From 681a4991f83742a0d2325afbf7b7f22045ad5b30 Mon Sep 17 00:00:00 2001 From: Russell King Date: Sun, 27 Aug 2006 12:38:34 +0100 Subject: [PATCH] [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 --- arch/arm/vfp/vfpmodule.c | 40 ++++++++++++++++------------------------ 1 file changed, 16 insertions(+), 24 deletions(-) diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c index 4178f6cc3d37..dedbb449632e 100644 --- a/arch/arm/vfp/vfpmodule.c +++ b/arch/arm/vfp/vfpmodule.c @@ -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; } -- GitLab