Files
clang-p2996/llvm/test/Transforms/BDCE/basic.ll
Florian Hahn 292077072e [Local] Treat calls that may not return as being alive.
With the addition of the `willreturn` attribute, functions that may
not return (e.g. due to an infinite loop) are well defined, if they are
not marked as `willreturn`.

This patch updates `wouldInstructionBeTriviallyDead` to not consider
calls that may not return as dead.

This patch still provides an escape hatch for intrinsics, which are
still assumed as willreturn unconditionally. It will be removed once
all intrinsics definitions have been reviewed and updated.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D94106
2021-01-23 16:05:14 +00:00

398 lines
14 KiB
LLVM

; RUN: opt -S -bdce -instsimplify < %s | FileCheck %s
; RUN: opt -S -instsimplify < %s | FileCheck %s -check-prefix=CHECK-IO
; RUN: opt -S -debugify -bdce < %s | FileCheck %s -check-prefix=DEBUGIFY
target datalayout = "E-m:e-i64:64-n32:64"
target triple = "powerpc64-unknown-linux-gnu"
; Function Attrs: nounwind readnone
define signext i32 @bar(i32 signext %x) #0 {
entry:
%call = tail call signext i32 @foo(i32 signext 5) #0
%and = and i32 %call, 4
%or = or i32 %and, %x
%call1 = tail call signext i32 @foo(i32 signext 3) #0
%and2 = and i32 %call1, 8
%or3 = or i32 %or, %and2
%call4 = tail call signext i32 @foo(i32 signext 2) #0
%and5 = and i32 %call4, 16
%or6 = or i32 %or3, %and5
%call7 = tail call signext i32 @foo(i32 signext 1) #0
%and8 = and i32 %call7, 32
%or9 = or i32 %or6, %and8
%call10 = tail call signext i32 @foo(i32 signext 0) #0
%and11 = and i32 %call10, 64
%or12 = or i32 %or9, %and11
%call13 = tail call signext i32 @foo(i32 signext 4) #0
%and14 = and i32 %call13, 128
%or15 = or i32 %or12, %and14
%shr = ashr i32 %or15, 4
ret i32 %shr
; CHECK-LABEL: @bar
; CHECK-NOT: tail call signext i32 @foo(i32 signext 5)
; CHECK-NOT: tail call signext i32 @foo(i32 signext 3)
; CHECK: tail call signext i32 @foo(i32 signext 2)
; CHECK: tail call signext i32 @foo(i32 signext 1)
; CHECK: tail call signext i32 @foo(i32 signext 0)
; CHECK: tail call signext i32 @foo(i32 signext 4)
; CHECK: ret i32
; Check that instsimplify is not doing this all on its own.
; CHECK-IO-LABEL: @bar
; CHECK-IO: tail call signext i32 @foo(i32 signext 5)
; CHECK-IO: tail call signext i32 @foo(i32 signext 3)
; CHECK-IO: tail call signext i32 @foo(i32 signext 2)
; CHECK-IO: tail call signext i32 @foo(i32 signext 1)
; CHECK-IO: tail call signext i32 @foo(i32 signext 0)
; CHECK-IO: tail call signext i32 @foo(i32 signext 4)
; CHECK-IO: ret i32
}
; Function Attrs: nounwind readnone
declare signext i32 @foo(i32 signext) #0
; Function Attrs: nounwind readnone
define signext i32 @far(i32 signext %x) #1 {
entry:
%call = tail call signext i32 @goo(i32 signext 5) #1
%and = and i32 %call, 4
%or = or i32 %and, %x
%call1 = tail call signext i32 @goo(i32 signext 3) #1
%and2 = and i32 %call1, 8
%or3 = or i32 %or, %and2
%call4 = tail call signext i32 @goo(i32 signext 2) #1
%and5 = and i32 %call4, 16
%or6 = or i32 %or3, %and5
%call7 = tail call signext i32 @goo(i32 signext 1) #1
%and8 = and i32 %call7, 32
%or9 = or i32 %or6, %and8
%call10 = tail call signext i32 @goo(i32 signext 0) #1
%and11 = and i32 %call10, 64
%or12 = or i32 %or9, %and11
%call13 = tail call signext i32 @goo(i32 signext 4) #1
%and14 = and i32 %call13, 128
%or15 = or i32 %or12, %and14
%shr = ashr i32 %or15, 4
ret i32 %shr
; CHECK-LABEL: @far
; Calls to foo(5) and foo(3) are still there, but their results are not used.
; CHECK: tail call signext i32 @goo(i32 signext 5)
; CHECK-NEXT: tail call signext i32 @goo(i32 signext 3)
; CHECK-NEXT: tail call signext i32 @goo(i32 signext 2)
; CHECK: tail call signext i32 @goo(i32 signext 1)
; CHECK: tail call signext i32 @goo(i32 signext 0)
; CHECK: tail call signext i32 @goo(i32 signext 4)
; CHECK: ret i32
; Check that instsimplify is not doing this all on its own.
; CHECK-IO-LABEL: @far
; CHECK-IO: tail call signext i32 @goo(i32 signext 5)
; CHECK-IO: tail call signext i32 @goo(i32 signext 3)
; CHECK-IO: tail call signext i32 @goo(i32 signext 2)
; CHECK-IO: tail call signext i32 @goo(i32 signext 1)
; CHECK-IO: tail call signext i32 @goo(i32 signext 0)
; CHECK-IO: tail call signext i32 @goo(i32 signext 4)
; CHECK-IO: ret i32
}
declare signext i32 @goo(i32 signext) #1
; Function Attrs: nounwind readnone
define signext i32 @tar1(i32 signext %x) #0 {
entry:
%call = tail call signext i32 @foo(i32 signext 5) #0
%and = and i32 %call, 33554432
%or = or i32 %and, %x
%call1 = tail call signext i32 @foo(i32 signext 3) #0
%and2 = and i32 %call1, 67108864
%or3 = or i32 %or, %and2
%call4 = tail call signext i32 @foo(i32 signext 2) #0
%and5 = and i32 %call4, 16
%or6 = or i32 %or3, %and5
%call7 = tail call signext i32 @foo(i32 signext 1) #0
%and8 = and i32 %call7, 32
%or9 = or i32 %or6, %and8
%call10 = tail call signext i32 @foo(i32 signext 0) #0
%and11 = and i32 %call10, 64
%or12 = or i32 %or9, %and11
%call13 = tail call signext i32 @foo(i32 signext 4) #0
%and14 = and i32 %call13, 128
%or15 = or i32 %or12, %and14
%bs = tail call i32 @llvm.bswap.i32(i32 %or15) #0
%shr = ashr i32 %bs, 4
ret i32 %shr
; CHECK-LABEL: @tar1
; CHECK-NOT: tail call signext i32 @foo(i32 signext 5)
; CHECK-NOT: tail call signext i32 @foo(i32 signext 3)
; CHECK: tail call signext i32 @foo(i32 signext 2)
; CHECK: tail call signext i32 @foo(i32 signext 1)
; CHECK: tail call signext i32 @foo(i32 signext 0)
; CHECK: tail call signext i32 @foo(i32 signext 4)
; CHECK: ret i32
}
; Function Attrs: nounwind readnone
declare i32 @llvm.bswap.i32(i32) #0
; Function Attrs: nounwind readnone
define signext i32 @tim(i32 signext %x) #0 {
entry:
%call = tail call signext i32 @foo(i32 signext 5) #0
%and = and i32 %call, 536870912
%or = or i32 %and, %x
%call1 = tail call signext i32 @foo(i32 signext 3) #0
%and2 = and i32 %call1, 1073741824
%or3 = or i32 %or, %and2
%call4 = tail call signext i32 @foo(i32 signext 2) #0
%and5 = and i32 %call4, 16
%or6 = or i32 %or3, %and5
%call7 = tail call signext i32 @foo(i32 signext 1) #0
%and8 = and i32 %call7, 32
%or9 = or i32 %or6, %and8
%call10 = tail call signext i32 @foo(i32 signext 0) #0
%and11 = and i32 %call10, 64
%or12 = or i32 %or9, %and11
%call13 = tail call signext i32 @foo(i32 signext 4) #0
%and14 = and i32 %call13, 128
%or15 = or i32 %or12, %and14
%bs = tail call i32 @llvm.bitreverse.i32(i32 %or15) #0
%shr = ashr i32 %bs, 4
ret i32 %shr
; CHECK-LABEL: @tim
; CHECK-NOT: tail call signext i32 @foo(i32 signext 5)
; CHECK-NOT: tail call signext i32 @foo(i32 signext 3)
; CHECK: tail call signext i32 @foo(i32 signext 2)
; CHECK: tail call signext i32 @foo(i32 signext 1)
; CHECK: tail call signext i32 @foo(i32 signext 0)
; CHECK: tail call signext i32 @foo(i32 signext 4)
; CHECK: ret i32
}
; Function Attrs: nounwind readnone
declare i32 @llvm.bitreverse.i32(i32) #0
; Function Attrs: nounwind readnone
define signext i32 @tar2(i32 signext %x) #0 {
entry:
%call = tail call signext i32 @foo(i32 signext 5) #0
%and = and i32 %call, 33554432
%or = or i32 %and, %x
%call1 = tail call signext i32 @foo(i32 signext 3) #0
%and2 = and i32 %call1, 67108864
%or3 = or i32 %or, %and2
%call4 = tail call signext i32 @foo(i32 signext 2) #0
%and5 = and i32 %call4, 16
%or6 = or i32 %or3, %and5
%call7 = tail call signext i32 @foo(i32 signext 1) #0
%and8 = and i32 %call7, 32
%or9 = or i32 %or6, %and8
%call10 = tail call signext i32 @foo(i32 signext 0) #0
%and11 = and i32 %call10, 64
%or12 = or i32 %or9, %and11
%call13 = tail call signext i32 @foo(i32 signext 4) #0
%and14 = and i32 %call13, 128
%or15 = or i32 %or12, %and14
%shl = shl i32 %or15, 10
ret i32 %shl
; CHECK-LABEL: @tar2
; CHECK-NOT: tail call signext i32 @foo(i32 signext 5)
; CHECK-NOT: tail call signext i32 @foo(i32 signext 3)
; CHECK: tail call signext i32 @foo(i32 signext 2)
; CHECK: tail call signext i32 @foo(i32 signext 1)
; CHECK: tail call signext i32 @foo(i32 signext 0)
; CHECK: tail call signext i32 @foo(i32 signext 4)
; CHECK: ret i32
}
; Function Attrs: nounwind readnone
define signext i32 @tar3(i32 signext %x) #0 {
entry:
%call = tail call signext i32 @foo(i32 signext 5) #0
%and = and i32 %call, 33554432
%or = or i32 %and, %x
%call1 = tail call signext i32 @foo(i32 signext 3) #0
%and2 = and i32 %call1, 67108864
%or3 = or i32 %or, %and2
%call4 = tail call signext i32 @foo(i32 signext 2) #0
%and5 = and i32 %call4, 16
%or6 = or i32 %or3, %and5
%call7 = tail call signext i32 @foo(i32 signext 1) #0
%and8 = and i32 %call7, 32
%or9 = or i32 %or6, %and8
%call10 = tail call signext i32 @foo(i32 signext 0) #0
%and11 = and i32 %call10, 64
%or12 = or i32 %or9, %and11
%call13 = tail call signext i32 @foo(i32 signext 4) #0
%and14 = and i32 %call13, 128
%or15 = or i32 %or12, %and14
%add = add i32 %or15, 5
%shl = shl i32 %add, 10
ret i32 %shl
; CHECK-LABEL: @tar3
; CHECK-NOT: tail call signext i32 @foo(i32 signext 5)
; CHECK-NOT: tail call signext i32 @foo(i32 signext 3)
; CHECK: tail call signext i32 @foo(i32 signext 2)
; CHECK: tail call signext i32 @foo(i32 signext 1)
; CHECK: tail call signext i32 @foo(i32 signext 0)
; CHECK: tail call signext i32 @foo(i32 signext 4)
; CHECK: ret i32
}
; Function Attrs: nounwind readnone
define signext i32 @tar4(i32 signext %x) #0 {
entry:
%call = tail call signext i32 @foo(i32 signext 5) #0
%and = and i32 %call, 33554432
%or = or i32 %and, %x
%call1 = tail call signext i32 @foo(i32 signext 3) #0
%and2 = and i32 %call1, 67108864
%or3 = or i32 %or, %and2
%call4 = tail call signext i32 @foo(i32 signext 2) #0
%and5 = and i32 %call4, 16
%or6 = or i32 %or3, %and5
%call7 = tail call signext i32 @foo(i32 signext 1) #0
%and8 = and i32 %call7, 32
%or9 = or i32 %or6, %and8
%call10 = tail call signext i32 @foo(i32 signext 0) #0
%and11 = and i32 %call10, 64
%or12 = or i32 %or9, %and11
%call13 = tail call signext i32 @foo(i32 signext 4) #0
%and14 = and i32 %call13, 128
%or15 = or i32 %or12, %and14
%sub = sub i32 %or15, 5
%shl = shl i32 %sub, 10
ret i32 %shl
; CHECK-LABEL: @tar4
; CHECK-NOT: tail call signext i32 @foo(i32 signext 5)
; CHECK-NOT: tail call signext i32 @foo(i32 signext 3)
; CHECK: tail call signext i32 @foo(i32 signext 2)
; CHECK: tail call signext i32 @foo(i32 signext 1)
; CHECK: tail call signext i32 @foo(i32 signext 0)
; CHECK: tail call signext i32 @foo(i32 signext 4)
; CHECK: ret i32
}
; Function Attrs: nounwind readnone
define signext i32 @tar5(i32 signext %x) #0 {
entry:
%call = tail call signext i32 @foo(i32 signext 5) #0
%and = and i32 %call, 33554432
%or = or i32 %and, %x
%call1 = tail call signext i32 @foo(i32 signext 3) #0
%and2 = and i32 %call1, 67108864
%or3 = or i32 %or, %and2
%call4 = tail call signext i32 @foo(i32 signext 2) #0
%and5 = and i32 %call4, 16
%or6 = or i32 %or3, %and5
%call7 = tail call signext i32 @foo(i32 signext 1) #0
%and8 = and i32 %call7, 32
%or9 = or i32 %or6, %and8
%call10 = tail call signext i32 @foo(i32 signext 0) #0
%and11 = and i32 %call10, 64
%or12 = or i32 %or9, %and11
%call13 = tail call signext i32 @foo(i32 signext 4) #0
%and14 = and i32 %call13, 128
%or15 = or i32 %or12, %and14
%xor = xor i32 %or15, 5
%shl = shl i32 %xor, 10
ret i32 %shl
; CHECK-LABEL: @tar5
; CHECK-NOT: tail call signext i32 @foo(i32 signext 5)
; CHECK-NOT: tail call signext i32 @foo(i32 signext 3)
; CHECK: tail call signext i32 @foo(i32 signext 2)
; CHECK: tail call signext i32 @foo(i32 signext 1)
; CHECK: tail call signext i32 @foo(i32 signext 0)
; CHECK: tail call signext i32 @foo(i32 signext 4)
; CHECK: ret i32
}
; Function Attrs: nounwind readnone
define signext i32 @tar7(i32 signext %x, i1 %b) #0 {
entry:
%call = tail call signext i32 @foo(i32 signext 5) #0
%and = and i32 %call, 33554432
%or = or i32 %and, %x
%call1 = tail call signext i32 @foo(i32 signext 3) #0
%and2 = and i32 %call1, 67108864
%or3 = or i32 %or, %and2
%call4 = tail call signext i32 @foo(i32 signext 2) #0
%and5 = and i32 %call4, 16
%or6 = or i32 %or3, %and5
%call7 = tail call signext i32 @foo(i32 signext 1) #0
%and8 = and i32 %call7, 32
%or9 = or i32 %or6, %and8
%call10 = tail call signext i32 @foo(i32 signext 0) #0
%and11 = and i32 %call10, 64
%or12 = or i32 %or9, %and11
%call13 = tail call signext i32 @foo(i32 signext 4) #0
%and14 = and i32 %call13, 128
%or15 = or i32 %or12, %and14
%v = select i1 %b, i32 %or15, i32 5
%shl = shl i32 %v, 10
ret i32 %shl
; CHECK-LABEL: @tar7
; CHECK-NOT: tail call signext i32 @foo(i32 signext 5)
; CHECK-NOT: tail call signext i32 @foo(i32 signext 3)
; CHECK: tail call signext i32 @foo(i32 signext 2)
; CHECK: tail call signext i32 @foo(i32 signext 1)
; CHECK: tail call signext i32 @foo(i32 signext 0)
; CHECK: tail call signext i32 @foo(i32 signext 4)
; CHECK: ret i32
}
; Function Attrs: nounwind readnone
define signext i16 @tar8(i32 signext %x) #0 {
entry:
%call = tail call signext i32 @foo(i32 signext 5) #0
%and = and i32 %call, 33554432
%or = or i32 %and, %x
%call1 = tail call signext i32 @foo(i32 signext 3) #0
%and2 = and i32 %call1, 67108864
%or3 = or i32 %or, %and2
%call4 = tail call signext i32 @foo(i32 signext 2) #0
%and5 = and i32 %call4, 16
%or6 = or i32 %or3, %and5
%call7 = tail call signext i32 @foo(i32 signext 1) #0
%and8 = and i32 %call7, 32
%or9 = or i32 %or6, %and8
%call10 = tail call signext i32 @foo(i32 signext 0) #0
%and11 = and i32 %call10, 64
%or12 = or i32 %or9, %and11
%call13 = tail call signext i32 @foo(i32 signext 4) #0
%and14 = and i32 %call13, 128
%or15 = or i32 %or12, %and14
%tr = trunc i32 %or15 to i16
ret i16 %tr
; CHECK-LABEL: @tar8
; CHECK-NOT: tail call signext i32 @foo(i32 signext 5)
; CHECK-NOT: tail call signext i32 @foo(i32 signext 3)
; CHECK: tail call signext i32 @foo(i32 signext 2)
; CHECK: tail call signext i32 @foo(i32 signext 1)
; CHECK: tail call signext i32 @foo(i32 signext 0)
; CHECK: tail call signext i32 @foo(i32 signext 4)
; CHECK: ret i16
}
; DEBUGIFY-LABEL: @tar9
define signext i16 @tar9(i32 signext %x) #0 {
entry:
%call = tail call signext i32 @foo(i32 signext 5) #0
%and = and i32 %call, 33554432
; DEBUGIFY: call void @llvm.dbg.value(metadata i32 %call, metadata {{.*}}, metadata !DIExpression(DW_OP_constu, 33554432, DW_OP_and, DW_OP_stack_value))
%cast = trunc i32 %call to i16
ret i16 %cast
}
attributes #0 = { nounwind readnone willreturn }
attributes #1 = { nounwind }