[PATCH 2/2] powerpc: avoid an unnecessary test and branch in longjmp()

Christophe Leroy christophe.leroy at c-s.fr
Mon Mar 19 23:23:17 AEDT 2018


Doing the test at exit of the function avoids an unnecessary
test and branch in longjmp()

Signed-off-by: Christophe Leroy <christophe.leroy at c-s.fr>
---
 arch/powerpc/kernel/misc.S | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/kernel/misc.S b/arch/powerpc/kernel/misc.S
index 739977a6be80..9b9207f60d28 100644
--- a/arch/powerpc/kernel/misc.S
+++ b/arch/powerpc/kernel/misc.S
@@ -90,14 +90,11 @@ _GLOBAL(setjmp)
 	blr
 
 _GLOBAL(longjmp)
-	PPC_LCMPI r4,0
-	bne	1f
-	li	r4,1
 #if defined(CONFIG_PPC32) && defined(CONFIG_CPU_BIG_ENDIAN)
-1:	lmw	r12, 3*SZL(r3)
+	lmw	r12, 3*SZL(r3)
 	mtcrf	0x38, r12
 #else
-1:	PPC_LL	r13,4*SZL(r3)
+	PPC_LL	r13,4*SZL(r3)
 	PPC_LL	r14,5*SZL(r3)
 	PPC_LL	r15,6*SZL(r3)
 	PPC_LL	r16,7*SZL(r3)
@@ -123,7 +120,9 @@ _GLOBAL(longjmp)
 	PPC_LL	r1,SZL(r3)
 	PPC_LL	r2,2*SZL(r3)
 	mtlr	r0
-	mr	r3,r4
+	mr.	r3, r4
+	bnelr
+	li	r3, 1
 	blr
 
 _GLOBAL(current_stack_pointer)
-- 
2.13.3



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