425626 - Enable PGO with Sun Studio on Solaris

Status: RESOLVED FIXED

(Firefox Build System :: General, defect)

Description

[Ginn Chen]

Comment 1

[Ginn Chen]

Attachment: draft patch

For firefox, the profile will be in directory objdir/browser.profile.

I changed rules.mk because bug 402824.

Comment 2

[Ginn Chen]

Attachment: patch

Changes:
Right place for PROFILE_GEN_*;
Add -xlinkopt=2 for SPARC, it gives ~3% performance enhancement.

From manpage of CC.
     -xlinkopt[=level]
               (SPARC) Perform link-time optimizations on relo-
               catable object files.

               The link optimizer performs a number of advanced
               performance optimizations on the binary object
               code at link-time. The value level sets the level
               of optimizations performed, and must be 0, 1, or
               2.

               The optimization levels are:

               0        The link optimizer is disabled. (This is
                        the default.)

               1        Perform optimizations based on control
                        flow analysis, including instruction
                        cache coloring and branch optimizations,
                        at link time.

               2        Perform additional data flow analysis,
                        including dead-code elimination and
                        address computation simplification, at
                        link time.
               Specifying -xlinkopt without a level parameter
               implies -xlinkopt=1.

               These optimizations are performed at link time by
               analyzing the object binary code. The object files
               are not rewritten but the resulting executable
               code may differ from the original object codes.

               This option is most effective when used to compile
               the whole program, and with profile feedback.

               When compiling in separate steps, -xlinkopt must
               appear on both compile and link steps:

               example% CC -c -xlinkopt a.cc b.cc
               example% CC -o myprog -xlinkopt=2 a.o

               Note that the level parameter is only used when
               the compiler is linking. In the example above, the
               link optimizer level is 2 even though the object
               binaries were compiled with an implied level of 1.

               Do not use the -zcompreloc linker option when you
               compile with -xlinkopt.

               You must use -xlinkopt on at least some of the
               compilation commands for -xlinkopt to be useful at
               link time. The optimizer can still perform some
               limited optimizations on object binaries not com-
               piled with -xlinkopt.

               -xlinkopt will optimize code coming from static
               libraries that appear on the compiler command
               line, but it will skip and not optimize code com-
               ing from shared (dynamic) libraries that appear on
               the command line. You can also use -xlinkopt when
               building shared libraries (compiling with -G ).

               The link optimizer is most effective when used
               with run-time profile feedback. Profiling reveals
               the most and least used parts of the code and
               directs the optimizer to focus its effort accord-
               ingly.  This is particularly important with large
               applications where optimal placement of code per-
               formed at link time can reduce instruction cache
               misses.  Typically, this would be compiled as fol-
               lows:

               example% CC -o progt -xO5 -xprofile=collect:prog file.cc
               example% progt
               example% CC -o prog -xO5 -xprofile=use:prog -xlinkopt file.cc

               For details on using profile feedback, see -xpro-
               file

               Note that compiling with this option increases
               link time slightly.  Object file sizes also
               increase, but the size of the executable remains
               the same. Compiling with -xlinkopt and -g
               increases the size of the executable by including
               debugging information.

Comment 3

[(not currently active) Ted Mielczarek]

Comment on attachment 312701 [details] [diff] [review]
patch

r=me *without* the rules.mk change. Simply removing that bit isn't the right way to fix that. See bug 402824 for discussion on the right way to fix it. I'm fine with the rest of this patch.

Comment 4

[Ginn Chen]

It's not the right way to fix it; it's not the right way to do it, either.

I agree to leave it as bug 402824, and go with the rest first.

Comment 5

[Ginn Chen]

Comment on attachment 312701 [details] [diff] [review]
patch

request approval1.9 with no change to rules.mk

It only affects Solaris build.

Comment 6

[Mike Beltzner [:beltzner, not reading bugmail]]

Comment on attachment 312701 [details] [diff] [review]
patch

a1.9=beltzner

Comment 7

[Ginn Chen]

Checking in configure.in;
/cvsroot/mozilla/configure.in,v  <--  configure.in
new revision: 1.1977; previous revision: 1.1976
done
Checking in xpcom/reflect/xptcall/src/md/unix/Makefile.in;
/cvsroot/mozilla/xpcom/reflect/xptcall/src/md/unix/Makefile.in,v  <--  Makefile.in
new revision: 1.102; previous revision: 1.101
done