diff options
Diffstat (limited to 'src/libmp/386/mpvecadd-Darwin.s')
| -rw-r--r-- | src/libmp/386/mpvecadd-Darwin.s | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/src/libmp/386/mpvecadd-Darwin.s b/src/libmp/386/mpvecadd-Darwin.s new file mode 100644 index 00000000..8d892331 --- /dev/null +++ b/src/libmp/386/mpvecadd-Darwin.s @@ -0,0 +1,70 @@ +/* mpvecadd(mpdigit *a, int alen, mpdigit *b, int blen, mpdigit *sum) */ +/* sum[0:alen] = a[0:alen-1] + b[0:blen-1] */ +/* prereq: alen >= blen, sum has room for alen+1 digits */ +/* (very old gnu assembler doesn't allow multiline comments) */ + +.text + +.p2align 2,0x90 +.globl _mpvecadd +_mpvecadd: + /* Prelude */ + pushl %ebp /* save on stack */ + pushl %ebx + pushl %esi + pushl %edi + + leal 20(%esp), %ebp /* %ebp = FP for now */ + + movl 4(%ebp), %edx /* alen */ + movl 12(%ebp), %ecx /* blen */ + movl 0(%ebp), %esi /* a */ + movl 8(%ebp), %ebx /* b */ + subl %ecx, %edx + movl 16(%ebp), %edi /* sum */ + xorl %ebp, %ebp /* this also sets carry to 0 */ + + /* skip addition if b is zero */ + testl %ecx,%ecx + je _add1 + + /* sum[0:blen-1],carry = a[0:blen-1] + b[0:blen-1] */ +_addloop1: + movl (%esi, %ebp, 4), %eax + adcl (%ebx, %ebp, 4), %eax + movl %eax, (%edi, %ebp, 4) + incl %ebp + loop _addloop1 + +_add1: + /* jump if alen > blen */ + incl %edx + movl %edx, %ecx + loop _addloop2 + + /* sum[alen] = carry */ +_addend: + jb _addcarry + movl $0, (%edi, %ebp, 4) + jmp done + +_addcarry: + movl $1, (%edi, %ebp, 4) + jmp done + + /* sum[blen:alen-1],carry = a[blen:alen-1] + 0 */ +_addloop2: + movl (%esi, %ebp, 4),%eax + adcl $0, %eax + movl %eax, (%edi, %ebp, 4) + incl %ebp + loop _addloop2 + jmp _addend + +done: + /* Postlude */ + popl %edi + popl %esi + popl %ebx + popl %ebp + ret |