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Diffstat (limited to 'lib/std/math/sin.zig')
| -rw-r--r-- | lib/std/math/sin.zig | 168 |
1 files changed, 0 insertions, 168 deletions
diff --git a/lib/std/math/sin.zig b/lib/std/math/sin.zig deleted file mode 100644 index cf663b1d9e..0000000000 --- a/lib/std/math/sin.zig +++ /dev/null @@ -1,168 +0,0 @@ -// Ported from musl, which is licensed under the MIT license: -// https://git.musl-libc.org/cgit/musl/tree/COPYRIGHT -// -// https://git.musl-libc.org/cgit/musl/tree/src/math/sinf.c -// https://git.musl-libc.org/cgit/musl/tree/src/math/sin.c -// -const std = @import("../std.zig"); -const math = std.math; -const expect = std.testing.expect; - -const kernel = @import("__trig.zig"); -const __rem_pio2 = @import("__rem_pio2.zig").__rem_pio2; -const __rem_pio2f = @import("__rem_pio2f.zig").__rem_pio2f; - -/// Returns the sine of the radian value x. -/// -/// Special Cases: -/// - sin(+-0) = +-0 -/// - sin(+-inf) = nan -/// - sin(nan) = nan -pub fn sin(x: anytype) @TypeOf(x) { - const T = @TypeOf(x); - return switch (T) { - f32 => sin32(x), - f64 => sin64(x), - else => @compileError("sin not implemented for " ++ @typeName(T)), - }; -} - -fn sin32(x: f32) f32 { - // Small multiples of pi/2 rounded to double precision. - const s1pio2: f64 = 1.0 * math.pi / 2.0; // 0x3FF921FB, 0x54442D18 - const s2pio2: f64 = 2.0 * math.pi / 2.0; // 0x400921FB, 0x54442D18 - const s3pio2: f64 = 3.0 * math.pi / 2.0; // 0x4012D97C, 0x7F3321D2 - const s4pio2: f64 = 4.0 * math.pi / 2.0; // 0x401921FB, 0x54442D18 - - var ix = @bitCast(u32, x); - const sign = ix >> 31 != 0; - ix &= 0x7fffffff; - - if (ix <= 0x3f490fda) { // |x| ~<= pi/4 - if (ix < 0x39800000) { // |x| < 2**-12 - // raise inexact if x!=0 and underflow if subnormal - math.doNotOptimizeAway(if (ix < 0x00800000) x / 0x1p120 else x + 0x1p120); - return x; - } - return kernel.__sindf(x); - } - if (ix <= 0x407b53d1) { // |x| ~<= 5*pi/4 - if (ix <= 0x4016cbe3) { // |x| ~<= 3pi/4 - if (sign) { - return -kernel.__cosdf(x + s1pio2); - } else { - return kernel.__cosdf(x - s1pio2); - } - } - return kernel.__sindf(if (sign) -(x + s2pio2) else -(x - s2pio2)); - } - if (ix <= 0x40e231d5) { // |x| ~<= 9*pi/4 - if (ix <= 0x40afeddf) { // |x| ~<= 7*pi/4 - if (sign) { - return kernel.__cosdf(x + s3pio2); - } else { - return -kernel.__cosdf(x - s3pio2); - } - } - return kernel.__sindf(if (sign) x + s4pio2 else x - s4pio2); - } - - // sin(Inf or NaN) is NaN - if (ix >= 0x7f800000) { - return x - x; - } - - var y: f64 = undefined; - const n = __rem_pio2f(x, &y); - return switch (n & 3) { - 0 => kernel.__sindf(y), - 1 => kernel.__cosdf(y), - 2 => kernel.__sindf(-y), - else => -kernel.__cosdf(y), - }; -} - -fn sin64(x: f64) f64 { - var ix = @bitCast(u64, x) >> 32; - ix &= 0x7fffffff; - - // |x| ~< pi/4 - if (ix <= 0x3fe921fb) { - if (ix < 0x3e500000) { // |x| < 2**-26 - // raise inexact if x != 0 and underflow if subnormal - math.doNotOptimizeAway(if (ix < 0x00100000) x / 0x1p120 else x + 0x1p120); - return x; - } - return kernel.__sin(x, 0.0, 0); - } - - // sin(Inf or NaN) is NaN - if (ix >= 0x7ff00000) { - return x - x; - } - - var y: [2]f64 = undefined; - const n = __rem_pio2(x, &y); - return switch (n & 3) { - 0 => kernel.__sin(y[0], y[1], 1), - 1 => kernel.__cos(y[0], y[1]), - 2 => -kernel.__sin(y[0], y[1], 1), - else => -kernel.__cos(y[0], y[1]), - }; -} - -test "math.sin" { - try expect(sin(@as(f32, 0.0)) == sin32(0.0)); - try expect(sin(@as(f64, 0.0)) == sin64(0.0)); - try expect(comptime (math.sin(@as(f64, 2))) == math.sin(@as(f64, 2))); -} - -test "math.sin32" { - const epsilon = 0.00001; - - try expect(math.approxEqAbs(f32, sin32(0.0), 0.0, epsilon)); - try expect(math.approxEqAbs(f32, sin32(0.2), 0.198669, epsilon)); - try expect(math.approxEqAbs(f32, sin32(0.8923), 0.778517, epsilon)); - try expect(math.approxEqAbs(f32, sin32(1.5), 0.997495, epsilon)); - try expect(math.approxEqAbs(f32, sin32(-1.5), -0.997495, epsilon)); - try expect(math.approxEqAbs(f32, sin32(37.45), -0.246544, epsilon)); - try expect(math.approxEqAbs(f32, sin32(89.123), 0.916166, epsilon)); -} - -test "math.sin64" { - const epsilon = 0.000001; - - try expect(math.approxEqAbs(f64, sin64(0.0), 0.0, epsilon)); - try expect(math.approxEqAbs(f64, sin64(0.2), 0.198669, epsilon)); - try expect(math.approxEqAbs(f64, sin64(0.8923), 0.778517, epsilon)); - try expect(math.approxEqAbs(f64, sin64(1.5), 0.997495, epsilon)); - try expect(math.approxEqAbs(f64, sin64(-1.5), -0.997495, epsilon)); - try expect(math.approxEqAbs(f64, sin64(37.45), -0.246543, epsilon)); - try expect(math.approxEqAbs(f64, sin64(89.123), 0.916166, epsilon)); -} - -test "math.sin32.special" { - try expect(sin32(0.0) == 0.0); - try expect(sin32(-0.0) == -0.0); - try expect(math.isNan(sin32(math.inf(f32)))); - try expect(math.isNan(sin32(-math.inf(f32)))); - try expect(math.isNan(sin32(math.nan(f32)))); -} - -test "math.sin64.special" { - try expect(sin64(0.0) == 0.0); - try expect(sin64(-0.0) == -0.0); - try expect(math.isNan(sin64(math.inf(f64)))); - try expect(math.isNan(sin64(-math.inf(f64)))); - try expect(math.isNan(sin64(math.nan(f64)))); -} - -test "math.sin32 #9901" { - const float = @bitCast(f32, @as(u32, 0b11100011111111110000000000000000)); - _ = std.math.sin(float); -} - -test "math.sin64 #9901" { - const float = @bitCast(f64, @as(u64, 0b1111111101000001000000001111110111111111100000000000000000000001)); - _ = std.math.sin(float); -} |
