From de1d8a544c1398cc34d4c865c5afa8b91f96316c Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Thu, 17 Feb 2011 01:29:24 +0000 Subject: [PATCH] fix PR9215, preventing -reassociate from clearing nsw/nuw when it swaps the LHS/RHS of a single binop. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125700 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/Reassociate.cpp | 7 ++++--- test/Transforms/Reassociate/optional-flags.ll | 7 +++++++ 2 files changed, 11 insertions(+), 3 deletions(-) diff --git a/lib/Transforms/Scalar/Reassociate.cpp b/lib/Transforms/Scalar/Reassociate.cpp index 5df6f3725a3..e093b52571a 100644 --- a/lib/Transforms/Scalar/Reassociate.cpp +++ b/lib/Transforms/Scalar/Reassociate.cpp @@ -348,9 +348,10 @@ void Reassociate::RewriteExprTree(BinaryOperator *I, I->setOperand(0, Ops[i].Op); I->setOperand(1, Ops[i+1].Op); - // Conservatively clear all the optional flags, which may not hold - // after the reassociation. - I->clearSubclassOptionalData(); + // Clear all the optional flags, which may not hold after the + // reassociation if the expression involved more than just this operation. + if (Ops.size() != 2) + I->clearSubclassOptionalData(); DEBUG(dbgs() << "TO: " << *I << '\n'); MadeChange = true; diff --git a/test/Transforms/Reassociate/optional-flags.ll b/test/Transforms/Reassociate/optional-flags.ll index 5ecc7675f8e..40f7d5bf5b8 100644 --- a/test/Transforms/Reassociate/optional-flags.ll +++ b/test/Transforms/Reassociate/optional-flags.ll @@ -20,3 +20,10 @@ define i64 @test1(i64 %a, i64 %b, i64 %c) { %z = add nsw i64 %y, %a ret i64 %z } + +; PR9215 +; CHECK: %s = add nsw i32 %y, %x +define i32 @test2(i32 %x, i32 %y) { + %s = add nsw i32 %x, %y + ret i32 %s +} -- 2.34.1