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clang-p2996/llvm/test/Transforms/JumpThreading/thread-loads.ll
Eli Friedman 41ee3977c4 [JumpThreading] Fix threading with unusual PHI nodes. 
If the block being cloned contains a PHI node, in general, we need to
clone that PHI node, even though it's trivial. If the operand of the PHI
is an instruction in the block being cloned, the correct value for the
operand doesn't exist until SSAUpdater constructs it.

We usually don't hit this issue because we try to avoid threading across
loop headers, but it's possible to hit this in some cases involving
irreducible CFGs.  I added a flag to allow threading across loop headers
to make the testcase easier to understand.

Thanks to Brian Rzycki for reducing the testcase.

Fixes https://bugs.llvm.org/show_bug.cgi?id=42085.

Differential Revision: https://reviews.llvm.org/D63913

llvm-svn: 365094
2019-07-03 23:12:39 +00:00

543 lines
13 KiB
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; RUN: opt < %s -jump-threading -S | FileCheck %s
; RUN: opt < %s -aa-pipeline=basic-aa -passes=jump-threading -S | FileCheck %s
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
target triple = "i386-apple-darwin7"
; Test that we can thread through the block with the partially redundant load (%2).
; rdar://6402033
define i32 @test1(i32* %P) nounwind {
; CHECK-LABEL: @test1(
entry:
%0 = tail call i32 (...) @f1() nounwind ; <i32> [#uses=1]
%1 = icmp eq i32 %0, 0 ; <i1> [#uses=1]
br i1 %1, label %bb1, label %bb
bb: ; preds = %entry
; CHECK: bb1.thread:
; CHECK: store
; CHECK: br label %bb3
store i32 42, i32* %P, align 4
br label %bb1
bb1: ; preds = %entry, %bb
%res.0 = phi i32 [ 1, %bb ], [ 0, %entry ] ; <i32> [#uses=2]
%2 = load i32, i32* %P, align 4 ; <i32> [#uses=1]
%3 = icmp sgt i32 %2, 36 ; <i1> [#uses=1]
br i1 %3, label %bb3, label %bb2
bb2: ; preds = %bb1
%4 = tail call i32 (...) @f2() nounwind ; <i32> [#uses=0]
ret i32 %res.0
bb3: ; preds = %bb1
; CHECK: bb3:
; CHECK: %res.02 = phi i32 [ 1, %bb1.thread ], [ 0, %bb1 ]
; CHECK: ret i32 %res.02
ret i32 %res.0
}
declare i32 @f1(...)
declare i32 @f2(...)
;; Check that we preserve TBAA information.
; rdar://11039258
define i32 @test2(i32* %P) nounwind {
; CHECK-LABEL: @test2(
entry:
%0 = tail call i32 (...) @f1() nounwind ; <i32> [#uses=1]
%1 = icmp eq i32 %0, 0 ; <i1> [#uses=1]
br i1 %1, label %bb1, label %bb
bb: ; preds = %entry
; CHECK: bb1.thread:
; CHECK: store{{.*}}, !tbaa !0
; CHECK: br label %bb3
store i32 42, i32* %P, align 4, !tbaa !0
br label %bb1
bb1: ; preds = %entry, %bb
%res.0 = phi i32 [ 1, %bb ], [ 0, %entry ]
%2 = load i32, i32* %P, align 4, !tbaa !0
%3 = icmp sgt i32 %2, 36
br i1 %3, label %bb3, label %bb2
bb2: ; preds = %bb1
%4 = tail call i32 (...) @f2() nounwind
ret i32 %res.0
bb3: ; preds = %bb1
; CHECK: bb3:
; CHECK: %res.02 = phi i32 [ 1, %bb1.thread ], [ 0, %bb1 ]
; CHECK: ret i32 %res.02
ret i32 %res.0
}
define i32 @test3(i8** %x, i1 %f) {
; Correctly thread loads of different (but compatible) types, placing bitcasts
; as necessary in the predecessors. This is especially tricky because the same
; predecessor ends up with two entries in the PHI node and they must share
; a single cast.
; CHECK-LABEL: @test3(
entry:
%0 = bitcast i8** %x to i32**
%1 = load i32*, i32** %0, align 8
br i1 %f, label %if.end57, label %if.then56
; CHECK: %[[LOAD:.*]] = load i32*, i32**
; CHECK: %[[CAST:.*]] = bitcast i32* %[[LOAD]] to i8*
if.then56:
br label %if.end57
if.end57:
%2 = load i8*, i8** %x, align 8
%tobool59 = icmp eq i8* %2, null
br i1 %tobool59, label %return, label %if.then60
; CHECK: %[[PHI:.*]] = phi i8* [ %[[CAST]], %[[PRED:[^ ]+]] ], [ %[[CAST]], %[[PRED]] ]
; CHECK-NEXT: %[[CMP:.*]] = icmp eq i8* %[[PHI]], null
; CHECK-NEXT: br i1 %[[CMP]]
if.then60:
ret i32 42
return:
ret i32 13
}
define i32 @test4(i32* %P) {
; CHECK-LABEL: @test4(
entry:
%v0 = tail call i32 (...) @f1()
%v1 = icmp eq i32 %v0, 0
br i1 %v1, label %bb1, label %bb
bb:
; CHECK: bb1.thread:
; CHECK: store atomic
; CHECK: br label %bb3
store atomic i32 42, i32* %P unordered, align 4
br label %bb1
bb1:
; CHECK: bb1:
; CHECK-NOT: phi
; CHECK: load atomic
%res.0 = phi i32 [ 1, %bb ], [ 0, %entry ]
%v2 = load atomic i32, i32* %P unordered, align 4
%v3 = icmp sgt i32 %v2, 36
br i1 %v3, label %bb3, label %bb2
bb2:
%v4 = tail call i32 (...) @f2()
ret i32 %res.0
bb3:
ret i32 %res.0
}
define i32 @test5(i32* %P) {
; Negative test
; CHECK-LABEL: @test5(
entry:
%v0 = tail call i32 (...) @f1()
%v1 = icmp eq i32 %v0, 0
br i1 %v1, label %bb1, label %bb
bb:
; CHECK: bb:
; CHECK-NEXT: store atomic i32 42, i32* %P release, align 4
; CHECK-NEXT: br label %bb1
store atomic i32 42, i32* %P release, align 4
br label %bb1
bb1:
; CHECK: bb1:
; CHECK-NEXT: %res.0 = phi i32 [ 1, %bb ], [ 0, %entry ]
; CHECK-NEXT: %v2 = load atomic i32, i32* %P acquire, align 4
; CHECK-NEXT: %v3 = icmp sgt i32 %v2, 36
; CHECK-NEXT: br i1 %v3, label %bb3, label %bb2
%res.0 = phi i32 [ 1, %bb ], [ 0, %entry ]
%v2 = load atomic i32, i32* %P acquire, align 4
%v3 = icmp sgt i32 %v2, 36
br i1 %v3, label %bb3, label %bb2
bb2:
%v4 = tail call i32 (...) @f2()
ret i32 %res.0
bb3:
ret i32 %res.0
}
define i32 @test6(i32* %P) {
; Negative test
; CHECK-LABEL: @test6(
entry:
%v0 = tail call i32 (...) @f1()
%v1 = icmp eq i32 %v0, 0
br i1 %v1, label %bb1, label %bb
bb:
; CHECK: bb:
; CHECK-NEXT: store i32 42, i32* %P
; CHECK-NEXT: br label %bb1
store i32 42, i32* %P
br label %bb1
bb1:
; CHECK: bb1:
; CHECK-NEXT: %res.0 = phi i32 [ 1, %bb ], [ 0, %entry ]
; CHECK-NEXT: %v2 = load atomic i32, i32* %P acquire, align 4
; CHECK-NEXT: %v3 = icmp sgt i32 %v2, 36
; CHECK-NEXT: br i1 %v3, label %bb3, label %bb2
%res.0 = phi i32 [ 1, %bb ], [ 0, %entry ]
%v2 = load atomic i32, i32* %P acquire, align 4
%v3 = icmp sgt i32 %v2, 36
br i1 %v3, label %bb3, label %bb2
bb2:
%v4 = tail call i32 (...) @f2()
ret i32 %res.0
bb3:
ret i32 %res.0
}
define i32 @test7(i32* %P) {
; Negative test
; CHECK-LABEL: @test7(
entry:
%v0 = tail call i32 (...) @f1()
%v1 = icmp eq i32 %v0, 0
br i1 %v1, label %bb1, label %bb
bb:
; CHECK: bb:
; CHECK-NEXT: %val = load i32, i32* %P
; CHECK-NEXT: br label %bb1
%val = load i32, i32* %P
br label %bb1
bb1:
; CHECK: bb1:
; CHECK-NEXT: %res.0 = phi i32 [ 1, %bb ], [ 0, %entry ]
; CHECK-NEXT: %v2 = load atomic i32, i32* %P acquire, align 4
; CHECK-NEXT: %v3 = icmp sgt i32 %v2, 36
; CHECK-NEXT: br i1 %v3, label %bb3, label %bb2
%res.0 = phi i32 [ 1, %bb ], [ 0, %entry ]
%v2 = load atomic i32, i32* %P acquire, align 4
%v3 = icmp sgt i32 %v2, 36
br i1 %v3, label %bb3, label %bb2
bb2:
%v4 = tail call i32 (...) @f2()
ret i32 %res.0
bb3:
ret i32 %res.0
}
; Make sure we merge the aliasing metadata. We keep the range metadata for the
; first load, as it dominates the second load. Hence we can eliminate the
; branch.
define void @test8(i32*, i32*, i32*) {
; CHECK-LABEL: @test8(
; CHECK: %a = load i32, i32* %0, !range ![[RANGE4:[0-9]+]]
; CHECK-NEXT: store i32 %a
; CHECK-NEXT: %xxx = tail call i32 (...) @f1()
; CHECK-NEXT: ret void
%a = load i32, i32* %0, !tbaa !0, !range !4, !alias.scope !9, !noalias !10
%b = load i32, i32* %0, !range !5
store i32 %a, i32* %1
%c = icmp eq i32 %b, 8
br i1 %c, label %ret1, label %ret2
ret1:
ret void
ret2:
%xxx = tail call i32 (...) @f1() nounwind
ret void
}
; Make sure we merge/PRE aliasing metadata correctly. That means that
; we need to remove metadata from the existing load, and add appropriate
; metadata to the newly inserted load.
define void @test9(i32*, i32*, i32*, i1 %c) {
; CHECK-LABEL: @test9(
br i1 %c, label %d1, label %d2
; CHECK: d1:
; CHECK-NEXT: %a = load i32, i32* %0{{$}}
d1:
%a = load i32, i32* %0, !range !4, !alias.scope !9, !noalias !10
br label %d3
; CHECK: d2:
; CHECK-NEXT: %xxxx = tail call i32 (...) @f1()
; CHECK-NEXT: %b.pr = load i32, i32* %0, !tbaa !0{{$}}
d2:
%xxxx = tail call i32 (...) @f1() nounwind
br label %d3
d3:
%p = phi i32 [ 1, %d2 ], [ %a, %d1 ]
%b = load i32, i32* %0, !tbaa !0
store i32 %p, i32* %1
%c2 = icmp eq i32 %b, 8
br i1 %c2, label %ret1, label %ret2
ret1:
ret void
ret2:
%xxx = tail call i32 (...) @f1() nounwind
ret void
}
define i32 @fn_noalias(i1 %c2,i64* noalias %P, i64* noalias %P2) {
; CHECK-LABEL: @fn_noalias
; CHECK-LABEL: cond1:
; CHECK: %[[LD1:.*]] = load i64, i64* %P
; CHECK: br i1 %c, label %[[THREAD:.*]], label %end
; CHECK-LABEL: cond2:
; CHECK: %[[LD2:.*]] = load i64, i64* %P
; CHECK-LABEL: cond3:
; CHECK: %[[PHI:.*]] = phi i64 [ %[[LD1]], %[[THREAD]] ], [ %[[LD2]], %cond2 ]
; CHECK: call void @fn3(i64 %[[PHI]])
entry:
br i1 %c2, label %cond2, label %cond1
cond1:
%l1 = load i64, i64* %P
store i64 42, i64* %P2
%c = icmp eq i64 %l1, 0
br i1 %c, label %cond2, label %end
cond2:
%l2 = load i64, i64* %P
call void @fn2(i64 %l2)
%c3 = icmp eq i64 %l2, 0
br i1 %c3, label %cond3, label %end
cond3:
call void @fn3(i64 %l2)
br label %end
end:
ret i32 0
}
; This tests if we can thread from %sw.bb.i to %do.body.preheader.i67 through
; %sw.bb21.i. To make this happen, %l2 should be detected as a partically
; redundant load with %l3 across the store to %phase in %sw.bb21.i.
%struct.NEXT_MOVE = type { i32, i32, i32* }
@hash_move = unnamed_addr global [65 x i32] zeroinitializer, align 4
@current_move = internal global [65 x i32] zeroinitializer, align 4
@last = internal unnamed_addr global [65 x i32*] zeroinitializer, align 8
@next_status = internal unnamed_addr global [65 x %struct.NEXT_MOVE] zeroinitializer, align 8
define fastcc i32 @Search(i64 %idxprom.i, i64 %idxprom.i89, i32 %c) {
; CHECK-LABEL: @Search
; CHECK-LABEL: sw.bb.i:
; CHECK: %[[LD1:.*]] = load i32, i32* %arrayidx185, align 4
; CHECK: %[[C1:.*]] = icmp eq i32 %[[LD1]], 0
; CHECK: br i1 %[[C1]], label %sw.bb21.i.thread, label %if.then.i64
; CHECK-LABEL: sw.bb21.i.thread:
; CHECK: br label %[[THREAD_TO:.*]]
; CHECK-LABEL: sw.bb21.i:
; CHECK: %[[LD2:.*]] = load i32, i32* %arrayidx185, align 4
; CHECK: %[[C2:.*]] = icmp eq i32 %[[LD2]], 0
; CHECK:br i1 %[[C2]], label %[[THREAD_TO]], label %cleanup
entry:
%arrayidx185 = getelementptr inbounds [65 x i32], [65 x i32]* @hash_move, i64 0, i64 %idxprom.i
%arrayidx307 = getelementptr inbounds [65 x i32], [65 x i32]* @current_move, i64 0, i64 %idxprom.i
%arrayidx89 = getelementptr inbounds [65 x i32*], [65 x i32*]* @last, i64 0, i64 %idxprom.i
%phase = getelementptr inbounds [65 x %struct.NEXT_MOVE], [65 x %struct.NEXT_MOVE]* @next_status, i64 0, i64 %idxprom.i, i32 0
br label %cond.true282
cond.true282:
switch i32 %c, label %sw.default.i [
i32 1, label %sw.bb.i
i32 0, label %sw.bb21.i
]
sw.default.i:
br label %cleanup
sw.bb.i:
%call.i62 = call fastcc i32* @GenerateCheckEvasions()
store i32* %call.i62, i32** %arrayidx89, align 8
%l2 = load i32, i32* %arrayidx185, align 4
%tobool.i63 = icmp eq i32 %l2, 0
br i1 %tobool.i63, label %sw.bb21.i, label %if.then.i64
if.then.i64: ; preds = %sw.bb.i
store i32 7, i32* %phase, align 8
store i32 %l2, i32* %arrayidx307, align 4
%call16.i = call fastcc i32 @ValidMove(i32 %l2)
%tobool17.i = icmp eq i32 %call16.i, 0
br i1 %tobool17.i, label %if.else.i65, label %cleanup
if.else.i65:
call void @f65()
br label %sw.bb21.i
sw.bb21.i:
store i32 10, i32* %phase, align 8
%l3= load i32, i32* %arrayidx185, align 4
%tobool27.i = icmp eq i32 %l3, 0
br i1 %tobool27.i, label %do.body.preheader.i67, label %cleanup
do.body.preheader.i67:
call void @f67()
ret i32 67
cleanup:
call void @Cleanup()
ret i32 0
}
declare fastcc i32* @GenerateCheckEvasions()
declare fastcc i32 @ValidMove(i32 %move)
declare void @f67()
declare void @Cleanup()
declare void @f65()
define i32 @fn_SinglePred(i1 %c2,i64* %P) {
; CHECK-LABEL: @fn_SinglePred
; CHECK-LABEL: entry:
; CHECK: %[[L1:.*]] = load i64, i64* %P
; CHECK: br i1 %c, label %cond3, label %cond1
; CHECK-LABEL: cond2:
; CHECK-NOT: load
; CHECK: %[[PHI:.*]] = phi i64 [ %[[L1]], %cond1 ]
; CHECK: call void @fn2(i64 %[[PHI]])
; CHECK: br label %end
; CHECK-LABEL: cond3:
; CHECK: call void @fn2(i64 %l1)
; CHECK: call void @fn3(i64 %l1)
entry:
%l1 = load i64, i64* %P
%c = icmp eq i64 %l1, 0
br i1 %c, label %cond2, label %cond1
cond1:
br i1 %c2, label %cond2, label %end
cond2:
%l2 = load i64, i64* %P
call void @fn2(i64 %l2)
%c3 = icmp eq i64 %l2, 0
br i1 %c3, label %cond3, label %end
cond3:
call void @fn3(i64 %l2)
br label %end
end:
ret i32 0
}
define i32 @fn_SinglePredMultihop(i1 %c1, i1 %c2,i64* %P) {
; CHECK-LABEL: @fn_SinglePredMultihop
; CHECK-LABEL: entry:
; CHECK: %[[L1:.*]] = load i64, i64* %P
; CHECK: br i1 %c0, label %cond3, label %cond0
; CHECK-LABEL: cond2:
; CHECK-NOT: load
; CHECK: %[[PHI:.*]] = phi i64 [ %[[L1]], %cond1 ]
; CHECK: call void @fn2(i64 %[[PHI]])
; CHECK: br label %end
; CHECK-LABEL: cond3:
; CHECK: call void @fn2(i64 %l1)
; CHECK: call void @fn3(i64 %l1)
entry:
%l1 = load i64, i64* %P
%c0 = icmp eq i64 %l1, 0
br i1 %c0, label %cond2, label %cond0
cond0:
br i1 %c1, label %cond1, label %end
cond1:
br i1 %c2, label %cond2, label %end
cond2:
%l2 = load i64, i64* %P
call void @fn2(i64 %l2)
%c3 = icmp eq i64 %l2, 0
br i1 %c3, label %cond3, label %end
cond3:
call void @fn3(i64 %l2)
br label %end
end:
ret i32 0
}
declare void @fn2(i64)
declare void @fn3(i64)
; Make sure we phi-translate and make the partially redundant load in
; merge fully redudant and then we can jump-thread the block with the
; store.
;
; CHECK-LABEL: define i32 @phi_translate_partial_redundant_loads(i32, i32*, i32*
; CHECK: merge.thread:
; CHECK: store
; CHECK: br label %left_x
;
; CHECK: left_x:
; CHECK-NEXT: ret i32 20
define i32 @phi_translate_partial_redundant_loads(i32, i32*, i32*) {
%cmp0 = icmp ne i32 %0, 0
br i1 %cmp0, label %left, label %right
left:
store i32 1, i32* %1, align 4
br label %merge
right:
br label %merge
merge:
%phiptr = phi i32* [ %1, %left ], [ %2, %right ]
%newload = load i32, i32* %phiptr, align 4
%cmp1 = icmp slt i32 %newload, 5
br i1 %cmp1, label %left_x, label %right_x
left_x:
ret i32 20
right_x:
ret i32 10
}
; CHECK: ![[RANGE4]] = !{i32 0, i32 1}
!0 = !{!3, !3, i64 0}
!1 = !{!"omnipotent char", !2}
!2 = !{!"Simple C/C++ TBAA"}
!3 = !{!"int", !1}
!4 = !{ i32 0, i32 1 }
!5 = !{ i32 8, i32 10 }
!6 = !{!6}
!7 = !{!7, !6}
!8 = !{!8, !6}
!9 = !{!7}
!10 = !{!8}
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