Revert "Prevent memory reordering"

This reverts commit 055e00c.

ChangeLog

@@ -1,7 +1,6 @@
 Changes in primecount-7.14, 2024-06-19
 
 * int128_t.hpp: Rename namespace port to pstd (portable std namespace).
-* cpuid.hpp: Prevent memory reordering.
 * Sieve.hpp: Tune AVX512 code.
 * multiarch_avx512_vpopcnt.cmake: Tune AVX512 code.
 

include/cpuid.hpp

@@ -28,23 +28,19 @@ inline void run_cpuid(int eax, int ecx, int* abcd)
   #if defined(__i386__) && \
       defined(__PIC__)
     /* in case of PIC under 32-bit EBX cannot be clobbered */
-    __asm__ __volatile__ (
-      "movl %%ebx, %%edi;"
-      "cpuid;"
-      "xchgl %%ebx, %%edi;"
-      : "=D" (ebx),
-        "+a" (eax),
-        "+c" (ecx),
-        "=d" (edx)
-      : "memory"
-    );
+    __asm__ ("movl %%ebx, %%edi;"
+             "cpuid;"
+             "xchgl %%ebx, %%edi;"
+             : "=D" (ebx),
+               "+a" (eax),
+               "+c" (ecx),
+               "=d" (edx));
   #else
-    __asm__ __volatile__ (
-        "cpuid"
-        : "=a" (eax), "=b" (ebx), "=c" (ecx), "=d" (edx)
-        : "0" (eax), "2" (ecx)
-        : "memory"
-    );
+    __asm__ ("cpuid;"
+             : "+b" (ebx),
+               "+a" (eax),
+               "+c" (ecx),
+               "=d" (edx));
   #endif
 
   abcd[0] = eax;