diff options
Diffstat (limited to 'newlib/libm/mathfp/sf_pow.c')
-rw-r--r-- | newlib/libm/mathfp/sf_pow.c | 68 |
1 files changed, 25 insertions, 43 deletions
diff --git a/newlib/libm/mathfp/sf_pow.c b/newlib/libm/mathfp/sf_pow.c index 489a71dd0..2b3bed3c7 100644 --- a/newlib/libm/mathfp/sf_pow.c +++ b/newlib/libm/mathfp/sf_pow.c @@ -6,68 +6,57 @@ float powf (float x, float y) { - float d, k, t, r = 1.0; - int n, sign, exponent_is_even_int = 0; + float d, t, r = 1.0; + int n, k, sign = 0; __int32_t px; GET_FLOAT_WORD (px, x); k = modff (y, &d); - if (k == 0.0) { - /* Exponent y is an integer. */ if (modff (ldexpf (y, -1), &t)) - { - /* y is odd. */ - exponent_is_even_int = 0; - } + sign = 0; else - { - /* y is even. */ - exponent_is_even_int = 1; - } + sign = 1; } - if (x == 0.0) - { - if (y <= 0.0) - errno = EDOM; - } + if (x == 0.0 && y <= 0.0) + errno = EDOM; + else if ((t = y * log (fabsf (x))) >= BIGX) { errno = ERANGE; if (px & 0x80000000) { - /* x is negative. */ - if (k) + if (!k) { - /* y is not an integer. */ errno = EDOM; x = 0.0; } - else if (exponent_is_even_int) - x = z_infinity_f.f; - else + else if (sign) x = -z_infinity_f.f; + else + x = z_infinity_f.f; } - else - { - x = z_infinity_f.f; - } - } + + else + x = z_infinity_f.f; + } + else if (t < SMALLX) { errno = ERANGE; x = 0.0; } + else { - if ( !k && fabsf (d) <= 32767 ) + if ( k && fabsf (d) <= 32767 ) { n = (int) d; - if ((sign = (n < 0))) + if (sign = (n < 0)) n = -n; while ( n > 0 ) @@ -83,14 +72,13 @@ float powf (float x, float y) return r; } + else { if ( px & 0x80000000 ) { - /* x is negative. */ - if (k) + if ( !k ) { - /* y is not an integer. */ errno = EDOM; return 0.0; } @@ -98,19 +86,13 @@ float powf (float x, float y) x = exp (t); - if (!exponent_is_even_int) + if ( sign ) { - if (px & 0x80000000) - { - /* y is an odd integer, and x is negative, - so the result is negative. */ - GET_FLOAT_WORD (px, x); - px |= 0x80000000; - SET_FLOAT_WORD (x, px); - } + px ^= 0x80000000; + SET_FLOAT_WORD (x, px); } } - } + } return x; } |