[llvm] Add option to turn off optimization for X86 assembler (PR #75895)
Yi Kong via llvm-commits
llvm-commits at lists.llvm.org
Mon Dec 18 22:20:07 PST 2023
https://github.com/kongy updated https://github.com/llvm/llvm-project/pull/75895
>From 8ec4144cad9566ff34e2089fbe6e59bf3399c74a Mon Sep 17 00:00:00 2001
From: Yi Kong <yikong at google.com>
Date: Tue, 19 Dec 2023 14:23:39 +0900
Subject: [PATCH] Add option to turn off optimization for X86 assembler
There are use cases that we are not expecting the assembler to produce
the exact instructions without any optimizations.
---
.../lib/Target/X86/AsmParser/X86AsmParser.cpp | 8 ++-
llvm/test/MC/X86/avx-64-att.s | 54 ++++++++++++-------
2 files changed, 42 insertions(+), 20 deletions(-)
diff --git a/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp b/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
index 1d40ce35c1b416..2da8ab4262835c 100644
--- a/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
+++ b/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
@@ -48,6 +48,10 @@ static cl::opt<bool> LVIInlineAsmHardening(
cl::desc("Harden inline assembly code that may be vulnerable to Load Value"
" Injection (LVI). This feature is experimental."), cl::Hidden);
+static cl::opt<bool> AsmOptimize("x86-asm-optimize", cl::init(true),
+ cl::desc("Optimize X86 inline assembly code."),
+ cl::Hidden);
+
static bool checkScale(unsigned Scale, StringRef &ErrMsg) {
if (Scale != 1 && Scale != 2 && Scale != 4 && Scale != 8) {
ErrMsg = "scale factor in address must be 1, 2, 4 or 8";
@@ -3670,11 +3674,11 @@ bool X86AsmParser::ParseInstruction(ParseInstructionInfo &Info, StringRef Name,
}
bool X86AsmParser::processInstruction(MCInst &Inst, const OperandVector &Ops) {
- if (ForcedVEXEncoding != VEXEncoding_VEX3 &&
+ if (AsmOptimize && ForcedVEXEncoding != VEXEncoding_VEX3 &&
X86::optimizeInstFromVEX3ToVEX2(Inst, MII.get(Inst.getOpcode())))
return true;
- if (X86::optimizeShiftRotateWithImmediateOne(Inst))
+ if (AsmOptimize && X86::optimizeShiftRotateWithImmediateOne(Inst))
return true;
switch (Inst.getOpcode()) {
diff --git a/llvm/test/MC/X86/avx-64-att.s b/llvm/test/MC/X86/avx-64-att.s
index 39ee048c3736d4..35e21ff67088a9 100644
--- a/llvm/test/MC/X86/avx-64-att.s
+++ b/llvm/test/MC/X86/avx-64-att.s
@@ -1,4 +1,5 @@
-// RUN: llvm-mc -triple x86_64-unknown-unknown --show-encoding %s | FileCheck %s
+// RUN: llvm-mc -triple x86_64-unknown-unknown --show-encoding %s | FileCheck --check-prefixes=CHECK,OPT %s
+// RUN: llvm-mc -triple x86_64-unknown-unknown --show-encoding -x86-asm-optimize=false %s | FileCheck --check-prefixes=CHECK,NOOPT %s
// CHECK: vaddss %xmm8, %xmm9, %xmm10
// CHECK: encoding: [0xc4,0x41,0x32,0x58,0xd0]
@@ -3168,20 +3169,28 @@ vdivpd -4(%rcx,%rbx,8), %xmm10, %xmm11
// CHECK: encoding: [0xc4,0xc1,0x5d,0x5e,0xf4]
vdivpd %ymm12, %ymm4, %ymm6
-// CHECK: vaddps %ymm4, %ymm12, %ymm6
-// CHECK: encoding: [0xc5,0x9c,0x58,0xf4]
+// OPT: vaddps %ymm4, %ymm12, %ymm6
+// OPT: encoding: [0xc5,0x9c,0x58,0xf4]
+// NOOPT: vaddps %ymm12, %ymm4, %ymm6
+// NOOPT: encoding: [0xc4,0xc1,0x5c,0x58,0xf4]
vaddps %ymm12, %ymm4, %ymm6
-// CHECK: vaddpd %ymm4, %ymm12, %ymm6
-// CHECK: encoding: [0xc5,0x9d,0x58,0xf4]
+// OPT: vaddpd %ymm4, %ymm12, %ymm6
+// OPT: encoding: [0xc5,0x9d,0x58,0xf4]
+// NOOPT: vaddpd %ymm12, %ymm4, %ymm6
+// NOOPT: encoding: [0xc4,0xc1,0x5d,0x58,0xf4]
vaddpd %ymm12, %ymm4, %ymm6
-// CHECK: vmulps %ymm4, %ymm12, %ymm6
-// CHECK: encoding: [0xc5,0x9c,0x59,0xf4]
+// OPT: vmulps %ymm4, %ymm12, %ymm6
+// OPT: encoding: [0xc5,0x9c,0x59,0xf4]
+// NOOPT: vmulps %ymm12, %ymm4, %ymm6
+// NOOPT: encoding: [0xc4,0xc1,0x5c,0x59,0xf4]
vmulps %ymm12, %ymm4, %ymm6
-// CHECK: vmulpd %ymm4, %ymm12, %ymm6
-// CHECK: encoding: [0xc5,0x9d,0x59,0xf4]
+// OPT: vmulpd %ymm4, %ymm12, %ymm6
+// OPT: encoding: [0xc5,0x9d,0x59,0xf4]
+// NOOPT: vmulpd %ymm12, %ymm4, %ymm6
+// NOOPT: encoding: [0xc4,0xc1,0x5d,0x59,0xf4]
vmulpd %ymm12, %ymm4, %ymm6
// CHECK: vmaxps (%rax), %ymm4, %ymm6
@@ -4203,7 +4212,8 @@ _foo2:
{vex3} vmovq %xmm0, %xmm8
// CHECK: vmovq %xmm8, %xmm0
-// CHECK: encoding: [0xc5,0x79,0xd6,0xc0]
+// OPT: encoding: [0xc5,0x79,0xd6,0xc0]
+// NOOPT: encoding: [0xc4,0xc1,0x7a,0x7e,0xc0]
vmovq %xmm8, %xmm0
// CHECK: vmovq %xmm8, %xmm0
@@ -4219,7 +4229,8 @@ _foo2:
{vex3} vmovdqa %xmm0, %xmm8
// CHECK: vmovdqa %xmm8, %xmm0
-// CHECK: encoding: [0xc5,0x79,0x7f,0xc0]
+// OPT: encoding: [0xc5,0x79,0x7f,0xc0]
+// NOOPT: encoding: [0xc4,0xc1,0x79,0x6f,0xc0]
vmovdqa %xmm8, %xmm0
// CHECK: vmovdqa %xmm8, %xmm0
@@ -4235,7 +4246,8 @@ _foo2:
{vex3} vmovdqu %xmm0, %xmm8
// CHECK: vmovdqu %xmm8, %xmm0
-// CHECK: encoding: [0xc5,0x7a,0x7f,0xc0]
+// OPT: encoding: [0xc5,0x7a,0x7f,0xc0]
+// NOOPT: encoding: [0xc4,0xc1,0x7a,0x6f,0xc0]
vmovdqu %xmm8, %xmm0
// CHECK: vmovdqu %xmm8, %xmm0
@@ -4251,7 +4263,8 @@ _foo2:
{vex3} vmovaps %xmm0, %xmm8
// CHECK: vmovaps %xmm8, %xmm0
-// CHECK: encoding: [0xc5,0x78,0x29,0xc0]
+// OPT: encoding: [0xc5,0x78,0x29,0xc0]
+// NOOPT: encoding: [0xc4,0xc1,0x78,0x28,0xc0]
vmovaps %xmm8, %xmm0
// CHECK: vmovaps %xmm8, %xmm0
@@ -4267,7 +4280,8 @@ _foo2:
{vex3} vmovaps %ymm0, %ymm8
// CHECK: vmovaps %ymm8, %ymm0
-// CHECK: encoding: [0xc5,0x7c,0x29,0xc0]
+// OPT: encoding: [0xc5,0x7c,0x29,0xc0]
+// NOOPT: encoding: [0xc4,0xc1,0x7c,0x28,0xc0]
vmovaps %ymm8, %ymm0
// CHECK: vmovaps %ymm8, %ymm0
@@ -4283,7 +4297,8 @@ _foo2:
{vex3} vmovups %xmm0, %xmm8
// CHECK: vmovups %xmm8, %xmm0
-// CHECK: encoding: [0xc5,0x78,0x11,0xc0]
+// OPT: encoding: [0xc5,0x78,0x11,0xc0]
+// NOOPT: encoding: [0xc4,0xc1,0x78,0x10,0xc0]
vmovups %xmm8, %xmm0
// CHECK: vmovups %xmm8, %xmm0
@@ -4299,7 +4314,8 @@ _foo2:
{vex3} vmovups %ymm0, %ymm8
// CHECK: vmovups %ymm8, %ymm0
-// CHECK: encoding: [0xc5,0x7c,0x11,0xc0]
+// OPT: encoding: [0xc5,0x7c,0x11,0xc0]
+// NOOPT: encoding: [0xc4,0xc1,0x7c,0x10,0xc0]
vmovups %ymm8, %ymm0
// CHECK: vmovups %ymm8, %ymm0
@@ -4323,7 +4339,8 @@ _foo2:
{vex3} vmovss %xmm0, %xmm8, %xmm0
// CHECK: vmovss %xmm8, %xmm0, %xmm0
-// CHECK: encoding: [0xc5,0x7a,0x11,0xc0]
+// OPT: encoding: [0xc5,0x7a,0x11,0xc0]
+// NOOPT: encoding: [0xc4,0xc1,0x7a,0x10,0xc0]
vmovss %xmm8, %xmm0, %xmm0
// CHECK: vmovss %xmm8, %xmm0, %xmm0
@@ -4347,7 +4364,8 @@ _foo2:
{vex3} vmovsd %xmm0, %xmm8, %xmm0
// CHECK: vmovsd %xmm8, %xmm0, %xmm0
-// CHECK: encoding: [0xc5,0x7b,0x11,0xc0]
+// OPT: encoding: [0xc5,0x7b,0x11,0xc0]
+// NOOPT: encoding: [0xc4,0xc1,0x7b,0x10,0xc0]
vmovsd %xmm8, %xmm0, %xmm0
// CHECK: vmovsd %xmm8, %xmm0, %xmm0
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