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authorUlrich Drepper <drepper@redhat.com>1999-06-13 13:36:34 +0000
committerUlrich Drepper <drepper@redhat.com>1999-06-13 13:36:34 +0000
commitec239360d13518a13f572b635d036c7d10028010 (patch)
treebdb5111363f45d2107849c2456b575d72779174c /db2/mutex/alpha.gcc
parentfc3703521650a9b6db910a50c4fc0f410496e134 (diff)
downloadglibc-ec239360d13518a13f572b635d036c7d10028010.tar.gz
glibc-ec239360d13518a13f572b635d036c7d10028010.tar.xz
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Update.
	* db2/Makefile (distribute): Remove files which do not exist
	anymore.
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diff --git a/db2/mutex/alpha.gcc b/db2/mutex/alpha.gcc
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-/*
- * @(#)alpha.gcc	10.1 (Sleepycat) 4/12/97
- *
- * The code appearing below is taken from Richard L. Sites, ed.  "Alpha
- * Architecture Reference Manual", Digital Press, 1992, page 5-7 and 5-8.
- * There are 2 modifications:
- *
- * 1. The jump from blbs __r1,30f to !__r1, which is dictated by the way the
- * TSL_SET macro is used.  The code suggested in Sites includes the main loop
- * of the spin lock, whereas in this code the rest the loop is specified in C.
- * The generated code might be suboptimal if the compiler generates a forward
- * branch for the usual case in which the mutex is uncontested.
- *
- * 2. At label 20, Sites suggests including code for testing for an excessive
- * number of _processor_ lock conflicts.  (The seq_c instruction stores its
- * first argument provided that no other processor has written to a byte range
- * including its memory-location argument.)  Absent such checking the code
- * below could conceivably stall silently on a multiprocessor alpha, depending
- * on how often processor/processor conflicts occur in a particular byte range.
- *
- * Note that the mb ("memory-barrier") instruction in TSL_UNSET is critical to
- * correct operation in a multiprocessor alpha (as is, of course, the mb in
- * the TSL_SET macro).  Without the mb, changes to shared memory that occurred
- * inside the critical section (before the TSL_UNSET) might reach shared memory
- * _after_ the change of tsl to 0, thereby permitting another processor to see
- * an inconsistent view of the data protected by the mutex.
- *
- * For gcc/alpha, 0 is clear, 1 is set.
- */
-#define TSL_SET(tsl) ({							\
-	register tsl_t *__l = (tsl);					\
-	register tsl_t __r1, __r2;					\
-	__asm__ volatile("						\n\
-	   10: ldq_l %0,(%2)						\n\
-	       blbs  %0,30f						\n\
-	       or    %0,1,%1						\n\
-	       stq_c %1,(%2)						\n\
-	       beq   %1,20f						\n\
-	       mb							\n\
-	       br    30f						\n\
-	   20: br    10b						\n\
-	   30: "							\
-	  : "=&r" (__r1), "=&r" (__r2)					\
-	  : "r" (__l));							\
-	!__r1;								\
-})
-
-#define TSL_UNSET(tsl) ({						\
-	register tsl_t *__l = (tsl);					\
-	__asm__ volatile("mb; stq $31,(%0);" : : "r" (__l));		\
-})
-#define	TSL_INIT(tsl)	TSL_UNSET(tsl)