2009-06-04 13:10:27

by Ingo Molnar

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Subject: [tip:perfcounters/core] perf_counter tools: Build with native optimization

Commit-ID: af794b94ae8a16fb4a9da6ce640c122efb44e2a0
Gitweb: http://git.kernel.org/tip/af794b94ae8a16fb4a9da6ce640c122efb44e2a0
Author: Ingo Molnar <[email protected]>
AuthorDate: Thu, 4 Jun 2009 13:58:13 +0200
Committer: Ingo Molnar <[email protected]>
CommitDate: Thu, 4 Jun 2009 14:00:52 +0200

perf_counter tools: Build with native optimization

Build the tools with -march=native by default.

No measurable difference in speed though, compared to the
default, on a Nehalem testbox.

Cc: Peter Zijlstra <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Corey Ashford <[email protected]>
Cc: Marcelo Tosatti <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Thomas Gleixner <[email protected]>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <[email protected]>


---
Documentation/perf_counter/Makefile | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/Documentation/perf_counter/Makefile b/Documentation/perf_counter/Makefile
index 005709b..414399c 100644
--- a/Documentation/perf_counter/Makefile
+++ b/Documentation/perf_counter/Makefile
@@ -159,7 +159,7 @@ uname_V := $(shell sh -c 'uname -v 2>/dev/null || echo not')

# CFLAGS and LDFLAGS are for the users to override from the command line.

-CFLAGS = -ggdb3 -Wall -Werror -Wstrict-prototypes -Wmissing-declarations -Wmissing-prototypes -std=gnu99 -Wdeclaration-after-statement -O6
+CFLAGS = -ggdb3 -Wall -Werror -Wstrict-prototypes -Wmissing-declarations -Wmissing-prototypes -std=gnu99 -Wdeclaration-after-statement -O6 -march=native
LDFLAGS = -lpthread -lrt -lelf
ALL_CFLAGS = $(CFLAGS)
ALL_LDFLAGS = $(LDFLAGS)


2009-06-05 01:03:51

by Paul Mackerras

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Subject: Re: [tip:perfcounters/core] perf_counter tools: Build with native optimization

tip-bot for Ingo Molnar writes:

> perf_counter tools: Build with native optimization
>
> Build the tools with -march=native by default.

On powerpc (RHEL5.2 on POWER5+, gcc 4.1.2), I get:

CC perf.o
cc1: error: unrecognized command line option "-march=native"
make: *** [perf.o] Error 1

Is there a way to make the default CFLAGS depend on the architecture?
We need -m64 on powerpc as well.

Paul.

2009-06-05 18:42:22

by Ingo Molnar

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Subject: Re: [tip:perfcounters/core] perf_counter tools: Build with native optimization


* Paul Mackerras <[email protected]> wrote:

> tip-bot for Ingo Molnar writes:
>
> > perf_counter tools: Build with native optimization
> >
> > Build the tools with -march=native by default.
>
> On powerpc (RHEL5.2 on POWER5+, gcc 4.1.2), I get:
>
> CC perf.o
> cc1: error: unrecognized command line option "-march=native"
> make: *** [perf.o] Error 1

ok, i removed that.

> Is there a way to make the default CFLAGS depend on the architecture?
> We need -m64 on powerpc as well.

Would be nice to add a Makefile rule to add -m64 on all 64-bit
architectures. That would avoid having to do PowerPC-specific magic.

(But, PowerPC-specific rules would be fine too, of course.)

Ingo