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Diffstat (limited to 'v_windows/v/vlib/math/pow.v')
-rw-r--r-- | v_windows/v/vlib/math/pow.v | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/v_windows/v/vlib/math/pow.v b/v_windows/v/vlib/math/pow.v new file mode 100644 index 0000000..bc8034b --- /dev/null +++ b/v_windows/v/vlib/math/pow.v @@ -0,0 +1,37 @@ +module math + +const ( + pow10tab = [f64(1e+00), 1e+01, 1e+02, 1e+03, 1e+04, 1e+05, 1e+06, 1e+07, 1e+08, 1e+09, + 1e+10, 1e+11, 1e+12, 1e+13, 1e+14, 1e+15, 1e+16, 1e+17, 1e+18, 1e+19, 1e+20, 1e+21, 1e+22, + 1e+23, 1e+24, 1e+25, 1e+26, 1e+27, 1e+28, 1e+29, 1e+30, 1e+31] + pow10postab32 = [f64(1e+00), 1e+32, 1e+64, 1e+96, 1e+128, 1e+160, 1e+192, 1e+224, 1e+256, 1e+288] + pow10negtab32 = [f64(1e-00), 1e-32, 1e-64, 1e-96, 1e-128, 1e-160, 1e-192, 1e-224, 1e-256, 1e-288, + 1e-320, + ] +) + +// powf returns base raised to the provided power. (float32) +[inline] +pub fn powf(a f32, b f32) f32 { + return f32(pow(a, b)) +} + +// pow10 returns 10**n, the base-10 exponential of n. +// +// special cases are: +// pow10(n) = 0 for n < -323 +// pow10(n) = +inf for n > 308 +pub fn pow10(n int) f64 { + if 0 <= n && n <= 308 { + return math.pow10postab32[u32(n) / 32] * math.pow10tab[u32(n) % 32] + } + if -323 <= n && n <= 0 { + return math.pow10negtab32[u32(-n) / 32] / math.pow10tab[u32(-n) % 32] + } + // n < -323 || 308 < n + if n > 0 { + return inf(1) + } + // n < -323 + return 0.0 +} |