[llvm-commits] [llvm] r164539 - in /llvm/trunk: lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp test/Transforms/InstCombine/2012-09-24-MemcpyFromGlobalCrash.ll
Richard Osborne
richard at xmos.com
Mon Sep 24 10:10:04 PDT 2012
Author: friedgold
Date: Mon Sep 24 12:10:03 2012
New Revision: 164539
URL: http://llvm.org/viewvc/llvm-project?rev=164539&view=rev
Log:
Add missing check for presence of target data.
This avoids a crash in visitAllocaInst when target data isn't available.
Added:
llvm/trunk/test/Transforms/InstCombine/2012-09-24-MemcpyFromGlobalCrash.ll
Modified:
llvm/trunk/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp?rev=164539&r1=164538&r2=164539&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp Mon Sep 24 12:10:03 2012
@@ -264,26 +264,28 @@
}
}
- // Check to see if this allocation is only modified by a memcpy/memmove from
- // a constant global whose alignment is equal to or exceeds that of the
- // allocation. If this is the case, we can change all users to use
- // the constant global instead. This is commonly produced by the CFE by
- // constructs like "void foo() { int A[] = {1,2,3,4,5,6,7,8,9...}; }" if 'A'
- // is only subsequently read.
- SmallVector<Instruction *, 4> ToDelete;
- if (MemTransferInst *Copy = isOnlyCopiedFromConstantGlobal(&AI, ToDelete)) {
- if (AI.getAlignment() <= getPointeeAlignment(Copy->getSource(), *TD)) {
- DEBUG(dbgs() << "Found alloca equal to global: " << AI << '\n');
- DEBUG(dbgs() << " memcpy = " << *Copy << '\n');
- for (unsigned i = 0, e = ToDelete.size(); i != e; ++i)
- EraseInstFromFunction(*ToDelete[i]);
- Constant *TheSrc = cast<Constant>(Copy->getSource());
- Instruction *NewI
- = ReplaceInstUsesWith(AI, ConstantExpr::getBitCast(TheSrc,
- AI.getType()));
- EraseInstFromFunction(*Copy);
- ++NumGlobalCopies;
- return NewI;
+ if (TD) {
+ // Check to see if this allocation is only modified by a memcpy/memmove from
+ // a constant global whose alignment is equal to or exceeds that of the
+ // allocation. If this is the case, we can change all users to use
+ // the constant global instead. This is commonly produced by the CFE by
+ // constructs like "void foo() { int A[] = {1,2,3,4,5,6,7,8,9...}; }" if 'A'
+ // is only subsequently read.
+ SmallVector<Instruction *, 4> ToDelete;
+ if (MemTransferInst *Copy = isOnlyCopiedFromConstantGlobal(&AI, ToDelete)) {
+ if (AI.getAlignment() <= getPointeeAlignment(Copy->getSource(), *TD)) {
+ DEBUG(dbgs() << "Found alloca equal to global: " << AI << '\n');
+ DEBUG(dbgs() << " memcpy = " << *Copy << '\n');
+ for (unsigned i = 0, e = ToDelete.size(); i != e; ++i)
+ EraseInstFromFunction(*ToDelete[i]);
+ Constant *TheSrc = cast<Constant>(Copy->getSource());
+ Instruction *NewI
+ = ReplaceInstUsesWith(AI, ConstantExpr::getBitCast(TheSrc,
+ AI.getType()));
+ EraseInstFromFunction(*Copy);
+ ++NumGlobalCopies;
+ return NewI;
+ }
}
}
Added: llvm/trunk/test/Transforms/InstCombine/2012-09-24-MemcpyFromGlobalCrash.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/2012-09-24-MemcpyFromGlobalCrash.ll?rev=164539&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/2012-09-24-MemcpyFromGlobalCrash.ll (added)
+++ llvm/trunk/test/Transforms/InstCombine/2012-09-24-MemcpyFromGlobalCrash.ll Mon Sep 24 12:10:03 2012
@@ -0,0 +1,19 @@
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+; Check we don't crash due to lack of target data.
+
+ at G = constant [100 x i8] zeroinitializer
+
+declare void @bar(i8*)
+declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i32, i1) nounwind
+
+define void @test() {
+; CHECK: @test
+; CHECK: llvm.memcpy
+; CHECK ret void
+ %A = alloca [100 x i8]
+ %a = getelementptr inbounds [100 x i8]* %A, i64 0, i64 0
+ call void @llvm.memcpy.p0i8.p0i8.i64(i8* %a, i8* getelementptr inbounds ([100 x i8]* @G, i64 0, i32 0), i64 100, i32 4, i1 false)
+ call void @bar(i8* %a) readonly
+ ret void
+}
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