RecursivelyDeleteTriviallyDeadInstructions() could remove

more than 1 instruction. The caller need to be aware of this
and adjust instruction iterators accordingly.

rdar://16679376

Repaired r207302.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207309 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Gerolf Hoflehner 2014-04-26 05:58:11 +00:00
parent 67a1d85141
commit b79f1fe084
3 changed files with 33 additions and 2 deletions

View File

@ -127,7 +127,15 @@ bool LoopInstSimplify::runOnLoop(Loop *L, LPPassManager &LPM) {
++NumSimplified;
}
}
LocalChanged |= RecursivelyDeleteTriviallyDeadInstructions(I, TLI);
bool res = RecursivelyDeleteTriviallyDeadInstructions(I, TLI);
if (res) {
// RecursivelyDeleteTriviallyDeadInstruction can remove
// more than one instruction, so simply incrementing the
// iterator does not work. When instructions get deleted
// re-iterate instead.
BI = BB->begin(); BE = BB->end();
LocalChanged |= res;
}
if (IsSubloopHeader && !isa<PHINode>(I))
break;

View File

@ -76,7 +76,15 @@ namespace {
++NumSimplified;
Changed = true;
}
Changed |= RecursivelyDeleteTriviallyDeadInstructions(I, TLI);
bool res = RecursivelyDeleteTriviallyDeadInstructions(I, TLI);
if (res) {
// RecursivelyDeleteTriviallyDeadInstruction can remove
// more than one instruction, so simply incrementing the
// iterator does not work. When instructions get deleted
// re-iterate instead.
BI = BB->begin(); BE = BB->end();
Changed |= res;
}
}
// Place the list of instructions to simplify on the next loop iteration

View File

@ -0,0 +1,15 @@
; RUN: opt -instsimplify -S < %s | FileCheck %s
define void @foo() nounwind {
br i1 undef, label %1, label %4
; <label>:1 ; preds = %1, %0
; CHECK-NOT: phi
; CHECK-NOT: sub
%2 = phi i32 [ %3, %1 ], [ undef, %0 ]
%3 = sub i32 0, undef
br label %1
; <label>:4 ; preds = %0
ret void
}