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Finished updating alignment issues for vector types; don't assume pointers

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are aligned to the natural vector width.
This commit is contained in:
Matt Pharr
2011-06-23 18:51:15 -07:00
parent 990bee5a86
commit 865e430b56
3 changed files with 44 additions and 74 deletions
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38
ctx.cpp
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@@ -1315,8 +1315,21 @@ FunctionEmitContext::LoadInst(llvm::Value *lvalue, const Type *type,
if (llvm::isa<const llvm::PointerType>(lvalue->getType())) {
// If the lvalue is a straight up regular pointer, then just issue
// a regular load
llvm::Instruction *inst = new llvm::LoadInst(lvalue, name ? name : "load", bblock);
// a regular load. First figure out the alignment; in general we
// can just assume the natural alignment (0 here), but for varying
// atomic types, we need to make sure that the compiler emits
// unaligned vector loads, so we specify a reduced alignment here.
int align = 0;
const AtomicType *atomicType = dynamic_cast<const AtomicType *>(type);
if (atomicType != NULL && atomicType->IsVaryingType())
// We actually just want to align to the vector element
// alignment, but can't easily get that here, so just tell LLVM
// it's totally unaligned. (This shouldn't make any difference
// vs the proper alignment in practice.)
align = 1;
llvm::Instruction *inst = new llvm::LoadInst(lvalue, name ? name : "load",
false /* not volatile */,
align, bblock);
AddDebugPos(inst);
return inst;
}
@@ -1644,8 +1657,16 @@ FunctionEmitContext::StoreInst(llvm::Value *rvalue, llvm::Value *lvalue,
return;
}
llvm::Instruction *inst = new llvm::StoreInst(rvalue, lvalue, false /* not volatile */,
4, bblock);
llvm::Instruction *inst;
if (llvm::isa<llvm::VectorType>(rvalue->getType()))
// Specify an unaligned store, since we don't know that the lvalue
// will in fact be aligned to a vector width here. (Actually
// should be aligned to the alignment of the vector elment type...)
inst = new llvm::StoreInst(rvalue, lvalue, false /* not volatile */,
1, bblock);
else
inst = new llvm::StoreInst(rvalue, lvalue, bblock);
AddDebugPos(inst);
}
@@ -1662,9 +1683,8 @@ FunctionEmitContext::StoreInst(llvm::Value *rvalue, llvm::Value *lvalue,
// Figure out what kind of store we're doing here
if (rvalueType->IsUniformType()) {
// The easy case; a regular store
llvm::Instruction *si = new llvm::StoreInst(rvalue, lvalue, false /* not volatile */,
4, bblock);
// The easy case; a regular store, natural alignment is fine
llvm::Instruction *si = new llvm::StoreInst(rvalue, lvalue, bblock);
AddDebugPos(si);
}
else if (llvm::isa<const llvm::ArrayType>(lvalue->getType()))
@@ -1674,9 +1694,7 @@ FunctionEmitContext::StoreInst(llvm::Value *rvalue, llvm::Value *lvalue,
else if (storeMask == LLVMMaskAllOn) {
// Otherwise it is a masked store unless we can determine that the
// mask is all on...
llvm::Instruction *si =
new llvm::StoreInst(rvalue, lvalue, false /*not volatile*/, 4, bblock);
AddDebugPos(si);
StoreInst(rvalue, lvalue, name);
}
else
maskedStore(rvalue, lvalue, rvalueType, storeMask);