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[ARM] Optimise VFP thread notify function a little 

The common case for the thread notifier is a context switch.  Tell
gcc that this is the most likely condition so it can optimise the
function for this case.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Russell King 2006-08-27 12:38:34 +01:00 committed by Russell King
parent b36e4758dc
commit 681a4991f8
1 changed files with 16 additions and 24 deletions
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40
arch/arm/vfp/vfpmodule.c
View File

@ -40,10 +40,19 @@ unsigned int VFP_arch;
static int vfp_notifier(struct notifier_block *self, unsigned long cmd, void *v)
{
struct thread_info *thread = v;
union vfp_state *vfp = &thread->vfpstate;
union vfp_state *vfp;
switch (cmd) {
case THREAD_NOTIFY_FLUSH:
if (likely(cmd == THREAD_NOTIFY_SWITCH)) {
/*
* Always disable VFP so we can lazily save/restore the
* old state.
*/
fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_ENABLE);
return NOTIFY_DONE;
}
vfp = &thread->vfpstate;
if (cmd == THREAD_NOTIFY_FLUSH) {
/*
* Per-thread VFP initialisation.
*/
@ -56,29 +65,12 @@ static int vfp_notifier(struct notifier_block *self, unsigned long cmd, void *v)
* Disable VFP to ensure we initialise it first.
*/
fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_ENABLE);
/*
* FALLTHROUGH: Ensure we don't try to overwrite our newly
* initialised state information on the first fault.
*/
case THREAD_NOTIFY_RELEASE:
/*
* Per-thread VFP cleanup.
*/
if (last_VFP_context == vfp)
last_VFP_context = NULL;
break;
case THREAD_NOTIFY_SWITCH:
/*
* Always disable VFP so we can lazily save/restore the
* old state.
*/
fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_ENABLE);
break;
}
/* flush and release case: Per-thread VFP cleanup. */
if (last_VFP_context == vfp)
last_VFP_context = NULL;
return NOTIFY_DONE;
}