forked from OSchip/llvm-project
72bc23ef02
Note, this was reviewed (and more details are in) http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151109/312083.html These intrinsics currently have an explicit alignment argument which is required to be a constant integer. It represents the alignment of the source and dest, and so must be the minimum of those. This change allows source and dest to each have their own alignments by using the alignment attribute on their arguments. The alignment argument itself is removed. There are a few places in the code for which the code needs to be checked by an expert as to whether using only src/dest alignment is safe. For those places, they currently take the minimum of src/dest alignments which matches the current behaviour. For example, code which used to read: call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dest, i8* %src, i32 500, i32 8, i1 false) will now read: call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 8 %dest, i8* align 8 %src, i32 500, i1 false) For out of tree owners, I was able to strip alignment from calls using sed by replacing: (call.*llvm\.memset.*)i32\ [0-9]*\,\ i1 false\) with: $1i1 false) and similarly for memmove and memcpy. I then added back in alignment to test cases which needed it. A similar commit will be made to clang which actually has many differences in alignment as now IRBuilder can generate different source/dest alignments on calls. In IRBuilder itself, a new argument was added. Instead of calling: CreateMemCpy(Dst, Src, getInt64(Size), DstAlign, /* isVolatile */ false) you now call CreateMemCpy(Dst, Src, getInt64(Size), DstAlign, SrcAlign, /* isVolatile */ false) There is a temporary class (IntegerAlignment) which takes the source alignment and rejects implicit conversion from bool. This is to prevent isVolatile here from passing its default parameter to the source alignment. Note, changes in future can now be made to codegen. I didn't change anything here, but this change should enable better memcpy code sequences. Reviewed by Hal Finkel. llvm-svn: 253511 |
||
|---|---|---|
| .. | ||
| AssumptionCache | ||
| BasicAA | ||
| BlockFrequencyInfo | ||
| BranchProbabilityInfo | ||
| CFLAliasAnalysis | ||
| CallGraph | ||
| CostModel | ||
| Delinearization | ||
| DemandedBits | ||
| DependenceAnalysis | ||
| DivergenceAnalysis/NVPTX | ||
| Dominators | ||
| GlobalsModRef | ||
| LazyCallGraph | ||
| Lint | ||
| LoopAccessAnalysis | ||
| LoopInfo | ||
| MemoryDependenceAnalysis | ||
| PostDominators | ||
| RegionInfo | ||
| ScalarEvolution | ||
| ScopedNoAliasAA | ||
| TypeBasedAliasAnalysis | ||
| ValueTracking | ||