[llvm-commits] [llvm] r132485 - in /llvm/trunk: lib/Transforms/Scalar/MemCpyOptimizer.cpp test/Transforms/MemCpyOpt/2011-06-02-CallSlotOverwritten.ll
Eli Friedman
eli.friedman at gmail.com
Thu Jun 2 14:24:42 PDT 2011
Author: efriedma
Date: Thu Jun 2 16:24:42 2011
New Revision: 132485
URL: http://llvm.org/viewvc/llvm-project?rev=132485&view=rev
Log:
PR10067: Add missing safety check to call return transformation in MemCpyOpt::processStore. If something accesses the dest of the "copy" between the call and the copy, the performCallSlotOptzn transformation is not valid.
Added:
llvm/trunk/test/Transforms/MemCpyOpt/2011-06-02-CallSlotOverwritten.ll
Modified:
llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp
Modified: llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp?rev=132485&r1=132484&r2=132485&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp Thu Jun 2 16:24:42 2011
@@ -488,11 +488,28 @@
// a memcpy.
if (LoadInst *LI = dyn_cast<LoadInst>(SI->getOperand(0))) {
if (!LI->isVolatile() && LI->hasOneUse()) {
- MemDepResult dep = MD->getDependency(LI);
+ MemDepResult ldep = MD->getDependency(LI);
CallInst *C = 0;
- if (dep.isClobber() && !isa<MemCpyInst>(dep.getInst()))
- C = dyn_cast<CallInst>(dep.getInst());
-
+ if (ldep.isClobber() && !isa<MemCpyInst>(ldep.getInst()))
+ C = dyn_cast<CallInst>(ldep.getInst());
+
+ if (C) {
+ // Check that nothing touches the dest of the "copy" between
+ // the call and the store.
+ MemDepResult sdep = MD->getDependency(SI);
+ if (!sdep.isNonLocal()) {
+ bool FoundCall = false;
+ for (BasicBlock::iterator I = SI, E = sdep.getInst(); I != E; --I) {
+ if (&*I == C) {
+ FoundCall = true;
+ break;
+ }
+ }
+ if (!FoundCall)
+ C = 0;
+ }
+ }
+
if (C) {
bool changed = performCallSlotOptzn(LI,
SI->getPointerOperand()->stripPointerCasts(),
Added: llvm/trunk/test/Transforms/MemCpyOpt/2011-06-02-CallSlotOverwritten.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/MemCpyOpt/2011-06-02-CallSlotOverwritten.ll?rev=132485&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/MemCpyOpt/2011-06-02-CallSlotOverwritten.ll (added)
+++ llvm/trunk/test/Transforms/MemCpyOpt/2011-06-02-CallSlotOverwritten.ll Thu Jun 2 16:24:42 2011
@@ -0,0 +1,36 @@
+; RUN: opt < %s -basicaa -memcpyopt -S | FileCheck %s
+; PR10067
+; Make sure the call+copy isn't optimized in such a way that
+; %ret ends up with the wrong value.
+
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128-n8:16:32"
+target triple = "i386-apple-darwin10"
+
+%struct1 = type { i32, i32 }
+%struct2 = type { %struct1, i8* }
+
+declare void @bar(%struct1* nocapture sret %agg.result) nounwind
+
+define i32 @foo() nounwind {
+ %x = alloca %struct1, align 8
+ %y = alloca %struct2, align 8
+ call void @bar(%struct1* sret %x) nounwind
+; CHECK: call void @bar(%struct1* sret %x)
+
+ %gepn1 = getelementptr inbounds %struct2* %y, i32 0, i32 0, i32 0
+ store i32 0, i32* %gepn1, align 8
+ %gepn2 = getelementptr inbounds %struct2* %y, i32 0, i32 0, i32 1
+ store i32 0, i32* %gepn2, align 4
+
+ %bit1 = bitcast %struct1* %x to i64*
+ %bit2 = bitcast %struct2* %y to i64*
+ %load = load i64* %bit1, align 8
+ store i64 %load, i64* %bit2, align 8
+
+; CHECK: %load = load i64* %bit1, align 8
+; CHECK: store i64 %load, i64* %bit2, align 8
+
+ %gep1 = getelementptr %struct2* %y, i32 0, i32 0, i32 0
+ %ret = load i32* %gep1
+ ret i32 %ret
+}
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