The increment of delay counter was 2 instructions:
Arithmatic Shfit Left (ASL) + set to 1 on overflow
This can be done in 1 using ROtate Left (ROL)
Suggested-by: Nigel Topham <ntop...@synopsys.com>
Cc: Peter Zijlstra (Intel) <pet...@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Vineet Gupta <vgu...@synopsys.com>
---
arch/arc/include/asm/atomic.h | 3 +--
arch/arc/include/asm/spinlock.h | 3 +--
2 files changed, 2 insertions(+), 4 deletions(-)
diff --git a/arch/arc/include/asm/atomic.h b/arch/arc/include/asm/atomic.h
index 629dfd0a0c6b..87d18ae53115 100644
--- a/arch/arc/include/asm/atomic.h
+++ b/arch/arc/include/asm/atomic.h
@@ -34,8 +34,7 @@
" mov %[tmp], %[delay] \n" /* tmp = delay */
\
"2: brne.d %[tmp], 0, 2b \n" /* while (tmp != 0) */
\
" sub %[tmp], %[tmp], 1 \n" /* tmp-- */
\
- " asl.f %[delay], %[delay], 1 \n" /* delay *= 2 */
\
- " mov.z %[delay], 1 \n" /* handle overflow */
\
+ " rol %[delay], %[delay] \n" /* delay *= 2 */
\
" b 1b \n" /* start over */
\
"4: ; --- success --- \n"
\
diff --git a/arch/arc/include/asm/spinlock.h b/arch/arc/include/asm/spinlock.h
index 7071fc0da56a..db8c59d1eaeb 100644
--- a/arch/arc/include/asm/spinlock.h
+++ b/arch/arc/include/asm/spinlock.h
@@ -260,8 +260,7 @@ static inline void arch_write_unlock(arch_rwlock_t *rw)
" mov %[tmp], %[delay] \n" /* tmp = delay */
\
"2: brne.d %[tmp], 0, 2b \n" /* while (tmp != 0) */
\
" sub %[tmp], %[tmp], 1 \n" /* tmp-- */
\
- " asl.f %[delay], %[delay], 1 \n" /* delay *= 2 */
\
- " mov.z %[delay], 1 \n" /* handle overflow */
\
+ " rol %[delay], %[delay] \n" /* delay *= 2 */
\
" b 1b \n" /* start over */
\
" \n"
\
"4: ; --- done --- \n"
\
--
1.9.1
--
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