Commit407885e

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Add comments that Solaris Sun compiler only supports sparc9 ASM,

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Lines changed: 17 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -16,6 +16,23 @@`
`16`	`16`	`.global pg_atomic_cas`
`17`	`17`	`pg_atomic_cas:`
`18`	`18`
	`19`	`+!"cas" only works on sparcv9 chips,and requies a compiler`
	`20`	`+! that is targeting sparcv9. It will fail on a compiler`
	`21`	`+! targeting sparcv8,and of course willnot be understood`
	`22`	`+! by a sparcv8 CPU. If this fails on existing Solaris`
	`23`	`+! systems, we need to use a !defined(__sparcv9)test`
	`24`	`+! to fall back to the old"ldstub"call for sparcv8 compiles.`
	`25`	`+! gcc continues to use"ldstub" because there is no indication`
	`26`	`+! which sparc version it is targeting.`
	`27`	`+!`
	`28`	`+! There actually is a trick for embedding"cas" for a compiler`
	`29`	`+! that is targetingsparcv8:`
	`30`	`+!`
	`31`	`+!http://cvs.opensolaris.org/source/xref/on/usr/src/lib/libc/sparc/threads/sparc.il`
	`32`	`+!`
	`33`	`+! This might work forsparc8:`
	`34`	`+! ldstub [%o0],%o1! moves only a byte`
	`35`	`+`
`19`	`36`	`cas [%o0],%o2,%o1`
`20`	`37`	`mov %o1,%o0`
`21`	`38`	`retl`

Lines changed: 5 additions & 1 deletion

Original file line number	Diff line number	Diff line change
`@@ -66,7 +66,7 @@`
`66`	`66`	`* Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group`
`67`	`67`	`* Portions Copyright (c) 1994, Regents of the University of California`
`68`	`68`	`*`
`69`		`- * $PostgreSQL: pgsql/src/include/storage/s_lock.h,v 1.152 2006/04/29 11:55:19 momjian Exp $`
	`69`	`+ * $PostgreSQL: pgsql/src/include/storage/s_lock.h,v 1.153 2006/05/17 23:57:03 momjian Exp $`
`70`	`70`	`*`
`71`	`71`	`*-------------------------------------------------------------------------`
`72`	`72`	`*/`
`@@ -311,6 +311,10 @@ tas(volatile slock_t *lock)`
`311`	`311`	`{`
`312`	`312`	`registerslock_t_res;`
`313`	`313`
	`314`	`+/*`
	`315`	`+ *See comment in /pg/backend/port/tas/solaris_sparc.s for why this`
	`316`	`+ *uses "ldstub", and that file uses "cas".`
	`317`	`+ */`
`314`	`318`	`__asm__ __volatile__(`
`315`	`319`	`"ldstub[%2], %0\n"`
`316`	`320`	`:"=r"(_res),"+m"(*lock)`

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