OpenXM_contrib/gmp/tune/alpha.asm - diff

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version 1.1.1.1, 2000/09/09 14:13:19

version 1.1.1.2, 2003/08/25 16:06:38

Line 1

dnl Alpha time stamp counter access routine.

dnl

dnl This file is part of the GNU MP Library.

dnl

Line 24 include(`../config.m4')

C void speed_cyclecounter (unsigned int p[2]);

C The rpcc instruction returns a 64-bit value split into two 32-bit fields.

C The lower 32 bits are set by the hardware, and the upper 32 bits are set

C by the operating system. The real per-process cycle count is the sum of

C these halves.

C Unfortunately, some operating systems don't get this right. NetBSD 1.3 is

C known to sometimes put garbage in the upper half. Whether newer NetBSD

C versions get it right, is unknown to us.

C rpcc measures cycles elapsed in the user program and hence should be very

C accurate even on a busy system. Losing cache contents due to task

C switching may have an effect though.

Line 31 C switching may have an effect though.

Line 41 C switching may have an effect though.

ASM_START()

PROLOGUE(speed_cyclecounter)

rpcc r0

srl r0,32,r1

addq r1,r0,r0

stl r0,0(r16)

srl r0,32,r0

stl r31,4(r16) C zero upper return word

stl r0,4(r16)

ret r31,(r26),1

EPILOGUE(speed_cyclecounter)

ASM_END()