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runtime: native xadd for 386/amd64

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benchmark                          old ns/op    new ns/op    delta
BenchmarkSemaUncontended               37.40        34.10   -8.82%
BenchmarkSemaUncontended-2             18.90        17.70   -6.35%
BenchmarkSemaUncontended-4             11.90        10.90   -8.40%
BenchmarkSemaUncontended-8              6.26         5.19  -17.09%
BenchmarkSemaUncontended-16             4.39         3.91  -10.93%
BenchmarkSemaSyntNonblock              38.00        35.30   -7.11%
BenchmarkSemaSyntNonblock-2            83.00        46.70  -43.73%
BenchmarkSemaSyntNonblock-4           124.00       101.00  -18.55%
BenchmarkSemaSyntNonblock-8           124.00       116.00   -6.45%
BenchmarkSemaSyntNonblock-16          148.00       114.00  -22.97%

(on HP Z600 2 x Xeon E5620, 8 HT cores, 2.40GHz)

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/4755041
This commit is contained in:
Dmitriy Vyukov 2011-07-15 11:27:16 -04:00 committed by Russ Cox
parent 8cf8806d31
commit 491aa1579d
4 changed files with 41 additions and 14 deletions
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13
src/pkg/runtime/386/asm.s
View File

@ -318,6 +318,19 @@ TEXT runtime·casp(SB), 7, $0
MOVL $1, AX
RET
// uint32 xadd(uint32 volatile *val, int32 delta)
// Atomically:
// *val += delta;
// return *val;
TEXT runtime·xadd(SB), 7, $0
MOVL 4(SP), BX
MOVL 8(SP), AX
MOVL AX, CX
LOCK
XADDL AX, 0(BX)
ADDL CX, AX
RET
TEXT runtime·atomicstorep(SB), 7, $0
MOVL 4(SP), BX
MOVL 8(SP), AX

13
src/pkg/runtime/amd64/asm.s
View File

@ -364,6 +364,19 @@ TEXT runtime·casp(SB), 7, $0
MOVL $1, AX
RET
// uint32 xadd(uint32 volatile *val, int32 delta)
// Atomically:
// *val += delta;
// return *val;
TEXT runtime·xadd(SB), 7, $0
MOVQ 8(SP), BX
MOVL 16(SP), AX
MOVL AX, CX
LOCK
XADDL AX, 0(BX)
ADDL CX, AX
RET
TEXT runtime·atomicstorep(SB), 7, $0
MOVQ 8(SP), BX
MOVQ 16(SP), AX

15
src/pkg/runtime/arm/atomic.c
View File

@ -4,6 +4,21 @@
#include "runtime.h"
// Atomic add and return new value.
#pragma textflag 7
uint32
runtime·xadd(uint32 volatile *val, int32 delta)
{
uint32 oval, nval;
for(;;){
oval = *val;
nval = oval + delta;
if(runtime·cas(val, oval, nval))
return nval;
}
}
#pragma textflag 7
uint32
runtime·atomicload(uint32 volatile* addr)

14
src/pkg/runtime/runtime.c
View File

@ -207,20 +207,6 @@ runtime·goenvs_unix(void)
os·Envs.cap = n;
}
// Atomic add and return new value.
uint32
runtime·xadd(uint32 volatile *val, int32 delta)
{
uint32 oval, nval;
for(;;){
oval = *val;
nval = oval + delta;
if(runtime·cas(val, oval, nval))
return nval;
}
}
byte*
runtime·getenv(int8 *s)
{