diff options
Diffstat (limited to 'lib/msun/src/e_rem_pio2.c')
| -rw-r--r-- | lib/msun/src/e_rem_pio2.c | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/lib/msun/src/e_rem_pio2.c b/lib/msun/src/e_rem_pio2.c index bf8bfe1..be7cd50 100644 --- a/lib/msun/src/e_rem_pio2.c +++ b/lib/msun/src/e_rem_pio2.c @@ -11,7 +11,7 @@ */ #ifndef lint -static char rcsid[] = "$Id: e_rem_pio2.c,v 1.5 1994/08/18 23:05:56 jtc Exp $"; +static char rcsid[] = "$Id: e_rem_pio2.c,v 1.1.1.1 1994/08/19 09:39:44 jkh Exp $"; #endif /* __ieee754_rem_pio2(x,y) @@ -99,6 +99,31 @@ pio2_3t = 8.47842766036889956997e-32; /* 0x397B839A, 0x252049C1 */ ix = hx&0x7fffffff; if(ix<=0x3fe921fb) /* |x| ~<= pi/4 , no need for reduction */ {y[0] = x; y[1] = 0; return 0;} + if(ix<0x4002d97c) { /* |x| < 3pi/4, special case with n=+-1 */ + if(hx>0) { + z = x - pio2_1; + if(ix!=0x3ff921fb) { /* 33+53 bit pi is good enough */ + y[0] = z - pio2_1t; + y[1] = (z-y[0])-pio2_1t; + } else { /* near pi/2, use 33+33+53 bit pi */ + z -= pio2_2; + y[0] = z - pio2_2t; + y[1] = (z-y[0])-pio2_2t; + } + return 1; + } else { /* negative x */ + z = x + pio2_1; + if(ix!=0x3ff921fb) { /* 33+53 bit pi is good enough */ + y[0] = z + pio2_1t; + y[1] = (z-y[0])+pio2_1t; + } else { /* near pi/2, use 33+33+53 bit pi */ + z += pio2_2; + y[0] = z + pio2_2t; + y[1] = (z-y[0])+pio2_2t; + } + return -1; + } + } if(ix<=0x413921fb) { /* |x| ~<= 2^19*(pi/2), medium size */ t = fabs(x); n = (int32_t) (t*invpio2+half); |
