diff mbox series

[v2,1/2] powerpc: avoid an unnecessary test and branch in longjmp()

Message ID 7fbae252f24ec4d30f52f57a549901fa3f799f8f.1523984745.git.christophe.leroy@c-s.fr (mailing list archive)
State Accepted
Commit 24c78586cc6798028205e12c34febf0337bcbded
Headers show
Series [v2,1/2] powerpc: avoid an unnecessary test and branch in longjmp() | expand

Commit Message

Christophe Leroy April 17, 2018, 5:08 p.m. UTC 
Doing the test at exit of the function avoids an unnecessary
test and branch inside longjmp()

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 v2: Swapped both patches in the serie to reduce number of impacted lines

 arch/powerpc/kernel/misc.S | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

Comments

Michael Ellerman May 21, 2018, 10:01 a.m. UTC | #1 
On Tue, 2018-04-17 at 17:08:16 UTC, Christophe Leroy wrote:
> Doing the test at exit of the function avoids an unnecessary
> test and branch inside longjmp()
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>

Series applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/24c78586cc6798028205e12c34febf

cheers
diff mbox series

Patch

diff --git a/arch/powerpc/kernel/misc.S b/arch/powerpc/kernel/misc.S
index e1f3a5d054c4..746ee0320ad4 100644
--- a/arch/powerpc/kernel/misc.S
+++ b/arch/powerpc/kernel/misc.S
@@ -74,10 +74,7 @@  _GLOBAL(setjmp)
 	blr
 
 _GLOBAL(longjmp)
-	PPC_LCMPI r4,0
-	bne	1f
-	li	r4,1
-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)
@@ -102,7 +99,9 @@  _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)