diff options
Diffstat (limited to 'sys/arch/m88k/fpu/fpu_implode.c')
| -rw-r--r-- | sys/arch/m88k/fpu/fpu_implode.c | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/sys/arch/m88k/fpu/fpu_implode.c b/sys/arch/m88k/fpu/fpu_implode.c index a2cfe2d8835..91b67ee2093 100644 --- a/sys/arch/m88k/fpu/fpu_implode.c +++ b/sys/arch/m88k/fpu/fpu_implode.c @@ -1,4 +1,4 @@ -/* $OpenBSD: fpu_implode.c,v 1.2 2007/12/25 15:47:16 miod Exp $ */ +/* $OpenBSD: fpu_implode.c,v 1.3 2007/12/26 18:29:33 miod Exp $ */ /* * Copyright (c) 1992, 1993 @@ -186,14 +186,12 @@ toinf(struct fpemu *fe, int sign) /* * fpn -> int (int value returned as return value). - * - * XXX This conversion always rounds towards zero. */ u_int fpu_ftoi(struct fpemu *fe, struct fpn *fp) { u_int i; - int sign, exp; + int sign, exp, sticky, rd; sign = fp->fp_sign; switch (fp->fp_class) { @@ -206,8 +204,8 @@ fpu_ftoi(struct fpemu *fe, struct fpn *fp) * If exp >= 2^32, overflow. Otherwise shift value right * into last mantissa word (this will not exceed 0xffffffff), * shifting any guard and round bits out into the sticky - * bit. Then ``round'' towards zero, i.e., just set an - * inexact exception if sticky is set (see round()). + * bit. + * Then round according to the rounding mode. * If the result is > 0x80000000, or is positive and equals * 0x80000000, overflow; otherwise the last fraction word * is the result. @@ -215,9 +213,15 @@ fpu_ftoi(struct fpemu *fe, struct fpn *fp) if ((exp = fp->fp_exp) >= 32) break; /* NB: the following includes exp < 0 cases */ - if (fpu_shr(fp, FP_NMANT - 1 - exp) != 0) + if ((sticky = fpu_shr(fp, FP_NMANT - 1 - exp)) != 0) fe->fe_fpsr |= FPSR_EFINX; i = fp->fp_mant[3]; + rd = (fe->fe_fpcr >> FPCR_RD_SHIFT) & FPCR_RD_MASK; + if ((rd == FP_RN && sticky != 0) || + (rd == FP_RM && sign != 0) || (rd == FP_RP && sign == 0)) { + /* round up */ + i++; + } if (i >= ((u_int)0x80000000 + sign)) break; return (sign ? -i : i); @@ -225,7 +229,8 @@ fpu_ftoi(struct fpemu *fe, struct fpn *fp) default: /* Inf, qNaN, sNaN */ break; } - /* overflow: replace any inexact exception with invalid */ + + /* Inf or NaN: replace any inexact exception with invalid */ fe->fe_fpsr = (fe->fe_fpsr & ~FPSR_EFINX) | FPSR_EFINV; return (0x7fffffff + sign); } |