/* * linux/kernel/math/mul.c * * (C) 1991 Linus Torvalds */ /* * temporary real multiplication routine. */ #include <linux/math_emu.h> static void shift(int * c) { __asm__("movl (%0),%%eax ; addl %%eax,(%0)\n\t" "movl 4(%0),%%eax ; adcl %%eax,4(%0)\n\t" "movl 8(%0),%%eax ; adcl %%eax,8(%0)\n\t" "movl 12(%0),%%eax ; adcl %%eax,12(%0)" ::"r" ((long) c):"ax"); } static void mul64(const temp_real * a, const temp_real * b, int * c) { __asm__("movl (%0),%%eax\n\t" "mull (%1)\n\t" "movl %%eax,(%2)\n\t" "movl %%edx,4(%2)\n\t" "movl 4(%0),%%eax\n\t" "mull 4(%1)\n\t" "movl %%eax,8(%2)\n\t" "movl %%edx,12(%2)\n\t" "movl (%0),%%eax\n\t" "mull 4(%1)\n\t" "addl %%eax,4(%2)\n\t" "adcl %%edx,8(%2)\n\t" "adcl $0,12(%2)\n\t" "movl 4(%0),%%eax\n\t" "mull (%1)\n\t" "addl %%eax,4(%2)\n\t" "adcl %%edx,8(%2)\n\t" "adcl $0,12(%2)" ::"S" ((long) a),"c" ((long) b),"D" ((long) c) :"ax","dx"); } void fmul(const temp_real * src1, const temp_real * src2, temp_real * result) { int i,sign; int tmp[4] = {0,0,0,0}; sign = (src1->exponent ^ src2->exponent) & 0x8000; i = (src1->exponent & 0x7fff) + (src2->exponent & 0x7fff) - 16383 + 1; if (i<0) { result->exponent = sign; result->a = result->b = 0; return; } if (i>0x7fff) { set_OE(); return; } mul64(src1,src2,tmp); if (tmp[0] || tmp[1] || tmp[2] || tmp[3]) while (i && tmp[3] >= 0) { i--; shift(tmp); } else i = 0; result->exponent = i | sign; result->a = tmp[2]; result->b = tmp[3]; }