diff options
Diffstat (limited to 'arch/mips/math-emu/dp_mul.c')
| -rw-r--r-- | arch/mips/math-emu/dp_mul.c | 132 |
1 files changed, 64 insertions, 68 deletions
diff --git a/arch/mips/math-emu/dp_mul.c b/arch/mips/math-emu/dp_mul.c index 74bc8101749..d3acdedb5b9 100644 --- a/arch/mips/math-emu/dp_mul.c +++ b/arch/mips/math-emu/dp_mul.c @@ -5,8 +5,6 @@ * MIPS floating point support * Copyright (C) 1994-2000 Algorithmics Ltd. * - * ######################################################################## - * * This program is free software; you can distribute it and/or modify it * under the terms of the GNU General Public License (Version 2) as * published by the Free Software Foundation. @@ -18,16 +16,25 @@ * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., - * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA. - * - * ######################################################################## + * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. */ - #include "ieee754dp.h" union ieee754dp ieee754dp_mul(union ieee754dp x, union ieee754dp y) { + int re; + int rs; + u64 rm; + unsigned lxm; + unsigned hxm; + unsigned lym; + unsigned hym; + u64 lrm; + u64 hrm; + u64 t; + u64 at; + COMPXDP; COMPYDP; @@ -68,8 +75,9 @@ union ieee754dp ieee754dp_mul(union ieee754dp x, union ieee754dp y) return x; - /* Infinity handling */ - + /* + * Infinity handling + */ case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_ZERO): case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_INF): ieee754_setcx(IEEE754_INVALID_OPERATION); @@ -107,71 +115,59 @@ union ieee754dp ieee754dp_mul(union ieee754dp x, union ieee754dp y) /* rm = xm * ym, re = xe+ye basically */ assert(xm & DP_HIDDEN_BIT); assert(ym & DP_HIDDEN_BIT); - { - int re = xe + ye; - int rs = xs ^ ys; - u64 rm; - /* shunt to top of word */ - xm <<= 64 - (DP_FBITS + 1); - ym <<= 64 - (DP_FBITS + 1); + re = xe + ye; + rs = xs ^ ys; + + /* shunt to top of word */ + xm <<= 64 - (DP_FBITS + 1); + ym <<= 64 - (DP_FBITS + 1); - /* multiply 32bits xm,ym to give high 32bits rm with stickness - */ + /* + * Multiply 32 bits xm, ym to give high 32 bits rm with stickness. + */ - /* 32 * 32 => 64 */ + /* 32 * 32 => 64 */ #define DPXMULT(x, y) ((u64)(x) * (u64)y) - { - unsigned lxm = xm; - unsigned hxm = xm >> 32; - unsigned lym = ym; - unsigned hym = ym >> 32; - u64 lrm; - u64 hrm; - - lrm = DPXMULT(lxm, lym); - hrm = DPXMULT(hxm, hym); - - { - u64 t = DPXMULT(lxm, hym); - { - u64 at = - lrm + (t << 32); - hrm += at < lrm; - lrm = at; - } - hrm = hrm + (t >> 32); - } - - { - u64 t = DPXMULT(hxm, lym); - { - u64 at = - lrm + (t << 32); - hrm += at < lrm; - lrm = at; - } - hrm = hrm + (t >> 32); - } - rm = hrm | (lrm != 0); - } - - /* - * sticky shift down to normal rounding precision - */ - if ((s64) rm < 0) { - rm = - (rm >> (64 - (DP_FBITS + 1 + 3))) | - ((rm << (DP_FBITS + 1 + 3)) != 0); + lxm = xm; + hxm = xm >> 32; + lym = ym; + hym = ym >> 32; + + lrm = DPXMULT(lxm, lym); + hrm = DPXMULT(hxm, hym); + + t = DPXMULT(lxm, hym); + + at = lrm + (t << 32); + hrm += at < lrm; + lrm = at; + + hrm = hrm + (t >> 32); + + t = DPXMULT(hxm, lym); + + at = lrm + (t << 32); + hrm += at < lrm; + lrm = at; + + hrm = hrm + (t >> 32); + + rm = hrm | (lrm != 0); + + /* + * Sticky shift down to normal rounding precision. + */ + if ((s64) rm < 0) { + rm = (rm >> (64 - (DP_FBITS + 1 + 3))) | + ((rm << (DP_FBITS + 1 + 3)) != 0); re++; - } else { - rm = - (rm >> (64 - (DP_FBITS + 1 + 3 + 1))) | - ((rm << (DP_FBITS + 1 + 3 + 1)) != 0); - } - assert(rm & (DP_HIDDEN_BIT << 3)); - - return ieee754dp_format(rs, re, rm); + } else { + rm = (rm >> (64 - (DP_FBITS + 1 + 3 + 1))) | + ((rm << (DP_FBITS + 1 + 3 + 1)) != 0); } + assert(rm & (DP_HIDDEN_BIT << 3)); + + return ieee754dp_format(rs, re, rm); } |