[llvm] [X86] For inline memset and memcpy with minsize, use size for alignment, rather than actual alignment (PR #87003)
via llvm-commits
llvm-commits at lists.llvm.org
Sat Jul 20 11:57:40 PDT 2024
https://github.com/AtariDreams updated https://github.com/llvm/llvm-project/pull/87003
>From 57ceebf33b6a9d33e24a97106058239d5d7b03b4 Mon Sep 17 00:00:00 2001
From: Rose <gfunni234 at gmail.com>
Date: Fri, 5 Apr 2024 14:16:40 -0400
Subject: [PATCH 1/3] [X86] Pre-commit test (NFC)
---
.../CodeGen/X86/memset-vs-memset-inline.ll | 137 ++++++++++++++++++
1 file changed, 137 insertions(+)
diff --git a/llvm/test/CodeGen/X86/memset-vs-memset-inline.ll b/llvm/test/CodeGen/X86/memset-vs-memset-inline.ll
index b8fdd936b4389..90a3f8e785e90 100644
--- a/llvm/test/CodeGen/X86/memset-vs-memset-inline.ll
+++ b/llvm/test/CodeGen/X86/memset-vs-memset-inline.ll
@@ -163,3 +163,140 @@ define void @inlined_set_doesnt_call_external_function(ptr %a, i8 %value) nounwi
tail call void @llvm.memset.inline.p0.i64(ptr %a, i8 %value, i64 1024, i1 0)
ret void
}
+
+define void @memset_inlined_insize(ptr %a) nounwind minsize {
+; CHECK-LABEL: memset_inlined_insize:
+; CHECK: # %bb.0:
+; CHECK-NEXT: movabsq $3038287259199220266, %rax # imm = 0x2A2A2A2A2A2A2A2A
+; CHECK-NEXT: movq %rax, 1016(%rdi)
+; CHECK-NEXT: movq %rax, 1008(%rdi)
+; CHECK-NEXT: movq %rax, 1000(%rdi)
+; CHECK-NEXT: movq %rax, 992(%rdi)
+; CHECK-NEXT: movq %rax, 984(%rdi)
+; CHECK-NEXT: movq %rax, 976(%rdi)
+; CHECK-NEXT: movq %rax, 968(%rdi)
+; CHECK-NEXT: movq %rax, 960(%rdi)
+; CHECK-NEXT: movq %rax, 952(%rdi)
+; CHECK-NEXT: movq %rax, 944(%rdi)
+; CHECK-NEXT: movq %rax, 936(%rdi)
+; CHECK-NEXT: movq %rax, 928(%rdi)
+; CHECK-NEXT: movq %rax, 920(%rdi)
+; CHECK-NEXT: movq %rax, 912(%rdi)
+; CHECK-NEXT: movq %rax, 904(%rdi)
+; CHECK-NEXT: movq %rax, 896(%rdi)
+; CHECK-NEXT: movq %rax, 888(%rdi)
+; CHECK-NEXT: movq %rax, 880(%rdi)
+; CHECK-NEXT: movq %rax, 872(%rdi)
+; CHECK-NEXT: movq %rax, 864(%rdi)
+; CHECK-NEXT: movq %rax, 856(%rdi)
+; CHECK-NEXT: movq %rax, 848(%rdi)
+; CHECK-NEXT: movq %rax, 840(%rdi)
+; CHECK-NEXT: movq %rax, 832(%rdi)
+; CHECK-NEXT: movq %rax, 824(%rdi)
+; CHECK-NEXT: movq %rax, 816(%rdi)
+; CHECK-NEXT: movq %rax, 808(%rdi)
+; CHECK-NEXT: movq %rax, 800(%rdi)
+; CHECK-NEXT: movq %rax, 792(%rdi)
+; CHECK-NEXT: movq %rax, 784(%rdi)
+; CHECK-NEXT: movq %rax, 776(%rdi)
+; CHECK-NEXT: movq %rax, 768(%rdi)
+; CHECK-NEXT: movq %rax, 760(%rdi)
+; CHECK-NEXT: movq %rax, 752(%rdi)
+; CHECK-NEXT: movq %rax, 744(%rdi)
+; CHECK-NEXT: movq %rax, 736(%rdi)
+; CHECK-NEXT: movq %rax, 728(%rdi)
+; CHECK-NEXT: movq %rax, 720(%rdi)
+; CHECK-NEXT: movq %rax, 712(%rdi)
+; CHECK-NEXT: movq %rax, 704(%rdi)
+; CHECK-NEXT: movq %rax, 696(%rdi)
+; CHECK-NEXT: movq %rax, 688(%rdi)
+; CHECK-NEXT: movq %rax, 680(%rdi)
+; CHECK-NEXT: movq %rax, 672(%rdi)
+; CHECK-NEXT: movq %rax, 664(%rdi)
+; CHECK-NEXT: movq %rax, 656(%rdi)
+; CHECK-NEXT: movq %rax, 648(%rdi)
+; CHECK-NEXT: movq %rax, 640(%rdi)
+; CHECK-NEXT: movq %rax, 632(%rdi)
+; CHECK-NEXT: movq %rax, 624(%rdi)
+; CHECK-NEXT: movq %rax, 616(%rdi)
+; CHECK-NEXT: movq %rax, 608(%rdi)
+; CHECK-NEXT: movq %rax, 600(%rdi)
+; CHECK-NEXT: movq %rax, 592(%rdi)
+; CHECK-NEXT: movq %rax, 584(%rdi)
+; CHECK-NEXT: movq %rax, 576(%rdi)
+; CHECK-NEXT: movq %rax, 568(%rdi)
+; CHECK-NEXT: movq %rax, 560(%rdi)
+; CHECK-NEXT: movq %rax, 552(%rdi)
+; CHECK-NEXT: movq %rax, 544(%rdi)
+; CHECK-NEXT: movq %rax, 536(%rdi)
+; CHECK-NEXT: movq %rax, 528(%rdi)
+; CHECK-NEXT: movq %rax, 520(%rdi)
+; CHECK-NEXT: movq %rax, 512(%rdi)
+; CHECK-NEXT: movq %rax, 504(%rdi)
+; CHECK-NEXT: movq %rax, 496(%rdi)
+; CHECK-NEXT: movq %rax, 488(%rdi)
+; CHECK-NEXT: movq %rax, 480(%rdi)
+; CHECK-NEXT: movq %rax, 472(%rdi)
+; CHECK-NEXT: movq %rax, 464(%rdi)
+; CHECK-NEXT: movq %rax, 456(%rdi)
+; CHECK-NEXT: movq %rax, 448(%rdi)
+; CHECK-NEXT: movq %rax, 440(%rdi)
+; CHECK-NEXT: movq %rax, 432(%rdi)
+; CHECK-NEXT: movq %rax, 424(%rdi)
+; CHECK-NEXT: movq %rax, 416(%rdi)
+; CHECK-NEXT: movq %rax, 408(%rdi)
+; CHECK-NEXT: movq %rax, 400(%rdi)
+; CHECK-NEXT: movq %rax, 392(%rdi)
+; CHECK-NEXT: movq %rax, 384(%rdi)
+; CHECK-NEXT: movq %rax, 376(%rdi)
+; CHECK-NEXT: movq %rax, 368(%rdi)
+; CHECK-NEXT: movq %rax, 360(%rdi)
+; CHECK-NEXT: movq %rax, 352(%rdi)
+; CHECK-NEXT: movq %rax, 344(%rdi)
+; CHECK-NEXT: movq %rax, 336(%rdi)
+; CHECK-NEXT: movq %rax, 328(%rdi)
+; CHECK-NEXT: movq %rax, 320(%rdi)
+; CHECK-NEXT: movq %rax, 312(%rdi)
+; CHECK-NEXT: movq %rax, 304(%rdi)
+; CHECK-NEXT: movq %rax, 296(%rdi)
+; CHECK-NEXT: movq %rax, 288(%rdi)
+; CHECK-NEXT: movq %rax, 280(%rdi)
+; CHECK-NEXT: movq %rax, 272(%rdi)
+; CHECK-NEXT: movq %rax, 264(%rdi)
+; CHECK-NEXT: movq %rax, 256(%rdi)
+; CHECK-NEXT: movq %rax, 248(%rdi)
+; CHECK-NEXT: movq %rax, 240(%rdi)
+; CHECK-NEXT: movq %rax, 232(%rdi)
+; CHECK-NEXT: movq %rax, 224(%rdi)
+; CHECK-NEXT: movq %rax, 216(%rdi)
+; CHECK-NEXT: movq %rax, 208(%rdi)
+; CHECK-NEXT: movq %rax, 200(%rdi)
+; CHECK-NEXT: movq %rax, 192(%rdi)
+; CHECK-NEXT: movq %rax, 184(%rdi)
+; CHECK-NEXT: movq %rax, 176(%rdi)
+; CHECK-NEXT: movq %rax, 168(%rdi)
+; CHECK-NEXT: movq %rax, 160(%rdi)
+; CHECK-NEXT: movq %rax, 152(%rdi)
+; CHECK-NEXT: movq %rax, 144(%rdi)
+; CHECK-NEXT: movq %rax, 136(%rdi)
+; CHECK-NEXT: movq %rax, 128(%rdi)
+; CHECK-NEXT: movq %rax, 120(%rdi)
+; CHECK-NEXT: movq %rax, 112(%rdi)
+; CHECK-NEXT: movq %rax, 104(%rdi)
+; CHECK-NEXT: movq %rax, 96(%rdi)
+; CHECK-NEXT: movq %rax, 88(%rdi)
+; CHECK-NEXT: movq %rax, 80(%rdi)
+; CHECK-NEXT: movq %rax, 72(%rdi)
+; CHECK-NEXT: movq %rax, 64(%rdi)
+; CHECK-NEXT: movq %rax, 56(%rdi)
+; CHECK-NEXT: movq %rax, 48(%rdi)
+; CHECK-NEXT: movq %rax, 40(%rdi)
+; CHECK-NEXT: movq %rax, 32(%rdi)
+; CHECK-NEXT: movq %rax, 24(%rdi)
+; CHECK-NEXT: movq %rax, 16(%rdi)
+; CHECK-NEXT: movq %rax, 8(%rdi)
+; CHECK-NEXT: movq %rax, (%rdi)
+; CHECK-NEXT: retq
+ tail call void @llvm.memset.inline.p0.i64(ptr %a, i8 42, i64 1024, i1 0)
+ ret void
+}
>From d1e01ecafe75778f8c79a42eca2d68a9b82cead9 Mon Sep 17 00:00:00 2001
From: Rose <gfunni234 at gmail.com>
Date: Thu, 28 Mar 2024 16:19:34 -0400
Subject: [PATCH 2/3] [X86] For minsize, use size for alignment, rather than
actual alignment
If we have minsize, then don't care about the alignment.
On x86, the CPU doesn't care and neither should you.
As long as the count is aligned, we can use less instructions.
---
llvm/lib/Target/X86/X86SelectionDAGInfo.cpp | 73 +++--
llvm/test/CodeGen/X86/memset-minsize.ll | 4 +-
.../CodeGen/X86/memset-vs-memset-inline.ll | 265 +-----------------
3 files changed, 59 insertions(+), 283 deletions(-)
diff --git a/llvm/lib/Target/X86/X86SelectionDAGInfo.cpp b/llvm/lib/Target/X86/X86SelectionDAGInfo.cpp
index 055466ac660cc..9bbaeffc889f1 100644
--- a/llvm/lib/Target/X86/X86SelectionDAGInfo.cpp
+++ b/llvm/lib/Target/X86/X86SelectionDAGInfo.cpp
@@ -62,18 +62,31 @@ SDValue X86SelectionDAGInfo::EmitTargetCodeForMemset(
const X86Subtarget &Subtarget =
DAG.getMachineFunction().getSubtarget<X86Subtarget>();
+ // If we have minsize, then don't care about the alignment.
+ // On x86, the CPU doesn't care and neither should you.
+ // As long as the count is aligned, we can use the minimum number of
+ // instructions without always having to resort to stosb.
+ //
+ // Because this is a feature specific to x86, we must handle it here.
+ if (!ConstantSize)
+ return SDValue();
+
+ uint64_t SizeVal = ConstantSize->getZExtValue();
+ if (DAG.getMachineFunction().getFunction().hasMinSize())
+ Alignment = commonAlignment(Align(Subtarget.is64Bit() ? 8 : 4), SizeVal);
+
// If not DWORD aligned or size is more than the threshold, call the library.
// The libc version is likely to be faster for these cases. It can use the
// address value and run time information about the CPU.
- if (Alignment < Align(4) || !ConstantSize ||
- ConstantSize->getZExtValue() > Subtarget.getMaxInlineSizeThreshold())
+
+ if (!AlwaysInline &&
+ (Alignment < Align(4) || SizeVal > Subtarget.getMaxInlineSizeThreshold()))
return SDValue();
- uint64_t SizeVal = ConstantSize->getZExtValue();
SDValue InGlue;
EVT AVT;
SDValue Count;
- unsigned BytesLeft = 0;
+ uint64_t BytesLeft = 0;
if (auto *ValC = dyn_cast<ConstantSDNode>(Val)) {
unsigned ValReg;
uint64_t Val = ValC->getZExtValue() & 255;
@@ -99,14 +112,12 @@ SDValue X86SelectionDAGInfo::EmitTargetCodeForMemset(
// Byte aligned
AVT = MVT::i8;
ValReg = X86::AL;
- Count = DAG.getIntPtrConstant(SizeVal, dl);
}
- if (AVT.bitsGT(MVT::i8)) {
- unsigned UBytes = AVT.getSizeInBits() / 8;
- Count = DAG.getIntPtrConstant(SizeVal / UBytes, dl);
- BytesLeft = SizeVal % UBytes;
- }
+ const uint64_t UBytes = AVT.getSizeInBits() / 8;
+ const uint64_t BlockCount = SizeVal / UBytes;
+ BytesLeft = SizeVal % UBytes;
+ Count = DAG.getIntPtrConstant(BlockCount, dl);
Chain = DAG.getCopyToReg(Chain, dl, ValReg, DAG.getConstant(Val, dl, AVT),
InGlue);
@@ -119,11 +130,11 @@ SDValue X86SelectionDAGInfo::EmitTargetCodeForMemset(
}
bool Use64BitRegs = Subtarget.isTarget64BitLP64();
- Chain = DAG.getCopyToReg(Chain, dl, Use64BitRegs ? X86::RCX : X86::ECX,
- Count, InGlue);
+ Chain = DAG.getCopyToReg(Chain, dl, Use64BitRegs ? X86::RCX : X86::ECX, Count,
+ InGlue);
InGlue = Chain.getValue(1);
- Chain = DAG.getCopyToReg(Chain, dl, Use64BitRegs ? X86::RDI : X86::EDI,
- Dst, InGlue);
+ Chain = DAG.getCopyToReg(Chain, dl, Use64BitRegs ? X86::RDI : X86::EDI, Dst,
+ InGlue);
InGlue = Chain.getValue(1);
SDVTList Tys = DAG.getVTList(MVT::Other, MVT::Glue);
@@ -131,6 +142,10 @@ SDValue X86SelectionDAGInfo::EmitTargetCodeForMemset(
SDValue RepStos = DAG.getNode(X86ISD::REP_STOS, dl, Tys, Ops);
/// RepStos can process the whole length.
+ //
+ // Because we changed the alignment earlier in the function to work on size
+ // when we have the minsize attribute, this is guaranteed to be 0 when we get
+ // here.
if (BytesLeft == 0)
return RepStos;
@@ -146,8 +161,8 @@ SDValue X86SelectionDAGInfo::EmitTargetCodeForMemset(
DAG.getNode(ISD::ADD, dl, AddrVT, Dst,
DAG.getConstant(Offset, dl, AddrVT)),
Val, DAG.getConstant(BytesLeft, dl, SizeVT), Alignment,
- isVolatile, AlwaysInline,
- /* CI */ nullptr, DstPtrInfo.getWithOffset(Offset)));
+ isVolatile, /*AlwaysInline*/ true, /* CI */ nullptr,
+ /* isTailCall */ false, DstPtrInfo.getWithOffset(Offset)));
return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Results);
}
@@ -222,13 +237,32 @@ static SDValue emitConstantSizeRepmov(
assert(!Subtarget.hasERMSB() && "No efficient RepMovs");
/// We assume runtime memcpy will do a better job for unaligned copies when
/// ERMS is not present.
- if (!AlwaysInline && (Alignment.value() & 3) != 0)
+ if (!AlwaysInline && (Alignment < Align(4)))
return SDValue();
+ // If we have minsize, then don't care about the alignment.
+ // On x86, the CPU doesn't care and neither should you.
+ // As long as the count is aligned, we can use the minimum number of
+ // instructions without always having to resort to movsb
+ //
+ // Because this is a feature specific to x86, we must handle it here.
+
+ if (DAG.getMachineFunction().getFunction().hasMinSize())
+ Alignment = commonAlignment(Align(Subtarget.is64Bit() ? 8 : 4), Size);
+
const MVT BlockType = getOptimalRepmovsType(Subtarget, Alignment);
const uint64_t BlockBytes = BlockType.getSizeInBits() / 8;
const uint64_t BlockCount = Size / BlockBytes;
const uint64_t BytesLeft = Size % BlockBytes;
+
+ if (DAG.getMachineFunction().getFunction().hasMinSize()) {
+ // Use the one instruction determined. Because we changed the alignment
+ // earlier in the function to work on size when we have the minsize
+ // attribute, it is guaranteed to process the entire length.
+ return emitRepmovs(Subtarget, DAG, dl, Chain, Dst, Src,
+ DAG.getIntPtrConstant(BlockCount, dl), BlockType);
+ }
+
SDValue RepMovs =
emitRepmovs(Subtarget, DAG, dl, Chain, Dst, Src,
DAG.getIntPtrConstant(BlockCount, dl), BlockType);
@@ -239,11 +273,6 @@ static SDValue emitConstantSizeRepmov(
assert(BytesLeft && "We have leftover at this point");
- /// In case we optimize for size we use repmovsb even if it's less efficient
- /// so we can save the loads/stores of the leftover.
- if (DAG.getMachineFunction().getFunction().hasMinSize())
- return emitRepmovsB(Subtarget, DAG, dl, Chain, Dst, Src, Size);
-
// Handle the last 1 - 7 bytes.
SmallVector<SDValue, 4> Results;
Results.push_back(RepMovs);
diff --git a/llvm/test/CodeGen/X86/memset-minsize.ll b/llvm/test/CodeGen/X86/memset-minsize.ll
index cc0f2156262bb..6d8fbc88e9020 100644
--- a/llvm/test/CodeGen/X86/memset-minsize.ll
+++ b/llvm/test/CodeGen/X86/memset-minsize.ll
@@ -14,10 +14,10 @@ entry:
define void @small_memset_to_rep_stos(ptr %ptr) minsize nounwind {
; CHECK-LABEL: small_memset_to_rep_stos:
; CHECK: # %bb.0: # %entry
-; CHECK-NEXT: pushq $32
+; CHECK-NEXT: pushq $16
; CHECK-NEXT: popq %rcx
; CHECK-NEXT: xorl %eax, %eax
-; CHECK-NEXT: rep;stosl %eax, %es:(%rdi)
+; CHECK-NEXT: rep;stosq %rax, %es:(%rdi)
; CHECK-NEXT: retq
entry:
call void @llvm.memset.p0.i32(ptr align 4 %ptr, i8 0, i32 128, i1 false)
diff --git a/llvm/test/CodeGen/X86/memset-vs-memset-inline.ll b/llvm/test/CodeGen/X86/memset-vs-memset-inline.ll
index 90a3f8e785e90..8f34cc813336c 100644
--- a/llvm/test/CodeGen/X86/memset-vs-memset-inline.ll
+++ b/llvm/test/CodeGen/X86/memset-vs-memset-inline.ll
@@ -28,137 +28,10 @@ define void @regular_memset_calls_external_function(ptr %a, i8 %value) nounwind
define void @inlined_set_doesnt_call_external_function(ptr %a, i8 %value) nounwind {
; CHECK-LABEL: inlined_set_doesnt_call_external_function:
; CHECK: # %bb.0:
-; CHECK-NEXT: movzbl %sil, %ecx
-; CHECK-NEXT: movabsq $72340172838076673, %rax # imm = 0x101010101010101
-; CHECK-NEXT: imulq %rcx, %rax
-; CHECK-NEXT: movq %rax, 1016(%rdi)
-; CHECK-NEXT: movq %rax, 1008(%rdi)
-; CHECK-NEXT: movq %rax, 1000(%rdi)
-; CHECK-NEXT: movq %rax, 992(%rdi)
-; CHECK-NEXT: movq %rax, 984(%rdi)
-; CHECK-NEXT: movq %rax, 976(%rdi)
-; CHECK-NEXT: movq %rax, 968(%rdi)
-; CHECK-NEXT: movq %rax, 960(%rdi)
-; CHECK-NEXT: movq %rax, 952(%rdi)
-; CHECK-NEXT: movq %rax, 944(%rdi)
-; CHECK-NEXT: movq %rax, 936(%rdi)
-; CHECK-NEXT: movq %rax, 928(%rdi)
-; CHECK-NEXT: movq %rax, 920(%rdi)
-; CHECK-NEXT: movq %rax, 912(%rdi)
-; CHECK-NEXT: movq %rax, 904(%rdi)
-; CHECK-NEXT: movq %rax, 896(%rdi)
-; CHECK-NEXT: movq %rax, 888(%rdi)
-; CHECK-NEXT: movq %rax, 880(%rdi)
-; CHECK-NEXT: movq %rax, 872(%rdi)
-; CHECK-NEXT: movq %rax, 864(%rdi)
-; CHECK-NEXT: movq %rax, 856(%rdi)
-; CHECK-NEXT: movq %rax, 848(%rdi)
-; CHECK-NEXT: movq %rax, 840(%rdi)
-; CHECK-NEXT: movq %rax, 832(%rdi)
-; CHECK-NEXT: movq %rax, 824(%rdi)
-; CHECK-NEXT: movq %rax, 816(%rdi)
-; CHECK-NEXT: movq %rax, 808(%rdi)
-; CHECK-NEXT: movq %rax, 800(%rdi)
-; CHECK-NEXT: movq %rax, 792(%rdi)
-; CHECK-NEXT: movq %rax, 784(%rdi)
-; CHECK-NEXT: movq %rax, 776(%rdi)
-; CHECK-NEXT: movq %rax, 768(%rdi)
-; CHECK-NEXT: movq %rax, 760(%rdi)
-; CHECK-NEXT: movq %rax, 752(%rdi)
-; CHECK-NEXT: movq %rax, 744(%rdi)
-; CHECK-NEXT: movq %rax, 736(%rdi)
-; CHECK-NEXT: movq %rax, 728(%rdi)
-; CHECK-NEXT: movq %rax, 720(%rdi)
-; CHECK-NEXT: movq %rax, 712(%rdi)
-; CHECK-NEXT: movq %rax, 704(%rdi)
-; CHECK-NEXT: movq %rax, 696(%rdi)
-; CHECK-NEXT: movq %rax, 688(%rdi)
-; CHECK-NEXT: movq %rax, 680(%rdi)
-; CHECK-NEXT: movq %rax, 672(%rdi)
-; CHECK-NEXT: movq %rax, 664(%rdi)
-; CHECK-NEXT: movq %rax, 656(%rdi)
-; CHECK-NEXT: movq %rax, 648(%rdi)
-; CHECK-NEXT: movq %rax, 640(%rdi)
-; CHECK-NEXT: movq %rax, 632(%rdi)
-; CHECK-NEXT: movq %rax, 624(%rdi)
-; CHECK-NEXT: movq %rax, 616(%rdi)
-; CHECK-NEXT: movq %rax, 608(%rdi)
-; CHECK-NEXT: movq %rax, 600(%rdi)
-; CHECK-NEXT: movq %rax, 592(%rdi)
-; CHECK-NEXT: movq %rax, 584(%rdi)
-; CHECK-NEXT: movq %rax, 576(%rdi)
-; CHECK-NEXT: movq %rax, 568(%rdi)
-; CHECK-NEXT: movq %rax, 560(%rdi)
-; CHECK-NEXT: movq %rax, 552(%rdi)
-; CHECK-NEXT: movq %rax, 544(%rdi)
-; CHECK-NEXT: movq %rax, 536(%rdi)
-; CHECK-NEXT: movq %rax, 528(%rdi)
-; CHECK-NEXT: movq %rax, 520(%rdi)
-; CHECK-NEXT: movq %rax, 512(%rdi)
-; CHECK-NEXT: movq %rax, 504(%rdi)
-; CHECK-NEXT: movq %rax, 496(%rdi)
-; CHECK-NEXT: movq %rax, 488(%rdi)
-; CHECK-NEXT: movq %rax, 480(%rdi)
-; CHECK-NEXT: movq %rax, 472(%rdi)
-; CHECK-NEXT: movq %rax, 464(%rdi)
-; CHECK-NEXT: movq %rax, 456(%rdi)
-; CHECK-NEXT: movq %rax, 448(%rdi)
-; CHECK-NEXT: movq %rax, 440(%rdi)
-; CHECK-NEXT: movq %rax, 432(%rdi)
-; CHECK-NEXT: movq %rax, 424(%rdi)
-; CHECK-NEXT: movq %rax, 416(%rdi)
-; CHECK-NEXT: movq %rax, 408(%rdi)
-; CHECK-NEXT: movq %rax, 400(%rdi)
-; CHECK-NEXT: movq %rax, 392(%rdi)
-; CHECK-NEXT: movq %rax, 384(%rdi)
-; CHECK-NEXT: movq %rax, 376(%rdi)
-; CHECK-NEXT: movq %rax, 368(%rdi)
-; CHECK-NEXT: movq %rax, 360(%rdi)
-; CHECK-NEXT: movq %rax, 352(%rdi)
-; CHECK-NEXT: movq %rax, 344(%rdi)
-; CHECK-NEXT: movq %rax, 336(%rdi)
-; CHECK-NEXT: movq %rax, 328(%rdi)
-; CHECK-NEXT: movq %rax, 320(%rdi)
-; CHECK-NEXT: movq %rax, 312(%rdi)
-; CHECK-NEXT: movq %rax, 304(%rdi)
-; CHECK-NEXT: movq %rax, 296(%rdi)
-; CHECK-NEXT: movq %rax, 288(%rdi)
-; CHECK-NEXT: movq %rax, 280(%rdi)
-; CHECK-NEXT: movq %rax, 272(%rdi)
-; CHECK-NEXT: movq %rax, 264(%rdi)
-; CHECK-NEXT: movq %rax, 256(%rdi)
-; CHECK-NEXT: movq %rax, 248(%rdi)
-; CHECK-NEXT: movq %rax, 240(%rdi)
-; CHECK-NEXT: movq %rax, 232(%rdi)
-; CHECK-NEXT: movq %rax, 224(%rdi)
-; CHECK-NEXT: movq %rax, 216(%rdi)
-; CHECK-NEXT: movq %rax, 208(%rdi)
-; CHECK-NEXT: movq %rax, 200(%rdi)
-; CHECK-NEXT: movq %rax, 192(%rdi)
-; CHECK-NEXT: movq %rax, 184(%rdi)
-; CHECK-NEXT: movq %rax, 176(%rdi)
-; CHECK-NEXT: movq %rax, 168(%rdi)
-; CHECK-NEXT: movq %rax, 160(%rdi)
-; CHECK-NEXT: movq %rax, 152(%rdi)
-; CHECK-NEXT: movq %rax, 144(%rdi)
-; CHECK-NEXT: movq %rax, 136(%rdi)
-; CHECK-NEXT: movq %rax, 128(%rdi)
-; CHECK-NEXT: movq %rax, 120(%rdi)
-; CHECK-NEXT: movq %rax, 112(%rdi)
-; CHECK-NEXT: movq %rax, 104(%rdi)
-; CHECK-NEXT: movq %rax, 96(%rdi)
-; CHECK-NEXT: movq %rax, 88(%rdi)
-; CHECK-NEXT: movq %rax, 80(%rdi)
-; CHECK-NEXT: movq %rax, 72(%rdi)
-; CHECK-NEXT: movq %rax, 64(%rdi)
-; CHECK-NEXT: movq %rax, 56(%rdi)
-; CHECK-NEXT: movq %rax, 48(%rdi)
-; CHECK-NEXT: movq %rax, 40(%rdi)
-; CHECK-NEXT: movq %rax, 32(%rdi)
-; CHECK-NEXT: movq %rax, 24(%rdi)
-; CHECK-NEXT: movq %rax, 16(%rdi)
-; CHECK-NEXT: movq %rax, 8(%rdi)
-; CHECK-NEXT: movq %rax, (%rdi)
+; CHECK-NEXT: movl %esi, %eax
+; CHECK-NEXT: movl $1024, %ecx # imm = 0x400
+; CHECK-NEXT: # kill: def $al killed $al killed $eax
+; CHECK-NEXT: rep;stosb %al, %es:(%rdi)
; CHECK-NEXT: retq
tail call void @llvm.memset.inline.p0.i64(ptr %a, i8 %value, i64 1024, i1 0)
ret void
@@ -168,134 +41,8 @@ define void @memset_inlined_insize(ptr %a) nounwind minsize {
; CHECK-LABEL: memset_inlined_insize:
; CHECK: # %bb.0:
; CHECK-NEXT: movabsq $3038287259199220266, %rax # imm = 0x2A2A2A2A2A2A2A2A
-; CHECK-NEXT: movq %rax, 1016(%rdi)
-; CHECK-NEXT: movq %rax, 1008(%rdi)
-; CHECK-NEXT: movq %rax, 1000(%rdi)
-; CHECK-NEXT: movq %rax, 992(%rdi)
-; CHECK-NEXT: movq %rax, 984(%rdi)
-; CHECK-NEXT: movq %rax, 976(%rdi)
-; CHECK-NEXT: movq %rax, 968(%rdi)
-; CHECK-NEXT: movq %rax, 960(%rdi)
-; CHECK-NEXT: movq %rax, 952(%rdi)
-; CHECK-NEXT: movq %rax, 944(%rdi)
-; CHECK-NEXT: movq %rax, 936(%rdi)
-; CHECK-NEXT: movq %rax, 928(%rdi)
-; CHECK-NEXT: movq %rax, 920(%rdi)
-; CHECK-NEXT: movq %rax, 912(%rdi)
-; CHECK-NEXT: movq %rax, 904(%rdi)
-; CHECK-NEXT: movq %rax, 896(%rdi)
-; CHECK-NEXT: movq %rax, 888(%rdi)
-; CHECK-NEXT: movq %rax, 880(%rdi)
-; CHECK-NEXT: movq %rax, 872(%rdi)
-; CHECK-NEXT: movq %rax, 864(%rdi)
-; CHECK-NEXT: movq %rax, 856(%rdi)
-; CHECK-NEXT: movq %rax, 848(%rdi)
-; CHECK-NEXT: movq %rax, 840(%rdi)
-; CHECK-NEXT: movq %rax, 832(%rdi)
-; CHECK-NEXT: movq %rax, 824(%rdi)
-; CHECK-NEXT: movq %rax, 816(%rdi)
-; CHECK-NEXT: movq %rax, 808(%rdi)
-; CHECK-NEXT: movq %rax, 800(%rdi)
-; CHECK-NEXT: movq %rax, 792(%rdi)
-; CHECK-NEXT: movq %rax, 784(%rdi)
-; CHECK-NEXT: movq %rax, 776(%rdi)
-; CHECK-NEXT: movq %rax, 768(%rdi)
-; CHECK-NEXT: movq %rax, 760(%rdi)
-; CHECK-NEXT: movq %rax, 752(%rdi)
-; CHECK-NEXT: movq %rax, 744(%rdi)
-; CHECK-NEXT: movq %rax, 736(%rdi)
-; CHECK-NEXT: movq %rax, 728(%rdi)
-; CHECK-NEXT: movq %rax, 720(%rdi)
-; CHECK-NEXT: movq %rax, 712(%rdi)
-; CHECK-NEXT: movq %rax, 704(%rdi)
-; CHECK-NEXT: movq %rax, 696(%rdi)
-; CHECK-NEXT: movq %rax, 688(%rdi)
-; CHECK-NEXT: movq %rax, 680(%rdi)
-; CHECK-NEXT: movq %rax, 672(%rdi)
-; CHECK-NEXT: movq %rax, 664(%rdi)
-; CHECK-NEXT: movq %rax, 656(%rdi)
-; CHECK-NEXT: movq %rax, 648(%rdi)
-; CHECK-NEXT: movq %rax, 640(%rdi)
-; CHECK-NEXT: movq %rax, 632(%rdi)
-; CHECK-NEXT: movq %rax, 624(%rdi)
-; CHECK-NEXT: movq %rax, 616(%rdi)
-; CHECK-NEXT: movq %rax, 608(%rdi)
-; CHECK-NEXT: movq %rax, 600(%rdi)
-; CHECK-NEXT: movq %rax, 592(%rdi)
-; CHECK-NEXT: movq %rax, 584(%rdi)
-; CHECK-NEXT: movq %rax, 576(%rdi)
-; CHECK-NEXT: movq %rax, 568(%rdi)
-; CHECK-NEXT: movq %rax, 560(%rdi)
-; CHECK-NEXT: movq %rax, 552(%rdi)
-; CHECK-NEXT: movq %rax, 544(%rdi)
-; CHECK-NEXT: movq %rax, 536(%rdi)
-; CHECK-NEXT: movq %rax, 528(%rdi)
-; CHECK-NEXT: movq %rax, 520(%rdi)
-; CHECK-NEXT: movq %rax, 512(%rdi)
-; CHECK-NEXT: movq %rax, 504(%rdi)
-; CHECK-NEXT: movq %rax, 496(%rdi)
-; CHECK-NEXT: movq %rax, 488(%rdi)
-; CHECK-NEXT: movq %rax, 480(%rdi)
-; CHECK-NEXT: movq %rax, 472(%rdi)
-; CHECK-NEXT: movq %rax, 464(%rdi)
-; CHECK-NEXT: movq %rax, 456(%rdi)
-; CHECK-NEXT: movq %rax, 448(%rdi)
-; CHECK-NEXT: movq %rax, 440(%rdi)
-; CHECK-NEXT: movq %rax, 432(%rdi)
-; CHECK-NEXT: movq %rax, 424(%rdi)
-; CHECK-NEXT: movq %rax, 416(%rdi)
-; CHECK-NEXT: movq %rax, 408(%rdi)
-; CHECK-NEXT: movq %rax, 400(%rdi)
-; CHECK-NEXT: movq %rax, 392(%rdi)
-; CHECK-NEXT: movq %rax, 384(%rdi)
-; CHECK-NEXT: movq %rax, 376(%rdi)
-; CHECK-NEXT: movq %rax, 368(%rdi)
-; CHECK-NEXT: movq %rax, 360(%rdi)
-; CHECK-NEXT: movq %rax, 352(%rdi)
-; CHECK-NEXT: movq %rax, 344(%rdi)
-; CHECK-NEXT: movq %rax, 336(%rdi)
-; CHECK-NEXT: movq %rax, 328(%rdi)
-; CHECK-NEXT: movq %rax, 320(%rdi)
-; CHECK-NEXT: movq %rax, 312(%rdi)
-; CHECK-NEXT: movq %rax, 304(%rdi)
-; CHECK-NEXT: movq %rax, 296(%rdi)
-; CHECK-NEXT: movq %rax, 288(%rdi)
-; CHECK-NEXT: movq %rax, 280(%rdi)
-; CHECK-NEXT: movq %rax, 272(%rdi)
-; CHECK-NEXT: movq %rax, 264(%rdi)
-; CHECK-NEXT: movq %rax, 256(%rdi)
-; CHECK-NEXT: movq %rax, 248(%rdi)
-; CHECK-NEXT: movq %rax, 240(%rdi)
-; CHECK-NEXT: movq %rax, 232(%rdi)
-; CHECK-NEXT: movq %rax, 224(%rdi)
-; CHECK-NEXT: movq %rax, 216(%rdi)
-; CHECK-NEXT: movq %rax, 208(%rdi)
-; CHECK-NEXT: movq %rax, 200(%rdi)
-; CHECK-NEXT: movq %rax, 192(%rdi)
-; CHECK-NEXT: movq %rax, 184(%rdi)
-; CHECK-NEXT: movq %rax, 176(%rdi)
-; CHECK-NEXT: movq %rax, 168(%rdi)
-; CHECK-NEXT: movq %rax, 160(%rdi)
-; CHECK-NEXT: movq %rax, 152(%rdi)
-; CHECK-NEXT: movq %rax, 144(%rdi)
-; CHECK-NEXT: movq %rax, 136(%rdi)
-; CHECK-NEXT: movq %rax, 128(%rdi)
-; CHECK-NEXT: movq %rax, 120(%rdi)
-; CHECK-NEXT: movq %rax, 112(%rdi)
-; CHECK-NEXT: movq %rax, 104(%rdi)
-; CHECK-NEXT: movq %rax, 96(%rdi)
-; CHECK-NEXT: movq %rax, 88(%rdi)
-; CHECK-NEXT: movq %rax, 80(%rdi)
-; CHECK-NEXT: movq %rax, 72(%rdi)
-; CHECK-NEXT: movq %rax, 64(%rdi)
-; CHECK-NEXT: movq %rax, 56(%rdi)
-; CHECK-NEXT: movq %rax, 48(%rdi)
-; CHECK-NEXT: movq %rax, 40(%rdi)
-; CHECK-NEXT: movq %rax, 32(%rdi)
-; CHECK-NEXT: movq %rax, 24(%rdi)
-; CHECK-NEXT: movq %rax, 16(%rdi)
-; CHECK-NEXT: movq %rax, 8(%rdi)
-; CHECK-NEXT: movq %rax, (%rdi)
+; CHECK-NEXT: movl $128, %ecx
+; CHECK-NEXT: rep;stosq %rax, %es:(%rdi)
; CHECK-NEXT: retq
tail call void @llvm.memset.inline.p0.i64(ptr %a, i8 42, i64 1024, i1 0)
ret void
>From f583a5655c5f7957678c2fce890a5abdaac763d3 Mon Sep 17 00:00:00 2001
From: Rose <gfunni234 at gmail.com>
Date: Sat, 20 Jul 2024 14:54:28 -0400
Subject: [PATCH 3/3] r
---
llvm/lib/Target/X86/X86SelectionDAGInfo.cpp | 19 +++----------------
1 file changed, 3 insertions(+), 16 deletions(-)
diff --git a/llvm/lib/Target/X86/X86SelectionDAGInfo.cpp b/llvm/lib/Target/X86/X86SelectionDAGInfo.cpp
index 9bbaeffc889f1..9512b5b0ff856 100644
--- a/llvm/lib/Target/X86/X86SelectionDAGInfo.cpp
+++ b/llvm/lib/Target/X86/X86SelectionDAGInfo.cpp
@@ -240,29 +240,16 @@ static SDValue emitConstantSizeRepmov(
if (!AlwaysInline && (Alignment < Align(4)))
return SDValue();
- // If we have minsize, then don't care about the alignment.
- // On x86, the CPU doesn't care and neither should you.
- // As long as the count is aligned, we can use the minimum number of
- // instructions without always having to resort to movsb
- //
- // Because this is a feature specific to x86, we must handle it here.
-
+ /// In case we optimize for size we use repmovsb even if it's less efficient
+ /// so we can save the loads/stores of the leftover.
if (DAG.getMachineFunction().getFunction().hasMinSize())
- Alignment = commonAlignment(Align(Subtarget.is64Bit() ? 8 : 4), Size);
+ return emitRepmovsB(Subtarget, DAG, dl, Chain, Dst, Src, Size);
const MVT BlockType = getOptimalRepmovsType(Subtarget, Alignment);
const uint64_t BlockBytes = BlockType.getSizeInBits() / 8;
const uint64_t BlockCount = Size / BlockBytes;
const uint64_t BytesLeft = Size % BlockBytes;
- if (DAG.getMachineFunction().getFunction().hasMinSize()) {
- // Use the one instruction determined. Because we changed the alignment
- // earlier in the function to work on size when we have the minsize
- // attribute, it is guaranteed to process the entire length.
- return emitRepmovs(Subtarget, DAG, dl, Chain, Dst, Src,
- DAG.getIntPtrConstant(BlockCount, dl), BlockType);
- }
-
SDValue RepMovs =
emitRepmovs(Subtarget, DAG, dl, Chain, Dst, Src,
DAG.getIntPtrConstant(BlockCount, dl), BlockType);
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