diff options
Diffstat (limited to 'lib/Transforms/Scalar/ScalarReplAggregates.cpp')
-rw-r--r-- | lib/Transforms/Scalar/ScalarReplAggregates.cpp | 32 |
1 files changed, 29 insertions, 3 deletions
diff --git a/lib/Transforms/Scalar/ScalarReplAggregates.cpp b/lib/Transforms/Scalar/ScalarReplAggregates.cpp index a6c3a5e..9fc4164 100644 --- a/lib/Transforms/Scalar/ScalarReplAggregates.cpp +++ b/lib/Transforms/Scalar/ScalarReplAggregates.cpp @@ -1642,6 +1642,8 @@ void SROA::isSafeGEP(GetElementPtrInst *GEPI, gep_type_iterator GEPIt = gep_type_begin(GEPI), E = gep_type_end(GEPI); if (GEPIt == E) return; + bool NonConstant = false; + unsigned NonConstantIdxSize = 0; // Walk through the GEP type indices, checking the types that this indexes // into. @@ -1651,15 +1653,30 @@ void SROA::isSafeGEP(GetElementPtrInst *GEPI, continue; ConstantInt *IdxVal = dyn_cast<ConstantInt>(GEPIt.getOperand()); - if (!IdxVal) - return MarkUnsafe(Info, GEPI); + if (!IdxVal) { + // Non constant GEPs are only a problem on arrays, structs, and pointers + // Vectors can be dynamically indexed. + // FIXME: Add support for dynamic indexing on arrays. This should be + // ok on any subarrays of the alloca array, eg, a[0][i] is ok, but a[i][0] + // isn't. + if (!(*GEPIt)->isVectorTy()) + return MarkUnsafe(Info, GEPI); + NonConstant = true; + NonConstantIdxSize = TD->getTypeAllocSize(*GEPIt); + } } // Compute the offset due to this GEP and check if the alloca has a // component element at that offset. SmallVector<Value*, 8> Indices(GEPI->op_begin() + 1, GEPI->op_end()); + // If this GEP is non constant then the last operand must have been a + // dynamic index into a vector. Pop this now as it has no impact on the + // constant part of the offset. + if (NonConstant) + Indices.pop_back(); Offset += TD->getIndexedOffset(GEPI->getPointerOperandType(), Indices); - if (!TypeHasComponent(Info.AI->getAllocatedType(), Offset, 0)) + if (!TypeHasComponent(Info.AI->getAllocatedType(), Offset, + NonConstantIdxSize)) MarkUnsafe(Info, GEPI); } @@ -1961,6 +1978,13 @@ void SROA::RewriteGEP(GetElementPtrInst *GEPI, AllocaInst *AI, uint64_t Offset, SmallVector<AllocaInst*, 32> &NewElts) { uint64_t OldOffset = Offset; SmallVector<Value*, 8> Indices(GEPI->op_begin() + 1, GEPI->op_end()); + // If the GEP was dynamic then it must have been a dynamic vector lookup. + // In this case, it must be the last GEP operand which is dynamic so keep that + // aside until we've found the constant GEP offset then add it back in at the + // end. + Value* NonConstantIdx = 0; + if (!GEPI->hasAllConstantIndices()) + NonConstantIdx = Indices.pop_back_val(); Offset += TD->getIndexedOffset(GEPI->getPointerOperandType(), Indices); RewriteForScalarRepl(GEPI, AI, Offset, NewElts); @@ -1987,6 +2011,8 @@ void SROA::RewriteGEP(GetElementPtrInst *GEPI, AllocaInst *AI, uint64_t Offset, uint64_t EltIdx = FindElementAndOffset(T, EltOffset, IdxTy); NewArgs.push_back(ConstantInt::get(IdxTy, EltIdx)); } + if (NonConstantIdx) + NewArgs.push_back(NonConstantIdx); Instruction *Val = NewElts[Idx]; if (NewArgs.size() > 1) { Val = GetElementPtrInst::CreateInBounds(Val, NewArgs, "", GEPI); |