From: Helge Deller <deller@gmx.de>
Date: Sat, 29 Jun 2013 20:08:03 +0000 (+0200)
Subject: parisc: optimize mtsp(0,sr) inline assembly
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=92b59929825d67db575043a76651865d16873b36;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git

parisc: optimize mtsp(0,sr) inline assembly

If the value which should be moved into a space register is zero, we can
optimize the inline assembly to become "mtsp %r0,%srX".

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # 3.10
---

diff --git a/arch/parisc/include/asm/special_insns.h b/arch/parisc/include/asm/special_insns.h
index d306b75bc77f..e1509308899f 100644
--- a/arch/parisc/include/asm/special_insns.h
+++ b/arch/parisc/include/asm/special_insns.h
@@ -32,9 +32,12 @@ static inline void set_eiem(unsigned long val)
 	cr;				\
 })
 
-#define mtsp(gr, cr) \
-	__asm__ __volatile__("mtsp %0,%1" \
+#define mtsp(val, cr) \
+	{ if (__builtin_constant_p(val) && ((val) == 0)) \
+	 __asm__ __volatile__("mtsp %%r0,%0" : : "i" (cr) : "memory"); \
+	else \
+	 __asm__ __volatile__("mtsp %0,%1" \
 		: /* no outputs */ \
-		: "r" (gr), "i" (cr) : "memory")
+		: "r" (val), "i" (cr) : "memory"); }
 
 #endif /* __PARISC_SPECIAL_INSNS_H */