authorgravatar for daggerfall-is-the-best-tes-game@noreply.codeberg.orgDaggerfall-is-the-best-TES-game <daggerfall-is-the-best-tes-game@noreply.codeberg.org> 2026-01-19 22:43:57+01:00
committergravatar for andrew@ziglang.orgAndrew Kelley <andrew@ziglang.org> 2026-01-19 22:43:57+01:00
log21fc85f035ef73d88d3b9864941a1670486af5ad
tree867f3eddabbc785be3b1a28ca9a5f95074c28699
parenta8002a85649447b3622a81bfcbb27b2ca6d3d482

Add acos to ziglibc (#30888)

Since this is my first time contributing I wanted to keep it simple and I added just one function I tested with ```bash stage3/bin/zig build -p stage4 -Dno-lib -Dno-langref -Denable-llvm=true --search-prefix ~/repos/zig-boostrap/out/native-linux-musl-baseline/ stage4/bin/zig build test-libc -Dlibc-test-path=../libc-test -Dtest-target-filter=x86_64-linux-musl ``` and the tests passed. I'm planning on doing more once I get the hang of it. Co-authored-by: david <davidc.fried@gmail.com> Reviewed-on: https://codeberg.org/ziglang/zig/pulls/30888 Reviewed-by: Andrew Kelley <andrew@ziglang.org> Co-authored-by: Daggerfall-is-the-best-TES-game <daggerfall-is-the-best-tes-game@noreply.codeberg.org> Co-committed-by: Daggerfall-is-the-best-TES-game <daggerfall-is-the-best-tes-game@noreply.codeberg.org>

4 files changed, 8 insertions(+), 103 deletions(-)

lib/c/math.zig+8
...@@ -33,6 +33,10 @@ comptime {...@@ -33,6 +33,10 @@ comptime {
33 @export(&nanl, .{ .name = "nanl", .linkage = common.linkage, .visibility = common.visibility });33 @export(&nanl, .{ .name = "nanl", .linkage = common.linkage, .visibility = common.visibility });
34 }34 }
3535
36 if (builtin.target.isMuslLibC() or builtin.target.isWasiLibC()) {
37 @export(&acos, .{ .name = "acos", .linkage = common.linkage, .visibility = common.visibility });
38 }
39
36 if (builtin.target.isMuslLibC()) {40 if (builtin.target.isMuslLibC()) {
37 @export(&copysignf, .{ .name = "copysignf", .linkage = common.linkage, .visibility = common.visibility });41 @export(&copysignf, .{ .name = "copysignf", .linkage = common.linkage, .visibility = common.visibility });
38 @export(&copysign, .{ .name = "copysign", .linkage = common.linkage, .visibility = common.visibility });42 @export(&copysign, .{ .name = "copysign", .linkage = common.linkage, .visibility = common.visibility });
...@@ -40,6 +44,10 @@ comptime {...@@ -40,6 +44,10 @@ comptime {
40 @export(&copysignl, .{ .name = "copysignl", .linkage = common.linkage, .visibility = common.visibility });44 @export(&copysignl, .{ .name = "copysignl", .linkage = common.linkage, .visibility = common.visibility });
41}45}
4246
47fn acos(x: f64) callconv(.c) f64 {
48 return std.math.acos(x);
49}
50
43fn isnan(x: f64) callconv(.c) c_int {51fn isnan(x: f64) callconv(.c) c_int {
44 return if (std.math.isNan(x)) 1 else 0;52 return if (std.math.isNan(x)) 1 else 0;
45}53}
lib/libc/musl/src/math/acos.c deleted-101
...@@ -1,101 +0,0 @@
1/* origin: FreeBSD /usr/src/lib/msun/src/e_acos.c */
2/*
3 * ====================================================
4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
5 *
6 * Developed at SunSoft, a Sun Microsystems, Inc. business.
7 * Permission to use, copy, modify, and distribute this
8 * software is freely granted, provided that this notice
9 * is preserved.
10 * ====================================================
11 */
12/* acos(x)
13 * Method :
14 * acos(x) = pi/2 - asin(x)
15 * acos(-x) = pi/2 + asin(x)
16 * For |x|<=0.5
17 * acos(x) = pi/2 - (x + x*x^2*R(x^2)) (see asin.c)
18 * For x>0.5
19 * acos(x) = pi/2 - (pi/2 - 2asin(sqrt((1-x)/2)))
20 * = 2asin(sqrt((1-x)/2))
21 * = 2s + 2s*z*R(z) ...z=(1-x)/2, s=sqrt(z)
22 * = 2f + (2c + 2s*z*R(z))
23 * where f=hi part of s, and c = (z-f*f)/(s+f) is the correction term
24 * for f so that f+c ~ sqrt(z).
25 * For x<-0.5
26 * acos(x) = pi - 2asin(sqrt((1-|x|)/2))
27 * = pi - 0.5*(s+s*z*R(z)), where z=(1-|x|)/2,s=sqrt(z)
28 *
29 * Special cases:
30 * if x is NaN, return x itself;
31 * if |x|>1, return NaN with invalid signal.
32 *
33 * Function needed: sqrt
34 */
35
36#include "libm.h"
37
38static const double
39pio2_hi = 1.57079632679489655800e+00, /* 0x3FF921FB, 0x54442D18 */
40pio2_lo = 6.12323399573676603587e-17, /* 0x3C91A626, 0x33145C07 */
41pS0 = 1.66666666666666657415e-01, /* 0x3FC55555, 0x55555555 */
42pS1 = -3.25565818622400915405e-01, /* 0xBFD4D612, 0x03EB6F7D */
43pS2 = 2.01212532134862925881e-01, /* 0x3FC9C155, 0x0E884455 */
44pS3 = -4.00555345006794114027e-02, /* 0xBFA48228, 0xB5688F3B */
45pS4 = 7.91534994289814532176e-04, /* 0x3F49EFE0, 0x7501B288 */
46pS5 = 3.47933107596021167570e-05, /* 0x3F023DE1, 0x0DFDF709 */
47qS1 = -2.40339491173441421878e+00, /* 0xC0033A27, 0x1C8A2D4B */
48qS2 = 2.02094576023350569471e+00, /* 0x40002AE5, 0x9C598AC8 */
49qS3 = -6.88283971605453293030e-01, /* 0xBFE6066C, 0x1B8D0159 */
50qS4 = 7.70381505559019352791e-02; /* 0x3FB3B8C5, 0xB12E9282 */
51
52static double R(double z)
53{
54 double_t p, q;
55 p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*pS5)))));
56 q = 1.0+z*(qS1+z*(qS2+z*(qS3+z*qS4)));
57 return p/q;
58}
59
60double acos(double x)
61{
62 double z,w,s,c,df;
63 uint32_t hx,ix;
64
65 GET_HIGH_WORD(hx, x);
66 ix = hx & 0x7fffffff;
67 /* |x| >= 1 or nan */
68 if (ix >= 0x3ff00000) {
69 uint32_t lx;
70
71 GET_LOW_WORD(lx,x);
72 if ((ix-0x3ff00000 | lx) == 0) {
73 /* acos(1)=0, acos(-1)=pi */
74 if (hx >> 31)
75 return 2*pio2_hi + 0x1p-120f;
76 return 0;
77 }
78 return 0/(x-x);
79 }
80 /* |x| < 0.5 */
81 if (ix < 0x3fe00000) {
82 if (ix <= 0x3c600000) /* |x| < 2**-57 */
83 return pio2_hi + 0x1p-120f;
84 return pio2_hi - (x - (pio2_lo-x*R(x*x)));
85 }
86 /* x < -0.5 */
87 if (hx >> 31) {
88 z = (1.0+x)*0.5;
89 s = sqrt(z);
90 w = R(z)*s-pio2_lo;
91 return 2*(pio2_hi - (s+w));
92 }
93 /* x > 0.5 */
94 z = (1.0-x)*0.5;
95 s = sqrt(z);
96 df = s;
97 SET_LOW_WORD(df,0);
98 c = (z-df*df)/(s+df);
99 w = R(z)*s+c;
100 return 2*(df+w);
101}
src/libs/musl.zig-1
...@@ -824,7 +824,6 @@ const src_files = [_][]const u8{...@@ -824,7 +824,6 @@ const src_files = [_][]const u8{
824 "musl/src/math/aarch64/rintf.c",824 "musl/src/math/aarch64/rintf.c",
825 "musl/src/math/aarch64/round.c",825 "musl/src/math/aarch64/round.c",
826 "musl/src/math/aarch64/roundf.c",826 "musl/src/math/aarch64/roundf.c",
827 "musl/src/math/acos.c",
828 "musl/src/math/acosf.c",827 "musl/src/math/acosf.c",
829 "musl/src/math/acosh.c",828 "musl/src/math/acosh.c",
830 "musl/src/math/acoshf.c",829 "musl/src/math/acoshf.c",
src/libs/wasi_libc.zig-1
...@@ -684,7 +684,6 @@ const libc_top_half_src_files = [_][]const u8{...@@ -684,7 +684,6 @@ const libc_top_half_src_files = [_][]const u8{
684 "musl/src/locale/strtod_l.c",684 "musl/src/locale/strtod_l.c",
685 "musl/src/locale/wcscoll.c",685 "musl/src/locale/wcscoll.c",
686 "musl/src/locale/wcsxfrm.c",686 "musl/src/locale/wcsxfrm.c",
687 "musl/src/math/acos.c",
688 "musl/src/math/acosf.c",687 "musl/src/math/acosf.c",
689 "musl/src/math/acosh.c",688 "musl/src/math/acosh.c",
690 "musl/src/math/acoshf.c",689 "musl/src/math/acoshf.c",