diff options
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineCalls.cpp | 17 | ||||
| -rw-r--r-- | test/Transforms/InstCombine/struct-assign-tbaa.ll | 26 |
2 files changed, 43 insertions, 0 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineCalls.cpp b/lib/Transforms/InstCombine/InstCombineCalls.cpp index 1b389b92e8..486dd1312a 100644 --- a/lib/Transforms/InstCombine/InstCombineCalls.cpp +++ b/lib/Transforms/InstCombine/InstCombineCalls.cpp @@ -94,6 +94,7 @@ Instruction *InstCombiner::SimplifyMemTransfer(MemIntrinsic *MI) { // dest address will be promotable. See if we can find a better type than the // integer datatype. Value *StrippedDest = MI->getArgOperand(0)->stripPointerCasts(); + MDNode *CopyMD = 0; if (StrippedDest != MI->getArgOperand(0)) { Type *SrcETy = cast<PointerType>(StrippedDest->getType()) ->getElementType(); @@ -105,6 +106,18 @@ Instruction *InstCombiner::SimplifyMemTransfer(MemIntrinsic *MI) { if (SrcETy->isSingleValueType()) { NewSrcPtrTy = PointerType::get(SrcETy, SrcAddrSp); NewDstPtrTy = PointerType::get(SrcETy, DstAddrSp); + + // If the memcpy has metadata describing the members, see if we can + // get the TBAA tag describing our copy. + if (MDNode *M = MI->getMetadata(LLVMContext::MD_tbaa_struct)) { + if (M->getNumOperands() == 3 && + isa<ConstantInt>(M->getOperand(0)) && + cast<ConstantInt>(M->getOperand(0))->isNullValue() && + isa<ConstantInt>(M->getOperand(1)) && + cast<ConstantInt>(M->getOperand(1))->getValue() == Size && + isa<MDNode>(M->getOperand(2))) + CopyMD = cast<MDNode>(M->getOperand(2)); + } } } } @@ -118,8 +131,12 @@ Instruction *InstCombiner::SimplifyMemTransfer(MemIntrinsic *MI) { Value *Dest = Builder->CreateBitCast(MI->getArgOperand(0), NewDstPtrTy); LoadInst *L = Builder->CreateLoad(Src, MI->isVolatile()); L->setAlignment(SrcAlign); + if (CopyMD) + L->setMetadata(LLVMContext::MD_tbaa, CopyMD); StoreInst *S = Builder->CreateStore(L, Dest, MI->isVolatile()); S->setAlignment(DstAlign); + if (CopyMD) + S->setMetadata(LLVMContext::MD_tbaa, CopyMD); // Set the size of the copy to 0, it will be deleted on the next iteration. MI->setArgOperand(2, Constant::getNullValue(MemOpLength->getType())); diff --git a/test/Transforms/InstCombine/struct-assign-tbaa.ll b/test/Transforms/InstCombine/struct-assign-tbaa.ll new file mode 100644 index 0000000000..4fbdb0ab67 --- /dev/null +++ b/test/Transforms/InstCombine/struct-assign-tbaa.ll @@ -0,0 +1,26 @@ +; RUN: opt -instcombine -S < %s | FileCheck %s + +target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128" + +%struct.foo = type { float } + +; Verify that instcombine preserves TBAA tags when converting a memcpy into +; a scalar load and store. + +; CHECK: %2 = load float* %0, align 4, !tbaa !0 +; CHECK: store float %2, float* %1, align 4, !tbaa !0 +; CHECK: !0 = metadata !{metadata !"float", metadata !1} +define void @test(%struct.foo* nocapture %a, %struct.foo* nocapture %b) { +entry: + %0 = bitcast %struct.foo* %a to i8* + %1 = bitcast %struct.foo* %b to i8* + tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %0, i8* %1, i64 4, i32 4, i1 false), !tbaa.struct !3 + ret void +} + +declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i32, i1) nounwind + +!0 = metadata !{metadata !"Simple C/C++ TBAA"} +!1 = metadata !{metadata !"omnipotent char", metadata !0} +!2 = metadata !{metadata !"float", metadata !0} +!3 = metadata !{i64 0, i64 4, metadata !2} |