From d084153a8fd8ee058fd4c39d4f15d3f988566d95 Mon Sep 17 00:00:00 2001 From: Juergen Ributzka Date: Thu, 24 Oct 2013 05:29:56 +0000 Subject: [PATCH] Fix a bug in LinearFunctionTestReplace that created invalid loop exit checks. Reviewed by Andy git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193303 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/IndVarSimplify.cpp | 8 ++++++- test/Transforms/IndVarSimplify/lftr-zext.ll | 26 +++++++++++++++++++++ 2 files changed, 33 insertions(+), 1 deletion(-) create mode 100644 test/Transforms/IndVarSimplify/lftr-zext.ll diff --git a/lib/Transforms/Scalar/IndVarSimplify.cpp b/lib/Transforms/Scalar/IndVarSimplify.cpp index 7785855d0e1..cfd8db0f6cc 100644 --- a/lib/Transforms/Scalar/IndVarSimplify.cpp +++ b/lib/Transforms/Scalar/IndVarSimplify.cpp @@ -1479,8 +1479,14 @@ static Value *genLoopLimit(PHINode *IndVar, const SCEV *IVCount, Loop *L, if (IndVar->getType()->isPointerTy() && !IVCount->getType()->isPointerTy()) { + // IVOffset will be the new GEP offset that is interpreted by GEP as a + // signed value. IVCount on the other hand represents the loop trip count, + // which is an unsigned value. FindLoopCounter only allows induction + // variables that have a positive unit stride of one. This means we don't + // have to handle the case of negative offsets (yet) and just need to zero + // extend IVCount. Type *OfsTy = SE->getEffectiveSCEVType(IVInit->getType()); - const SCEV *IVOffset = SE->getTruncateOrSignExtend(IVCount, OfsTy); + const SCEV *IVOffset = SE->getTruncateOrZeroExtend(IVCount, OfsTy); // Expand the code for the iteration count. assert(SE->isLoopInvariant(IVOffset, L) && diff --git a/test/Transforms/IndVarSimplify/lftr-zext.ll b/test/Transforms/IndVarSimplify/lftr-zext.ll new file mode 100644 index 00000000000..32fa61af180 --- /dev/null +++ b/test/Transforms/IndVarSimplify/lftr-zext.ll @@ -0,0 +1,26 @@ +; RUN: opt < %s -indvars -S | FileCheck %s +target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128" +target triple = "x86_64-apple-macosx10.9.0" + +@data = common global [240 x i8] zeroinitializer, align 16 + +define void @foo(i8* %a) nounwind uwtable ssp { +; CHECK: %exitcond +; CHECK-NOT: ([240 x i8]* @data, i64 0, i64 -16) + br label %1 + +;