[ofa-general] RE: [Bug 408] dapltest compilation fails on x86 [PATCH]

[James Lentini]

On Wed, 7 Mar 2007, Arlin Davis wrote:

> 
> James, please review this fix for dapltest build issue.

Hi Arlin,

Just returning from vacation and catching up on email.

> Signed-off by: Arlin Davis ardavis at ichips.intel.com
> 
> diff --git a/test/dapltest/mdep/linux/dapl_mdep_user.h b/test/dapltest/mdep/linux/dapl_mdep_user.h
> index c05dd30..2903e78 100644
> --- a/test/dapltest/mdep/linux/dapl_mdep_user.h
> +++ b/test/dapltest/mdep/linux/dapl_mdep_user.h
> @@ -117,7 +117,7 @@ typedef unsigned long long int 		DT_Mdep_TimeStamp;
>  static _INLINE_ DT_Mdep_TimeStamp
>  DT_Mdep_GetTimeStamp ( void )
>  {
> -#if defined(__GNUC__) && defined(__PENTIUM__)
> +#if defined(__GNUC__) && defined(__i386__)
>      DT_Mdep_TimeStamp x;
>      __asm__ volatile (".byte 0x0f, 0x31" : "=A" (x));

This is the opcode for a RDTSC instruction. My copy of the "Intel 64 
and IA-32 Architectures Software Developer's Manual" says that the 
RDTSC instruction was introduced by the Pentium. Although I don't 
think anyone is going to use RDMA on a 486, making the change 
above would create code that attempted to use an RDTSC instruction on 
pre-Pentium processors. 

What is the processor that is being excluded by the Pentium test? 
Would it be possible to recode the compile guard to check for either 
Pentium or X?

As a side note, the code could use the rdtsc mnemonic, as we do below, 
instead of the raw opcode.

>      return x;
> @@ -143,7 +143,7 @@ DT_Mdep_GetTimeStamp ( void )
>        asm volatile("rdtsc" : "=a" (__a), "=d" (__d)); 
>        return ((unsigned long)__a) | (((unsigned long)__d)<<32);
>  #else
> -#error "Non-Pentium and Non-PPC Linux - unimplemented"
> +#error "Linux CPU architecture - unimplemented"
>  #endif
>  #endif
>  #endif