From 01a67111d1a87c34a88127a20f1711e98e5be4c3 Mon Sep 17 00:00:00 2001 From: Eli Friedman Date: Mon, 15 Aug 2011 23:55:52 +0000 Subject: Add comments and test for atomic load/store and mem2reg. llvm-svn: 137690 --- llvm/lib/Transforms/Utils/PromoteMemoryToRegister.cpp | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'llvm/lib/Transforms/Utils/PromoteMemoryToRegister.cpp') diff --git a/llvm/lib/Transforms/Utils/PromoteMemoryToRegister.cpp b/llvm/lib/Transforms/Utils/PromoteMemoryToRegister.cpp index e5a00f4e977..db3e9425135 100644 --- a/llvm/lib/Transforms/Utils/PromoteMemoryToRegister.cpp +++ b/llvm/lib/Transforms/Utils/PromoteMemoryToRegister.cpp @@ -86,11 +86,15 @@ bool llvm::isAllocaPromotable(const AllocaInst *AI) { UI != UE; ++UI) { // Loop over all of the uses of the alloca const User *U = *UI; if (const LoadInst *LI = dyn_cast(U)) { + // Note that atomic loads can be transformed; atomic semantics do + // not have any meaning for a local alloca. if (LI->isVolatile()) return false; } else if (const StoreInst *SI = dyn_cast(U)) { if (SI->getOperand(0) == AI) return false; // Don't allow a store OF the AI, only INTO the AI. + // Note that atomic stores can be transformed; atomic semantics do + // not have any meaning for a local alloca. if (SI->isVolatile()) return false; } else if (const IntrinsicInst *II = dyn_cast(U)) { -- cgit v1.2.3