commit 21fc85f035ef73d88d3b9864941a1670486af5ad (tree)
parent a8002a85649447b3622a81bfcbb27b2ca6d3d482
Author: Daggerfall-is-the-best-TES-game <daggerfall-is-the-best-tes-game@noreply.codeberg.org>
Date: Mon, 19 Jan 2026 22:43:57 +0100
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>
Diffstat:
4 files changed, 8 insertions(+), 103 deletions(-)
diff --git a/lib/c/math.zig b/lib/c/math.zig
@@ -33,6 +33,10 @@ comptime {
@export(&nanl, .{ .name = "nanl", .linkage = common.linkage, .visibility = common.visibility });
}
+ if (builtin.target.isMuslLibC() or builtin.target.isWasiLibC()) {
+ @export(&acos, .{ .name = "acos", .linkage = common.linkage, .visibility = common.visibility });
+ }
+
if (builtin.target.isMuslLibC()) {
@export(©signf, .{ .name = "copysignf", .linkage = common.linkage, .visibility = common.visibility });
@export(©sign, .{ .name = "copysign", .linkage = common.linkage, .visibility = common.visibility });
@@ -40,6 +44,10 @@ comptime {
@export(©signl, .{ .name = "copysignl", .linkage = common.linkage, .visibility = common.visibility });
}
+fn acos(x: f64) callconv(.c) f64 {
+ return std.math.acos(x);
+}
+
fn isnan(x: f64) callconv(.c) c_int {
return if (std.math.isNan(x)) 1 else 0;
}
diff --git a/lib/libc/musl/src/math/acos.c b/lib/libc/musl/src/math/acos.c
@@ -1,101 +0,0 @@
-/* origin: FreeBSD /usr/src/lib/msun/src/e_acos.c */
-/*
- * ====================================================
- * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
- *
- * Developed at SunSoft, a Sun Microsystems, Inc. business.
- * Permission to use, copy, modify, and distribute this
- * software is freely granted, provided that this notice
- * is preserved.
- * ====================================================
- */
-/* acos(x)
- * Method :
- * acos(x) = pi/2 - asin(x)
- * acos(-x) = pi/2 + asin(x)
- * For |x|<=0.5
- * acos(x) = pi/2 - (x + x*x^2*R(x^2)) (see asin.c)
- * For x>0.5
- * acos(x) = pi/2 - (pi/2 - 2asin(sqrt((1-x)/2)))
- * = 2asin(sqrt((1-x)/2))
- * = 2s + 2s*z*R(z) ...z=(1-x)/2, s=sqrt(z)
- * = 2f + (2c + 2s*z*R(z))
- * where f=hi part of s, and c = (z-f*f)/(s+f) is the correction term
- * for f so that f+c ~ sqrt(z).
- * For x<-0.5
- * acos(x) = pi - 2asin(sqrt((1-|x|)/2))
- * = pi - 0.5*(s+s*z*R(z)), where z=(1-|x|)/2,s=sqrt(z)
- *
- * Special cases:
- * if x is NaN, return x itself;
- * if |x|>1, return NaN with invalid signal.
- *
- * Function needed: sqrt
- */
-
-#include "libm.h"
-
-static const double
-pio2_hi = 1.57079632679489655800e+00, /* 0x3FF921FB, 0x54442D18 */
-pio2_lo = 6.12323399573676603587e-17, /* 0x3C91A626, 0x33145C07 */
-pS0 = 1.66666666666666657415e-01, /* 0x3FC55555, 0x55555555 */
-pS1 = -3.25565818622400915405e-01, /* 0xBFD4D612, 0x03EB6F7D */
-pS2 = 2.01212532134862925881e-01, /* 0x3FC9C155, 0x0E884455 */
-pS3 = -4.00555345006794114027e-02, /* 0xBFA48228, 0xB5688F3B */
-pS4 = 7.91534994289814532176e-04, /* 0x3F49EFE0, 0x7501B288 */
-pS5 = 3.47933107596021167570e-05, /* 0x3F023DE1, 0x0DFDF709 */
-qS1 = -2.40339491173441421878e+00, /* 0xC0033A27, 0x1C8A2D4B */
-qS2 = 2.02094576023350569471e+00, /* 0x40002AE5, 0x9C598AC8 */
-qS3 = -6.88283971605453293030e-01, /* 0xBFE6066C, 0x1B8D0159 */
-qS4 = 7.70381505559019352791e-02; /* 0x3FB3B8C5, 0xB12E9282 */
-
-static double R(double z)
-{
- double_t p, q;
- p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*pS5)))));
- q = 1.0+z*(qS1+z*(qS2+z*(qS3+z*qS4)));
- return p/q;
-}
-
-double acos(double x)
-{
- double z,w,s,c,df;
- uint32_t hx,ix;
-
- GET_HIGH_WORD(hx, x);
- ix = hx & 0x7fffffff;
- /* |x| >= 1 or nan */
- if (ix >= 0x3ff00000) {
- uint32_t lx;
-
- GET_LOW_WORD(lx,x);
- if ((ix-0x3ff00000 | lx) == 0) {
- /* acos(1)=0, acos(-1)=pi */
- if (hx >> 31)
- return 2*pio2_hi + 0x1p-120f;
- return 0;
- }
- return 0/(x-x);
- }
- /* |x| < 0.5 */
- if (ix < 0x3fe00000) {
- if (ix <= 0x3c600000) /* |x| < 2**-57 */
- return pio2_hi + 0x1p-120f;
- return pio2_hi - (x - (pio2_lo-x*R(x*x)));
- }
- /* x < -0.5 */
- if (hx >> 31) {
- z = (1.0+x)*0.5;
- s = sqrt(z);
- w = R(z)*s-pio2_lo;
- return 2*(pio2_hi - (s+w));
- }
- /* x > 0.5 */
- z = (1.0-x)*0.5;
- s = sqrt(z);
- df = s;
- SET_LOW_WORD(df,0);
- c = (z-df*df)/(s+df);
- w = R(z)*s+c;
- return 2*(df+w);
-}
diff --git a/src/libs/musl.zig b/src/libs/musl.zig
@@ -824,7 +824,6 @@ const src_files = [_][]const u8{
"musl/src/math/aarch64/rintf.c",
"musl/src/math/aarch64/round.c",
"musl/src/math/aarch64/roundf.c",
- "musl/src/math/acos.c",
"musl/src/math/acosf.c",
"musl/src/math/acosh.c",
"musl/src/math/acoshf.c",
diff --git a/src/libs/wasi_libc.zig b/src/libs/wasi_libc.zig
@@ -684,7 +684,6 @@ const libc_top_half_src_files = [_][]const u8{
"musl/src/locale/strtod_l.c",
"musl/src/locale/wcscoll.c",
"musl/src/locale/wcsxfrm.c",
- "musl/src/math/acos.c",
"musl/src/math/acosf.c",
"musl/src/math/acosh.c",
"musl/src/math/acoshf.c",
