Re: solaris build problem with Sun compilers

[Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>]

Alan Stange wrote:
> Hello,
> 
> I removed the whole tas_dummy() block for sparc from s_lock.c.  I 
> recompiled and installed with and without --enable-debug.   I then ran 
> pgbench on the box.  This is using the Sun 11 compilers on Solaris 10.
> 
> I tested using pgbench
> 
> $ pgbench -i -s 32 pgbench
> $ pgbench -s 32 -c 1 -t 10000 -v
> 
> for up to 8 clients on an 8 core UltraSparc IV+ system.
> 
> Everything compiled and ran fine.
> 
> 
> 
> 
> I took a look at backend/port/tas/solaris_sparc.s file.  Isn't that code 
> a bit longer than needed?
> 
> Aren't the callers of this doing
> while (tas(lock)) {
>    // wait a bit without smashing the kernel/memory bus
> }
> 
> in which case the code should just be
> 
> 	ldstub [%o0],%o0
> 	retl
> 	nop
> 
> without the extra comparisons and branching.  Unless I'm missing something.

Basically the original 8.1 ASM code was placing its own address into the
shared memory address:

	ldstub [%o0],%o0

and then based on what it got back, it was returning 1/0.  The new code
in CVS HEAD places '1' in, so there is no longer a need for the tests.

-- 
  Bruce Momjian   http://candle.pha.pa.us
  EnterpriseDB    http://www.enterprisedb.com

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