From 5f94af0f725690a75b18909da2ff8cee0f93bebb Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Tue, 5 Jan 2010 04:55:35 +0000 Subject: [PATCH] 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 --- lib/Transforms/Scalar/Reassociate.cpp | 4 ++++ test/Transforms/Reassociate/crash.ll | 15 +++++++++++++++ 2 files changed, 19 insertions(+) create mode 100644 test/Transforms/Reassociate/crash.ll diff --git a/lib/Transforms/Scalar/Reassociate.cpp b/lib/Transforms/Scalar/Reassociate.cpp index 564036bba3e..f2a8633f97a 100644 --- a/lib/Transforms/Scalar/Reassociate.cpp +++ b/lib/Transforms/Scalar/Reassociate.cpp @@ -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 diff --git a/test/Transforms/Reassociate/crash.ll b/test/Transforms/Reassociate/crash.ll new file mode 100644 index 00000000000..12f8a376fdb --- /dev/null +++ b/test/Transforms/Reassociate/crash.ll @@ -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 ; [#uses=2] + br label %for.cond + +for.cond: ; preds = %for.body, %entry + %sub889 = sub i32 undef, undef ; [#uses=1] + %sub891 = sub i32 %sub889, %cond ; [#uses=0] + %add896 = sub i32 0, %cond ; [#uses=0] + ret i32 undef +} -- 2.34.1