diff options
Diffstat (limited to 'src/libmp/386/mpvecdigmulsub-Darwin.s')
| -rw-r--r-- | src/libmp/386/mpvecdigmulsub-Darwin.s | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/src/libmp/386/mpvecdigmulsub-Darwin.s b/src/libmp/386/mpvecdigmulsub-Darwin.s new file mode 100644 index 00000000..8aef933d --- /dev/null +++ b/src/libmp/386/mpvecdigmulsub-Darwin.s @@ -0,0 +1,70 @@ +/* + * mpvecdigmulsub(mpdigit *b, int n, mpdigit m, mpdigit *p) + * + * p -= b*m + * + * each step look like: + * hi,lo = m*b[i] + * lo += oldhi + carry + * hi += carry + * p[i] += lo + * oldhi = hi + * + * the registers are: + * hi = DX - constrained by hardware + * lo = AX - constrained by hardware + * b = SI - can't be BP + * p = DI - can't be BP + * i = BP + * n = CX - constrained by LOOP instr + * m = BX + * oldhi = EX + * + */ +.text + +.p2align 2,0x90 +.globl _mpvecdigmulsub +_mpvecdigmulsub: + /* Prelude */ + pushl %ebp /* save on stack */ + pushl %ebx + pushl %esi + pushl %edi + + leal 20(%esp), %ebp /* %ebp = FP for now */ + movl 0(%ebp), %esi /* b */ + movl 4(%ebp), %ecx /* n */ + movl 8(%ebp), %ebx /* m */ + movl 12(%ebp), %edi /* p */ + xorl %ebp, %ebp + pushl %ebp +_mulsubloop: + movl (%esi, %ebp, 4),%eax /* lo = b[i] */ + mull %ebx /* hi, lo = b[i] * m */ + addl 0(%esp), %eax /* lo += oldhi */ + jae _mulsubnocarry1 + incl %edx /* hi += carry */ +_mulsubnocarry1: + subl %eax, (%edi, %ebp, 4) + jae _mulsubnocarry2 + incl %edx /* hi += carry */ +_mulsubnocarry2: + movl %edx, 0(%esp) + incl %ebp + loop _mulsubloop + popl %eax + subl %eax, (%edi, %ebp, 4) + jae _mulsubnocarry3 + movl $-1, %eax + jmp done +_mulsubnocarry3: + movl $1, %eax +done: + /* Postlude */ + popl %edi + popl %esi + popl %ebx + popl %ebp + ret + |