diff options
author | Shuxin Yang <shuxin.llvm@gmail.com> | 2013-06-07 22:45:21 +0000 |
---|---|---|
committer | Shuxin Yang <shuxin.llvm@gmail.com> | 2013-06-07 22:45:21 +0000 |
commit | 1c2b03aae9e56e69d215e9b39928a1340e3ca0c3 (patch) | |
tree | 99cdbcaa19b85e4e0e133e79adf62143ccdbc1ec | |
parent | 40be73bed71a69853720a7f0609cb1f2f77dc3bd (diff) | |
download | llvm-1c2b03aae9e56e69d215e9b39928a1340e3ca0c3.tar.gz llvm-1c2b03aae9e56e69d215e9b39928a1340e3ca0c3.tar.bz2 llvm-1c2b03aae9e56e69d215e9b39928a1340e3ca0c3.tar.xz |
Fix an assertion in MemCpyOpt pass.
The MemCpyOpt pass is capable of optimizing:
callee(&S); copy N bytes from S to D.
into:
callee(&D);
subject to some legality constraints.
Assertion is triggered when the compiler tries to evalute "sizeof(typeof(D))",
while D is an opaque-typed, 'sret' formal argument of function being compiled.
i.e. the signature of the func being compiled is something like this:
T caller(...,%opaque* noalias nocapture sret %D, ...)
The fix is that when come across such situation, instead of calling some
utility functions to get the size of D's type (which will crash), we simply
assume D has at least N bytes as implified by the copy-instruction.
rdar://14073661
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183584 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r-- | lib/Transforms/Scalar/MemCpyOptimizer.cpp | 6 | ||||
-rw-r--r-- | test/Transforms/MemCpyOpt/memcpy.ll | 39 |
2 files changed, 43 insertions, 2 deletions
diff --git a/lib/Transforms/Scalar/MemCpyOptimizer.cpp b/lib/Transforms/Scalar/MemCpyOptimizer.cpp index be0f0e8a25..8600c9ebf7 100644 --- a/lib/Transforms/Scalar/MemCpyOptimizer.cpp +++ b/lib/Transforms/Scalar/MemCpyOptimizer.cpp @@ -626,8 +626,10 @@ bool MemCpyOpt::performCallSlotOptzn(Instruction *cpy, return false; Type *StructTy = cast<PointerType>(A->getType())->getElementType(); - uint64_t destSize = TD->getTypeAllocSize(StructTy); - + // If StructTy is an opaque type, it should have at least <cpyLen> bytes, + // as implified by the copy-instruction. + uint64_t destSize = StructTy->isSized() ? + TD->getTypeAllocSize(StructTy) : cpyLen; if (destSize < srcSize) return false; } else { diff --git a/test/Transforms/MemCpyOpt/memcpy.ll b/test/Transforms/MemCpyOpt/memcpy.ll index 582a57b5d3..fa768712ec 100644 --- a/test/Transforms/MemCpyOpt/memcpy.ll +++ b/test/Transforms/MemCpyOpt/memcpy.ll @@ -168,6 +168,45 @@ entry: ret void } +; rdar://14073661. +; Test10 triggered assertion when the compiler try to get the size of the +; opaque type of *x, where the x is the formal argument with attribute 'sret'. + +%opaque = type opaque +declare void @foo(i32* noalias nocapture) + +define void @test10(%opaque* noalias nocapture sret %x, i32 %y) { + %a = alloca i32, align 4 + store i32 %y, i32* %a + call void @foo(i32* noalias nocapture %a) + %c = load i32* %a + %d = bitcast %opaque* %x to i32* + store i32 %c, i32* %d + ret void +} + +; Test11 is similar to test10 except that the instruction "store i32 %y, i32* %a" +; before the call-site is deleted. MemCopyOpt is able to optimize this snippet into +; +; %x1 = bitcast %opaque* %x to i32* +; call void @foo(i32* noalias nocapture %x1) +; ret void +; + +define void @test11(%opaque* noalias nocapture sret %x, i32 %y) { +; CHECK: test11 +; CHECK: %x1 = bitcast %opaque* %x to i32* +; CHECK: call void @foo(i32* noalias nocapture %x1) +; CHECK: ret void + + %a = alloca i32, align 4 + call void @foo(i32* noalias nocapture %a) + %c = load i32* %a + %d = bitcast %opaque* %x to i32* + store i32 %c, i32* %d + ret void +} + declare void @f1(%struct.big* sret) declare void @f2(%struct.big*) |