[cfe-commits] r145149 - /cfe/trunk/lib/Headers/cpuid.h

[Eli Friedman]

On Sat, Nov 26, 2011 at 12:53 PM, Rafael Espindola
<rafael.espindola at gmail.com> wrote:
> Author: rafael
> Date: Sat Nov 26 14:53:19 2011
> New Revision: 145149
>
> URL: http://llvm.org/viewvc/llvm-project?rev=145149&view=rev
> Log:
> Add the minimum implementation of cpuid.h. This works on "modern" intel cpus
> and on clang, which seams to handled "=b" correctly even when ebx is the
> PIC register.
>
> Added:
>    cfe/trunk/lib/Headers/cpuid.h
>
> Added: cfe/trunk/lib/Headers/cpuid.h
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Headers/cpuid.h?rev=145149&view=auto
> ==============================================================================
> --- cfe/trunk/lib/Headers/cpuid.h (added)
> +++ cfe/trunk/lib/Headers/cpuid.h Sat Nov 26 14:53:19 2011
> @@ -0,0 +1,29 @@
> +/*===---- stddef.h - Basic type definitions --------------------------------===
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a copy
> + * of this software and associated documentation files (the "Software"), to deal
> + * in the Software without restriction, including without limitation the rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
> + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.
> + *
> + *===-----------------------------------------------------------------------===
> + */

Could you add a #error for non-x86 architectures?

> +static inline int __get_cpuid (unsigned int level, unsigned int *eax,
> +                               unsigned int *ebx, unsigned int *ecx,
> +                               unsigned int *edx) {
> +    asm("cpuid" : "=a"(*eax), "=b" (*ebx), "=c"(*ecx), "=d"(*edx) : "0"(level));
> +    return 1;
> +}

This implementation appears to be incomplete; at the very least, it
will SIGILL on CPUs which don't support the CPUID instruction.

-Eli