From 3f119989c3839c98b20bf6ea00c2ccc95aacff69 Mon Sep 17 00:00:00 2001 From: Kostya Serebryany Date: Fri, 27 Apr 2012 10:04:53 +0000 Subject: [PATCH] [asan] small optimization: do not emit "x+0" instructions git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155701 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Instrumentation/AddressSanitizer.cpp | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/lib/Transforms/Instrumentation/AddressSanitizer.cpp index 33b56d50365..b01cdbf680a 100644 --- a/lib/Transforms/Instrumentation/AddressSanitizer.cpp +++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp @@ -363,11 +363,12 @@ void AddressSanitizer::instrumentAddress(Instruction *OrigIns, size_t Granularity = 1 << MappingScale; if (TypeSize < 8 * Granularity) { // Addr & (Granularity - 1) - Value *Lower3Bits = IRB2.CreateAnd( + Value *LastAccessedByte = IRB2.CreateAnd( AddrLong, ConstantInt::get(IntptrTy, Granularity - 1)); // (Addr & (Granularity - 1)) + size - 1 - Value *LastAccessedByte = IRB2.CreateAdd( - Lower3Bits, ConstantInt::get(IntptrTy, TypeSize / 8 - 1)); + if (TypeSize / 8 > 1) + LastAccessedByte = IRB2.CreateAdd( + LastAccessedByte, ConstantInt::get(IntptrTy, TypeSize / 8 - 1)); // (uint8_t) ((Addr & (Granularity-1)) + size - 1) LastAccessedByte = IRB2.CreateIntCast( LastAccessedByte, IRB.getInt8Ty(), false); -- 2.34.1