Re: [PATCH x86 for review III] [1/29] i386: avoid gcc extension

From: Randy Dunlap
Date: Mon Feb 12 2007 - 15:23:03 EST


On Mon, 12 Feb 2007 19:43:36 +0000 Jochen Voß wrote:

> Hi,
>
> On 12/02/07, Andi Kleen <ak@xxxxxxx> wrote:
> > setcc() in math-emu is written as a gcc extension statement expression
> > macro that returns a value. However, it's not used that way and it's not
> > needed like that, so just make it a do-while non-extension macro so that we
> > don't use an extension when it's not needed.
>
> This description ...
>
> ... seems to contradict the implementation. No "do-while" here.
>
> I hope this helps,

Yes, thanks. First version was do-while, latter was inline.

Here's an updated patch/description.

---
From: Randy Dunlap <randy.dunlap@xxxxxxxxxx>

setcc() in math-emu is written as a gcc extension statement expression
macro that returns a value. However, it's not used that way and it's
not needed like that, so just make it an inline void so that
we don't use an extension when it's not needed.

Signed-off-by: Randy Dunlap <randy.dunlap@xxxxxxxxxx>
---
arch/i386/math-emu/status_w.h | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

--- linux-2620-rc2.orig/arch/i386/math-emu/status_w.h
+++ linux-2620-rc2/arch/i386/math-emu/status_w.h
@@ -48,9 +48,11 @@

#define status_word() \
((partial_status & ~SW_Top & 0xffff) | ((top << SW_Top_Shift) & SW_Top))
-#define setcc(cc) ({ \
- partial_status &= ~(SW_C0|SW_C1|SW_C2|SW_C3); \
- partial_status |= (cc) & (SW_C0|SW_C1|SW_C2|SW_C3); })
+static inline void setcc(int cc)
+{
+ partial_status &= ~(SW_C0|SW_C1|SW_C2|SW_C3);
+ partial_status |= (cc) & (SW_C0|SW_C1|SW_C2|SW_C3);
+}

#ifdef PECULIAR_486
/* Default, this conveys no information, but an 80486 does it. */
-
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