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| author |   Daniel Jacobowitz <drow@false.org> | 2006-08-30 15:02:08 +0100 |
|---|---|---|
| committer |   Russell King <rmk+kernel@arm.linux.org.uk> | 2006-09-20 14:58:35 +0100 |
| commit | 6a39dd6222dda5ee2414a1b42e8e62118742a49e (patch) | |
| tree | 8c4eeeb2d48b583aed900f2a3e8c57f0536a0193 /include/asm-arm/arch-l7200 | |
| parent | [ARM] Optimise VFP thread notify function a little (diff) | |
| download | linux-dev-6a39dd6222dda5ee2414a1b42e8e62118742a49e.tar.xz linux-dev-6a39dd6222dda5ee2414a1b42e8e62118742a49e.zip | |
[ARM] 3759/2: Remove uses of %?
Patch from Daniel Jacobowitz
The ARM kernel has several uses of asm("foo%?"). %? is a GCC internal
modifier used to output conditional execution predicates. However, no
version of GCC supports conditionalizing asm statements. GCC 4.2 will
correctly expand %? to the empty string in user asms. Earlier versions may
reuse the condition from the previous instruction. In 'if (foo) asm
("bar%?");' this is somewhat likely to be right... but not reliable.
So, the only safe thing to do is to remove the uses of %?. I believe
the tlbflush.h occurances were supposed to be removed before, based
on the comment about %? not working at the top of that file.
Old versions of GCC could omit branches around user asms if the asm didn't
mark the condition codes as clobbered. This problem hasn't been seen on any
recent (3.x or 4.x) GCC, but it could theoretically happen. So, where
%? was removed a cc clobber was added.
Signed-off-by: Daniel Jacobowitz <dan@codesourcery.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'include/asm-arm/arch-l7200')
| -rw-r--r-- | include/asm-arm/arch-l7200/io.h | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/include/asm-arm/arch-l7200/io.h b/include/asm-arm/arch-l7200/io.h index cd080d8384d9..d744d97c18a5 100644 --- a/include/asm-arm/arch-l7200/io.h +++ b/include/asm-arm/arch-l7200/io.h @@ -31,9 +31,9 @@ static inline unsigned int __arch_getw(unsigned long a) { unsigned int value; - __asm__ __volatile__("ldr%?h %0, [%1, #0] @ getw" + __asm__ __volatile__("ldrh %0, [%1, #0] @ getw" : "=&r" (value) - : "r" (a)); + : "r" (a) : "cc"); return value; } @@ -42,8 +42,8 @@ static inline unsigned int __arch_getw(unsigned long a) static inline void __arch_putw(unsigned int value, unsigned long a) { - __asm__ __volatile__("str%?h %0, [%1, #0] @ putw" - : : "r" (value), "r" (a)); + __asm__ __volatile__("strh %0, [%1, #0] @ putw" + : : "r" (value), "r" (a) : "cc"); } /* |