* [PATCH] arch/i386/Makefile,scripts/gcc-version.sh,Makefile small fixes
@ 2004-01-24 14:04 Serge Belyshev
2004-01-24 18:17 ` Andrew Morton
0 siblings, 1 reply; 6+ messages in thread
From: Serge Belyshev @ 2004-01-24 14:04 UTC (permalink / raw)
To: Andrew Morton; +Cc: linux-kernel
[This patch is against 2.6.2-rc1-mm2]
arch/i386/Makefile:
* omitted $(KBUILD_SRC)/ in script call.
scripts/gcc-version.sh:
* GNU tail no longer supports 'tail -1' syntax.
Makefile:
* There is no point in adding -funit-at-a-time option because it is
enabled by default at levels -Os, -O2 and -O3.
* Consider adding -fweb option:
vanilla:
$ size vmlinux
text data bss dec hex filename
3056270 526780 386056 3969106 3c9052 vmlinux
with -fweb:
$ size vmlinux
text data bss dec hex filename
3049523 526780 386056 3962359 3c75f7 vmlinux
Also note 0.1 ... 1.0% speedup in various benchmarks.
This option is not enabled by default at -O2 because it
(like -fomit-frame-pointer) makes debugging impossible.
diff -urN vanilla-2.6.2-rc1-mm2/arch/i386/Makefile hack/arch/i386/Makefile
--- vanilla-2.6.2-rc1-mm2/arch/i386/Makefile Sat Jan 24 15:49:56 2004
+++ hack/arch/i386/Makefile Sat Jan 24 15:32:13 2004
@@ -70,7 +70,7 @@
# -mregparm=3 works ok on gcc-3.0 and later
#
-GCC_VERSION := $(shell $(CONFIG_SHELL) scripts/gcc-version.sh $(CC))
+GCC_VERSION := $(shell $(CONFIG_SHELL) $(KBUILD_SRC)/scripts/gcc-version.sh $(CC))
cflags-$(CONFIG_REGPARM) += $(shell if [ $(GCC_VERSION) -ge 0300 ] ; then echo "-mregparm=3"; fi ;)
CFLAGS += $(cflags-y)
diff -urN vanilla-2.6.2-rc1-mm2/scripts/gcc-version.sh hack/scripts/gcc-version.sh
--- vanilla-2.6.2-rc1-mm2/scripts/gcc-version.sh Sat Jan 24 15:49:59 2004
+++ hack/scripts/gcc-version.sh Sat Jan 24 15:28:02 2004
@@ -8,7 +8,7 @@
compiler="$*"
-MAJOR=$(echo __GNUC__ | $compiler -E -xc - | tail -1)
-MINOR=$(echo __GNUC_MINOR__ | $compiler -E -xc - | tail -1)
+MAJOR=$(echo __GNUC__ | $compiler -E -xc - | tail -n 1)
+MINOR=$(echo __GNUC_MINOR__ | $compiler -E -xc - | tail -n 1)
printf "%02d%02d\\n" $MAJOR $MINOR
diff -urN vanilla-2.6.2-rc1-mm2/Makefile hack/Makefile
--- vanilla-2.6.2-rc1-mm2/Makefile Sat Jan 24 15:49:59 2004
+++ hack/Makefile Sat Jan 24 15:51:30 2004
@@ -435,15 +435,12 @@
ifndef CONFIG_FRAME_POINTER
CFLAGS += -fomit-frame-pointer
+CFLAGS += $(call check_gcc,-fweb,)
endif
ifdef CONFIG_DEBUG_INFO
CFLAGS += -g
endif
-
-# Enable unit-at-a-time mode when possible. It shrinks the
-# kernel considerably.
-CFLAGS += $(call check_gcc,-funit-at-a-time,)
# warn about C99 declaration after statement
CFLAGS += $(call check_gcc,-Wdeclaration-after-statement,)
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] arch/i386/Makefile,scripts/gcc-version.sh,Makefile small fixes
@ 2004-01-24 14:37 sam
0 siblings, 0 replies; 6+ messages in thread
From: sam @ 2004-01-24 14:37 UTC (permalink / raw)
To: Serge Belyshev; +Cc: linux-kernel, Andrew Morton
Date: 24 Jan 2004 17:04:54 +0300 skrev Serge Belyshev <33554432@mtu-net.ru> :
>[This patch is against 2.6.2-rc1-mm2]
>
>arch/i386/Makefile:
>* omitted $(KBUILD_SRC)/ in script call.
This should be $(srctree).
Sam
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] arch/i386/Makefile,scripts/gcc-version.sh,Makefile small fixes
2004-01-24 14:04 [PATCH] arch/i386/Makefile,scripts/gcc-version.sh,Makefile small fixes Serge Belyshev
@ 2004-01-24 18:17 ` Andrew Morton
2004-01-24 18:32 ` Valdis.Kletnieks
2004-01-25 1:40 ` Serge Belyshev
0 siblings, 2 replies; 6+ messages in thread
From: Andrew Morton @ 2004-01-24 18:17 UTC (permalink / raw)
To: Serge Belyshev; +Cc: linux-kernel
Serge Belyshev <33554432@mtu-net.ru> wrote:
>
> [This patch is against 2.6.2-rc1-mm2]
Is appreciated, thanks.
> arch/i386/Makefile:
> * omitted $(KBUILD_SRC)/ in script call.
OK
> scripts/gcc-version.sh:
> * GNU tail no longer supports 'tail -1' syntax.
OK.
> Makefile:
> * There is no point in adding -funit-at-a-time option because it is
> enabled by default at levels -Os, -O2 and -O3.
hm. Didn't Andi say that adding -fno-unit-at-a-time caused code shrinkage?
> * Consider adding -fweb option:
What does it do?
> vanilla:
> $ size vmlinux
> text data bss dec hex filename
> 3056270 526780 386056 3969106 3c9052 vmlinux
>
> with -fweb:
> $ size vmlinux
> text data bss dec hex filename
> 3049523 526780 386056 3962359 3c75f7 vmlinux
>
> Also note 0.1 ... 1.0% speedup in various benchmarks.
> This option is not enabled by default at -O2 because it
> (like -fomit-frame-pointer) makes debugging impossible.
OK, then we'd need a config option for it.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] arch/i386/Makefile,scripts/gcc-version.sh,Makefile small fixes
2004-01-24 18:17 ` Andrew Morton
@ 2004-01-24 18:32 ` Valdis.Kletnieks
2004-01-25 1:55 ` Serge Belyshev
2004-01-25 1:40 ` Serge Belyshev
1 sibling, 1 reply; 6+ messages in thread
From: Valdis.Kletnieks @ 2004-01-24 18:32 UTC (permalink / raw)
To: Andrew Morton; +Cc: Serge Belyshev, linux-kernel
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On Sat, 24 Jan 2004 10:17:04 PST, Andrew Morton said:
> > Makefile:
> > * There is no point in adding -funit-at-a-time option because it is
> > enabled by default at levels -Os, -O2 and -O3.
>
> hm. Didn't Andi say that adding -fno-unit-at-a-time caused code shrinkage?
Also, at least for the Fedora gcc-ssa compiler, -funit-at-a-time is *not* a
default option (provably so - building with gcc-ssa makes a kernel that hangs
*very* early on (right after 'decompressing the kernel' - I haven't dug into
this yet) - but commenting out this:
# Enable unit-at-a-time mode when possible. It shrinks the
# kernel considerably.
CFLAGS += $(call check_gcc,-funit-at-a-time,)
results in a working kernel. This is with:
% gcc-ssa --version
gcc-ssa (GCC) 3.5-tree-ssa 20040115 (Fedora Core Rawhide 3.5ssa-108)
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^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] arch/i386/Makefile,scripts/gcc-version.sh,Makefile small fixes
2004-01-24 18:17 ` Andrew Morton
2004-01-24 18:32 ` Valdis.Kletnieks
@ 2004-01-25 1:40 ` Serge Belyshev
1 sibling, 0 replies; 6+ messages in thread
From: Serge Belyshev @ 2004-01-25 1:40 UTC (permalink / raw)
To: Andrew Morton; +Cc: linux-kernel
>> * Consider adding -fweb option:
>
>What does it do?
>From gcc(1):
-fweb
Constructs webs as commonly used for register allocation purposes and
assign each web individual pseudo register. This allows our register
allocation pass to operate on pseudos directly, but also strengthens
several other optimization passes, such as CSE, loop optimizer and
trivial dead code remover. It can, however, make debugging impossible,
since variables will no longer stay in a ``home register''.
Enabled at levels -O3.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] arch/i386/Makefile,scripts/gcc-version.sh,Makefile small fixes
2004-01-24 18:32 ` Valdis.Kletnieks
@ 2004-01-25 1:55 ` Serge Belyshev
0 siblings, 0 replies; 6+ messages in thread
From: Serge Belyshev @ 2004-01-25 1:55 UTC (permalink / raw)
To: Valdis.Kletnieks; +Cc: akpm, linux-kernel
>Also, at least for the Fedora gcc-ssa compiler, -funit-at-a-time is *not* a
>default option (provably so - building with gcc-ssa makes a kernel that hangs
>*very* early on (right after 'decompressing the kernel' - I haven't dug into
But for gcc-3_4-branch (3.4.0 prerelease) and mainline (3.5.0 experimental)
-funit-at-a-time is default (at -O2 and higher) and works (at least for me :-).
^ permalink raw reply [flat|nested] 6+ messages in thread
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2004-01-24 14:04 [PATCH] arch/i386/Makefile,scripts/gcc-version.sh,Makefile small fixes Serge Belyshev
2004-01-24 18:17 ` Andrew Morton
2004-01-24 18:32 ` Valdis.Kletnieks
2004-01-25 1:55 ` Serge Belyshev
2004-01-25 1:40 ` Serge Belyshev
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2004-01-24 14:37 sam
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