GEP index may be negative constant value as below: %arrayidx = getelementptr inbounds <4 x i32> addrspace(1)* %src4, i32 %add.ptr.sum, i32 -4
The previous implementation assumes it's a unsigned value which is incorrect and may cause infinite loop. Signed-off-by: Zhigang Gong <[email protected]> --- backend/src/llvm/llvm_gen_backend.cpp | 5 +++-- backend/src/llvm/llvm_gen_backend.hpp | 2 +- backend/src/llvm/llvm_passes.cpp | 17 +++++++++-------- 3 files changed, 13 insertions(+), 11 deletions(-) diff --git a/backend/src/llvm/llvm_gen_backend.cpp b/backend/src/llvm/llvm_gen_backend.cpp index a41c94c..3d74a0a 100644 --- a/backend/src/llvm/llvm_gen_backend.cpp +++ b/backend/src/llvm/llvm_gen_backend.cpp @@ -1126,7 +1126,7 @@ namespace gbe return pointer_reg; } else if (expr->getOpcode() == Instruction::GetElementPtr) { - uint32_t TypeIndex; + int32_t TypeIndex; uint32_t constantOffset = 0; Value *pointer = val; @@ -1136,6 +1136,7 @@ namespace gbe ConstantInt* ConstOP = dyn_cast<ConstantInt>(expr->getOperand(op)); GBE_ASSERT(ConstOP); TypeIndex = ConstOP->getZExtValue(); + GBE_ASSERT(TypeIndex >= 0); if (op == 1) { if (TypeIndex != 0) { Type *elementType = (cast<PointerType>(pointer->getType()))->getElementType(); @@ -1145,7 +1146,7 @@ namespace gbe offset += elementSize * TypeIndex; } } else { - for(uint32_t ty_i=0; ty_i<TypeIndex; ty_i++) + for(int32_t ty_i=0; ty_i<TypeIndex; ty_i++) { Type* elementType = CompTy->getTypeAtIndex(ty_i); uint32_t align = getAlignmentByte(unit, elementType); diff --git a/backend/src/llvm/llvm_gen_backend.hpp b/backend/src/llvm/llvm_gen_backend.hpp index 5dac3ea..ae0a818 100644 --- a/backend/src/llvm/llvm_gen_backend.hpp +++ b/backend/src/llvm/llvm_gen_backend.hpp @@ -66,7 +66,7 @@ namespace gbe static const OCLIntrinsicMap instrinsicMap; /*! Pad the offset */ - uint32_t getPadding(uint32_t offset, uint32_t align); + int32_t getPadding(int32_t offset, int32_t align); /*! Get the type alignment in bytes */ uint32_t getAlignmentByte(const ir::Unit &unit, llvm::Type* Ty); diff --git a/backend/src/llvm/llvm_passes.cpp b/backend/src/llvm/llvm_passes.cpp index f9fda4d..0f61526 100644 --- a/backend/src/llvm/llvm_passes.cpp +++ b/backend/src/llvm/llvm_passes.cpp @@ -126,7 +126,7 @@ namespace gbe return bKernel; } - uint32_t getPadding(uint32_t offset, uint32_t align) { + int32_t getPadding(int32_t offset, int32_t align) { return (align - (offset % align)) % align; } @@ -279,32 +279,33 @@ namespace gbe for(uint32_t op=1; op<GEPInst->getNumOperands(); ++op) { - uint32_t TypeIndex; + int32_t TypeIndex; //we have a constant struct/array acces if(ConstantInt* ConstOP = dyn_cast<ConstantInt>(GEPInst->getOperand(op))) { - uint32_t offset = 0; + int32_t offset = 0; TypeIndex = ConstOP->getZExtValue(); + int32_t step = TypeIndex > 0 ? 1 : -1; if (op == 1) { if (TypeIndex != 0) { Type *elementType = (cast<PointerType>(parentPointer->getType()))->getElementType(); uint32_t elementSize = getTypeByteSize(unit, elementType); uint32_t align = getAlignmentByte(unit, elementType); elementSize += getPadding(elementSize, align); - offset += elementSize * TypeIndex; + offset += elementSize * TypeIndex * step; } } else { - for(uint32_t ty_i=0; ty_i<TypeIndex; ty_i++) + for(int32_t ty_i=0; ty_i != TypeIndex; ty_i += step) { Type* elementType = CompTy->getTypeAtIndex(ty_i); uint32_t align = getAlignmentByte(unit, elementType); - offset += getPadding(offset, align); - offset += getTypeByteSize(unit, elementType); + offset += getPadding(offset, align * step); + offset += getTypeByteSize(unit, elementType) * step; } //add getPaddingding for accessed type const uint32_t align = getAlignmentByte(unit, CompTy->getTypeAtIndex(TypeIndex)); - offset += getPadding(offset, align); + offset += getPadding(offset, align * step); } constantOffset += offset; -- 1.8.3.2 _______________________________________________ Beignet mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/beignet
