lock.c

Optimized GotoBLAS libraries

/*********************************************************************/
/*                                                                   */
/*             Optimized BLAS libraries                              */
/*                     By Kazushige Goto <[e-mail]>     */
/*                                                                   */
/* Copyright (c) The University of Texas, 2005. All rights reserved. */
/* UNIVERSITY EXPRESSLY DISCLAIMS ANY AND ALL WARRANTIES CONCERNING  */
/* THIS SOFTWARE AND DOCUMENTATION, INCLUDING ANY WARRANTIES OF      */
/* MERCHANTABILITY, FITNESS FOR ANY PARTICULAR PURPOSE,              */
/* NON-INFRINGEMENT AND WARRANTIES OF PERFORMANCE, AND ANY WARRANTY  */
/* THAT MIGHT OTHERWISE ARISE FROM COURSE OF DEALING OR USAGE OF     */
/* TRADE. NO WARRANTY IS EITHER EXPRESS OR IMPLIED WITH RESPECT TO   */
/* THE USE OF THE SOFTWARE OR DOCUMENTATION.                         */
/* Under no circumstances shall University be liable for incidental, */
/* special, indirect, direct or consequential damages or loss of     */
/* profits, interruption of business, or related expenses which may  */
/* arise from use of Software or Documentation, including but not    */
/* limited to those resulting from defects in Software and/or        */
/* Documentation, or loss or inaccuracy of data of any kind.         */
/*********************************************************************/

static void __inline blas_lock(volatile BLASULONG *address){

#ifdef __GNUC__

  BLASLONG int ret, val = 1;

  __asm__ __volatile__ (
	   "      .machine \"any\" ;"
	   "0:    lwarx %0,0, %1 ;"
	   "      cmpwi  0,%0,0;"
	   "      bne 1f;"
	   "      stwcx. %2,0, %1 ;"
	   "      bne- 0b;"
	   "1:    "
	: "=&r"(ret)
	: "r"(address), "r" (val)
	: "cr0", "memory");

#else
  while (*address) {};
  *address = 1;
#endif
}