:.*]] = phi i32 [ %[[A]], %loop_a.us ]
; CHECK-NEXT: %[[AC_LCSSA:.*]] = phi i32 [ %[[AC]], %loop_a.us ]
; CHECK-NEXT: br label %loop_exit
loop_b:
%b = load i32, i32* %b.ptr
%bc = load i32, i32* %c.ptr
br i1 %v, label %loop_begin, label %loop_exit
; The 'loop_b' unswitched loop.
;
; CHECK: entry.split:
; CHECK-NEXT: br label %loop_begin
;
; CHECK: loop_begin:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br label %loop_b
;
; CHECK: loop_b:
; CHECK-NEXT: %[[B:.*]] = load i32, i32* %b.ptr
; CHECK-NEXT: %[[BC:.*]] = load i32, i32* %c.ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_begin.backedge, label %loop_exit.split
;
; CHECK: loop_exit.split:
; CHECK-NEXT: %[[B_LCSSA:.*]] = phi i32 [ %[[B]], %loop_b ]
; CHECK-NEXT: %[[BC_LCSSA:.*]] = phi i32 [ %[[BC]], %loop_b ]
; CHECK-NEXT: br label %loop_exit
loop_exit:
%ab.phi = phi i32 [ %a, %loop_a ], [ %b, %loop_b ]
%c.phi = phi i32 [ %ac, %loop_a ], [ %bc, %loop_b ]
%result = add i32 %ab.phi, %c.phi
ret i32 %result
; CHECK: loop_exit:
; CHECK-NEXT: %[[AB_PHI:.*]] = phi i32 [ %[[B_LCSSA]], %loop_exit.split ], [ %[[A_LCSSA]], %loop_exit.split.us ]
; CHECK-NEXT: %[[C_PHI:.*]] = phi i32 [ %[[BC_LCSSA]], %loop_exit.split ], [ %[[AC_LCSSA]], %loop_exit.split.us ]
; CHECK-NEXT: %[[RESULT:.*]] = add i32 %[[AB_PHI]], %[[C_PHI]]
; CHECK-NEXT: ret i32 %[[RESULT]]
}
; Test a non-trivial unswitch of an exiting edge to an exit block with other
; in-loop predecessors.
define i32 @test3a(i1* %ptr, i1 %cond1, i32* %a.ptr, i32* %b.ptr) {
; CHECK-LABEL: @test3a(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 %cond1, label %entry.split.us, label %entry.split
loop_begin:
%v = load i1, i1* %ptr
%a = load i32, i32* %a.ptr
br i1 %cond1, label %loop_exit, label %loop_b
; The 'loop_exit' clone.
;
; CHECK: entry.split.us:
; CHECK-NEXT: br label %loop_begin.us
;
; CHECK: loop_begin.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %loop_exit.split.us
;
; CHECK: loop_exit.split.us:
; CHECK-NEXT: %[[A_LCSSA:.*]] = phi i32 [ %[[A]], %loop_begin.us ]
; CHECK-NEXT: br label %loop_exit
loop_b:
%b = load i32, i32* %b.ptr
br i1 %v, label %loop_begin, label %loop_exit
; The 'loop_b' unswitched loop.
;
; CHECK: entry.split:
; CHECK-NEXT: br label %loop_begin
;
; CHECK: loop_begin:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %loop_b
;
; CHECK: loop_b:
; CHECK-NEXT: %[[B:.*]] = load i32, i32* %b.ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_begin, label %loop_exit.split
;
; CHECK: loop_exit.split:
; CHECK-NEXT: %[[B_LCSSA:.*]] = phi i32 [ %[[B]], %loop_b ]
; CHECK-NEXT: br label %loop_exit
loop_exit:
%ab.phi = phi i32 [ %a, %loop_begin ], [ %b, %loop_b ]
ret i32 %ab.phi
; CHECK: loop_exit:
; CHECK-NEXT: %[[AB_PHI:.*]] = phi i32 [ %[[B_LCSSA]], %loop_exit.split ], [ %[[A_LCSSA]], %loop_exit.split.us ]
; CHECK-NEXT: ret i32 %[[AB_PHI]]
}
; Test a non-trivial unswitch of an exiting edge to an exit block with other
; in-loop predecessors. This is the same as @test3a but with the reversed order
; of successors so that the exiting edge is *not* the cloned edge.
define i32 @test3b(i1* %ptr, i1 %cond1, i32* %a.ptr, i32* %b.ptr) {
; CHECK-LABEL: @test3b(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 %cond1, label %entry.split.us, label %entry.split
loop_begin:
%v = load i1, i1* %ptr
%a = load i32, i32* %a.ptr
br i1 %cond1, label %loop_b, label %loop_exit
; The 'loop_b' unswitched loop.
;
; CHECK: entry.split.us:
; CHECK-NEXT: br label %loop_begin.us
;
; CHECK: loop_begin.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %loop_b.us
;
; CHECK: loop_b.us:
; CHECK-NEXT: %[[B:.*]] = load i32, i32* %b.ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_begin.us, label %loop_exit.split.us
;
; CHECK: loop_exit.split.us:
; CHECK-NEXT: %[[B_LCSSA:.*]] = phi i32 [ %[[B]], %loop_b.us ]
; CHECK-NEXT: br label %loop_exit
loop_b:
%b = load i32, i32* %b.ptr
br i1 %v, label %loop_begin, label %loop_exit
; The original loop, now non-looping due to unswitching..
;
; CHECK: entry.split:
; CHECK-NEXT: br label %loop_begin
;
; CHECK: loop_begin:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %loop_exit.split
;
; CHECK: loop_exit.split:
; CHECK-NEXT: br label %loop_exit
loop_exit:
%ab.phi = phi i32 [ %b, %loop_b ], [ %a, %loop_begin ]
ret i32 %ab.phi
; CHECK: loop_exit:
; CHECK-NEXT: %[[AB_PHI:.*]] = phi i32 [ %[[A]], %loop_exit.split ], [ %[[B_LCSSA]], %loop_exit.split.us ]
; CHECK-NEXT: ret i32 %[[AB_PHI]]
}
; Test a non-trivial unswitch of an exiting edge to an exit block with no other
; in-loop predecessors.
define void @test4a(i1* %ptr, i1 %cond1, i32* %a.ptr, i32* %b.ptr) {
; CHECK-LABEL: @test4a(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 %cond1, label %entry.split.us, label %entry.split
loop_begin:
%v = load i1, i1* %ptr
%a = load i32, i32* %a.ptr
br i1 %cond1, label %loop_exit1, label %loop_b
; The 'loop_exit' clone.
;
; CHECK: entry.split.us:
; CHECK-NEXT: br label %loop_begin.us
;
; CHECK: loop_begin.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %loop_exit1.split.us
;
; CHECK: loop_exit1.split.us:
; CHECK-NEXT: %[[A_LCSSA:.*]] = phi i32 [ %[[A]], %loop_begin.us ]
; CHECK-NEXT: br label %loop_exit1
loop_b:
%b = load i32, i32* %b.ptr
br i1 %v, label %loop_begin, label %loop_exit2
; The 'loop_b' unswitched loop.
;
; CHECK: entry.split:
; CHECK-NEXT: br label %loop_begin
;
; CHECK: loop_begin:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %loop_b
;
; CHECK: loop_b:
; CHECK-NEXT: %[[B:.*]] = load i32, i32* %b.ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_begin, label %loop_exit2
loop_exit1:
%a.phi = phi i32 [ %a, %loop_begin ]
call void @sink1(i32 %a.phi)
ret void
; CHECK: loop_exit1:
; CHECK-NEXT: call void @sink1(i32 %[[A_LCSSA]])
; CHECK-NEXT: ret void
loop_exit2:
%b.phi = phi i32 [ %b, %loop_b ]
call void @sink2(i32 %b.phi)
ret void
; CHECK: loop_exit2:
; CHECK-NEXT: %[[B_LCSSA:.*]] = phi i32 [ %[[B]], %loop_b ]
; CHECK-NEXT: call void @sink2(i32 %[[B_LCSSA]])
; CHECK-NEXT: ret void
}
; Test a non-trivial unswitch of an exiting edge to an exit block with no other
; in-loop predecessors. This is the same as @test4a but with the edges reversed
; so that the exiting edge is *not* the cloned edge.
define void @test4b(i1* %ptr, i1 %cond1, i32* %a.ptr, i32* %b.ptr) {
; CHECK-LABEL: @test4b(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 %cond1, label %entry.split.us, label %entry.split
loop_begin:
%v = load i1, i1* %ptr
%a = load i32, i32* %a.ptr
br i1 %cond1, label %loop_b, label %loop_exit1
; The 'loop_b' clone.
;
; CHECK: entry.split.us:
; CHECK-NEXT: br label %loop_begin.us
;
; CHECK: loop_begin.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %loop_b.us
;
; CHECK: loop_b.us:
; CHECK-NEXT: %[[B:.*]] = load i32, i32* %b.ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_begin.us, label %loop_exit2.split.us
;
; CHECK: loop_exit2.split.us:
; CHECK-NEXT: %[[B_LCSSA:.*]] = phi i32 [ %[[B]], %loop_b.us ]
; CHECK-NEXT: br label %loop_exit2
loop_b:
%b = load i32, i32* %b.ptr
br i1 %v, label %loop_begin, label %loop_exit2
; The 'loop_exit' unswitched path.
;
; CHECK: entry.split:
; CHECK-NEXT: br label %loop_begin
;
; CHECK: loop_begin:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %loop_exit1
loop_exit1:
%a.phi = phi i32 [ %a, %loop_begin ]
call void @sink1(i32 %a.phi)
ret void
; CHECK: loop_exit1:
; CHECK-NEXT: %[[A_PHI:.*]] = phi i32 [ %[[A]], %loop_begin ]
; CHECK-NEXT: call void @sink1(i32 %[[A_PHI]])
; CHECK-NEXT: ret void
loop_exit2:
%b.phi = phi i32 [ %b, %loop_b ]
call void @sink2(i32 %b.phi)
ret void
; CHECK: loop_exit2:
; CHECK-NEXT: call void @sink2(i32 %[[B_LCSSA]])
; CHECK-NEXT: ret void
}
; Test a non-trivial unswitch of an exiting edge to an exit block with no other
; in-loop predecessors. This is the same as @test4a but with a common merge
; block after the independent loop exits. This requires a different structural
; update to the dominator tree.
define void @test4c(i1* %ptr, i1 %cond1, i32* %a.ptr, i32* %b.ptr) {
; CHECK-LABEL: @test4c(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 %cond1, label %entry.split.us, label %entry.split
loop_begin:
%v = load i1, i1* %ptr
%a = load i32, i32* %a.ptr
br i1 %cond1, label %loop_exit1, label %loop_b
; The 'loop_exit' clone.
;
; CHECK: entry.split.us:
; CHECK-NEXT: br label %loop_begin.us
;
; CHECK: loop_begin.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %loop_exit1.split.us
;
; CHECK: loop_exit1.split.us:
; CHECK-NEXT: %[[A_LCSSA:.*]] = phi i32 [ %[[A]], %loop_begin.us ]
; CHECK-NEXT: br label %loop_exit1
loop_b:
%b = load i32, i32* %b.ptr
br i1 %v, label %loop_begin, label %loop_exit2
; The 'loop_b' unswitched loop.
;
; CHECK: entry.split:
; CHECK-NEXT: br label %loop_begin
;
; CHECK: loop_begin:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %loop_b
;
; CHECK: loop_b:
; CHECK-NEXT: %[[B:.*]] = load i32, i32* %b.ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_begin, label %loop_exit2
loop_exit1:
%a.phi = phi i32 [ %a, %loop_begin ]
call void @sink1(i32 %a.phi)
br label %exit
; CHECK: loop_exit1:
; CHECK-NEXT: call void @sink1(i32 %[[A_LCSSA]])
; CHECK-NEXT: br label %exit
loop_exit2:
%b.phi = phi i32 [ %b, %loop_b ]
call void @sink2(i32 %b.phi)
br label %exit
; CHECK: loop_exit2:
; CHECK-NEXT: %[[B_LCSSA:.*]] = phi i32 [ %[[B]], %loop_b ]
; CHECK-NEXT: call void @sink2(i32 %[[B_LCSSA]])
; CHECK-NEXT: br label %exit
exit:
ret void
; CHECK: exit:
; CHECK-NEXT: ret void
}
; Test that we can unswitch a condition out of multiple layers of a loop nest.
define i32 @test5(i1* %ptr, i1 %cond1, i32* %a.ptr, i32* %b.ptr) {
; CHECK-LABEL: @test5(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 %cond1, label %loop_begin.split.us, label %entry.split
;
; CHECK: entry.split:
; CHECK-NEXT: br label %loop_begin
;
; CHECK: loop_begin:
; CHECK-NEXT: br label %loop_begin.split
loop_begin:
br label %inner_loop_begin
inner_loop_begin:
%v = load i1, i1* %ptr
%a = load i32, i32* %a.ptr
br i1 %cond1, label %loop_exit, label %inner_loop_b
; The 'loop_exit' clone.
;
; CHECK: loop_begin.split.us:
; CHECK-NEXT: br label %inner_loop_begin.us
;
; CHECK: inner_loop_begin.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %loop_exit.loopexit.split.us
;
; CHECK: loop_exit.loopexit.split.us:
; CHECK-NEXT: %[[A_LCSSA:.*]] = phi i32 [ %[[A]], %inner_loop_begin.us ]
; CHECK-NEXT: br label %loop_exit
inner_loop_b:
%b = load i32, i32* %b.ptr
br i1 %v, label %inner_loop_begin, label %loop_latch
; The 'inner_loop_b' unswitched loop.
;
; CHECK: loop_begin.split:
; CHECK-NEXT: br label %inner_loop_begin
;
; CHECK: inner_loop_begin:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %inner_loop_b
;
; CHECK: inner_loop_b:
; CHECK-NEXT: %[[B:.*]] = load i32, i32* %b.ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_loop_begin, label %loop_latch
loop_latch:
%b.phi = phi i32 [ %b, %inner_loop_b ]
%v2 = load i1, i1* %ptr
br i1 %v2, label %loop_begin, label %loop_exit
; CHECK: loop_latch:
; CHECK-NEXT: %[[B_INNER_LCSSA:.*]] = phi i32 [ %[[B]], %inner_loop_b ]
; CHECK-NEXT: %[[V2:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V2]], label %loop_begin, label %loop_exit.loopexit1
loop_exit:
%ab.phi = phi i32 [ %a, %inner_loop_begin ], [ %b.phi, %loop_latch ]
ret i32 %ab.phi
; CHECK: loop_exit.loopexit:
; CHECK-NEXT: br label %loop_exit
;
; CHECK: loop_exit.loopexit1:
; CHECK-NEXT: %[[B_LCSSA:.*]] = phi i32 [ %[[B_INNER_LCSSA]], %loop_latch ]
; CHECK-NEXT: br label %loop_exit
;
; CHECK: loop_exit:
; CHECK-NEXT: %[[AB_PHI:.*]] = phi i32 [ %[[A_LCSSA]], %loop_exit.loopexit ], [ %[[B_LCSSA]], %loop_exit.loopexit1 ]
; CHECK-NEXT: ret i32 %[[AB_PHI]]
}
; Test that we can unswitch a condition where we end up only cloning some of
; the nested loops and needing to delete some of the nested loops.
define i32 @test6(i1* %ptr, i1 %cond1, i32* %a.ptr, i32* %b.ptr) {
; CHECK-LABEL: @test6(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 %cond1, label %entry.split.us, label %entry.split
loop_begin:
%v = load i1, i1* %ptr
br i1 %cond1, label %loop_a, label %loop_b
loop_a:
br label %loop_a_inner
loop_a_inner:
%va = load i1, i1* %ptr
%a = load i32, i32* %a.ptr
br i1 %va, label %loop_a_inner, label %loop_a_inner_exit
loop_a_inner_exit:
%a.lcssa = phi i32 [ %a, %loop_a_inner ]
br label %latch
; The 'loop_a' cloned loop.
;
; CHECK: entry.split.us:
; CHECK-NEXT: br label %loop_begin.us
;
; CHECK: loop_begin.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br label %loop_a.us
;
; CHECK: loop_a.us:
; CHECK-NEXT: br label %loop_a_inner.us
;
; CHECK: loop_a_inner.us
; CHECK-NEXT: %[[VA:.*]] = load i1, i1* %ptr
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br i1 %[[VA]], label %loop_a_inner.us, label %loop_a_inner_exit.us
;
; CHECK: loop_a_inner_exit.us:
; CHECK-NEXT: %[[A_INNER_LCSSA:.*]] = phi i32 [ %[[A]], %loop_a_inner.us ]
; CHECK-NEXT: br label %latch.us
;
; CHECK: latch.us:
; CHECK-NEXT: %[[A_PHI:.*]] = phi i32 [ %[[A_INNER_LCSSA]], %loop_a_inner_exit.us ]
; CHECK-NEXT: br i1 %[[V]], label %loop_begin.us, label %loop_exit.split.us
;
; CHECK: loop_exit.split.us:
; CHECK-NEXT: %[[A_LCSSA:.*]] = phi i32 [ %[[A_PHI]], %latch.us ]
; CHECK-NEXT: br label %loop_exit
loop_b:
br label %loop_b_inner
loop_b_inner:
%vb = load i1, i1* %ptr
%b = load i32, i32* %b.ptr
br i1 %vb, label %loop_b_inner, label %loop_b_inner_exit
loop_b_inner_exit:
%b.lcssa = phi i32 [ %b, %loop_b_inner ]
br label %latch
latch:
%ab.phi = phi i32 [ %a.lcssa, %loop_a_inner_exit ], [ %b.lcssa, %loop_b_inner_exit ]
br i1 %v, label %loop_begin, label %loop_exit
; The 'loop_b' unswitched loop.
;
; CHECK: entry.split:
; CHECK-NEXT: br label %loop_begin
;
; CHECK: loop_begin:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br label %loop_b
;
; CHECK: loop_b:
; CHECK-NEXT: br label %loop_b_inner
;
; CHECK: loop_b_inner
; CHECK-NEXT: %[[VB:.*]] = load i1, i1* %ptr
; CHECK-NEXT: %[[B:.*]] = load i32, i32* %b.ptr
; CHECK-NEXT: br i1 %[[VB]], label %loop_b_inner, label %loop_b_inner_exit
;
; CHECK: loop_b_inner_exit:
; CHECK-NEXT: %[[B_INNER_LCSSA:.*]] = phi i32 [ %[[B]], %loop_b_inner ]
; CHECK-NEXT: br label %latch
;
; CHECK: latch:
; CHECK-NEXT: br i1 %[[V]], label %loop_begin, label %loop_exit.split
;
; CHECK: loop_exit.split:
; CHECK-NEXT: %[[B_LCSSA:.*]] = phi i32 [ %[[B_INNER_LCSSA]], %latch ]
; CHECK-NEXT: br label %loop_exit
loop_exit:
%ab.lcssa = phi i32 [ %ab.phi, %latch ]
ret i32 %ab.lcssa
; CHECK: loop_exit:
; CHECK-NEXT: %[[AB_PHI:.*]] = phi i32 [ %[[B_LCSSA]], %loop_exit.split ], [ %[[A_LCSSA]], %loop_exit.split.us ]
; CHECK-NEXT: ret i32 %[[AB_PHI]]
}
; Test that when unswitching a deeply nested loop condition in a way that
; produces a non-loop clone that can reach multiple exit blocks which are part
; of different outer loops we correctly divide the cloned loop blocks between
; the outer loops based on reachability.
define i32 @test7a(i1* %ptr, i1* %cond.ptr, i32* %a.ptr, i32* %b.ptr) {
; CHECK-LABEL: @test7a(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br label %loop_begin
loop_begin:
%a = load i32, i32* %a.ptr
br label %inner_loop_begin
; CHECK: loop_begin:
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %inner_loop_begin
inner_loop_begin:
%a.phi = phi i32 [ %a, %loop_begin ], [ %a2, %inner_inner_loop_exit ]
%cond = load i1, i1* %cond.ptr
%b = load i32, i32* %b.ptr
br label %inner_inner_loop_begin
; CHECK: inner_loop_begin:
; CHECK-NEXT: %[[A_INNER_PHI:.*]] = phi i32 [ %[[A]], %loop_begin ], [ %[[A2:.*]], %inner_inner_loop_exit ]
; CHECK-NEXT: %[[COND:.*]] = load i1, i1* %cond.ptr
; CHECK-NEXT: %[[B:.*]] = load i32, i32* %b.ptr
; CHECK-NEXT: br i1 %[[COND]], label %inner_loop_begin.split.us, label %inner_loop_begin.split
inner_inner_loop_begin:
%v1 = load i1, i1* %ptr
br i1 %v1, label %inner_inner_loop_a, label %inner_inner_loop_b
inner_inner_loop_a:
%v2 = load i1, i1* %ptr
br i1 %v2, label %loop_exit, label %inner_inner_loop_c
inner_inner_loop_b:
%v3 = load i1, i1* %ptr
br i1 %v3, label %inner_inner_loop_exit, label %inner_inner_loop_c
inner_inner_loop_c:
%v4 = load i1, i1* %ptr
br i1 %v4, label %inner_loop_exit, label %inner_inner_loop_d
inner_inner_loop_d:
br i1 %cond, label %inner_loop_exit, label %inner_inner_loop_begin
; The cloned copy that always exits with the adjustments required to fix up
; loop exits.
;
; CHECK: inner_loop_begin.split.us:
; CHECK-NEXT: br label %inner_inner_loop_begin.us
;
; CHECK: inner_inner_loop_begin.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_inner_loop_a.us, label %inner_inner_loop_b.us
;
; CHECK: inner_inner_loop_b.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_inner_loop_exit.split.us, label %inner_inner_loop_c.us.loopexit
;
; CHECK: inner_inner_loop_a.us:
; CHECK-NEXT: %[[A_NEW_LCSSA:.*]] = phi i32 [ %[[A_INNER_PHI]], %inner_inner_loop_begin.us ]
; CHECK-NEXT: %[[B_NEW_LCSSA:.*]] = phi i32 [ %[[B]], %inner_inner_loop_begin.us ]
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_exit.split.us, label %inner_inner_loop_c.us
;
; CHECK: inner_inner_loop_c.us.loopexit:
; CHECK-NEXT: br label %inner_inner_loop_c.us
;
; CHECK: inner_inner_loop_c.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_loop_exit.loopexit.split.us, label %inner_inner_loop_d.us
;
; CHECK: inner_inner_loop_d.us:
; CHECK-NEXT: br label %inner_loop_exit.loopexit.split
;
; CHECK: inner_inner_loop_exit.split.us:
; CHECK-NEXT: br label %inner_inner_loop_exit
;
; CHECK: loop_exit.split.us:
; CHECK-NEXT: %[[A_LCSSA_US:.*]] = phi i32 [ %[[A_NEW_LCSSA]], %inner_inner_loop_a.us ]
; CHECK-NEXT: %[[B_LCSSA_US:.*]] = phi i32 [ %[[B_NEW_LCSSA]], %inner_inner_loop_a.us ]
; CHECK-NEXT: br label %loop_exit
;
; CHECK: inner_loop_exit.loopexit.split.us:
; CHECK-NEXT: br label %inner_loop_exit.loopexit
;
; The original copy that continues to loop.
;
; CHECK: inner_loop_begin.split:
; CHECK-NEXT: br label %inner_inner_loop_begin
;
; CHECK: inner_inner_loop_begin:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_inner_loop_a, label %inner_inner_loop_b
;
; CHECK: inner_inner_loop_a:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_exit.split, label %inner_inner_loop_c
;
; CHECK: inner_inner_loop_b:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_inner_loop_exit.split, label %inner_inner_loop_c
;
; CHECK: inner_inner_loop_c:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_loop_exit.loopexit.split, label %inner_inner_loop_d
;
; CHECK: inner_inner_loop_d:
; CHECK-NEXT: br label %inner_inner_loop_begin
;
; CHECK: inner_inner_loop_exit.split:
; CHECK-NEXT: br label %inner_inner_loop_exit
inner_inner_loop_exit:
%a2 = load i32, i32* %a.ptr
%v5 = load i1, i1* %ptr
br i1 %v5, label %inner_loop_exit, label %inner_loop_begin
; CHECK: inner_inner_loop_exit:
; CHECK-NEXT: %[[A2]] = load i32, i32* %a.ptr
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_loop_exit.loopexit1, label %inner_loop_begin
inner_loop_exit:
br label %loop_begin
; CHECK: inner_loop_exit.loopexit.split:
; CHECK-NEXT: br label %inner_loop_exit.loopexit
;
; CHECK: inner_loop_exit.loopexit:
; CHECK-NEXT: br label %inner_loop_exit
;
; CHECK: inner_loop_exit.loopexit1:
; CHECK-NEXT: br label %inner_loop_exit
;
; CHECK: inner_loop_exit:
; CHECK-NEXT: br label %loop_begin
loop_exit:
%a.lcssa = phi i32 [ %a.phi, %inner_inner_loop_a ]
%b.lcssa = phi i32 [ %b, %inner_inner_loop_a ]
%result = add i32 %a.lcssa, %b.lcssa
ret i32 %result
; CHECK: loop_exit.split:
; CHECK-NEXT: %[[A_LCSSA:.*]] = phi i32 [ %[[A_INNER_PHI]], %inner_inner_loop_a ]
; CHECK-NEXT: %[[B_LCSSA:.*]] = phi i32 [ %[[B]], %inner_inner_loop_a ]
; CHECK-NEXT: br label %loop_exit
;
; CHECK: loop_exit:
; CHECK-NEXT: %[[A_PHI:.*]] = phi i32 [ %[[A_LCSSA]], %loop_exit.split ], [ %[[A_LCSSA_US]], %loop_exit.split.us ]
; CHECK-NEXT: %[[B_PHI:.*]] = phi i32 [ %[[B_LCSSA]], %loop_exit.split ], [ %[[B_LCSSA_US]], %loop_exit.split.us ]
; CHECK-NEXT: %[[RESULT:.*]] = add i32 %[[A_PHI]], %[[B_PHI]]
; CHECK-NEXT: ret i32 %[[RESULT]]
}
; Same pattern as @test7a but here the original loop becomes a non-loop that
; can reach multiple exit blocks which are part of different outer loops.
define i32 @test7b(i1* %ptr, i1* %cond.ptr, i32* %a.ptr, i32* %b.ptr) {
; CHECK-LABEL: @test7b(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br label %loop_begin
loop_begin:
%a = load i32, i32* %a.ptr
br label %inner_loop_begin
; CHECK: loop_begin:
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %inner_loop_begin
inner_loop_begin:
%a.phi = phi i32 [ %a, %loop_begin ], [ %a2, %inner_inner_loop_exit ]
%cond = load i1, i1* %cond.ptr
%b = load i32, i32* %b.ptr
br label %inner_inner_loop_begin
; CHECK: inner_loop_begin:
; CHECK-NEXT: %[[A_INNER_PHI:.*]] = phi i32 [ %[[A]], %loop_begin ], [ %[[A2:.*]], %inner_inner_loop_exit ]
; CHECK-NEXT: %[[COND:.*]] = load i1, i1* %cond.ptr
; CHECK-NEXT: %[[B:.*]] = load i32, i32* %b.ptr
; CHECK-NEXT: br i1 %[[COND]], label %inner_loop_begin.split.us, label %inner_loop_begin.split
inner_inner_loop_begin:
%v1 = load i1, i1* %ptr
br i1 %v1, label %inner_inner_loop_a, label %inner_inner_loop_b
inner_inner_loop_a:
%v2 = load i1, i1* %ptr
br i1 %v2, label %loop_exit, label %inner_inner_loop_c
inner_inner_loop_b:
%v3 = load i1, i1* %ptr
br i1 %v3, label %inner_inner_loop_exit, label %inner_inner_loop_c
inner_inner_loop_c:
%v4 = load i1, i1* %ptr
br i1 %v4, label %inner_loop_exit, label %inner_inner_loop_d
inner_inner_loop_d:
br i1 %cond, label %inner_inner_loop_begin, label %inner_loop_exit
; The cloned copy that continues looping.
;
; CHECK: inner_loop_begin.split.us:
; CHECK-NEXT: br label %inner_inner_loop_begin.us
;
; CHECK: inner_inner_loop_begin.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_inner_loop_a.us, label %inner_inner_loop_b.us
;
; CHECK: inner_inner_loop_b.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_inner_loop_exit.split.us, label %inner_inner_loop_c.us
;
; CHECK: inner_inner_loop_a.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_exit.split.us, label %inner_inner_loop_c.us
;
; CHECK: inner_inner_loop_c.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_loop_exit.loopexit.split.us, label %inner_inner_loop_d.us
;
; CHECK: inner_inner_loop_d.us:
; CHECK-NEXT: br label %inner_inner_loop_begin.us
;
; CHECK: inner_inner_loop_exit.split.us:
; CHECK-NEXT: br label %inner_inner_loop_exit
;
; CHECK: loop_exit.split.us:
; CHECK-NEXT: %[[A_LCSSA_US:.*]] = phi i32 [ %[[A_INNER_PHI]], %inner_inner_loop_a.us ]
; CHECK-NEXT: %[[B_LCSSA_US:.*]] = phi i32 [ %[[B]], %inner_inner_loop_a.us ]
; CHECK-NEXT: br label %loop_exit
;
; CHECK: inner_loop_exit.loopexit.split.us:
; CHECK-NEXT: br label %inner_loop_exit.loopexit
;
; The original copy that now always exits and needs adjustments for exit
; blocks.
;
; CHECK: inner_loop_begin.split:
; CHECK-NEXT: br label %inner_inner_loop_begin
;
; CHECK: inner_inner_loop_begin:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_inner_loop_a, label %inner_inner_loop_b
;
; CHECK: inner_inner_loop_a:
; CHECK-NEXT: %[[A_NEW_LCSSA:.*]] = phi i32 [ %[[A_INNER_PHI]], %inner_inner_loop_begin ]
; CHECK-NEXT: %[[B_NEW_LCSSA:.*]] = phi i32 [ %[[B]], %inner_inner_loop_begin ]
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_exit.split, label %inner_inner_loop_c
;
; CHECK: inner_inner_loop_b:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_inner_loop_exit.split, label %inner_inner_loop_c.loopexit
;
; CHECK: inner_inner_loop_c.loopexit:
; CHECK-NEXT: br label %inner_inner_loop_c
;
; CHECK: inner_inner_loop_c:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_loop_exit.loopexit.split, label %inner_inner_loop_d
;
; CHECK: inner_inner_loop_d:
; CHECK-NEXT: br label %inner_loop_exit.loopexit.split
;
; CHECK: inner_inner_loop_exit.split:
; CHECK-NEXT: br label %inner_inner_loop_exit
inner_inner_loop_exit:
%a2 = load i32, i32* %a.ptr
%v5 = load i1, i1* %ptr
br i1 %v5, label %inner_loop_exit, label %inner_loop_begin
; CHECK: inner_inner_loop_exit:
; CHECK-NEXT: %[[A2]] = load i32, i32* %a.ptr
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_loop_exit.loopexit1, label %inner_loop_begin
inner_loop_exit:
br label %loop_begin
; CHECK: inner_loop_exit.loopexit.split:
; CHECK-NEXT: br label %inner_loop_exit.loopexit
;
; CHECK: inner_loop_exit.loopexit:
; CHECK-NEXT: br label %inner_loop_exit
;
; CHECK: inner_loop_exit.loopexit1:
; CHECK-NEXT: br label %inner_loop_exit
;
; CHECK: inner_loop_exit:
; CHECK-NEXT: br label %loop_begin
loop_exit:
%a.lcssa = phi i32 [ %a.phi, %inner_inner_loop_a ]
%b.lcssa = phi i32 [ %b, %inner_inner_loop_a ]
%result = add i32 %a.lcssa, %b.lcssa
ret i32 %result
; CHECK: loop_exit.split:
; CHECK-NEXT: %[[A_LCSSA:.*]] = phi i32 [ %[[A_NEW_LCSSA]], %inner_inner_loop_a ]
; CHECK-NEXT: %[[B_LCSSA:.*]] = phi i32 [ %[[B_NEW_LCSSA]], %inner_inner_loop_a ]
; CHECK-NEXT: br label %loop_exit
;
; CHECK: loop_exit:
; CHECK-NEXT: %[[A_PHI:.*]] = phi i32 [ %[[A_LCSSA]], %loop_exit.split ], [ %[[A_LCSSA_US]], %loop_exit.split.us ]
; CHECK-NEXT: %[[B_PHI:.*]] = phi i32 [ %[[B_LCSSA]], %loop_exit.split ], [ %[[B_LCSSA_US]], %loop_exit.split.us ]
; CHECK-NEXT: %[[RESULT:.*]] = add i32 %[[A_PHI]], %[[B_PHI]]
; CHECK-NEXT: ret i32 %[[RESULT]]
}
; Test that when the exit block set of an inner loop changes to start at a less
; high level of the loop nest we correctly hoist the loop up the nest.
define i32 @test8a(i1* %ptr, i1* %cond.ptr, i32* %a.ptr, i32* %b.ptr) {
; CHECK-LABEL: @test8a(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br label %loop_begin
loop_begin:
%a = load i32, i32* %a.ptr
br label %inner_loop_begin
; CHECK: loop_begin:
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %inner_loop_begin
inner_loop_begin:
%a.phi = phi i32 [ %a, %loop_begin ], [ %a2, %inner_inner_loop_exit ]
%cond = load i1, i1* %cond.ptr
%b = load i32, i32* %b.ptr
br label %inner_inner_loop_begin
; CHECK: inner_loop_begin:
; CHECK-NEXT: %[[A_INNER_PHI:.*]] = phi i32 [ %[[A]], %loop_begin ], [ %[[A2:.*]], %inner_inner_loop_exit ]
; CHECK-NEXT: %[[COND:.*]] = load i1, i1* %cond.ptr
; CHECK-NEXT: %[[B:.*]] = load i32, i32* %b.ptr
; CHECK-NEXT: br i1 %[[COND]], label %inner_loop_begin.split.us, label %inner_loop_begin.split
inner_inner_loop_begin:
%v1 = load i1, i1* %ptr
br i1 %v1, label %inner_inner_loop_a, label %inner_inner_loop_b
inner_inner_loop_a:
%v2 = load i1, i1* %ptr
br i1 %v2, label %inner_inner_loop_latch, label %inner_loop_exit
inner_inner_loop_b:
br i1 %cond, label %inner_inner_loop_latch, label %inner_inner_loop_exit
inner_inner_loop_latch:
br label %inner_inner_loop_begin
; The cloned region is now an exit from the inner loop.
;
; CHECK: inner_loop_begin.split.us:
; CHECK-NEXT: %[[A_INNER_INNER_LCSSA:.*]] = phi i32 [ %[[A_INNER_PHI]], %inner_loop_begin ]
; CHECK-NEXT: br label %inner_inner_loop_begin.us
;
; CHECK: inner_inner_loop_begin.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_inner_loop_a.us, label %inner_inner_loop_b.us
;
; CHECK: inner_inner_loop_b.us:
; CHECK-NEXT: br label %inner_inner_loop_latch.us
;
; CHECK: inner_inner_loop_a.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_inner_loop_latch.us, label %inner_loop_exit.loopexit.split.us
;
; CHECK: inner_inner_loop_latch.us:
; CHECK-NEXT: br label %inner_inner_loop_begin.us
;
; CHECK: inner_loop_exit.loopexit.split.us:
; CHECK-NEXT: %[[A_INNER_LCSSA_US:.*]] = phi i32 [ %[[A_INNER_INNER_LCSSA]], %inner_inner_loop_a.us ]
; CHECK-NEXT: br label %inner_loop_exit.loopexit
;
; The original region exits the loop earlier.
;
; CHECK: inner_loop_begin.split:
; CHECK-NEXT: br label %inner_inner_loop_begin
;
; CHECK: inner_inner_loop_begin:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_inner_loop_a, label %inner_inner_loop_b
;
; CHECK: inner_inner_loop_a:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_inner_loop_latch, label %inner_loop_exit.loopexit.split
;
; CHECK: inner_inner_loop_b:
; CHECK-NEXT: br label %inner_inner_loop_exit
;
; CHECK: inner_inner_loop_latch:
; CHECK-NEXT: br label %inner_inner_loop_begin
inner_inner_loop_exit:
%a2 = load i32, i32* %a.ptr
%v4 = load i1, i1* %ptr
br i1 %v4, label %inner_loop_exit, label %inner_loop_begin
; CHECK: inner_inner_loop_exit:
; CHECK-NEXT: %[[A2]] = load i32, i32* %a.ptr
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_loop_exit.loopexit1, label %inner_loop_begin
inner_loop_exit:
%v5 = load i1, i1* %ptr
br i1 %v5, label %loop_exit, label %loop_begin
; CHECK: inner_loop_exit.loopexit.split:
; CHECK-NEXT: %[[A_INNER_LCSSA:.*]] = phi i32 [ %[[A_INNER_PHI]], %inner_inner_loop_a ]
; CHECK-NEXT: br label %inner_loop_exit.loopexit
;
; CHECK: inner_loop_exit.loopexit:
; CHECK-NEXT: %[[A_INNER_US_PHI:.*]] = phi i32 [ %[[A_INNER_LCSSA]], %inner_loop_exit.loopexit.split ], [ %[[A_INNER_LCSSA_US]], %inner_loop_exit.loopexit.split.us ]
; CHECK-NEXT: br label %inner_loop_exit
;
; CHECK: inner_loop_exit.loopexit1:
; CHECK-NEXT: %[[A_INNER_LCSSA2:.*]] = phi i32 [ %[[A_INNER_PHI]], %inner_inner_loop_exit ]
; CHECK-NEXT: br label %inner_loop_exit
;
; CHECK: inner_loop_exit:
; CHECK-NEXT: %[[A_INNER_PHI:.*]] = phi i32 [ %[[A_INNER_LCSSA2]], %inner_loop_exit.loopexit1 ], [ %[[A_INNER_US_PHI]], %inner_loop_exit.loopexit ]
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_exit, label %loop_begin
loop_exit:
%a.lcssa = phi i32 [ %a.phi, %inner_loop_exit ]
ret i32 %a.lcssa
; CHECK: loop_exit:
; CHECK-NEXT: %[[A_LCSSA:.*]] = phi i32 [ %[[A_INNER_PHI]], %inner_loop_exit ]
; CHECK-NEXT: ret i32 %[[A_LCSSA]]
}
; Same pattern as @test8a but where the original loop looses an exit block and
; needs to be hoisted up the nest.
define i32 @test8b(i1* %ptr, i1* %cond.ptr, i32* %a.ptr, i32* %b.ptr) {
; CHECK-LABEL: @test8b(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br label %loop_begin
loop_begin:
%a = load i32, i32* %a.ptr
br label %inner_loop_begin
; CHECK: loop_begin:
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %inner_loop_begin
inner_loop_begin:
%a.phi = phi i32 [ %a, %loop_begin ], [ %a2, %inner_inner_loop_exit ]
%cond = load i1, i1* %cond.ptr
%b = load i32, i32* %b.ptr
br label %inner_inner_loop_begin
; CHECK: inner_loop_begin:
; CHECK-NEXT: %[[A_INNER_PHI:.*]] = phi i32 [ %[[A]], %loop_begin ], [ %[[A2:.*]], %inner_inner_loop_exit ]
; CHECK-NEXT: %[[COND:.*]] = load i1, i1* %cond.ptr
; CHECK-NEXT: %[[B:.*]] = load i32, i32* %b.ptr
; CHECK-NEXT: br i1 %[[COND]], label %inner_loop_begin.split.us, label %inner_loop_begin.split
inner_inner_loop_begin:
%v1 = load i1, i1* %ptr
br i1 %v1, label %inner_inner_loop_a, label %inner_inner_loop_b
inner_inner_loop_a:
%v2 = load i1, i1* %ptr
br i1 %v2, label %inner_inner_loop_latch, label %inner_loop_exit
inner_inner_loop_b:
br i1 %cond, label %inner_inner_loop_exit, label %inner_inner_loop_latch
inner_inner_loop_latch:
br label %inner_inner_loop_begin
; The cloned region is similar to before but with one earlier exit.
;
; CHECK: inner_loop_begin.split.us:
; CHECK-NEXT: br label %inner_inner_loop_begin.us
;
; CHECK: inner_inner_loop_begin.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_inner_loop_a.us, label %inner_inner_loop_b.us
;
; CHECK: inner_inner_loop_b.us:
; CHECK-NEXT: br label %inner_inner_loop_exit.split.us
;
; CHECK: inner_inner_loop_a.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_inner_loop_latch.us, label %inner_loop_exit.loopexit.split.us
;
; CHECK: inner_inner_loop_latch.us:
; CHECK-NEXT: br label %inner_inner_loop_begin.us
;
; CHECK: inner_inner_loop_exit.split.us:
; CHECK-NEXT: br label %inner_inner_loop_exit
;
; CHECK: inner_loop_exit.loopexit.split.us:
; CHECK-NEXT: %[[A_INNER_LCSSA_US:.*]] = phi i32 [ %[[A_INNER_PHI]], %inner_inner_loop_a.us ]
; CHECK-NEXT: br label %inner_loop_exit.loopexit
;
; The original region is now an exit in the preheader.
;
; CHECK: inner_loop_begin.split:
; CHECK-NEXT: %[[A_INNER_INNER_LCSSA:.*]] = phi i32 [ %[[A_INNER_PHI]], %inner_loop_begin ]
; CHECK-NEXT: br label %inner_inner_loop_begin
;
; CHECK: inner_inner_loop_begin:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_inner_loop_a, label %inner_inner_loop_b
;
; CHECK: inner_inner_loop_a:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_inner_loop_latch, label %inner_loop_exit.loopexit.split
;
; CHECK: inner_inner_loop_b:
; CHECK-NEXT: br label %inner_inner_loop_latch
;
; CHECK: inner_inner_loop_latch:
; CHECK-NEXT: br label %inner_inner_loop_begin
inner_inner_loop_exit:
%a2 = load i32, i32* %a.ptr
%v4 = load i1, i1* %ptr
br i1 %v4, label %inner_loop_exit, label %inner_loop_begin
; CHECK: inner_inner_loop_exit:
; CHECK-NEXT: %[[A2]] = load i32, i32* %a.ptr
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_loop_exit.loopexit1, label %inner_loop_begin
inner_loop_exit:
%v5 = load i1, i1* %ptr
br i1 %v5, label %loop_exit, label %loop_begin
; CHECK: inner_loop_exit.loopexit.split:
; CHECK-NEXT: %[[A_INNER_LCSSA:.*]] = phi i32 [ %[[A_INNER_INNER_LCSSA]], %inner_inner_loop_a ]
; CHECK-NEXT: br label %inner_loop_exit.loopexit
;
; CHECK: inner_loop_exit.loopexit:
; CHECK-NEXT: %[[A_INNER_US_PHI:.*]] = phi i32 [ %[[A_INNER_LCSSA]], %inner_loop_exit.loopexit.split ], [ %[[A_INNER_LCSSA_US]], %inner_loop_exit.loopexit.split.us ]
; CHECK-NEXT: br label %inner_loop_exit
;
; CHECK: inner_loop_exit.loopexit1:
; CHECK-NEXT: %[[A_INNER_LCSSA2:.*]] = phi i32 [ %[[A_INNER_PHI]], %inner_inner_loop_exit ]
; CHECK-NEXT: br label %inner_loop_exit
;
; CHECK: inner_loop_exit:
; CHECK-NEXT: %[[A_INNER_PHI:.*]] = phi i32 [ %[[A_INNER_LCSSA2]], %inner_loop_exit.loopexit1 ], [ %[[A_INNER_US_PHI]], %inner_loop_exit.loopexit ]
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_exit, label %loop_begin
loop_exit:
%a.lcssa = phi i32 [ %a.phi, %inner_loop_exit ]
ret i32 %a.lcssa
; CHECK: loop_exit:
; CHECK-NEXT: %[[A_LCSSA:.*]] = phi i32 [ %[[A_INNER_PHI]], %inner_loop_exit ]
; CHECK-NEXT: ret i32 %[[A_LCSSA]]
}
; Test for when unswitching produces a clone of an inner loop but
; the clone no longer has an exiting edge *at all* and loops infinitely.
; Because it doesn't ever exit to the outer loop it is no longer an inner loop
; but needs to be hoisted up the nest to be a top-level loop.
define i32 @test9a(i1* %ptr, i1* %cond.ptr, i32* %a.ptr, i32* %b.ptr) {
; CHECK-LABEL: @test9a(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br label %loop_begin
loop_begin:
%b = load i32, i32* %b.ptr
%cond = load i1, i1* %cond.ptr
br label %inner_loop_begin
; CHECK: loop_begin:
; CHECK-NEXT: %[[B:.*]] = load i32, i32* %b.ptr
; CHECK-NEXT: %[[COND:.*]] = load i1, i1* %cond.ptr
; CHECK-NEXT: br i1 %[[COND]], label %loop_begin.split.us, label %loop_begin.split
inner_loop_begin:
%a = load i32, i32* %a.ptr
br i1 %cond, label %inner_loop_latch, label %inner_loop_exit
inner_loop_latch:
call void @sink1(i32 %b)
br label %inner_loop_begin
; The cloned inner loop ends up as an infinite loop and thus being a top-level
; loop with the preheader as an exit block of the outer loop.
;
; CHECK: loop_begin.split.us
; CHECK-NEXT: %[[B_LCSSA:.*]] = phi i32 [ %[[B]], %loop_begin ]
; CHECK-NEXT: br label %inner_loop_begin.us
;
; CHECK: inner_loop_begin.us:
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %inner_loop_latch.us
;
; CHECK: inner_loop_latch.us:
; CHECK-NEXT: call void @sink1(i32 %[[B_LCSSA]])
; CHECK-NEXT: br label %inner_loop_begin.us
;
; The original loop becomes boring non-loop code.
;
; CHECK: loop_begin.split
; CHECK-NEXT: br label %inner_loop_begin
;
; CHECK: inner_loop_begin:
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %inner_loop_exit
inner_loop_exit:
%a.inner_lcssa = phi i32 [ %a, %inner_loop_begin ]
%v = load i1, i1* %ptr
br i1 %v, label %loop_begin, label %loop_exit
; CHECK: inner_loop_exit:
; CHECK-NEXT: %[[A_INNER_LCSSA:.*]] = phi i32 [ %[[A]], %inner_loop_begin ]
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_begin, label %loop_exit
loop_exit:
%a.lcssa = phi i32 [ %a.inner_lcssa, %inner_loop_exit ]
ret i32 %a.lcssa
; CHECK: loop_exit:
; CHECK-NEXT: %[[A_LCSSA:.*]] = phi i32 [ %[[A_INNER_LCSSA]], %inner_loop_exit ]
; CHECK-NEXT: ret i32 %[[A_LCSSA]]
}
; The same core pattern as @test9a, but instead of the cloned loop becoming an
; infinite loop, the original loop has its only exit unswitched and the
; original loop becomes infinite and must be hoisted out of the loop nest.
define i32 @test9b(i1* %ptr, i1* %cond.ptr, i32* %a.ptr, i32* %b.ptr) {
; CHECK-LABEL: @test9b(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br label %loop_begin
loop_begin:
%b = load i32, i32* %b.ptr
%cond = load i1, i1* %cond.ptr
br label %inner_loop_begin
; CHECK: loop_begin:
; CHECK-NEXT: %[[B:.*]] = load i32, i32* %b.ptr
; CHECK-NEXT: %[[COND:.*]] = load i1, i1* %cond.ptr
; CHECK-NEXT: br i1 %[[COND]], label %loop_begin.split.us, label %loop_begin.split
inner_loop_begin:
%a = load i32, i32* %a.ptr
br i1 %cond, label %inner_loop_exit, label %inner_loop_latch
inner_loop_latch:
call void @sink1(i32 %b)
br label %inner_loop_begin
; The cloned inner loop becomes a boring non-loop.
;
; CHECK: loop_begin.split.us
; CHECK-NEXT: br label %inner_loop_begin.us
;
; CHECK: inner_loop_begin.us:
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %inner_loop_exit.split.us
;
; CHECK: inner_loop_exit.split.us
; CHECK-NEXT: %[[A_INNER_LCSSA_US:.*]] = phi i32 [ %[[A]], %inner_loop_begin.us ]
; CHECK-NEXT: br label %inner_loop_exit
;
; The original loop becomes an infinite loop and thus a top-level loop with the
; preheader as an exit block for the outer loop.
;
; CHECK: loop_begin.split
; CHECK-NEXT: %[[B_LCSSA:.*]] = phi i32 [ %[[B]], %loop_begin ]
; CHECK-NEXT: br label %inner_loop_begin
;
; CHECK: inner_loop_begin:
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %inner_loop_latch
;
; CHECK: inner_loop_latch:
; CHECK-NEXT: call void @sink1(i32 %[[B_LCSSA]])
; CHECK-NEXT: br label %inner_loop_begin
inner_loop_exit:
%a.inner_lcssa = phi i32 [ %a, %inner_loop_begin ]
%v = load i1, i1* %ptr
br i1 %v, label %loop_begin, label %loop_exit
; CHECK: inner_loop_exit:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_begin, label %loop_exit
loop_exit:
%a.lcssa = phi i32 [ %a.inner_lcssa, %inner_loop_exit ]
ret i32 %a.lcssa
; CHECK: loop_exit:
; CHECK-NEXT: %[[A_LCSSA:.*]] = phi i32 [ %[[A_INNER_LCSSA_US]], %inner_loop_exit ]
; CHECK-NEXT: ret i32 %[[A_LCSSA]]
}
; Test that requires re-forming dedicated exits for the cloned loop.
define i32 @test10a(i1* %ptr, i1 %cond, i32* %a.ptr) {
; CHECK-LABEL: @test10a(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 %cond, label %entry.split.us, label %entry.split
loop_begin:
%a = load i32, i32* %a.ptr
%v1 = load i1, i1* %ptr
br i1 %v1, label %loop_a, label %loop_b
loop_a:
%v2 = load i1, i1* %ptr
br i1 %v2, label %loop_exit, label %loop_begin
loop_b:
br i1 %cond, label %loop_exit, label %loop_begin
; The cloned loop with one edge as a direct exit.
;
; CHECK: entry.split.us:
; CHECK-NEXT: br label %loop_begin.us
;
; CHECK: loop_begin.us:
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_a.us, label %loop_b.us
;
; CHECK: loop_b.us:
; CHECK-NEXT: %[[A_LCSSA_B:.*]] = phi i32 [ %[[A]], %loop_begin.us ]
; CHECK-NEXT: br label %loop_exit.split.us
;
; CHECK: loop_a.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_exit.split.us.loopexit, label %loop_begin.backedge.us
;
; CHECK: loop_begin.backedge.us:
; CHECK-NEXT: br label %loop_begin.us
;
; CHECK: loop_exit.split.us.loopexit:
; CHECK-NEXT: %[[A_LCSSA_A:.*]] = phi i32 [ %[[A]], %loop_a.us ]
; CHECK-NEXT: br label %loop_exit
;
; CHECK: loop_exit.split.us:
; CHECK-NEXT: %[[A_PHI_US:.*]] = phi i32 [ %[[A_LCSSA_B]], %loop_b.us ], [ %[[A_LCSSA_A]], %loop_exit.split.us.loopexit ]
; CHECK-NEXT: br label %loop_exit
; The original loop without one 'loop_exit' edge.
;
; CHECK: entry.split:
; CHECK-NEXT: br label %loop_begin
;
; CHECK: loop_begin:
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_a, label %loop_b
;
; CHECK: loop_a:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_exit.split, label %loop_begin.backedge
;
; CHECK: loop_begin.backedge:
; CHECK-NEXT: br label %loop_begin
;
; CHECK: loop_b:
; CHECK-NEXT: br label %loop_begin.backedge
;
; CHECK: loop_exit.split:
; CHECK-NEXT: %[[A_LCSSA:.*]] = phi i32 [ %[[A]], %loop_a ]
; CHECK-NEXT: br label %loop_exit
loop_exit:
%a.lcssa = phi i32 [ %a, %loop_a ], [ %a, %loop_b ]
ret i32 %a.lcssa
; CHECK: loop_exit:
; CHECK-NEXT: %[[A_PHI:.*]] = phi i32 [ %[[A_LCSSA]], %loop_exit.split ], [ %[[A_PHI_US]], %loop_exit.split.us ]
; CHECK-NEXT: ret i32 %[[A_PHI]]
}
; Test that requires re-forming dedicated exits for the original loop.
define i32 @test10b(i1* %ptr, i1 %cond, i32* %a.ptr) {
; CHECK-LABEL: @test10b(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 %cond, label %entry.split.us, label %entry.split
loop_begin:
%a = load i32, i32* %a.ptr
%v1 = load i1, i1* %ptr
br i1 %v1, label %loop_a, label %loop_b
loop_a:
%v2 = load i1, i1* %ptr
br i1 %v2, label %loop_begin, label %loop_exit
loop_b:
br i1 %cond, label %loop_begin, label %loop_exit
; The cloned loop without one of the exits.
;
; CHECK: entry.split.us:
; CHECK-NEXT: br label %loop_begin.us
;
; CHECK: loop_begin.us:
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_a.us, label %loop_b.us
;
; CHECK: loop_b.us:
; CHECK-NEXT: br label %loop_begin.backedge.us
;
; CHECK: loop_a.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_begin.backedge.us, label %loop_exit.split.us
;
; CHECK: loop_begin.backedge.us:
; CHECK-NEXT: br label %loop_begin.us
;
; CHECK: loop_exit.split.us:
; CHECK-NEXT: %[[A_LCSSA_US:.*]] = phi i32 [ %[[A]], %loop_a.us ]
; CHECK-NEXT: br label %loop_exit
; The original loop without one 'loop_exit' edge.
;
; CHECK: entry.split:
; CHECK-NEXT: br label %loop_begin
;
; CHECK: loop_begin:
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_a, label %loop_b
;
; CHECK: loop_a:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_begin.backedge, label %loop_exit.split.loopexit
;
; CHECK: loop_begin.backedge:
; CHECK-NEXT: br label %loop_begin
;
; CHECK: loop_b:
; CHECK-NEXT: %[[A_LCSSA_B:.*]] = phi i32 [ %[[A]], %loop_begin ]
; CHECK-NEXT: br label %loop_exit.split
;
; CHECK: loop_exit.split.loopexit:
; CHECK-NEXT: %[[A_LCSSA_A:.*]] = phi i32 [ %[[A]], %loop_a ]
; CHECK-NEXT: br label %loop_exit.split
;
; CHECK: loop_exit.split:
; CHECK-NEXT: %[[A_PHI_SPLIT:.*]] = phi i32 [ %[[A_LCSSA_B]], %loop_b ], [ %[[A_LCSSA_A]], %loop_exit.split.loopexit ]
; CHECK-NEXT: br label %loop_exit
loop_exit:
%a.lcssa = phi i32 [ %a, %loop_a ], [ %a, %loop_b ]
ret i32 %a.lcssa
; CHECK: loop_exit:
; CHECK-NEXT: %[[A_PHI:.*]] = phi i32 [ %[[A_PHI_SPLIT]], %loop_exit.split ], [ %[[A_LCSSA_US]], %loop_exit.split.us ]
; CHECK-NEXT: ret i32 %[[A_PHI]]
}
; Check that if a cloned inner loop after unswitching doesn't loop and directly
; exits even an outer loop, we don't add the cloned preheader to the outer
; loop and do add the needed LCSSA phi nodes for the new exit block from the
; outer loop.
define i32 @test11a(i1* %ptr, i1* %cond.ptr, i32* %a.ptr, i32* %b.ptr) {
; CHECK-LABEL: @test11a(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br label %loop_begin
loop_begin:
%b = load i32, i32* %b.ptr
%v1 = load i1, i1* %ptr
br i1 %v1, label %loop_latch, label %inner_loop_ph
; CHECK: loop_begin:
; CHECK-NEXT: %[[B:.*]] = load i32, i32* %b.ptr
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_latch, label %inner_loop_ph
inner_loop_ph:
%cond = load i1, i1* %cond.ptr
br label %inner_loop_begin
; CHECK: inner_loop_ph:
; CHECK-NEXT: %[[COND:.*]] = load i1, i1* %cond.ptr
; CHECK-NEXT: br i1 %[[COND]], label %inner_loop_ph.split.us, label %inner_loop_ph.split
inner_loop_begin:
call void @sink1(i32 %b)
%a = load i32, i32* %a.ptr
br i1 %cond, label %loop_exit, label %inner_loop_a
inner_loop_a:
%v2 = load i1, i1* %ptr
br i1 %v2, label %inner_loop_exit, label %inner_loop_begin
; The cloned path doesn't actually loop and is an exit from the outer loop as
; well.
;
; CHECK: inner_loop_ph.split.us:
; CHECK-NEXT: %[[B_LCSSA:.*]] = phi i32 [ %[[B]], %inner_loop_ph ]
; CHECK-NEXT: br label %inner_loop_begin.us
;
; CHECK: inner_loop_begin.us:
; CHECK-NEXT: call void @sink1(i32 %[[B_LCSSA]])
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %loop_exit.loopexit.split.us
;
; CHECK: loop_exit.loopexit.split.us:
; CHECK-NEXT: %[[A_INNER_LCSSA_US:.*]] = phi i32 [ %[[A]], %inner_loop_begin.us ]
; CHECK-NEXT: br label %loop_exit.loopexit
;
; The original remains a loop losing the exit edge.
;
; CHECK: inner_loop_ph.split:
; CHECK-NEXT: br label %inner_loop_begin
;
; CHECK: inner_loop_begin:
; CHECK-NEXT: call void @sink1(i32 %[[B]])
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %inner_loop_a
;
; CHECK: inner_loop_a:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_loop_exit, label %inner_loop_begin
inner_loop_exit:
%a.inner_lcssa = phi i32 [ %a, %inner_loop_a ]
%v3 = load i1, i1* %ptr
br i1 %v3, label %loop_latch, label %loop_exit
; CHECK: inner_loop_exit:
; CHECK-NEXT: %[[A_INNER_LCSSA:.*]] = phi i32 [ %[[A]], %inner_loop_a ]
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_latch, label %loop_exit.loopexit1
loop_latch:
br label %loop_begin
; CHECK: loop_latch:
; CHECK-NEXT: br label %loop_begin
loop_exit:
%a.lcssa = phi i32 [ %a, %inner_loop_begin ], [ %a.inner_lcssa, %inner_loop_exit ]
ret i32 %a.lcssa
; CHECK: loop_exit.loopexit:
; CHECK-NEXT: br label %loop_exit
;
; CHECK: loop_exit.loopexit1:
; CHECK-NEXT: %[[A_LCSSA:.*]] = phi i32 [ %[[A_INNER_LCSSA]], %inner_loop_exit ]
; CHECK-NEXT: br label %loop_exit
;
; CHECK: loop_exit:
; CHECK-NEXT: %[[A_PHI:.*]] = phi i32 [ %[[A_INNER_LCSSA_US]], %loop_exit.loopexit ], [ %[[A_LCSSA]], %loop_exit.loopexit1 ]
; CHECK-NEXT: ret i32 %[[A_PHI]]
}
; Check that if the original inner loop after unswitching doesn't loop and
; directly exits even an outer loop, we remove the original preheader from the
; outer loop and add needed LCSSA phi nodes for the new exit block from the
; outer loop.
define i32 @test11b(i1* %ptr, i1* %cond.ptr, i32* %a.ptr, i32* %b.ptr) {
; CHECK-LABEL: @test11b(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br label %loop_begin
loop_begin:
%b = load i32, i32* %b.ptr
%v1 = load i1, i1* %ptr
br i1 %v1, label %loop_latch, label %inner_loop_ph
; CHECK: loop_begin:
; CHECK-NEXT: %[[B:.*]] = load i32, i32* %b.ptr
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_latch, label %inner_loop_ph
inner_loop_ph:
%cond = load i1, i1* %cond.ptr
br label %inner_loop_begin
; CHECK: inner_loop_ph:
; CHECK-NEXT: %[[COND:.*]] = load i1, i1* %cond.ptr
; CHECK-NEXT: br i1 %[[COND]], label %inner_loop_ph.split.us, label %inner_loop_ph.split
inner_loop_begin:
call void @sink1(i32 %b)
%a = load i32, i32* %a.ptr
br i1 %cond, label %inner_loop_a, label %loop_exit
inner_loop_a:
%v2 = load i1, i1* %ptr
br i1 %v2, label %inner_loop_exit, label %inner_loop_begin
; The cloned path continues to loop without the exit out of the entire nest.
;
; CHECK: inner_loop_ph.split.us:
; CHECK-NEXT: br label %inner_loop_begin.us
;
; CHECK: inner_loop_begin.us:
; CHECK-NEXT: call void @sink1(i32 %[[B]])
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %inner_loop_a.us
;
; CHECK: inner_loop_a.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_loop_exit.split.us, label %inner_loop_begin.us
;
; CHECK: inner_loop_exit.split.us:
; CHECK-NEXT: %[[A_INNER_LCSSA_US:.*]] = phi i32 [ %[[A]], %inner_loop_a.us ]
; CHECK-NEXT: br label %inner_loop_exit
;
; The original remains a loop losing the exit edge.
;
; CHECK: inner_loop_ph.split:
; CHECK-NEXT: %[[B_LCSSA:.*]] = phi i32 [ %[[B]], %inner_loop_ph ]
; CHECK-NEXT: br label %inner_loop_begin
;
; CHECK: inner_loop_begin:
; CHECK-NEXT: call void @sink1(i32 %[[B_LCSSA]])
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %loop_exit.loopexit
inner_loop_exit:
%a.inner_lcssa = phi i32 [ %a, %inner_loop_a ]
%v3 = load i1, i1* %ptr
br i1 %v3, label %loop_latch, label %loop_exit
; CHECK: inner_loop_exit:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_latch, label %loop_exit.loopexit1
loop_latch:
br label %loop_begin
; CHECK: loop_latch:
; CHECK-NEXT: br label %loop_begin
loop_exit:
%a.lcssa = phi i32 [ %a, %inner_loop_begin ], [ %a.inner_lcssa, %inner_loop_exit ]
ret i32 %a.lcssa
; CHECK: loop_exit.loopexit:
; CHECK-NEXT: %[[A_LCSSA:.*]] = phi i32 [ %[[A]], %inner_loop_begin ]
; CHECK-NEXT: br label %loop_exit
;
; CHECK: loop_exit.loopexit1:
; CHECK-NEXT: %[[A_LCSSA_US:.*]] = phi i32 [ %[[A_INNER_LCSSA_US]], %inner_loop_exit ]
; CHECK-NEXT: br label %loop_exit
;
; CHECK: loop_exit:
; CHECK-NEXT: %[[A_PHI:.*]] = phi i32 [ %[[A_LCSSA]], %loop_exit.loopexit ], [ %[[A_LCSSA_US]], %loop_exit.loopexit1 ]
; CHECK-NEXT: ret i32 %[[A_PHI]]
}
; Like test11a, but checking that when the whole thing is wrapped in yet
; another loop, we correctly attribute the cloned preheader to that outermost
; loop rather than only handling the case where the preheader is not in any loop
; at all.
define i32 @test12a(i1* %ptr, i1* %cond.ptr, i32* %a.ptr, i32* %b.ptr) {
; CHECK-LABEL: @test12a(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br label %loop_begin
loop_begin:
br label %inner_loop_begin
; CHECK: loop_begin:
; CHECK-NEXT: br label %inner_loop_begin
inner_loop_begin:
%b = load i32, i32* %b.ptr
%v1 = load i1, i1* %ptr
br i1 %v1, label %inner_loop_latch, label %inner_inner_loop_ph
; CHECK: inner_loop_begin:
; CHECK-NEXT: %[[B:.*]] = load i32, i32* %b.ptr
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_loop_latch, label %inner_inner_loop_ph
inner_inner_loop_ph:
%cond = load i1, i1* %cond.ptr
br label %inner_inner_loop_begin
; CHECK: inner_inner_loop_ph:
; CHECK-NEXT: %[[COND:.*]] = load i1, i1* %cond.ptr
; CHECK-NEXT: br i1 %[[COND]], label %inner_inner_loop_ph.split.us, label %inner_inner_loop_ph.split
inner_inner_loop_begin:
call void @sink1(i32 %b)
%a = load i32, i32* %a.ptr
br i1 %cond, label %inner_loop_exit, label %inner_inner_loop_a
inner_inner_loop_a:
%v2 = load i1, i1* %ptr
br i1 %v2, label %inner_inner_loop_exit, label %inner_inner_loop_begin
; The cloned path doesn't actually loop and is an exit from the outer loop as
; well.
;
; CHECK: inner_inner_loop_ph.split.us:
; CHECK-NEXT: %[[B_LCSSA:.*]] = phi i32 [ %[[B]], %inner_inner_loop_ph ]
; CHECK-NEXT: br label %inner_inner_loop_begin.us
;
; CHECK: inner_inner_loop_begin.us:
; CHECK-NEXT: call void @sink1(i32 %[[B_LCSSA]])
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %inner_loop_exit.loopexit.split.us
;
; CHECK: inner_loop_exit.loopexit.split.us:
; CHECK-NEXT: %[[A_INNER_INNER_LCSSA_US:.*]] = phi i32 [ %[[A]], %inner_inner_loop_begin.us ]
; CHECK-NEXT: br label %inner_loop_exit.loopexit
;
; The original remains a loop losing the exit edge.
;
; CHECK: inner_inner_loop_ph.split:
; CHECK-NEXT: br label %inner_inner_loop_begin
;
; CHECK: inner_inner_loop_begin:
; CHECK-NEXT: call void @sink1(i32 %[[B]])
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %inner_inner_loop_a
;
; CHECK: inner_inner_loop_a:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_inner_loop_exit, label %inner_inner_loop_begin
inner_inner_loop_exit:
%a.inner_inner_lcssa = phi i32 [ %a, %inner_inner_loop_a ]
%v3 = load i1, i1* %ptr
br i1 %v3, label %inner_loop_latch, label %inner_loop_exit
; CHECK: inner_inner_loop_exit:
; CHECK-NEXT: %[[A_INNER_INNER_LCSSA:.*]] = phi i32 [ %[[A]], %inner_inner_loop_a ]
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_loop_latch, label %inner_loop_exit.loopexit1
inner_loop_latch:
br label %inner_loop_begin
; CHECK: inner_loop_latch:
; CHECK-NEXT: br label %inner_loop_begin
inner_loop_exit:
%a.inner_lcssa = phi i32 [ %a, %inner_inner_loop_begin ], [ %a.inner_inner_lcssa, %inner_inner_loop_exit ]
%v4 = load i1, i1* %ptr
br i1 %v4, label %loop_begin, label %loop_exit
; CHECK: inner_loop_exit.loopexit:
; CHECK-NEXT: br label %inner_loop_exit
;
; CHECK: inner_loop_exit.loopexit1:
; CHECK-NEXT: %[[A_INNER_LCSSA:.*]] = phi i32 [ %[[A_INNER_INNER_LCSSA]], %inner_inner_loop_exit ]
; CHECK-NEXT: br label %inner_loop_exit
;
; CHECK: inner_loop_exit:
; CHECK-NEXT: %[[A_INNER_PHI:.*]] = phi i32 [ %[[A_INNER_INNER_LCSSA_US]], %inner_loop_exit.loopexit ], [ %[[A_INNER_LCSSA]], %inner_loop_exit.loopexit1 ]
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_begin, label %loop_exit
loop_exit:
%a.lcssa = phi i32 [ %a.inner_lcssa, %inner_loop_exit ]
ret i32 %a.lcssa
; CHECK: loop_exit:
; CHECK-NEXT: %[[A_LCSSA:.*]] = phi i32 [ %[[A_INNER_PHI]], %inner_loop_exit ]
; CHECK-NEXT: ret i32 %[[A_LCSSA]]
}
; Like test11b, but checking that when the whole thing is wrapped in yet
; another loop, we correctly sink the preheader to the outermost loop rather
; than only handling the case where the preheader is completely removed from
; a loop.
define i32 @test12b(i1* %ptr, i1* %cond.ptr, i32* %a.ptr, i32* %b.ptr) {
; CHECK-LABEL: @test12b(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br label %loop_begin
loop_begin:
br label %inner_loop_begin
; CHECK: loop_begin:
; CHECK-NEXT: br label %inner_loop_begin
inner_loop_begin:
%b = load i32, i32* %b.ptr
%v1 = load i1, i1* %ptr
br i1 %v1, label %inner_loop_latch, label %inner_inner_loop_ph
; CHECK: inner_loop_begin:
; CHECK-NEXT: %[[B:.*]] = load i32, i32* %b.ptr
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_loop_latch, label %inner_inner_loop_ph
inner_inner_loop_ph:
%cond = load i1, i1* %cond.ptr
br label %inner_inner_loop_begin
; CHECK: inner_inner_loop_ph:
; CHECK-NEXT: %[[COND:.*]] = load i1, i1* %cond.ptr
; CHECK-NEXT: br i1 %[[COND]], label %inner_inner_loop_ph.split.us, label %inner_inner_loop_ph.split
inner_inner_loop_begin:
call void @sink1(i32 %b)
%a = load i32, i32* %a.ptr
br i1 %cond, label %inner_inner_loop_a, label %inner_loop_exit
inner_inner_loop_a:
%v2 = load i1, i1* %ptr
br i1 %v2, label %inner_inner_loop_exit, label %inner_inner_loop_begin
; The cloned path continues to loop without the exit out of the entire nest.
;
; CHECK: inner_inner_loop_ph.split.us:
; CHECK-NEXT: br label %inner_inner_loop_begin.us
;
; CHECK: inner_inner_loop_begin.us:
; CHECK-NEXT: call void @sink1(i32 %[[B]])
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %inner_inner_loop_a.us
;
; CHECK: inner_inner_loop_a.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_inner_loop_exit.split.us, label %inner_inner_loop_begin.us
;
; CHECK: inner_inner_loop_exit.split.us:
; CHECK-NEXT: %[[A_INNER_INNER_LCSSA_US:.*]] = phi i32 [ %[[A]], %inner_inner_loop_a.us ]
; CHECK-NEXT: br label %inner_inner_loop_exit
;
; The original remains a loop losing the exit edge.
;
; CHECK: inner_inner_loop_ph.split:
; CHECK-NEXT: %[[B_LCSSA:.*]] = phi i32 [ %[[B]], %inner_inner_loop_ph ]
; CHECK-NEXT: br label %inner_inner_loop_begin
;
; CHECK: inner_inner_loop_begin:
; CHECK-NEXT: call void @sink1(i32 %[[B_LCSSA]])
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: br label %inner_loop_exit.loopexit
inner_inner_loop_exit:
%a.inner_inner_lcssa = phi i32 [ %a, %inner_inner_loop_a ]
%v3 = load i1, i1* %ptr
br i1 %v3, label %inner_loop_latch, label %inner_loop_exit
; CHECK: inner_inner_loop_exit:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %inner_loop_latch, label %inner_loop_exit.loopexit1
inner_loop_latch:
br label %inner_loop_begin
; CHECK: inner_loop_latch:
; CHECK-NEXT: br label %inner_loop_begin
inner_loop_exit:
%a.inner_lcssa = phi i32 [ %a, %inner_inner_loop_begin ], [ %a.inner_inner_lcssa, %inner_inner_loop_exit ]
%v4 = load i1, i1* %ptr
br i1 %v4, label %loop_begin, label %loop_exit
; CHECK: inner_loop_exit.loopexit:
; CHECK-NEXT: %[[A_INNER_LCSSA:.*]] = phi i32 [ %[[A]], %inner_inner_loop_begin ]
; CHECK-NEXT: br label %inner_loop_exit
;
; CHECK: inner_loop_exit.loopexit1:
; CHECK-NEXT: %[[A_INNER_LCSSA_US:.*]] = phi i32 [ %[[A_INNER_INNER_LCSSA_US]], %inner_inner_loop_exit ]
; CHECK-NEXT: br label %inner_loop_exit
;
; CHECK: inner_loop_exit:
; CHECK-NEXT: %[[A_INNER_PHI:.*]] = phi i32 [ %[[A_INNER_LCSSA]], %inner_loop_exit.loopexit ], [ %[[A_INNER_LCSSA_US]], %inner_loop_exit.loopexit1 ]
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_begin, label %loop_exit
loop_exit:
%a.lcssa = phi i32 [ %a.inner_lcssa, %inner_loop_exit ]
ret i32 %a.lcssa
; CHECK: loop_exit:
; CHECK-NEXT: %[[A_LCSSA:.*]] = phi i32 [ %[[A_INNER_PHI]], %inner_loop_exit ]
; CHECK-NEXT: ret i32 %[[A_LCSSA]]
}
; Test where the cloned loop has an inner loop that has to be traversed to form
; the cloned loop, and where this inner loop has multiple blocks, and where the
; exiting block that connects the inner loop to the cloned loop is not the header
; block. This ensures that we correctly handle interesting corner cases of
; traversing back to the header when establishing the cloned loop.
define i32 @test13a(i1* %ptr, i1 %cond, i32* %a.ptr, i32* %b.ptr) {
; CHECK-LABEL: @test13a(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 %cond, label %entry.split.us, label %entry.split
loop_begin:
%a = load i32, i32* %a.ptr
%v1 = load i1, i1* %ptr
br i1 %v1, label %loop_a, label %loop_b
loop_a:
%v2 = load i1, i1* %ptr
br i1 %v2, label %loop_exit, label %loop_latch
loop_b:
%b = load i32, i32* %b.ptr
br i1 %cond, label %loop_b_inner_ph, label %loop_exit
loop_b_inner_ph:
br label %loop_b_inner_header
loop_b_inner_header:
%v3 = load i1, i1* %ptr
br i1 %v3, label %loop_b_inner_latch, label %loop_b_inner_body
loop_b_inner_body:
%v4 = load i1, i1* %ptr
br i1 %v4, label %loop_b_inner_latch, label %loop_b_inner_exit
loop_b_inner_latch:
br label %loop_b_inner_header
loop_b_inner_exit:
br label %loop_latch
loop_latch:
br label %loop_begin
; The cloned loop contains an inner loop within it.
;
; CHECK: entry.split.us:
; CHECK-NEXT: br label %loop_begin.us
;
; CHECK: loop_begin.us:
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_a.us, label %loop_b.us
;
; CHECK: loop_b.us:
; CHECK-NEXT: %[[B:.*]] = load i32, i32* %b.ptr
; CHECK-NEXT: br label %loop_b_inner_ph.us
;
; CHECK: loop_b_inner_ph.us:
; CHECK-NEXT: br label %loop_b_inner_header.us
;
; CHECK: loop_b_inner_header.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_b_inner_latch.us, label %loop_b_inner_body.us
;
; CHECK: loop_b_inner_body.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_b_inner_latch.us, label %loop_b_inner_exit.us
;
; CHECK: loop_b_inner_exit.us:
; CHECK-NEXT: br label %loop_latch.us
;
; CHECK: loop_b_inner_latch.us:
; CHECK-NEXT: br label %loop_b_inner_header.us
;
; CHECK: loop_a.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_exit.split.us, label %loop_latch.us
;
; CHECK: loop_latch.us:
; CHECK-NEXT: br label %loop_begin.us
;
; CHECK: loop_exit.split.us:
; CHECK-NEXT: %[[A_LCSSA_US:.*]] = phi i32 [ %[[A]], %loop_a.us ]
; CHECK-NEXT: br label %loop_exit
;
; And the original loop no longer contains an inner loop.
;
; CHECK: entry.split:
; CHECK-NEXT: br label %loop_begin
;
; CHECK: loop_begin:
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_a, label %loop_b
;
; CHECK: loop_a:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_exit.split.loopexit, label %loop_latch
;
; CHECK: loop_b:
; CHECK-NEXT: %[[B:.*]] = load i32, i32* %b.ptr
; CHECK-NEXT: br label %loop_exit.split
;
; CHECK: loop_latch:
; CHECK-NEXT: br label %loop_begin
loop_exit:
%lcssa = phi i32 [ %a, %loop_a ], [ %b, %loop_b ]
ret i32 %lcssa
; CHECK: loop_exit.split.loopexit:
; CHECK-NEXT: %[[A_LCSSA:.*]] = phi i32 [ %[[A]], %loop_a ]
; CHECK-NEXT: br label %loop_exit.split
;
; CHECK: loop_exit.split:
; CHECK-NEXT: %[[AB_PHI:.*]] = phi i32 [ %[[B]], %loop_b ], [ %[[A_LCSSA]], %loop_exit.split.loopexit ]
; CHECK-NEXT: br label %loop_exit
;
; CHECK: loop_exit:
; CHECK-NEXT: %[[AB_PHI_US:.*]] = phi i32 [ %[[AB_PHI]], %loop_exit.split ], [ %[[A_LCSSA_US]], %loop_exit.split.us ]
; CHECK-NEXT: ret i32 %[[AB_PHI_US]]
}
; Test where the original loop has an inner loop that has to be traversed to
; rebuild the loop, and where this inner loop has multiple blocks, and where
; the exiting block that connects the inner loop to the original loop is not
; the header block. This ensures that we correctly handle interesting corner
; cases of traversing back to the header when re-establishing the original loop
; still exists after unswitching.
define i32 @test13b(i1* %ptr, i1 %cond, i32* %a.ptr, i32* %b.ptr) {
; CHECK-LABEL: @test13b(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 %cond, label %entry.split.us, label %entry.split
loop_begin:
%a = load i32, i32* %a.ptr
%v1 = load i1, i1* %ptr
br i1 %v1, label %loop_a, label %loop_b
loop_a:
%v2 = load i1, i1* %ptr
br i1 %v2, label %loop_exit, label %loop_latch
loop_b:
%b = load i32, i32* %b.ptr
br i1 %cond, label %loop_exit, label %loop_b_inner_ph
loop_b_inner_ph:
br label %loop_b_inner_header
loop_b_inner_header:
%v3 = load i1, i1* %ptr
br i1 %v3, label %loop_b_inner_latch, label %loop_b_inner_body
loop_b_inner_body:
%v4 = load i1, i1* %ptr
br i1 %v4, label %loop_b_inner_latch, label %loop_b_inner_exit
loop_b_inner_latch:
br label %loop_b_inner_header
loop_b_inner_exit:
br label %loop_latch
loop_latch:
br label %loop_begin
; The cloned loop doesn't contain an inner loop.
;
; CHECK: entry.split.us:
; CHECK-NEXT: br label %loop_begin.us
;
; CHECK: loop_begin.us:
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_a.us, label %loop_b.us
;
; CHECK: loop_b.us:
; CHECK-NEXT: %[[B:.*]] = load i32, i32* %b.ptr
; CHECK-NEXT: br label %loop_exit.split.us
;
; CHECK: loop_a.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_exit.split.us.loopexit, label %loop_latch.us
;
; CHECK: loop_latch.us:
; CHECK-NEXT: br label %loop_begin.us
;
; CHECK: loop_exit.split.us.loopexit:
; CHECK-NEXT: %[[A_LCSSA_US:.*]] = phi i32 [ %[[A]], %loop_a.us ]
; CHECK-NEXT: br label %loop_exit.split.us
;
; CHECK: loop_exit.split.us:
; CHECK-NEXT: %[[AB_PHI_US:.*]] = phi i32 [ %[[B]], %loop_b.us ], [ %[[A_LCSSA_US]], %loop_exit.split.us.loopexit ]
; CHECK-NEXT: br label %loop_exit
;
; But the original loop contains an inner loop that must be traversed.;
;
; CHECK: entry.split:
; CHECK-NEXT: br label %loop_begin
;
; CHECK: loop_begin:
; CHECK-NEXT: %[[A:.*]] = load i32, i32* %a.ptr
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_a, label %loop_b
;
; CHECK: loop_a:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_exit.split, label %loop_latch
;
; CHECK: loop_b:
; CHECK-NEXT: %[[B:.*]] = load i32, i32* %b.ptr
; CHECK-NEXT: br label %loop_b_inner_ph
;
; CHECK: loop_b_inner_ph:
; CHECK-NEXT: br label %loop_b_inner_header
;
; CHECK: loop_b_inner_header:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_b_inner_latch, label %loop_b_inner_body
;
; CHECK: loop_b_inner_body:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_b_inner_latch, label %loop_b_inner_exit
;
; CHECK: loop_b_inner_latch:
; CHECK-NEXT: br label %loop_b_inner_header
;
; CHECK: loop_b_inner_exit:
; CHECK-NEXT: br label %loop_latch
;
; CHECK: loop_latch:
; CHECK-NEXT: br label %loop_begin
loop_exit:
%lcssa = phi i32 [ %a, %loop_a ], [ %b, %loop_b ]
ret i32 %lcssa
; CHECK: loop_exit.split:
; CHECK-NEXT: %[[A_LCSSA:.*]] = phi i32 [ %[[A]], %loop_a ]
; CHECK-NEXT: br label %loop_exit
;
; CHECK: loop_exit:
; CHECK-NEXT: %[[AB_PHI:.*]] = phi i32 [ %[[A_LCSSA]], %loop_exit.split ], [ %[[AB_PHI_US]], %loop_exit.split.us ]
; CHECK-NEXT: ret i32 %[[AB_PHI]]
}
define i32 @test20(i32* %var, i32 %cond1, i32 %cond2) {
; CHECK-LABEL: @test20(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: switch i32 %cond2, label %[[ENTRY_SPLIT_EXIT:.*]] [
; CHECK-NEXT: i32 0, label %[[ENTRY_SPLIT_A:.*]]
; CHECK-NEXT: i32 1, label %[[ENTRY_SPLIT_A]]
; CHECK-NEXT: i32 13, label %[[ENTRY_SPLIT_B:.*]]
; CHECK-NEXT: i32 2, label %[[ENTRY_SPLIT_A]]
; CHECK-NEXT: i32 42, label %[[ENTRY_SPLIT_C:.*]]
; CHECK-NEXT: ]
loop_begin:
%var_val = load i32, i32* %var
switch i32 %cond2, label %loop_exit [
i32 0, label %loop_a
i32 1, label %loop_a
i32 13, label %loop_b
i32 2, label %loop_a
i32 42, label %loop_c
]
loop_a:
call void @a()
br label %loop_latch
; Unswitched 'a' loop.
;
; CHECK: [[ENTRY_SPLIT_A]]:
; CHECK-NEXT: br label %[[LOOP_BEGIN_A:.*]]
;
; CHECK: [[LOOP_BEGIN_A]]:
; CHECK-NEXT: %{{.*}} = load i32, i32* %var
; CHECK-NEXT: br label %[[LOOP_A:.*]]
;
; CHECK: [[LOOP_A]]:
; CHECK-NEXT: call void @a()
; CHECK-NEXT: br label %[[LOOP_LATCH_A:.*]]
;
; CHECK: [[LOOP_LATCH_A]]:
; CHECK: br label %[[LOOP_BEGIN_A]]
loop_b:
call void @b()
br label %loop_latch
; Unswitched 'b' loop.
;
; CHECK: [[ENTRY_SPLIT_B]]:
; CHECK-NEXT: br label %[[LOOP_BEGIN_B:.*]]
;
; CHECK: [[LOOP_BEGIN_B]]:
; CHECK-NEXT: %{{.*}} = load i32, i32* %var
; CHECK-NEXT: br label %[[LOOP_B:.*]]
;
; CHECK: [[LOOP_B]]:
; CHECK-NEXT: call void @b()
; CHECK-NEXT: br label %[[LOOP_LATCH_B:.*]]
;
; CHECK: [[LOOP_LATCH_B]]:
; CHECK: br label %[[LOOP_BEGIN_B]]
loop_c:
call void @c() noreturn nounwind
br label %loop_latch
; Unswitched 'c' loop.
;
; CHECK: [[ENTRY_SPLIT_C]]:
; CHECK-NEXT: br label %[[LOOP_BEGIN_C:.*]]
;
; CHECK: [[LOOP_BEGIN_C]]:
; CHECK-NEXT: %{{.*}} = load i32, i32* %var
; CHECK-NEXT: br label %[[LOOP_C:.*]]
;
; CHECK: [[LOOP_C]]:
; CHECK-NEXT: call void @c()
; CHECK-NEXT: br label %[[LOOP_LATCH_C:.*]]
;
; CHECK: [[LOOP_LATCH_C]]:
; CHECK: br label %[[LOOP_BEGIN_C]]
loop_latch:
br label %loop_begin
loop_exit:
%lcssa = phi i32 [ %var_val, %loop_begin ]
ret i32 %lcssa
; Unswitched exit edge (no longer a loop).
;
; CHECK: [[ENTRY_SPLIT_EXIT]]:
; CHECK-NEXT: br label %loop_begin
;
; CHECK: loop_begin:
; CHECK-NEXT: %[[V:.*]] = load i32, i32* %var
; CHECK-NEXT: br label %loop_exit
;
; CHECK: loop_exit:
; CHECK-NEXT: %[[LCSSA:.*]] = phi i32 [ %[[V]], %loop_begin ]
; CHECK-NEXT: ret i32 %[[LCSSA]]
}
; Negative test: we do not switch when the loop contains unstructured control
; flows as it would significantly complicate the process as novel loops might
; be formed, etc.
define void @test_no_unswitch_unstructured_cfg(i1* %ptr, i1 %cond) {
; CHECK-LABEL: @test_no_unswitch_unstructured_cfg(
entry:
br label %loop_begin
loop_begin:
br i1 %cond, label %loop_left, label %loop_right
loop_left:
%v1 = load i1, i1* %ptr
br i1 %v1, label %loop_right, label %loop_merge
loop_right:
%v2 = load i1, i1* %ptr
br i1 %v2, label %loop_left, label %loop_merge
loop_merge:
%v3 = load i1, i1* %ptr
br i1 %v3, label %loop_latch, label %loop_exit
loop_latch:
br label %loop_begin
loop_exit:
ret void
}
; A test reduced out of 403.gcc with interesting nested loops that trigger
; multiple unswitches. A key component of this test is that there are multiple
; paths to reach an inner loop after unswitching, and one of them is via the
; predecessors of the unswitched loop header. That can allow us to find the loop
; through multiple different paths.
define void @test21(i1 %a, i1 %b) {
; CHECK-LABEL: @test21(
bb:
br label %bb3
; CHECK-NOT: br i1 %a
;
; CHECK: br i1 %a, label %[[BB_SPLIT_US:.*]], label %[[BB_SPLIT:.*]]
;
; CHECK-NOT: br i1 %a
; CHECK-NOT: br i1 %b
;
; CHECK: [[BB_SPLIT]]:
; CHECK: br i1 %b
;
; CHECK-NOT: br i1 %a
; CHECK-NOT: br i1 %b
bb3:
%tmp1.0 = phi i32 [ 0, %bb ], [ %tmp1.3, %bb23 ]
br label %bb7
bb7:
%tmp.0 = phi i1 [ true, %bb3 ], [ false, %bb19 ]
%tmp1.1 = phi i32 [ %tmp1.0, %bb3 ], [ %tmp1.2.lcssa, %bb19 ]
br i1 %tmp.0, label %bb11.preheader, label %bb23
bb11.preheader:
br i1 %a, label %bb19, label %bb14.lr.ph
bb14.lr.ph:
br label %bb14
bb14:
%tmp2.02 = phi i32 [ 0, %bb14.lr.ph ], [ 1, %bb14 ]
br i1 %b, label %bb11.bb19_crit_edge, label %bb14
bb11.bb19_crit_edge:
%split = phi i32 [ %tmp2.02, %bb14 ]
br label %bb19
bb19:
%tmp1.2.lcssa = phi i32 [ %split, %bb11.bb19_crit_edge ], [ %tmp1.1, %bb11.preheader ]
%tmp21 = icmp eq i32 %tmp1.2.lcssa, 0
br i1 %tmp21, label %bb23, label %bb7
bb23:
%tmp1.3 = phi i32 [ %tmp1.2.lcssa, %bb19 ], [ %tmp1.1, %bb7 ]
br label %bb3
}
; A test reduced out of 400.perlbench that when unswitching the `%stop`
; condition clones a loop nest outside of a containing loop. This excercises a
; different cloning path from our other test cases and in turn verifying the
; resulting structure can catch any failures to correctly clone these nested
; loops.
declare void @f()
declare void @g()
declare i32 @h(i32 %arg)
define void @test22(i32 %arg) {
; CHECK-LABEL: define void @test22(
entry:
br label %loop1.header
loop1.header:
%stop = phi i1 [ true, %loop1.latch ], [ false, %entry ]
%i = phi i32 [ %i.lcssa, %loop1.latch ], [ %arg, %entry ]
; CHECK: %[[I:.*]] = phi i32 [ %{{.*}}, %loop1.latch ], [ %arg, %entry ]
br i1 %stop, label %loop1.exit, label %loop1.body.loop2.ph
; CHECK: br i1 %stop, label %loop1.exit, label %loop1.body.loop2.ph
loop1.body.loop2.ph:
br label %loop2.header
; Just check that the we unswitched the key condition and that leads to the
; inner loop header.
;
; CHECK: loop1.body.loop2.ph:
; CHECK-NEXT: br i1 %stop, label %[[SPLIT_US:.*]], label %[[SPLIT:.*]]
;
; CHECK: [[SPLIT_US]]:
; CHECK-NEXT: br label %[[LOOP2_HEADER_US:.*]]
;
; CHECK: [[LOOP2_HEADER_US]]:
; CHECK-NEXT: %{{.*}} = phi i32 [ %[[I]], %[[SPLIT_US]] ]
;
; CHECK: [[SPLIT]]:
; CHECK-NEXT: br label %[[LOOP2_HEADER:.*]]
;
; CHECK: [[LOOP2_HEADER]]:
; CHECK-NEXT: %{{.*}} = phi i32 [ %[[I]], %[[SPLIT]] ]
loop2.header:
%i.inner = phi i32 [ %i, %loop1.body.loop2.ph ], [ %i.next, %loop2.latch ]
br label %loop3.header
loop3.header:
%sw = call i32 @h(i32 %i.inner)
switch i32 %sw, label %loop3.exit [
i32 32, label %loop3.header
i32 59, label %loop2.latch
i32 36, label %loop1.latch
]
loop2.latch:
%i.next = add i32 %i.inner, 1
br i1 %stop, label %loop2.exit, label %loop2.header
loop1.latch:
%i.lcssa = phi i32 [ %i.inner, %loop3.header ]
br label %loop1.header
loop3.exit:
call void @f()
ret void
loop2.exit:
call void @g()
ret void
loop1.exit:
call void @g()
ret void
}
; Test that when we are unswitching and need to rebuild the loop block set we
; correctly skip past inner loops. We want to use the inner loop to efficiently
; skip whole subregions of the outer loop blocks but just because the header of
; the outer loop is also the preheader of an inner loop shouldn't confuse this
; walk.
define void @test23(i1 %arg, i1* %ptr) {
; CHECK-LABEL: define void @test23(
entry:
br label %outer.header
; CHECK: entry:
; CHECK-NEXT: br i1 %arg,
;
; Just verify that we unswitched the correct bits. We should call `@f` twice in
; one unswitch and `@f` and then `@g` in the other.
; CHECK: call void
; CHECK-SAME: @f
; CHECK: call void
; CHECK-SAME: @f
;
; CHECK: call void
; CHECK-SAME: @f
; CHECK: call void
; CHECK-SAME: @g
outer.header:
br label %inner.header
inner.header:
call void @f()
br label %inner.latch
inner.latch:
%inner.cond = load i1, i1* %ptr
br i1 %inner.cond, label %inner.header, label %outer.body
outer.body:
br i1 %arg, label %outer.body.left, label %outer.body.right
outer.body.left:
call void @f()
br label %outer.latch
outer.body.right:
call void @g()
br label %outer.latch
outer.latch:
%outer.cond = load i1, i1* %ptr
br i1 %outer.cond, label %outer.header, label %exit
exit:
ret void
}
; Non-trivial loop unswitching where there are two invariant conditions, but the
; second one is only in the cloned copy of the loop after unswitching.
define i32 @test24(i1* %ptr, i1 %cond1, i1 %cond2) {
; CHECK-LABEL: @test24(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 %cond1, label %entry.split.us, label %entry.split
loop_begin:
br i1 %cond1, label %loop_a, label %loop_b
loop_a:
br i1 %cond2, label %loop_a_a, label %loop_a_c
; The second unswitched condition.
;
; CHECK: entry.split.us:
; CHECK-NEXT: br i1 %cond2, label %entry.split.us.split.us, label %entry.split.us.split
loop_a_a:
call void @a()
br label %latch
; The 'loop_a_a' unswitched loop.
;
; CHECK: entry.split.us.split.us:
; CHECK-NEXT: br label %loop_begin.us.us
;
; CHECK: loop_begin.us.us:
; CHECK-NEXT: br label %loop_a.us.us
;
; CHECK: loop_a.us.us:
; CHECK-NEXT: br label %loop_a_a.us.us
;
; CHECK: loop_a_a.us.us:
; CHECK-NEXT: call void @a()
; CHECK-NEXT: br label %latch.us.us
;
; CHECK: latch.us.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_begin.us.us, label %loop_exit.split.us.split.us
;
; CHECK: loop_exit.split.us.split.us:
; CHECK-NEXT: br label %loop_exit.split
loop_a_c:
call void @c()
br label %latch
; The 'loop_a_c' unswitched loop.
;
; CHECK: entry.split.us.split:
; CHECK-NEXT: br label %loop_begin.us
;
; CHECK: loop_begin.us:
; CHECK-NEXT: br label %loop_a.us
;
; CHECK: loop_a.us:
; CHECK-NEXT: br label %loop_a_c.us
;
; CHECK: loop_a_c.us:
; CHECK-NEXT: call void @c()
; CHECK-NEXT: br label %latch
;
; CHECK: latch.us:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_begin.us, label %loop_exit.split.us.split
;
; CHECK: loop_exit.split.us.split:
; CHECK-NEXT: br label %loop_exit.split
loop_b:
call void @b()
br label %latch
; The 'loop_b' unswitched loop.
;
; CHECK: entry.split:
; CHECK-NEXT: br label %loop_begin
;
; CHECK: loop_begin:
; CHECK-NEXT: br label %loop_b
;
; CHECK: loop_b:
; CHECK-NEXT: call void @b()
; CHECK-NEXT: br label %latch
;
; CHECK: latch:
; CHECK-NEXT: %[[V:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V]], label %loop_begin, label %loop_exit.split
;
; CHECK: loop_exit.split:
; CHECK-NEXT: br label %loop_exit
latch:
%v = load i1, i1* %ptr
br i1 %v, label %loop_begin, label %loop_exit
loop_exit:
ret i32 0
; CHECK: loop_exit:
; CHECK-NEXT: ret
}
; Non-trivial partial loop unswitching of an invariant input to an 'or'.
define i32 @test25(i1* %ptr, i1 %cond) {
; CHECK-LABEL: @test25(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 %cond, label %entry.split.us, label %entry.split
loop_begin:
%v1 = load i1, i1* %ptr
%cond_or = or i1 %v1, %cond
br i1 %cond_or, label %loop_a, label %loop_b
loop_a:
call void @a()
br label %latch
; The 'loop_a' unswitched loop.
;
; CHECK: entry.split.us:
; CHECK-NEXT: br label %loop_begin.us
;
; CHECK: loop_begin.us:
; CHECK-NEXT: %[[V1_US:.*]] = load i1, i1* %ptr
; CHECK-NEXT: %[[OR_US:.*]] = or i1 %[[V1_US]], true
; CHECK-NEXT: br label %loop_a.us
;
; CHECK: loop_a.us:
; CHECK-NEXT: call void @a()
; CHECK-NEXT: br label %latch.us
;
; CHECK: latch.us:
; CHECK-NEXT: %[[V2_US:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V2_US]], label %loop_begin.us, label %loop_exit.split.us
;
; CHECK: loop_exit.split.us:
; CHECK-NEXT: br label %loop_exit
loop_b:
call void @b()
br label %latch
; The original loop.
;
; CHECK: entry.split:
; CHECK-NEXT: br label %loop_begin
;
; CHECK: loop_begin:
; CHECK-NEXT: %[[V1:.*]] = load i1, i1* %ptr
; CHECK-NEXT: %[[OR:.*]] = or i1 %[[V1]], false
; CHECK-NEXT: br i1 %[[OR]], label %loop_a, label %loop_b
;
; CHECK: loop_a:
; CHECK-NEXT: call void @a()
; CHECK-NEXT: br label %latch
;
; CHECK: loop_b:
; CHECK-NEXT: call void @b()
; CHECK-NEXT: br label %latch
latch:
%v2 = load i1, i1* %ptr
br i1 %v2, label %loop_begin, label %loop_exit
; CHECK: latch:
; CHECK-NEXT: %[[V2:.*]] = load i1, i1* %ptr
; CHECK-NEXT: br i1 %[[V2]], label %loop_begin, label %loop_exit.split
loop_exit:
ret i32 0
; CHECK: loop_exit.split:
; CHECK-NEXT: br label %loop_exit
;
; CHECK: loop_exit:
; CHECK-NEXT: ret
}
; Non-trivial partial loop unswitching of multiple invariant inputs to an `and`
; chain.
define i32 @test26(i1* %ptr1, i1* %ptr2, i1* %ptr3, i1 %cond1, i1 %cond2, i1 %cond3) {
; CHECK-LABEL: @test26(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: %[[INV_AND:.*]] = and i1 %cond3, %cond1
; CHECK-NEXT: br i1 %[[INV_AND]], label %entry.split, label %entry.split.us
loop_begin:
%v1 = load i1, i1* %ptr1
%v2 = load i1, i1* %ptr2
%cond_and1 = and i1 %v1, %cond1
%cond_or1 = or i1 %v2, %cond2
%cond_and2 = and i1 %cond_and1, %cond_or1
%cond_and3 = and i1 %cond_and2, %cond3
br i1 %cond_and3, label %loop_a, label %loop_b
; The 'loop_b' unswitched loop.
;
; CHECK: entry.split.us:
; CHECK-NEXT: br label %loop_begin.us
;
; CHECK: loop_begin.us:
; CHECK-NEXT: %[[V1_US:.*]] = load i1, i1* %ptr1
; CHECK-NEXT: %[[V2_US:.*]] = load i1, i1* %ptr2
; CHECK-NEXT: %[[AND1_US:.*]] = and i1 %[[V1_US]], false
; CHECK-NEXT: %[[OR1_US:.*]] = or i1 %[[V2_US]], %cond2
; CHECK-NEXT: %[[AND2_US:.*]] = and i1 %[[AND1_US]], %[[OR1_US]]
; CHECK-NEXT: %[[AND3_US:.*]] = and i1 %[[AND2_US]], false
; CHECK-NEXT: br label %loop_b.us
;
; CHECK: loop_b.us:
; CHECK-NEXT: call void @b()
; CHECK-NEXT: br label %latch.us
;
; CHECK: latch.us:
; CHECK-NEXT: %[[V3_US:.*]] = load i1, i1* %ptr3
; CHECK-NEXT: br i1 %[[V3_US]], label %loop_begin.us, label %loop_exit.split.us
;
; CHECK: loop_exit.split.us:
; CHECK-NEXT: br label %loop_exit
; The original loop.
;
; CHECK: entry.split:
; CHECK-NEXT: br label %loop_begin
;
; CHECK: loop_begin:
; CHECK-NEXT: %[[V1:.*]] = load i1, i1* %ptr1
; CHECK-NEXT: %[[V2:.*]] = load i1, i1* %ptr2
; CHECK-NEXT: %[[AND1:.*]] = and i1 %[[V1]], true
; CHECK-NEXT: %[[OR1:.*]] = or i1 %[[V2]], %cond2
; CHECK-NEXT: %[[AND2:.*]] = and i1 %[[AND1]], %[[OR1]]
; CHECK-NEXT: %[[AND3:.*]] = and i1 %[[AND2]], true
; CHECK-NEXT: br i1 %[[AND3]], label %loop_a, label %loop_b
loop_a:
call void @a()
br label %latch
; CHECK: loop_a:
; CHECK-NEXT: call void @a()
; CHECK-NEXT: br label %latch
loop_b:
call void @b()
br label %latch
; CHECK: loop_b:
; CHECK-NEXT: call void @b()
; CHECK-NEXT: br label %latch
latch:
%v3 = load i1, i1* %ptr3
br i1 %v3, label %loop_begin, label %loop_exit
; CHECK: latch:
; CHECK-NEXT: %[[V3:.*]] = load i1, i1* %ptr3
; CHECK-NEXT: br i1 %[[V3]], label %loop_begin, label %loop_exit.split
loop_exit:
ret i32 0
; CHECK: loop_exit.split:
; CHECK-NEXT: br label %loop_exit
;
; CHECK: loop_exit:
; CHECK-NEXT: ret
}
; Non-trivial unswitching of a switch.
define i32 @test27(i1* %ptr, i32 %cond) {
; CHECK-LABEL: @test27(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: switch i32 %cond, label %[[ENTRY_SPLIT_LATCH:.*]] [
; CHECK-NEXT: i32 0, label %[[ENTRY_SPLIT_A:.*]]
; CHECK-NEXT: i32 1, label %[[ENTRY_SPLIT_B:.*]]
; CHECK-NEXT: i32 2, label %[[ENTRY_SPLIT_C:.*]]
; CHECK-NEXT: ]
loop_begin:
switch i32 %cond, label %latch [
i32 0, label %loop_a
i32 1, label %loop_b
i32 2, label %loop_c
]
loop_a:
call void @a()
br label %latch
; Unswitched 'a' loop.
;
; CHECK: [[ENTRY_SPLIT_A]]:
; CHECK-NEXT: br label %[[LOOP_BEGIN_A:.*]]
;
; CHECK: [[LOOP_BEGIN_A]]:
; CHECK-NEXT: br label %[[LOOP_A:.*]]
;
; CHECK: [[LOOP_A]]:
; CHECK-NEXT: call void @a()
; CHECK-NEXT: br label %[[LOOP_LATCH_A:.*]]
;
; CHECK: [[LOOP_LATCH_A]]:
; CHECK-NEXT: %[[V_A:.*]] = load i1, i1* %ptr
; CHECK: br i1 %[[V_A]], label %[[LOOP_BEGIN_A]], label %[[LOOP_EXIT_A:.*]]
;
; CHECK: [[LOOP_EXIT_A]]:
; CHECK-NEXT: br label %loop_exit
loop_b:
call void @b()
br label %latch
; Unswitched 'b' loop.
;
; CHECK: [[ENTRY_SPLIT_B]]:
; CHECK-NEXT: br label %[[LOOP_BEGIN_B:.*]]
;
; CHECK: [[LOOP_BEGIN_B]]:
; CHECK-NEXT: br label %[[LOOP_B:.*]]
;
; CHECK: [[LOOP_B]]:
; CHECK-NEXT: call void @b()
; CHECK-NEXT: br label %[[LOOP_LATCH_B:.*]]
;
; CHECK: [[LOOP_LATCH_B]]:
; CHECK-NEXT: %[[V_B:.*]] = load i1, i1* %ptr
; CHECK: br i1 %[[V_B]], label %[[LOOP_BEGIN_B]], label %[[LOOP_EXIT_B:.*]]
;
; CHECK: [[LOOP_EXIT_B]]:
; CHECK-NEXT: br label %loop_exit
loop_c:
call void @c()
br label %latch
; Unswitched 'c' loop.
;
; CHECK: [[ENTRY_SPLIT_C]]:
; CHECK-NEXT: br label %[[LOOP_BEGIN_C:.*]]
;
; CHECK: [[LOOP_BEGIN_C]]:
; CHECK-NEXT: br label %[[LOOP_C:.*]]
;
; CHECK: [[LOOP_C]]:
; CHECK-NEXT: call void @c()
; CHECK-NEXT: br label %[[LOOP_LATCH_C:.*]]
;
; CHECK: [[LOOP_LATCH_C]]:
; CHECK-NEXT: %[[V_C:.*]] = load i1, i1* %ptr
; CHECK: br i1 %[[V_C]], label %[[LOOP_BEGIN_C]], label %[[LOOP_EXIT_C:.*]]
;
; CHECK: [[LOOP_EXIT_C]]:
; CHECK-NEXT: br label %loop_exit
latch:
%v = load i1, i1* %ptr
br i1 %v, label %loop_begin, label %loop_exit
; Unswitched the 'latch' only loop.
;
; CHECK: [[ENTRY_SPLIT_LATCH]]:
; CHECK-NEXT: br label %[[LOOP_BEGIN_LATCH:.*]]
;
; CHECK: [[LOOP_BEGIN_LATCH]]:
; CHECK-NEXT: br label %[[LOOP_LATCH_LATCH:.*]]
;
; CHECK: [[LOOP_LATCH_LATCH]]:
; CHECK-NEXT: %[[V_LATCH:.*]] = load i1, i1* %ptr
; CHECK: br i1 %[[V_LATCH]], label %[[LOOP_BEGIN_LATCH]], label %[[LOOP_EXIT_LATCH:.*]]
;
; CHECK: [[LOOP_EXIT_LATCH]]:
; CHECK-NEXT: br label %loop_exit
loop_exit:
ret i32 0
; CHECK: loop_exit:
; CHECK-NEXT: ret i32 0
}
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