From 23785c65ac364f32437ef5d9981c80e770ed01c6 Mon Sep 17 00:00:00 2001 From: QingShan Zhang Date: Wed, 8 May 2019 07:32:12 +0000 Subject: [PATCH] [CodeGenPrepare] Don't split the store if it is volatile We shouldn't split the store when it is volatile. Differential Revision: https://reviews.llvm.org/D61169 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@360228 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/CodeGenPrepare.cpp | 4 ++++ .../PowerPC/splitstore-check-volatile.ll | 17 +++++++++++++++++ 2 files changed, 21 insertions(+) create mode 100644 test/CodeGen/PowerPC/splitstore-check-volatile.ll diff --git a/lib/CodeGen/CodeGenPrepare.cpp b/lib/CodeGen/CodeGenPrepare.cpp index 355455a6146..fad3d4a596e 100644 --- a/lib/CodeGen/CodeGenPrepare.cpp +++ b/lib/CodeGen/CodeGenPrepare.cpp @@ -6657,6 +6657,10 @@ static bool splitMergedValStore(StoreInst &SI, const DataLayout &DL, DL.getTypeSizeInBits(SplitStoreType)) return false; + // Don't split the store if it is volatile. + if (SI.isVolatile()) + return false; + // Match the following patterns: // (store (or (zext LValue to i64), // (shl (zext HValue to i64), 32)), HalfValBitSize) diff --git a/test/CodeGen/PowerPC/splitstore-check-volatile.ll b/test/CodeGen/PowerPC/splitstore-check-volatile.ll new file mode 100644 index 00000000000..e40817d2e32 --- /dev/null +++ b/test/CodeGen/PowerPC/splitstore-check-volatile.ll @@ -0,0 +1,17 @@ +; Test that CodeGenPrepare respect the volatile flag when splitting a store. +; +; RUN: opt -S -codegenprepare -force-split-store < %s | FileCheck %s + +define void @fun(i16* %Src, i16* %Dst) { +; CHECK: store volatile i16 %8, i16* %Dst + %1 = load i16, i16* %Src + %2 = trunc i16 %1 to i8 + %3 = lshr i16 %1, 8 + %4 = trunc i16 %3 to i8 + %5 = zext i8 %2 to i16 + %6 = zext i8 %4 to i16 + %7 = shl nuw i16 %6, 8 + %8 = or i16 %7, %5 + store volatile i16 %8, i16* %Dst + ret void +} -- 2.50.1