From: Chris Lattner Date: Thu, 29 Jul 2010 18:13:09 +0000 (+0000) Subject: fix rdar://8251384, another case where we could access beyond the X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=f47c944b5710a545d564b4d4b641a2f8bac96af3;p=clang fix rdar://8251384, another case where we could access beyond the end of a struct. This improves the case when the struct being passed contains 3 floats, either due to a struct or array of 3 things. Before we'd generate this IR for the testcase: define float @bar(double %X.coerce0, double %X.coerce1) nounwind { entry: %X = alloca %struct.foof, align 8 ; <%struct.foof*> [#uses=2] %0 = bitcast %struct.foof* %X to %1* ; <%1*> [#uses=2] %1 = getelementptr %1* %0, i32 0, i32 0 ; [#uses=1] store double %X.coerce0, double* %1 %2 = getelementptr %1* %0, i32 0, i32 1 ; [#uses=1] store double %X.coerce1, double* %2 %tmp = getelementptr inbounds %struct.foof* %X, i32 0, i32 2 ; [#uses=1] %tmp1 = load float* %tmp ; [#uses=1] ret float %tmp1 } which compiled (with optimization) to: _bar: ## @bar ## BB#0: ## %entry movd %xmm1, %rax movd %eax, %xmm0 ret Now we produce: define float @bar(double %X.coerce0, float %X.coerce1) nounwind { entry: %X = alloca %struct.foof, align 8 ; <%struct.foof*> [#uses=2] %0 = bitcast %struct.foof* %X to %0* ; <%0*> [#uses=2] %1 = getelementptr %0* %0, i32 0, i32 0 ; [#uses=1] store double %X.coerce0, double* %1 %2 = getelementptr %0* %0, i32 0, i32 1 ; [#uses=1] store float %X.coerce1, float* %2 %tmp = getelementptr inbounds %struct.foof* %X, i32 0, i32 2 ; [#uses=1] %tmp1 = load float* %tmp ; [#uses=1] ret float %tmp1 } and: _bar: ## @bar ## BB#0: ## %entry movaps %xmm1, %xmm0 ret git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@109776 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/lib/CodeGen/TargetInfo.cpp b/lib/CodeGen/TargetInfo.cpp index 1e66f046b0..ec52b93bdf 100644 --- a/lib/CodeGen/TargetInfo.cpp +++ b/lib/CodeGen/TargetInfo.cpp @@ -719,7 +719,8 @@ class X86_64ABIInfo : public ABIInfo { const llvm::Type *Get16ByteVectorType(QualType Ty) const; const llvm::Type *GetSSETypeAtOffset(const llvm::Type *IRType, - unsigned IROffset) const; + unsigned IROffset, QualType SourceTy, + unsigned SourceOffset) const; const llvm::Type *GetINTEGERTypeAtOffset(const llvm::Type *IRType, unsigned IROffset, QualType SourceTy, unsigned SourceOffset) const; @@ -1211,21 +1212,6 @@ const llvm::Type *X86_64ABIInfo::Get16ByteVectorType(QualType Ty) const { return llvm::VectorType::get(llvm::Type::getDoubleTy(getVMContext()), 2); } - -/// GetSSETypeAtOffset - Return a type that will be passed by the backend in the -/// low 8 bytes of an XMM register, corresponding to the SSE class. -const llvm::Type *X86_64ABIInfo::GetSSETypeAtOffset(const llvm::Type *IRType, - unsigned IROffset) const { - // The only two choices we have are either double or <2 x float>. - - // FIXME: <2 x float> doesn't pass as one XMM register yet. Don't enable this - // code until it does. - - return llvm::Type::getDoubleTy(getVMContext()); -} - - - /// BitsContainNoUserData - Return true if the specified [start,end) bit range /// is known to either be off the end of the specified type or being in /// alignment padding. The user type specified is known to be at most 128 bits @@ -1311,6 +1297,27 @@ static bool BitsContainNoUserData(QualType Ty, unsigned StartBit, return false; } + +/// GetSSETypeAtOffset - Return a type that will be passed by the backend in the +/// low 8 bytes of an XMM register, corresponding to the SSE class. +const llvm::Type *X86_64ABIInfo:: +GetSSETypeAtOffset(const llvm::Type *IRType, unsigned IROffset, + QualType SourceTy, unsigned SourceOffset) const { + // The only two choices we have are either double, <2 x float>, or float. We + // pass as float if the last 4 bytes is just padding. This happens for + // structs that contain 3 floats. + if (BitsContainNoUserData(SourceTy, SourceOffset*8+32, + SourceOffset*8+64, getContext())) + return llvm::Type::getFloatTy(getVMContext()); + + // FIXME: <2 x float> doesn't pass as one XMM register yet. Don't enable this + // code until it does. + //return llvm::VectorType::get(llvm::Type::getFloatTy(getVMContext()), 2); + + return llvm::Type::getDoubleTy(getVMContext()); +} + + /// GetINTEGERTypeAtOffset - The ABI specifies that a value should be passed in /// an 8-byte GPR. This means that we either have a scalar or we are talking /// about the high or low part of an up-to-16-byte struct. This routine picks @@ -1420,7 +1427,7 @@ classifyReturnType(QualType RetTy) const { // AMD64-ABI 3.2.3p4: Rule 4. If the class is SSE, the next // available SSE register of the sequence %xmm0, %xmm1 is used. case SSE: - ResType = GetSSETypeAtOffset(CGT.ConvertTypeRecursive(RetTy), 0); + ResType = GetSSETypeAtOffset(CGT.ConvertTypeRecursive(RetTy), 0, RetTy, 0); break; // AMD64-ABI 3.2.3p4: Rule 6. If the class is X87, the value is @@ -1460,7 +1467,7 @@ classifyReturnType(QualType RetTy) const { } case SSE: { const llvm::Type *HiType = - GetSSETypeAtOffset(CGT.ConvertTypeRecursive(RetTy), 8); + GetSSETypeAtOffset(CGT.ConvertTypeRecursive(RetTy), 8, RetTy, 8); ResType = llvm::StructType::get(getVMContext(), ResType, HiType,NULL); break; } @@ -1483,7 +1490,7 @@ classifyReturnType(QualType RetTy) const { // extra bits in an SSE reg. if (Lo != X87) { const llvm::Type *HiType = - GetSSETypeAtOffset(CGT.ConvertTypeRecursive(RetTy), 8); + GetSSETypeAtOffset(CGT.ConvertTypeRecursive(RetTy), 8, RetTy, 8); ResType = llvm::StructType::get(getVMContext(), ResType, HiType, NULL); } break; @@ -1539,7 +1546,7 @@ ABIArgInfo X86_64ABIInfo::classifyArgumentType(QualType Ty, unsigned &neededInt, // order from %xmm0 to %xmm7. case SSE: ++neededSSE; - ResType = GetSSETypeAtOffset(CGT.ConvertTypeRecursive(Ty), 0); + ResType = GetSSETypeAtOffset(CGT.ConvertTypeRecursive(Ty), 0, Ty, 0); break; } @@ -1569,7 +1576,7 @@ ABIArgInfo X86_64ABIInfo::classifyArgumentType(QualType Ty, unsigned &neededInt, case X87Up: case SSE: { const llvm::Type *HiType = - GetSSETypeAtOffset(CGT.ConvertTypeRecursive(Ty), 8); + GetSSETypeAtOffset(CGT.ConvertTypeRecursive(Ty), 8, Ty, 8); ResType = llvm::StructType::get(getVMContext(), ResType, HiType, NULL); ++neededSSE; break; diff --git a/test/CodeGen/x86_64-arguments.c b/test/CodeGen/x86_64-arguments.c index 1243dd7239..9fd08dd4a8 100644 --- a/test/CodeGen/x86_64-arguments.c +++ b/test/CodeGen/x86_64-arguments.c @@ -210,3 +210,13 @@ struct S0 { char f0[8]; char f2; char f3; char f4; }; void f30(struct S0 p_4) { // CHECK: define void @f30(i64 %p_4.coerce0, i24 %p_4.coerce1) } + +// Pass the third element as a float when followed by tail padding. +// rdar://8251384 +struct f31foo { float a, b, c; }; +float f31(struct f31foo X) { + // CHECK: define float @f31(double %X.coerce0, float %X.coerce1) + return X.c; +} + +