Magic-Mirror/llvm-capstone
1
0
Fork 0
mirror of https://github.com/capstone-engine/llvm-capstone.git synced 2025-02-27 05:50:12 +00:00
Code Issues Actions 2 Packages Projects Releases Wiki Activity

[LowerMemIntrinsics] Explicitly use i8 type in memmove lowering

Browse Source 
By convention, memcpy/memmove intrinsics are always used with i8
pointers (though this is not enforced), so in practice this code
was always using an i8 type. Make that explicit.

Of course, i8 is not a very profitable choice, and this code could
be more performant by picking an appropriate larger type. But that
would require additional test coverage and correctness review, and
certainly shouldn't be a decision based on the pointer element type.
This commit is contained in:
Nikita Popov 2022-02-16 16:29:10 +01:00
parent 8f7f3c1f99
commit c9032f1a69
1 changed files with 7 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
llvm/lib/Transforms/Utils/LowerMemIntrinsics.cpp
View File

@ -297,7 +297,13 @@ static void createMemMoveLoop(Instruction *InsertBefore, Value *SrcAddr,
Function *F = OrigBB->getParent();
const DataLayout &DL = F->getParent()->getDataLayout();
Type *EltTy = SrcAddr->getType()->getPointerElementType();
// TODO: Use different element type if possible?
IRBuilder<> CastBuilder(InsertBefore);
Type *EltTy = CastBuilder.getInt8Ty();
Type *PtrTy =
CastBuilder.getInt8PtrTy(SrcAddr->getType()->getPointerAddressSpace());
SrcAddr = CastBuilder.CreateBitCast(SrcAddr, PtrTy);
DstAddr = CastBuilder.CreateBitCast(DstAddr, PtrTy);
// Create the a comparison of src and dst, based on which we jump to either
// the forward-copy part of the function (if src >= dst) or the backwards-copy