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MIPS: Remove redundant instructions from arch_spin_{,try}lock. 

We were doing:
   SRL  $r,$?,16
   ANDI $r,$r,0xffff

The logical right shift by 16 leaves the upper 16 bits clear, so the
subsequent masking out of those bits is redundant, and can safely be
removed.

Signed-off-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
David Daney 2013-04-25 15:48:53 +00:00 committed by Ralf Baechle
parent e01961ceea
commit 3d39019a16
1 changed files with 0 additions and 4 deletions
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4
arch/mips/include/asm/spinlock.h
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@ -71,7 +71,6 @@ static inline void arch_spin_lock(arch_spinlock_t *lock)
" nop \n"
" srl %[my_ticket], %[ticket], 16 \n"
" andi %[ticket], %[ticket], 0xffff \n"
" andi %[my_ticket], %[my_ticket], 0xffff \n"
" bne %[ticket], %[my_ticket], 4f \n"
" subu %[ticket], %[my_ticket], %[ticket] \n"
"2: \n"
@ -105,7 +104,6 @@ static inline void arch_spin_lock(arch_spinlock_t *lock)
" beqz %[my_ticket], 1b \n"
" srl %[my_ticket], %[ticket], 16 \n"
" andi %[ticket], %[ticket], 0xffff \n"
" andi %[my_ticket], %[my_ticket], 0xffff \n"
" bne %[ticket], %[my_ticket], 4f \n"
" subu %[ticket], %[my_ticket], %[ticket] \n"
"2: \n"
@ -153,7 +151,6 @@ static inline unsigned int arch_spin_trylock(arch_spinlock_t *lock)
" \n"
"1: ll %[ticket], %[ticket_ptr] \n"
" srl %[my_ticket], %[ticket], 16 \n"
" andi %[my_ticket], %[my_ticket], 0xffff \n"
" andi %[now_serving], %[ticket], 0xffff \n"
" bne %[my_ticket], %[now_serving], 3f \n"
" addu %[ticket], %[ticket], %[inc] \n"
@ -178,7 +175,6 @@ static inline unsigned int arch_spin_trylock(arch_spinlock_t *lock)
" \n"
"1: ll %[ticket], %[ticket_ptr] \n"
" srl %[my_ticket], %[ticket], 16 \n"
" andi %[my_ticket], %[my_ticket], 0xffff \n"
" andi %[now_serving], %[ticket], 0xffff \n"
" bne %[my_ticket], %[now_serving], 3f \n"
" addu %[ticket], %[ticket], %[inc] \n"