From ba6797e185b7dcd7c6b757cdadd695e06280af4b Mon Sep 17 00:00:00 2001 From: Daniel Neilson Date: Wed, 31 Jan 2018 17:24:53 +0000 Subject: [PATCH] [CodeGenPrepare] Improve source and dest alignments of memory intrinsics independently Summary: This change is part of step five in the series of changes to remove alignment argument from memcpy/memmove/memset in favour of alignment attributes. In particular, this changes the CodeGenPrepare pass to be more aggressive in improving the source and destination alignments of memcpy/memmove/memset by exploiting our new ability to record independent alignments for each argument. Steps: Step 1) Remove alignment parameter and create alignment parameter attributes for memcpy/memmove/memset. ( rL322965, rC322964, rL322963 ) Step 2) Expand the IRBuilder API to allow creation of memcpy/memmove with differing source and dest alignments. ( rL323597 ) Step 3) Update Clang to use the new IRBuilder API. ( rC323617 ) Step 4) Update Polly to use the new IRBuilder API. ( rL323618 ) Step 5) Update LLVM passes that create memcpy/memmove calls to use the new IRBuilder API, and those that use use MemIntrinsicInst::[get|set]Alignment() to use [get|set]DestAlignment() and [get|set]SourceAlignment() instead. ( rL323886 ) Step 6) Remove the single-alignment IRBuilder API for memcpy/memmove, and the MemIntrinsicInst::[get|set]Alignment() methods. Reference http://lists.llvm.org/pipermail/llvm-dev/2015-August/089384.html http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151109/312083.html llvm-svn: 323891 --- lib/CodeGen/CodeGenPrepare.cpp | 13 +++--- .../CodeGenPrepare/ARM/memory-intrinsics.ll | 43 +++++++++++++++++++ 2 files changed, 51 insertions(+), 5 deletions(-) create mode 100644 test/Transforms/CodeGenPrepare/ARM/memory-intrinsics.ll diff --git a/lib/CodeGen/CodeGenPrepare.cpp b/lib/CodeGen/CodeGenPrepare.cpp index af6f399dfc4..78b1ec02ba3 100644 --- a/lib/CodeGen/CodeGenPrepare.cpp +++ b/lib/CodeGen/CodeGenPrepare.cpp @@ -1606,11 +1606,14 @@ bool CodeGenPrepare::optimizeCallInst(CallInst *CI, bool &ModifiedDT) { // If this is a memcpy (or similar) then we may be able to improve the // alignment if (MemIntrinsic *MI = dyn_cast(CI)) { - unsigned Align = getKnownAlignment(MI->getDest(), *DL); - if (MemTransferInst *MTI = dyn_cast(MI)) - Align = std::min(Align, getKnownAlignment(MTI->getSource(), *DL)); - if (Align > MI->getAlignment()) - MI->setAlignment(Align); + unsigned DestAlign = getKnownAlignment(MI->getDest(), *DL); + if (DestAlign > MI->getDestAlignment()) + MI->setDestAlignment(DestAlign); + if (MemTransferInst *MTI = dyn_cast(MI)) { + unsigned SrcAlign = getKnownAlignment(MTI->getSource(), *DL); + if (SrcAlign > MTI->getSourceAlignment()) + MTI->setSourceAlignment(SrcAlign); + } } } diff --git a/test/Transforms/CodeGenPrepare/ARM/memory-intrinsics.ll b/test/Transforms/CodeGenPrepare/ARM/memory-intrinsics.ll new file mode 100644 index 00000000000..8b70d9381cd --- /dev/null +++ b/test/Transforms/CodeGenPrepare/ARM/memory-intrinsics.ll @@ -0,0 +1,43 @@ +; RUN: opt -codegenprepare -mtriple=arm7-unknown-unknown -S < %s | FileCheck %s + +declare void @llvm.memcpy.p0i8.p0i8.i32(i8*, i8*, i32, i1) nounwind +declare void @llvm.memmove.p0i8.p0i8.i32(i8*, i8*, i32, i1) nounwind +declare void @llvm.memset.p0i8.i32(i8*, i8, i32, i1) nounwind + +define void @test_memcpy(i8* align 4 %dst, i8* align 8 %src, i32 %N) { +; CHECK-LABEL: @test_memcpy +; CHECK: call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 4 %dst, i8* align 8 %src, i32 %N, i1 false) +; CHECK: call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 4 %dst, i8* align 8 %src, i32 %N, i1 false) +; CHECK: call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 8 %dst, i8* align 16 %src, i32 %N, i1 false) +entry: + call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dst, i8* %src, i32 %N, i1 false) + call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 2 %dst, i8* align 2 %src, i32 %N, i1 false) + call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 8 %dst, i8* align 16 %src, i32 %N, i1 false) + ret void +} + +define void @test_memmove(i8* align 4 %dst, i8* align 8 %src, i32 %N) { +; CHECK-LABEL: @test_memmove +; CHECK: call void @llvm.memmove.p0i8.p0i8.i32(i8* align 4 %dst, i8* align 8 %src, i32 %N, i1 false) +; CHECK: call void @llvm.memmove.p0i8.p0i8.i32(i8* align 4 %dst, i8* align 8 %src, i32 %N, i1 false) +; CHECK: call void @llvm.memmove.p0i8.p0i8.i32(i8* align 8 %dst, i8* align 16 %src, i32 %N, i1 false) +entry: + call void @llvm.memmove.p0i8.p0i8.i32(i8* %dst, i8* %src, i32 %N, i1 false) + call void @llvm.memmove.p0i8.p0i8.i32(i8* align 2 %dst, i8* align 2 %src, i32 %N, i1 false) + call void @llvm.memmove.p0i8.p0i8.i32(i8* align 8 %dst, i8* align 16 %src, i32 %N, i1 false) + ret void +} + +define void @test_memset(i8* align 4 %dst, i8 %val, i32 %N) { +; CHECK-LABEL: @test_memset +; CHECK: call void @llvm.memset.p0i8.i32(i8* align 4 %dst, i8 %val, i32 %N, i1 false) +; CHECK: call void @llvm.memset.p0i8.i32(i8* align 4 %dst, i8 %val, i32 %N, i1 false) +; CHECK: call void @llvm.memset.p0i8.i32(i8* align 8 %dst, i8 %val, i32 %N, i1 false) +entry: + call void @llvm.memset.p0i8.i32(i8* %dst, i8 %val, i32 %N, i1 false) + call void @llvm.memset.p0i8.i32(i8* align 2 %dst, i8 %val, i32 %N, i1 false) + call void @llvm.memset.p0i8.i32(i8* align 8 %dst, i8 %val, i32 %N, i1 false) + ret void +} + +