Re: [PATCH] Fix Immediate Values x86_64 support old gcc (v2)

On Wed, May 21, 2008 at 05:57:56PM -0400, Mathieu Desnoyers wrote:
* Sam Ravnborg (sam@xxxxxxxxxxxx) wrote:

Same with USE_IMMEDIATE - as USE_IMMEDIATE is only used in a x86 Makefile.
Or did I miss sothing?


Given that I want to change every use of CONFIG_IMMEDIATE into
USE_IMMEDIATE, both in architecture specific and independant C files and
also in arch spec. and indep. Makefiles, I will have to define
USE_IMMEDIATE on other arch too.

Here is the updated patch. It applies on top of the sched-devel.git
tree.

Fix Immediate Values x86_64 support old gcc

GCC < 4, on x86_64, does not accept symbol+offset operands for "i" constraints
asm statements. Fallback on generic immediate values if this compiler is
detected.

Changelog :
- USE_IMMEDIATE must now be used in lieue of CONFIG_IMMEDIATE in Makefiles and
in C code.
- Every architecture implementing immediate values must declare USE_IMMEDIATE
in their Makefile.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxx>
CC: Sam Ravnborg <sam@xxxxxxxxxxxx>
CC: "H. Peter Anvin" <hpa@xxxxxxxxx>
CC: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
CC: Ingo Molnar <mingo@xxxxxxx>
CC: David Miller <davem@xxxxxxxxxxxxx>
CC: Paul Mackerras paulus@xxxxxxxxx
---
Makefile | 5 +++++
arch/powerpc/Makefile | 2 ++
arch/powerpc/kernel/Makefile | 2 +-
arch/x86/Makefile | 5 +++++
arch/x86/kernel/Makefile | 2 +-
arch/x86/kernel/traps_32.c | 4 ++--
include/linux/immediate.h | 2 +-
include/linux/module.h | 4 ++--
kernel/Makefile | 2 +-
kernel/module.c | 8 ++++----
10 files changed, 24 insertions(+), 12 deletions(-)

Index: linux-2.6-sched-devel/arch/x86/Makefile
===================================================================
--- linux-2.6-sched-devel.orig/arch/x86/Makefile 2008-05-21 09:04:52.000000000 -0400
+++ linux-2.6-sched-devel/arch/x86/Makefile 2008-05-21 14:18:16.000000000 -0400
@@ -43,6 +43,7 @@

# temporary until string.h is fixed
KBUILD_CFLAGS += -ffreestanding
+ export USE_IMMEDIATE := $(CONFIG_IMMEDIATE)
tabs has a special sematic purpose in makefiles so do not
use tabs for indent.

else
BITS := 64
UTS_MACHINE := x86_64
@@ -78,6 +79,10 @@
"$(CC)" -fstack-protector-all )

KBUILD_CFLAGS += $(stackp-y)
+
+ # x86_64 gcc 3.x has problems with passing symbol+offset in
+ # asm "i" constraint.
+ export USE_IMMEDIATE := $(call cc-ifversion, -ge, 0400, $(CONFIG_IMMEDIATE))
tabs -> spaces again.

Other than that I like this patch much better.

Thanks,
Sam
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