From 228e6d4cf347820fce53e57c24b266f67a413d85 Mon Sep 17 00:00:00 2001 From: Richard Smith Date: Fri, 24 Aug 2012 23:29:28 +0000 Subject: Fix integer undefined behavior due to signed left shift overflow in LLVM. Reviewed offline by chandlerc. llvm-svn: 162623 --- llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp | 7 +++---- llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 5 ++--- 2 files changed, 5 insertions(+), 7 deletions(-) (limited to 'llvm/lib/CodeGen') diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp index 375bd7eb88d..aa5d140e9f6 100644 --- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp +++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp @@ -1475,10 +1475,9 @@ static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) { return Base; // Truncate/sext the offset to the pointer size. - if (TD.getPointerSizeInBits() != 64) { - int SExtAmount = 64-TD.getPointerSizeInBits(); - Offset = (Offset << SExtAmount) >> SExtAmount; - } + unsigned Width = TD.getPointerSizeInBits(); + if (Width < 64) + Offset = SignExtend64(Offset, Width); return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx), Ctx); diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp index f4fe8927f69..3ab0b46def8 100644 --- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp @@ -1097,10 +1097,9 @@ SDValue SelectionDAG::getGlobalAddress(const GlobalValue *GV, DebugLoc DL, "Cannot set target flags on target-independent globals"); // Truncate (with sign-extension) the offset value to the pointer size. - EVT PTy = TLI.getPointerTy(); - unsigned BitWidth = PTy.getSizeInBits(); + unsigned BitWidth = TLI.getPointerTy().getSizeInBits(); if (BitWidth < 64) - Offset = (Offset << (64 - BitWidth) >> (64 - BitWidth)); + Offset = SignExtend64(Offset, BitWidth); const GlobalVariable *GVar = dyn_cast(GV); if (!GVar) { -- cgit v1.2.3