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| author | Mikulas Patocka <mpatocka@redhat.com> | 2010-08-18 08:03:37 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-08-18 22:51:08 -0700 |
| commit | 6ec274750c99448c3412bbc10c97ce0c993f8a4e (patch) | |
| tree | 1ec5f1b5a964d893dee6f2b4ba3eb691a3dc78a7 /arch/sparc | |
| parent | 9b3bb86acabe0c05923cea1ed3b0bee9439fef4b (diff) | |
| download | linux-6ec274750c99448c3412bbc10c97ce0c993f8a4e.tar.bz2 | |
sparc64: simple microoptimizations for atomic functions
Simple microoptimizations for sparc64 atomic functions:
Save one instruction by using a delay slot.
Use %g1 instead of %g7, because %g1 is written earlier.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc')
| -rw-r--r-- | arch/sparc/lib/atomic_64.S | 20 |
1 files changed, 8 insertions, 12 deletions
diff --git a/arch/sparc/lib/atomic_64.S b/arch/sparc/lib/atomic_64.S index 0268210ca168..703c9c3935b7 100644 --- a/arch/sparc/lib/atomic_64.S +++ b/arch/sparc/lib/atomic_64.S @@ -52,10 +52,9 @@ atomic_add_ret: /* %o0 = increment, %o1 = atomic_ptr */ cas [%o1], %g1, %g7 cmp %g1, %g7 bne,pn %icc, 2f - add %g7, %o0, %g7 - sra %g7, 0, %o0 + add %g1, %o0, %g1 retl - nop + sra %g1, 0, %o0 2: BACKOFF_SPIN(%o2, %o3, 1b) .size atomic_add_ret, .-atomic_add_ret @@ -68,10 +67,9 @@ atomic_sub_ret: /* %o0 = decrement, %o1 = atomic_ptr */ cas [%o1], %g1, %g7 cmp %g1, %g7 bne,pn %icc, 2f - sub %g7, %o0, %g7 - sra %g7, 0, %o0 + sub %g1, %o0, %g1 retl - nop + sra %g1, 0, %o0 2: BACKOFF_SPIN(%o2, %o3, 1b) .size atomic_sub_ret, .-atomic_sub_ret @@ -114,10 +112,9 @@ atomic64_add_ret: /* %o0 = increment, %o1 = atomic_ptr */ casx [%o1], %g1, %g7 cmp %g1, %g7 bne,pn %xcc, 2f - add %g7, %o0, %g7 - mov %g7, %o0 - retl nop + retl + add %g1, %o0, %o0 2: BACKOFF_SPIN(%o2, %o3, 1b) .size atomic64_add_ret, .-atomic64_add_ret @@ -130,9 +127,8 @@ atomic64_sub_ret: /* %o0 = decrement, %o1 = atomic_ptr */ casx [%o1], %g1, %g7 cmp %g1, %g7 bne,pn %xcc, 2f - sub %g7, %o0, %g7 - mov %g7, %o0 - retl nop + retl + sub %g1, %o0, %o0 2: BACKOFF_SPIN(%o2, %o3, 1b) .size atomic64_sub_ret, .-atomic64_sub_ret |