Keep CodeGenPrepare from preserving the domtree.

CGP modifies the domtree in some cases, so saying that it preserves the
domtree is a lie. We'll be able to selectively preserve it with the new
pass manager.

Differential Revision: http://reviews.llvm.org/D16893

llvm-svn: 264099
This commit is contained in:
George Burgess IV 2016-03-22 21:25:08 +00:00
parent 87b1f010b0
commit 1b9e3ea6ac
2 changed files with 43 additions and 1 deletions

View File

@ -158,7 +158,7 @@ class TypePromotionTransaction;
const char *getPassName() const override { return "CodeGen Prepare"; }
void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.addPreserved<DominatorTreeWrapperPass>();
// FIXME: When we can selectively preserve passes, preserve the domtree.
AU.addRequired<TargetLibraryInfoWrapperPass>();
AU.addRequired<TargetTransformInfoWrapperPass>();
}
@ -5277,6 +5277,7 @@ bool CodeGenPrepare::optimizeBlock(BasicBlock &BB, bool& ModifiedDT) {
for (auto &I : reverse(BB)) {
if (makeBitReverse(I, *DL, *TLI)) {
MadeBitReverse = MadeChange = true;
ModifiedDT = true;
break;
}
}

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@ -0,0 +1,41 @@
; RUN: opt -S -loop-unroll -codegenprepare < %s -domtree -analyze | FileCheck %s
;
; Checks that the dom tree is properly invalidated after an operation that will
; invalidate it in CodeGenPrepare. If the domtree isn't properly invalidated,
; this will likely segfault, or print badref.
; CHECK-NOT: <badref>
target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
target triple = "armv7--linux-gnueabihf"
define i32 @f(i32 %a) #0 {
entry:
br label %for.body
for.cond.cleanup:
ret i32 %or
for.body:
%i.08 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
%b.07 = phi i32 [ 0, %entry ], [ %or, %for.body ]
%shr = lshr i32 %a, %i.08
%and = and i32 %shr, 1
%sub = sub nuw nsw i32 31, %i.08
%shl = shl i32 %and, %sub
%or = or i32 %shl, %b.07
%inc = add nuw nsw i32 %i.08, 1
%exitcond = icmp eq i32 %inc, 32
br i1 %exitcond, label %for.cond.cleanup, label %for.body, !llvm.loop !3
}
attributes #0 = { norecurse nounwind readnone "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="cortex-a8" "target-features"="+dsp,+neon,+vfp3" "unsafe-fp-math"="false" "use-soft-float"="false" }
!llvm.module.flags = !{!0, !1}
!llvm.ident = !{!2}
!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{i32 1, !"min_enum_size", i32 4}
!2 = !{!"clang version 3.8.0 (http://llvm.org/git/clang.git b7441a0f42c43a8eea9e3e706be187252db747fa)"}
!3 = distinct !{!3, !4}
!4 = !{!"llvm.loop.unroll.full"}