[PATCH] D86883: [X86] Add support for using fast short rep mov for memcpy lowering.
Hiroshi Yamauchi via Phabricator via llvm-commits
llvm-commits at lists.llvm.org
Wed Sep 9 12:47:07 PDT 2020
This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rG0ab6a1569806: [X86] Add support for using fast short rep mov for memcpy lowering. (authored by yamauchi).
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D86883/new/
https://reviews.llvm.org/D86883
Files:
llvm/lib/Target/X86/X86ISelLowering.cpp
llvm/lib/Target/X86/X86SelectionDAGInfo.cpp
llvm/test/CodeGen/X86/memcpy-inline-fsrm.ll
Index: llvm/test/CodeGen/X86/memcpy-inline-fsrm.ll
===================================================================
--- /dev/null
+++ llvm/test/CodeGen/X86/memcpy-inline-fsrm.ll
@@ -0,0 +1,31 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mtriple=x86_64-linux-gnu -x86-use-fsrm-for-memcpy -mattr=-fsrm < %s -o - | FileCheck %s --check-prefix=NOFSRM
+; RUN: llc -mtriple=x86_64-linux-gnu -x86-use-fsrm-for-memcpy -mattr=+fsrm < %s -o - | FileCheck %s --check-prefix=FSRM
+; RUN: llc -mtriple=x86_64-linux-gnu -x86-use-fsrm-for-memcpy -mcpu=haswell < %s | FileCheck %s --check-prefix=NOFSRM
+; RUN: llc -mtriple=x86_64-linux-gnu -x86-use-fsrm-for-memcpy -mcpu=icelake-client < %s | FileCheck %s --check-prefix=FSRM
+; RUN: llc -mtriple=x86_64-linux-gnu -x86-use-fsrm-for-memcpy -mcpu=icelake-server < %s | FileCheck %s --check-prefix=FSRM
+
+declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i1) nounwind
+
+define void @test1(i8* %a, i8* %b, i64 %s) nounwind {
+; NOFSRM-LABEL: test1
+; NOFSRM: # %bb.0:
+; NOFSRM: jmp memcpy
+;
+; FSRM-LABEL: test1
+; FSRM: # %bb.0:
+; FSRM-NEXT: movq %rdx, %rcx
+; FSRM-NEXT: rep;movsb (%rsi), %es:(%rdi)
+; FSRM-NEXT: retq
+ tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %a, i8* %b, i64 %s, i1 0)
+ ret void
+}
+
+; Check that we don't crash due to a memcpy size type mismatch error ("Cannot
+; emit physreg copy instruction") in X86InstrInfo::copyPhysReg.
+%struct = type { [4096 x i8] }
+declare void @foo(%struct* byval)
+define void @test2(%struct* %x) {
+ call void @foo(%struct* byval %x)
+ ret void
+}
Index: llvm/lib/Target/X86/X86SelectionDAGInfo.cpp
===================================================================
--- llvm/lib/Target/X86/X86SelectionDAGInfo.cpp
+++ llvm/lib/Target/X86/X86SelectionDAGInfo.cpp
@@ -24,6 +24,10 @@
#define DEBUG_TYPE "x86-selectiondag-info"
+static cl::opt<bool>
+ UseFSRMForMemcpy("x86-use-fsrm-for-memcpy", cl::Hidden, cl::init(false),
+ cl::desc("Use fast short rep mov in memcpy lowering"));
+
bool X86SelectionDAGInfo::isBaseRegConflictPossible(
SelectionDAG &DAG, ArrayRef<MCPhysReg> ClobberSet) const {
// We cannot use TRI->hasBasePointer() until *after* we select all basic
@@ -306,6 +310,10 @@
const X86Subtarget &Subtarget =
DAG.getMachineFunction().getSubtarget<X86Subtarget>();
+ // If enabled and available, use fast short rep mov.
+ if (UseFSRMForMemcpy && Subtarget.hasFSRM())
+ return emitRepmovs(Subtarget, DAG, dl, Chain, Dst, Src, Size, MVT::i8);
+
/// Handle constant sizes,
if (ConstantSDNode *ConstantSize = dyn_cast<ConstantSDNode>(Size))
return emitConstantSizeRepmov(
Index: llvm/lib/Target/X86/X86ISelLowering.cpp
===================================================================
--- llvm/lib/Target/X86/X86ISelLowering.cpp
+++ llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -3109,7 +3109,7 @@
static SDValue CreateCopyOfByValArgument(SDValue Src, SDValue Dst,
SDValue Chain, ISD::ArgFlagsTy Flags,
SelectionDAG &DAG, const SDLoc &dl) {
- SDValue SizeNode = DAG.getConstant(Flags.getByValSize(), dl, MVT::i32);
+ SDValue SizeNode = DAG.getIntPtrConstant(Flags.getByValSize(), dl);
return DAG.getMemcpy(
Chain, dl, Dst, Src, SizeNode, Flags.getNonZeroByValAlign(),
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