diff options
Diffstat (limited to 'libkern/memcpy-386.s')
| -rw-r--r-- | libkern/memcpy-386.s | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/libkern/memcpy-386.s b/libkern/memcpy-386.s new file mode 100644 index 00000000..e85bb232 --- /dev/null +++ b/libkern/memcpy-386.s @@ -0,0 +1,58 @@ + TEXT memmove(SB), $0 + TEXT memcpy(SB), $0 + + MOVL p1+0(FP), DI + MOVL p2+4(FP), SI + MOVL n+8(FP), BX + CMPL BX, $0 + JGE ok + MOVL $0, SI +ok: + CLD +/* + * check and set for backwards + */ + CMPL SI, DI + JLS back +/* + * copy whole longs + */ + MOVL BX, CX + SHRL $2, CX + REP; MOVSL +/* + * copy the rest, by bytes + */ + ANDL $3, BX + MOVL BX, CX + REP; MOVSB + + MOVL p+0(FP),AX + RET +/* + * whole thing backwards has + * adjusted addresses + */ +back: + ADDL BX, DI + ADDL BX, SI + SUBL $4, DI + SUBL $4, SI + STD +/* + * copy whole longs + */ + MOVL BX, CX + SHRL $2, CX + ANDL $3, BX + REP; MOVSL +/* + * copy the rest, by bytes + */ + ADDL $3, DI + ADDL $3, SI + MOVL BX, CX + REP; MOVSB + + MOVL p+0(FP),AX + RET |