diff options
| author | Ralf Baechle <ralf@linux-mips.org> | 2006-09-28 04:45:21 +0400 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2007-02-14 01:40:50 +0300 |
| commit | f65e4fa8e0c6022ad58dc88d1b11b12589ed7f9f (patch) | |
| tree | 2405e012e079693e0fcfde9ff981c549d6c68a21 /include/asm-mips/atomic.h | |
| parent | 509cb37e173d4e39cec47238397e91b718730794 (diff) | |
| download | linux-f65e4fa8e0c6022ad58dc88d1b11b12589ed7f9f.tar.xz | |
[MIPS] Improve branch prediction in ll/sc atomic operations.
Now that finally all supported versions of binutils have functioning
support for .subsection use .subsection to tweak the branch prediction
I did not modify the R10000 errata variants because it seems unclear if
this will invalidate the workaround which actually relies on the cheesy
prediction of branch likely to cause a misspredict if the sc was
successful.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'include/asm-mips/atomic.h')
| -rw-r--r-- | include/asm-mips/atomic.h | 50 |
1 files changed, 40 insertions, 10 deletions
diff --git a/include/asm-mips/atomic.h b/include/asm-mips/atomic.h index c1a2409bb52a..8578869a8bcf 100644 --- a/include/asm-mips/atomic.h +++ b/include/asm-mips/atomic.h @@ -69,7 +69,10 @@ static __inline__ void atomic_add(int i, atomic_t * v) "1: ll %0, %1 # atomic_add \n" " addu %0, %2 \n" " sc %0, %1 \n" - " beqz %0, 1b \n" + " beqz %0, 2f \n" + " .subsection 2 \n" + "2: b 1b \n" + " .previous \n" " .set mips0 \n" : "=&r" (temp), "=m" (v->counter) : "Ir" (i), "m" (v->counter)); @@ -111,7 +114,10 @@ static __inline__ void atomic_sub(int i, atomic_t * v) "1: ll %0, %1 # atomic_sub \n" " subu %0, %2 \n" " sc %0, %1 \n" - " beqz %0, 1b \n" + " beqz %0, 2f \n" + " .subsection 2 \n" + "2: b 1b \n" + " .previous \n" " .set mips0 \n" : "=&r" (temp), "=m" (v->counter) : "Ir" (i), "m" (v->counter)); @@ -155,8 +161,11 @@ static __inline__ int atomic_add_return(int i, atomic_t * v) "1: ll %1, %2 # atomic_add_return \n" " addu %0, %1, %3 \n" " sc %0, %2 \n" - " beqz %0, 1b \n" + " beqz %0, 2f \n" " addu %0, %1, %3 \n" + " .subsection 2 \n" + "2: b 1b \n" + " .previous \n" " .set mips0 \n" : "=&r" (result), "=&r" (temp), "=m" (v->counter) : "Ir" (i), "m" (v->counter) @@ -204,8 +213,11 @@ static __inline__ int atomic_sub_return(int i, atomic_t * v) "1: ll %1, %2 # atomic_sub_return \n" " subu %0, %1, %3 \n" " sc %0, %2 \n" - " beqz %0, 1b \n" + " beqz %0, 2f \n" " subu %0, %1, %3 \n" + " .subsection 2 \n" + "2: b 1b \n" + " .previous \n" " .set mips0 \n" : "=&r" (result), "=&r" (temp), "=m" (v->counter) : "Ir" (i), "m" (v->counter) @@ -267,10 +279,13 @@ static __inline__ int atomic_sub_if_positive(int i, atomic_t * v) " bltz %0, 1f \n" " sc %0, %2 \n" " .set noreorder \n" - " beqz %0, 1b \n" + " beqz %0, 2f \n" " subu %0, %1, %3 \n" " .set reorder \n" "1: \n" + " .subsection 2 \n" + "2: b 1b \n" + " .previous \n" " .set mips0 \n" : "=&r" (result), "=&r" (temp), "=m" (v->counter) : "Ir" (i), "m" (v->counter) @@ -429,7 +444,10 @@ static __inline__ void atomic64_add(long i, atomic64_t * v) "1: lld %0, %1 # atomic64_add \n" " addu %0, %2 \n" " scd %0, %1 \n" - " beqz %0, 1b \n" + " beqz %0, 2f \n" + " .subsection 2 \n" + "2: b 1b \n" + " .previous \n" " .set mips0 \n" : "=&r" (temp), "=m" (v->counter) : "Ir" (i), "m" (v->counter)); @@ -471,7 +489,10 @@ static __inline__ void atomic64_sub(long i, atomic64_t * v) "1: lld %0, %1 # atomic64_sub \n" " subu %0, %2 \n" " scd %0, %1 \n" - " beqz %0, 1b \n" + " beqz %0, 2f \n" + " .subsection 2 \n" + "2: b 1b \n" + " .previous \n" " .set mips0 \n" : "=&r" (temp), "=m" (v->counter) : "Ir" (i), "m" (v->counter)); @@ -515,8 +536,11 @@ static __inline__ long atomic64_add_return(long i, atomic64_t * v) "1: lld %1, %2 # atomic64_add_return \n" " addu %0, %1, %3 \n" " scd %0, %2 \n" - " beqz %0, 1b \n" + " beqz %0, 2f \n" " addu %0, %1, %3 \n" + " .subsection 2 \n" + "2: b 1b \n" + " .previous \n" " .set mips0 \n" : "=&r" (result), "=&r" (temp), "=m" (v->counter) : "Ir" (i), "m" (v->counter) @@ -564,8 +588,11 @@ static __inline__ long atomic64_sub_return(long i, atomic64_t * v) "1: lld %1, %2 # atomic64_sub_return \n" " subu %0, %1, %3 \n" " scd %0, %2 \n" - " beqz %0, 1b \n" + " beqz %0, 2f \n" " subu %0, %1, %3 \n" + " .subsection 2 \n" + "2: b 1b \n" + " .previous \n" " .set mips0 \n" : "=&r" (result), "=&r" (temp), "=m" (v->counter) : "Ir" (i), "m" (v->counter) @@ -627,10 +654,13 @@ static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v) " bltz %0, 1f \n" " scd %0, %2 \n" " .set noreorder \n" - " beqz %0, 1b \n" + " beqz %0, 2f \n" " dsubu %0, %1, %3 \n" " .set reorder \n" "1: \n" + " .subsection 2 \n" + "2: b 1b \n" + " .previous \n" " .set mips0 \n" : "=&r" (result), "=&r" (temp), "=m" (v->counter) : "Ir" (i), "m" (v->counter) |