diff options
Diffstat (limited to 'runtime/powerpc/i64_smod.s')
| -rw-r--r-- | runtime/powerpc/i64_smod.s | 29 |
1 files changed, 17 insertions, 12 deletions
diff --git a/runtime/powerpc/i64_smod.s b/runtime/powerpc/i64_smod.s index 320571d..df6bfd8 100644 --- a/runtime/powerpc/i64_smod.s +++ b/runtime/powerpc/i64_smod.s @@ -41,23 +41,28 @@ .balign 16 .globl __i64_smod __i64_smod: - mflr r11 # save return address - srawi r12, r3, 31 # save sign of result in r12 (sign of N) - xor r4, r4, r12 # and take absolute value of N - xor r3, r3, r12 - subfc r4, r12, r4 - subfe r3, r12, r3 + mflr r0 + stw r0, 4(r1) # save return address in caller's frame + mtctr r3 # save sign of result in CTR (sign of N) + srawi r0, r3, 31 # take absolute value of N + xor r4, r4, r0 # (i.e. N = N ^ r0 - r0, + xor r3, r3, r0 # where r0 = 0 if N >= 0 and r0 = -1 if N < 0) + subfc r4, r0, r4 + subfe r3, r0, r3 srawi r0, r5, 31 # take absolute value of D - xor r6, r6, r0 + xor r6, r6, r0 # (same trick) xor r5, r5, r0 subfc r6, r0, r6 subfe r5, r0, r5 bl __i64_udivmod # do unsigned division - mtlr r11 # restore return address - xor r4, r4, r12 # apply expected sign to remainder - xor r3, r3, r12 # RES = R if r12 == 0, -R if r12 == -1 - subfc r4, r12, r4 - subfe r3, r12, r3 + lwz r0, 4(r1) + mtlr r0 # restore return address + mfctr r0 + srawi r0, r0, 31 # apply expected sign to remainder + xor r4, r4, r0 # RES = R if CTR >= 0, -Q if CTR < 0 + xor r3, r3, r0 + subfc r4, r0, r4 + subfe r3, r0, r3 blr .type __i64_smod, @function .size __i64_smod, .-__i64_smod |