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authorIndrajith K L2022-12-03 17:00:20 +0530
committerIndrajith K L2022-12-03 17:00:20 +0530
commitf5c4671bfbad96bf346bd7e9a21fc4317b4959df (patch)
tree2764fc62da58f2ba8da7ed341643fc359873142f /v_windows/v/vlib/math/bits.v
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Adds most of the toolsHEADmaster
Diffstat (limited to 'v_windows/v/vlib/math/bits.v')
-rw-r--r--v_windows/v/vlib/math/bits.v63
1 files changed, 63 insertions, 0 deletions
diff --git a/v_windows/v/vlib/math/bits.v b/v_windows/v/vlib/math/bits.v
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+// Copyright (c) 2019-2021 Alexander Medvednikov. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+module math
+
+const (
+ uvnan = u64(0x7FF8000000000001)
+ uvinf = u64(0x7FF0000000000000)
+ uvneginf = u64(0xFFF0000000000000)
+ uvone = u64(0x3FF0000000000000)
+ mask = 0x7FF
+ shift = 64 - 11 - 1
+ bias = 1023
+ normalize_smallest_mask = (u64(1) << 52)
+ sign_mask = (u64(1) << 63)
+ frac_mask = ((u64(1) << u64(shift)) - u64(1))
+)
+
+// inf returns positive infinity if sign >= 0, negative infinity if sign < 0.
+pub fn inf(sign int) f64 {
+ v := if sign >= 0 { math.uvinf } else { math.uvneginf }
+ return f64_from_bits(v)
+}
+
+// nan returns an IEEE 754 ``not-a-number'' value.
+pub fn nan() f64 {
+ return f64_from_bits(math.uvnan)
+}
+
+// is_nan reports whether f is an IEEE 754 ``not-a-number'' value.
+pub fn is_nan(f f64) bool {
+ // IEEE 754 says that only NaNs satisfy f != f.
+ // To avoid the floating-point hardware, could use:
+ // x := f64_bits(f);
+ // return u32(x>>shift)&mask == mask && x != uvinf && x != uvneginf
+ return f != f
+}
+
+// is_inf reports whether f is an infinity, according to sign.
+// If sign > 0, is_inf reports whether f is positive infinity.
+// If sign < 0, is_inf reports whether f is negative infinity.
+// If sign == 0, is_inf reports whether f is either infinity.
+pub fn is_inf(f f64, sign int) bool {
+ // Test for infinity by comparing against maximum float.
+ // To avoid the floating-point hardware, could use:
+ // x := f64_bits(f);
+ // return sign >= 0 && x == uvinf || sign <= 0 && x == uvneginf;
+ return (sign >= 0 && f > max_f64) || (sign <= 0 && f < -max_f64)
+}
+
+pub fn is_finite(f f64) bool {
+ return !is_nan(f) && !is_inf(f, 0)
+}
+
+// normalize returns a normal number y and exponent exp
+// satisfying x == y × 2**exp. It assumes x is finite and non-zero.
+pub fn normalize(x f64) (f64, int) {
+ smallest_normal := 2.2250738585072014e-308 // 2**-1022
+ if abs(x) < smallest_normal {
+ return x * math.normalize_smallest_mask, -52
+ }
+ return x, 0
+}