[clang] [clang][x86] Support -masm=intel in cpuid.h (PR #127331)

[via cfe-commits]

https://github.com/Alcaro created https://github.com/llvm/llvm-project/pull/127331

Fixes #127271

Testing mostly done in Compiler Explorer https://godbolt.org/z/q1h3ohxr7

>From 90e3f502e582f44cd19e1b8b71d218330b13c9e4 Mon Sep 17 00:00:00 2001
From: Alcaro <floating at muncher.se>
Date: Sat, 15 Feb 2025 16:05:40 +0100
Subject: [PATCH] [clang][x86] Support -masm=intel in cpuid.h

---
 clang/lib/Headers/cpuid.h | 30 +++++++++++++++---------------
 1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/clang/lib/Headers/cpuid.h b/clang/lib/Headers/cpuid.h
index 2601aa5724f05..d8ace39d4e7d1 100644
--- a/clang/lib/Headers/cpuid.h
+++ b/clang/lib/Headers/cpuid.h
@@ -268,16 +268,16 @@
 #else
 /* x86-64 uses %rbx as the base register, so preserve it. */
 #define __cpuid(__leaf, __eax, __ebx, __ecx, __edx) \
-    __asm("  xchgq  %%rbx,%q1\n" \
+    __asm("  xchg{q|}  {%%|}rbx,%q1\n" \
           "  cpuid\n" \
-          "  xchgq  %%rbx,%q1" \
+          "  xchg{q|}  {%%|}rbx,%q1" \
         : "=a"(__eax), "=r" (__ebx), "=c"(__ecx), "=d"(__edx) \
         : "0"(__leaf))
 
 #define __cpuid_count(__leaf, __count, __eax, __ebx, __ecx, __edx) \
-    __asm("  xchgq  %%rbx,%q1\n" \
+    __asm("  xchg{q|}  {%%|}rbx,%q1\n" \
           "  cpuid\n" \
-          "  xchgq  %%rbx,%q1" \
+          "  xchg{q|}  {%%|}rbx,%q1" \
         : "=a"(__eax), "=r" (__ebx), "=c"(__ecx), "=d"(__edx) \
         : "0"(__leaf), "2"(__count))
 #endif
@@ -289,18 +289,18 @@ static __inline unsigned int __get_cpuid_max (unsigned int __leaf,
 #ifdef __i386__
     int __cpuid_supported;
 
-    __asm("  pushfl\n"
-          "  popl   %%eax\n"
-          "  movl   %%eax,%%ecx\n"
-          "  xorl   $0x00200000,%%eax\n"
-          "  pushl  %%eax\n"
-          "  popfl\n"
-          "  pushfl\n"
-          "  popl   %%eax\n"
-          "  movl   $0,%0\n"
-          "  cmpl   %%eax,%%ecx\n"
+    __asm("  pushf{l|d}\n"
+          "  pop{l|}   {%%|}eax\n"
+          "  mov{l|}   {%%eax,%%ecx|ecx,eax}\n"
+          "  xor{l|}   {$0x00200000,%%eax|eax,0x00200000}\n"
+          "  push{l|}  {%%|}eax\n"
+          "  popf{l|d}\n"
+          "  pushf{l|d}\n"
+          "  pop{l|}   {%%|}eax\n"
+          "  mov{l|}   {$0,%0|%0,0}\n"
+          "  cmp{l|}   {%%eax,%%ecx|ecx,eax}\n"
           "  je     1f\n"
-          "  movl   $1,%0\n"
+          "  mov{l|}   {$1,%0|%0,1}\n"
           "1:"
         : "=r" (__cpuid_supported) : : "eax", "ecx");
     if (!__cpuid_supported)