fix an infinite loop in reassociate building emacs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92679 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2010-01-05 04:55:35 +00:00
parent 2abc1ec2dd
commit 5f94af0f72
2 changed files with 19 additions and 0 deletions

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@ -932,6 +932,10 @@ void Reassociate::ReassociateBB(BasicBlock *BB) {
if (BI->getOpcode() == Instruction::Sub) {
if (ShouldBreakUpSubtract(BI)) {
BI = BreakUpSubtract(BI, ValueRankMap);
// Reset the BBI iterator in case BreakUpSubtract changed the
// instruction it points to.
BBI = BI;
++BBI;
MadeChange = true;
} else if (BinaryOperator::isNeg(BI)) {
// Otherwise, this is a negation. See if the operand is a multiply tree

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@ -0,0 +1,15 @@
; RUN: opt -reassociate -disable-output %s
; rdar://7507855
define fastcc i32 @test() nounwind {
entry:
%cond = select i1 undef, i32 1, i32 -1 ; <i32> [#uses=2]
br label %for.cond
for.cond: ; preds = %for.body, %entry
%sub889 = sub i32 undef, undef ; <i32> [#uses=1]
%sub891 = sub i32 %sub889, %cond ; <i32> [#uses=0]
%add896 = sub i32 0, %cond ; <i32> [#uses=0]
ret i32 undef
}