common.h

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/*
 * s390/common.h (cloned from s390/common.h by ROSSP)
 * Common s390 configuration information.
 *
 * Copyright (c) 1996, 1997, 1998, 1999
 * Transvirtual Technologies, Inc.  All rights reserved.
 *
 * Copyright (c) 2003
 *      Kaffe.org contributors. See ChangeLog for details.
 *
 * See the file "license.terms" for information on usage and redistribution 
 * of this file. 
 */

#ifndef __s390_h
#define __s390_h

/* The s390 gcc port aligns to the appropriate boundary: 1->1, 2->2, 4->4,
   and 8->8.  So alignment is pretty simple: */
#define  ALIGNMENT_OF_SIZE(S) (S)

#if defined(__GNUC__)
#define KAFFE_PROFILER 1
#endif

#if defined(KAFFE_PROFILER)

/* profiler clicks counter type.  */
typedef int64  profiler_click_t;

/* ReaD the processor Time Stamp Counter.
 * This is a macro to help GCC optimization. 
 * The rdtsc instruction load TSC to edx:eax aka A register.  */
#if 1 /* Not ready yet */
#define profiler_get_clicks(COUNTER)    \
   The s390 port does not have a profiler_get_clicks macro yet!
#else
#define profiler_get_clicks(COUNTER)    \
   asm volatile (".byte 0xf; .byte 0x31" /* "rdtsc" */ : "=A" (COUNTER))
#endif /* if 1 */

#endif

/*
 * Do an atomic compare and exchange.  The address 'A' is checked against  
 * value 'O' and if they match it's exchanged with value 'N'.
 * We return '1' if the exchange is sucessful, otherwise 0.
 */
#define COMPARE_AND_EXCHANGE(A,O,N)                                     \
   ({                                                                   \
      char ret;                                                         \
      asm volatile(" \n"						\
"         # gcc will invoke us with *A in %1, O in %3 and N in %2 \n"	\
"         cs %3,%2,0(%1) # compare O to A and exchange A and N if \n"	\
"                        # equal, else load O from A \n"		\
"         je 1f          # branch if equal \n"				\
"         la %0,0        # compare did not match \n"			\
"         j  2f          # skip  \n"					\
"      1: la %0,1        # compare matched \n"				\
"      2: \n"								\
"         "                                                             \
        : "=r&" (ret),                                 /* sets these */ \
          "+r" (A)                                                      \
        : "r" (N),                                     /* uses these */ \
          "r" (O)                                                       \
        : "cc" );                                  /* clobbers these */ \
      (ret);                                                            \
   })

#endif