diff options
Diffstat (limited to 'libkern/memmove-mips.s')
| -rw-r--r-- | libkern/memmove-mips.s | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/libkern/memmove-mips.s b/libkern/memmove-mips.s new file mode 100644 index 00000000..c14d2a82 --- /dev/null +++ b/libkern/memmove-mips.s @@ -0,0 +1,237 @@ + TEXT memmove(SB), $0 + + JMP move + + TEXT memcpy(SB), $0 +move: + MOVW R1, s1+0(FP) + + MOVW n+8(FP), R3 /* R3 is count */ + MOVW R1, R4 /* R4 is to-pointer */ + SGT R0, R3, R5 + BEQ R5, ok + MOVW (R0), R0 /* abort if negative count */ +ok: + MOVW s2+4(FP), R5 /* R5 is from-pointer */ + ADDU R3,R5, R7 /* R7 is end from-pointer */ + ADDU R3,R4, R6 /* R6 is end to-pointer */ + +/* + * easiest test is copy backwards if + * destination string has higher mem address + */ + SGT $4,R3, R2 + SGTU R4,R5, R1 + BNE R1, back + +/* + * if not at least 4 chars, + * don't even mess around. + * 3 chars to guarantee any + * rounding up to a word + * boundary and 4 characters + * to get at least maybe one + * full word store. + */ + BNE R2, fout + + +/* + * byte at a time to word align destination + */ +f1: + AND $3,R4, R1 + BEQ R1, f2 + MOVB 0(R5), R8 + ADDU $1, R5 + MOVB R8, 0(R4) + ADDU $1, R4 + JMP f1 + +/* + * test if source is now word aligned + */ +f2: + AND $3, R5, R1 + BNE R1, fun2 +/* + * turn R3 into to-end pointer-15 + * copy 16 at a time while theres room. + * R6 is smaller than R7 -- + * there are problems if R7 is 0. + */ + ADDU $-15,R6, R3 +f3: + SGTU R3,R4, R1 + BEQ R1, f4 + MOVW 0(R5), R8 + MOVW 4(R5), R9 + MOVW R8, 0(R4) + MOVW 8(R5), R8 + MOVW R9, 4(R4) + MOVW 12(R5), R9 + ADDU $16, R5 + MOVW R8, 8(R4) + MOVW R9, 12(R4) + ADDU $16, R4 + JMP f3 + +/* + * turn R3 into to-end pointer-3 + * copy 4 at a time while theres room + */ +f4: + ADDU $-3,R6, R3 +f5: + SGTU R3,R4, R1 + BEQ R1, fout + MOVW 0(R5), R8 + ADDU $4, R5 + MOVW R8, 0(R4) + ADDU $4, R4 + JMP f5 + +/* + * forward copy, unaligned + * turn R3 into to-end pointer-15 + * copy 16 at a time while theres room. + * R6 is smaller than R7 -- + * there are problems if R7 is 0. + */ +fun2: + ADDU $-15,R6, R3 +fun3: + SGTU R3,R4, R1 + BEQ R1, fun4 + MOVWL 0(R5), R8 + MOVWR 3(R5), R8 + MOVWL 4(R5), R9 + MOVWR 7(R5), R9 + MOVW R8, 0(R4) + MOVWL 8(R5), R8 + MOVWR 11(R5), R8 + MOVW R9, 4(R4) + MOVWL 12(R5), R9 + MOVWR 15(R5), R9 + ADDU $16, R5 + MOVW R8, 8(R4) + MOVW R9, 12(R4) + ADDU $16, R4 + JMP fun3 + +/* + * turn R3 into to-end pointer-3 + * copy 4 at a time while theres room + */ +fun4: + ADDU $-3,R6, R3 +fun5: + SGTU R3,R4, R1 + BEQ R1, fout + MOVWL 0(R5), R8 + MOVWR 3(R5), R8 + ADDU $4, R5 + MOVW R8, 0(R4) + ADDU $4, R4 + JMP fun5 + +/* + * last loop, copy byte at a time + */ +fout: + BEQ R7,R5, ret + MOVB 0(R5), R8 + ADDU $1, R5 + MOVB R8, 0(R4) + ADDU $1, R4 + JMP fout + +/* + * whole thing repeated for backwards + */ +back: + BNE R2, bout +b1: + AND $3,R6, R1 + BEQ R1, b2 + MOVB -1(R7), R8 + ADDU $-1, R7 + MOVB R8, -1(R6) + ADDU $-1, R6 + JMP b1 + +b2: + AND $3, R7, R1 + BNE R1, bun2 + + ADDU $15,R5, R3 +b3: + SGTU R7,R3, R1 + BEQ R1, b4 + MOVW -4(R7), R8 + MOVW -8(R7), R9 + MOVW R8, -4(R6) + MOVW -12(R7), R8 + MOVW R9, -8(R6) + MOVW -16(R7), R9 + ADDU $-16, R7 + MOVW R8, -12(R6) + MOVW R9, -16(R6) + ADDU $-16, R6 + JMP b3 +b4: + ADDU $3,R5, R3 +b5: + SGTU R7,R3, R1 + BEQ R1, bout + MOVW -4(R7), R8 + ADDU $-4, R7 + MOVW R8, -4(R6) + ADDU $-4, R6 + JMP b5 + +bun2: + ADDU $15,R5, R3 +bun3: + SGTU R7,R3, R1 + BEQ R1, bun4 + MOVWL -4(R7), R8 + MOVWR -1(R7), R8 + MOVWL -8(R7), R9 + MOVWR -5(R7), R9 + MOVW R8, -4(R6) + MOVWL -12(R7), R8 + MOVWR -9(R7), R8 + MOVW R9, -8(R6) + MOVWL -16(R7), R9 + MOVWR -13(R7), R9 + ADDU $-16, R7 + MOVW R8, -12(R6) + MOVW R9, -16(R6) + ADDU $-16, R6 + JMP bun3 + +bun4: + ADDU $3,R5, R3 +bun5: + SGTU R7,R3, R1 + BEQ R1, bout + MOVWL -4(R7), R8 + MOVWR -1(R7), R8 + ADDU $-4, R7 + MOVW R8, -4(R6) + ADDU $-4, R6 + JMP bun5 + +bout: + BEQ R7,R5, ret + MOVB -1(R7), R8 + ADDU $-1, R7 + MOVB R8, -1(R6) + ADDU $-1, R6 + JMP bout + +ret: + MOVW s1+0(FP), R1 + RET + END |