diff options
Diffstat (limited to 'libkern/memset-68000.s')
| -rw-r--r-- | libkern/memset-68000.s | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/libkern/memset-68000.s b/libkern/memset-68000.s new file mode 100644 index 00000000..318f61a7 --- /dev/null +++ b/libkern/memset-68000.s @@ -0,0 +1,57 @@ + TEXT memset(SB), $0 + MOVL n+8(FP), R0 + BLE return + MOVL s1+0(FP), A1 + CLRL R1 + MOVB c+7(FP), R1 + BEQ l1 + +/* + * create 4 replicated copies + * of the byte in R1 + */ + MOVL R1, R2 + ASLL $8, R2 + ORL R2, R1 + MOVL R1, R2 + SWAP R2 + ORL R2, R1 + +/* + * byte-at-a-time until alligned + */ +l1: + MOVL A1, R1 + ANDL $3, R1 + BEQ l2 + SUBL $1, R0 + BLT return + MOVB R1, (A1)+ + BRA l1 + +/* + * quad-long-at-a-time set + */ +l2: + SUBL $16, R0 + BLT l3 + MOVL R1, (A1)+ + MOVL R1, (A1)+ + MOVL R1, (A1)+ + MOVL R1, (A1)+ + BRA l2 + +/* + * cleanup byte-at-a-time + */ +l3: + ADDL $15, R0 + BLT return +l4: + MOVB R1, (A1)+ + SUBL $1, R0 + BGE l4 + +return: + MOVL s1+0(FP),R0 + RTS |