diff options
Diffstat (limited to 'lib/msun/src/s_sinf.c')
| -rw-r--r-- | lib/msun/src/s_sinf.c | 45 |
1 files changed, 41 insertions, 4 deletions
diff --git a/lib/msun/src/s_sinf.c b/lib/msun/src/s_sinf.c index 7ddb8b6..cac6e26 100644 --- a/lib/msun/src/s_sinf.c +++ b/lib/msun/src/s_sinf.c @@ -20,25 +20,62 @@ static char rcsid[] = "$FreeBSD$"; #include "math.h" #include "math_private.h" +/* Small multiples of pi/2 rounded to double precision. */ +static const double +s1pio2 = 1*M_PI_2, /* 0x3FF921FB, 0x54442D18 */ +s2pio2 = 2*M_PI_2, /* 0x400921FB, 0x54442D18 */ +s3pio2 = 3*M_PI_2, /* 0x4012D97C, 0x7F3321D2 */ +s4pio2 = 4*M_PI_2; /* 0x401921FB, 0x54442D18 */ + +static inline float +__kernel_cosdf(double x) +{ + return __kernel_cosf((float)x, x - (float)x); +} + +static inline float +__kernel_sindf(double x) +{ + return __kernel_sinf((float)x, x - (float)x, 1); +} + float sinf(float x) { float y[2]; - int32_t n, ix; + int32_t n, hx, ix; - GET_FLOAT_WORD(ix,x); - ix &= 0x7fffffff; + GET_FLOAT_WORD(hx,x); + ix = hx & 0x7fffffff; if(ix <= 0x3f490fda) { /* |x| ~<= pi/4 */ if(ix<0x39800000) /* |x| < 2**-12 */ if(((int)x)==0) return x; /* x with inexact if x != 0 */ return __kernel_sinf(x,0.0,0); } + if(ix<=0x407b53d1) { /* |x| <= ~5*pi/4 */ + if(ix<=0x4016cbe3) { /* |x| <= ~3pi/4 */ + if(hx>0) + return __kernel_cosdf(x - s1pio2); + else + return -__kernel_cosdf(x + s1pio2); + } else + return -__kernel_sindf(x + (hx > 0 ? -s2pio2 : s2pio2)); + } + if(ix<=0x40e231d5) { /* |x| <= ~9*pi/4 */ + if(ix<=0x40afeddf) { /* |x| <= ~7*pi/4 */ + if(hx>0) + return -__kernel_cosdf(x - s3pio2); + else + return __kernel_cosdf(x + s3pio2); + } else + return __kernel_sindf(x + (hx > 0 ? -s4pio2 : s4pio2)); + } /* sin(Inf or NaN) is NaN */ else if (ix>=0x7f800000) return x-x; - /* argument reduction needed */ + /* general argument reduction needed */ else { n = __ieee754_rem_pio2f(x,y); switch(n&3) { |
