From ef23e8848051d1b0abfa7c5fbc3ea7a6e4b41d16 Mon Sep 17 00:00:00 2001 From: Nikita Popov Date: Wed, 10 Apr 2019 16:18:01 +0000 Subject: [PATCH] [InstCombine] Handle saddo always overflow Followup to D60483: Handle AlwaysOverflow conditions for saddo as well. Differential Revision: https://reviews.llvm.org/D60497 llvm-svn: 358095 --- llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp | 6 +++--- llvm/test/Transforms/InstCombine/with_overflow.ll | 5 +++-- 2 files changed, 6 insertions(+), 5 deletions(-) diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp index 7ec7535..bc99b17 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -3973,15 +3973,15 @@ bool InstCombiner::OptimizeOverflowCheck(OverflowCheckFlavor OCF, Value *LHS, if (OR == OverflowResult::NeverOverflows) return SetResult(Builder.CreateNUWAdd(LHS, RHS), Builder.getFalse(), true); - - if (OR == OverflowResult::AlwaysOverflows) - return SetResult(Builder.CreateAdd(LHS, RHS), Builder.getTrue(), true); } else { OR = computeOverflowForSignedAdd(LHS, RHS, &OrigI); if (OR == OverflowResult::NeverOverflows) return SetResult(Builder.CreateNSWAdd(LHS, RHS), Builder.getFalse(), true); } + + if (OR == OverflowResult::AlwaysOverflows) + return SetResult(Builder.CreateAdd(LHS, RHS), Builder.getTrue(), true); break; } diff --git a/llvm/test/Transforms/InstCombine/with_overflow.ll b/llvm/test/Transforms/InstCombine/with_overflow.ll index d5a727e..af9b133 100644 --- a/llvm/test/Transforms/InstCombine/with_overflow.ll +++ b/llvm/test/Transforms/InstCombine/with_overflow.ll @@ -568,8 +568,9 @@ define { i8, i1 } @sadd_always_overflow(i8 %x) nounwind { ; CHECK-LABEL: @sadd_always_overflow( ; CHECK-NEXT: [[C:%.*]] = icmp sgt i8 [[X:%.*]], 100 ; CHECK-NEXT: [[Y:%.*]] = select i1 [[C]], i8 [[X]], i8 100 -; CHECK-NEXT: [[A:%.*]] = call { i8, i1 } @llvm.sadd.with.overflow.i8(i8 [[Y]], i8 28) -; CHECK-NEXT: ret { i8, i1 } [[A]] +; CHECK-NEXT: [[A:%.*]] = add nuw i8 [[Y]], 28 +; CHECK-NEXT: [[TMP1:%.*]] = insertvalue { i8, i1 } { i8 undef, i1 true }, i8 [[A]], 0 +; CHECK-NEXT: ret { i8, i1 } [[TMP1]] ; %c = icmp sgt i8 %x, 100 %y = select i1 %c, i8 %x, i8 100 -- 2.7.4