Commit 691416c24d3c99574f1b168931f8fcd6227760b8 | zig

author	mihael <hi@mihaelm.com> 2026-03-15 23:28:13+01:00
committer	mihael <hi@mihaelm.com> 2026-03-17 23:33:10+01:00
log	691416c24d3c99574f1b168931f8fcd6227760b8
tree	211322c8f2c7ce3e73ad5b6d2a2166a5306495ff
parent	fd680ba5fbe99dde71b6ec28ecae1cddf4fed71b
signature	Signed by SSH key SHA256:aoFoShdYLdrqMichqKXSSieTKUfACUIDJHsKc4V2tQg

`libzigc`: Implement `tanhf`

The changes were tested by running:

```
$ ./build/stage3/bin/zig build -p stage4 -Denable-llvm -Dno-lib

$ stage4/bin/zig build test-libc -Dlibc-test-path=<LIBC-TEST-PATH> -Dtest-filter=tanhf -fqemu -fwasmtime --summary line
Build Summary: 553/553 steps succeeded
```

6 files changed, 5 insertions(+), 52 deletions(-)

lib
- c
  - math.zig
- libc
  - mingw
    math
    tanhf.c
  - musl
    src
    math
    tanhf.c
src
- libs

lib/c/math.zig+5

...	...	@@ -43,6 +43,7 @@ comptime {
43	43	symbol(&nan, "nan");
44	44	symbol(&nanf, "nanf");
45	45	symbol(&nanl, "nanl");
	46	symbol(&tanhf, "tanhf");
46	47	}
47	48
48	49	if (builtin.target.isMuslLibC() or builtin.target.isWasiLibC()) {
...	...	@@ -343,3 +344,7 @@ test "rint" {
343	344	fn tanh(x: f64) callconv(.c) f64 {
344	345	return math.tanh(x);
345	346	}
	347
	348	fn tanhf(x: f32) callconv(.c) f32 {
	349	return math.tanh(x);
	350	}

lib/libc/mingw/math/tanhf.c deleted-10

...	...	@@ -1,10 +0,0 @@
1		/**
2		* This file has no copyright assigned and is placed in the Public Domain.
3		* This file is part of the mingw-w64 runtime package.
4		* No warranty is given; refer to the file DISCLAIMER.PD within this package.
5		*/
6		#include <math.h>
7		float tanhf (float x)
8		{
9		return (float) tanh (x);
10		}

lib/libc/musl/src/math/tanhf.c deleted-39

...	...	@@ -1,39 +0,0 @@
1		#include "libm.h"
2
3		float tanhf(float x)
4		{
5		union {float f; uint32_t i;} u = {.f = x};
6		uint32_t w;
7		int sign;
8		float t;
9
10		/* x = \|x\| */
11		sign = u.i >> 31;
12		u.i &= 0x7fffffff;
13		x = u.f;
14		w = u.i;
15
16		if (w > 0x3f0c9f54) {
17		/* \|x\| > log(3)/2 ~= 0.5493 or nan */
18		if (w > 0x41200000) {
19		/* \|x\| > 10 */
20		t = 1 + 0/x;
21		} else {
22		t = expm1f(2*x);
23		t = 1 - 2/(t+2);
24		}
25		} else if (w > 0x3e82c578) {
26		/* \|x\| > log(5/3)/2 ~= 0.2554 */
27		t = expm1f(2*x);
28		t = t/(t+2);
29		} else if (w >= 0x00800000) {
30		/* \|x\| >= 0x1p-126 */
31		t = expm1f(-2*x);
32		t = -t/(t+2);
33		} else {
34		/* \|x\| is subnormal */
35		FORCE_EVAL(x*x);
36		t = x;
37		}
38		return sign ? -t : t;
39		}

src/libs/mingw.zig-1

...	...	@@ -978,7 +978,6 @@ const mingw32_x86_32_src = [_][]const u8{
978	978	// ucrtbase
979	979	"math" ++ path.sep_str ++ "powf.c",
980	980	"math" ++ path.sep_str ++ "sinhf.c",
981		"math" ++ path.sep_str ++ "tanhf.c",
982	981	"math" ++ path.sep_str ++ "x86" ++ path.sep_str ++ "acosf.c",
983	982	"math" ++ path.sep_str ++ "x86" ++ path.sep_str ++ "asinf.c",
984	983	"math" ++ path.sep_str ++ "x86" ++ path.sep_str ++ "atan2f.c",

src/libs/musl.zig-1

...	...	@@ -1003,7 +1003,6 @@ const src_files = [_][]const u8{
1003	1003	"musl/src/math/sinl.c",
1004	1004	"musl/src/math/__tan.c",
1005	1005	"musl/src/math/__tandf.c",
1006		"musl/src/math/tanhf.c",
1007	1006	"musl/src/math/tanhl.c",
1008	1007	"musl/src/math/__tanl.c",
1009	1008	"musl/src/math/tanl.c",

src/libs/wasi_libc.zig-1

...	...	@@ -793,7 +793,6 @@ const libc_top_half_src_files = [_][]const u8{
793	793	"musl/src/math/sinl.c",
794	794	"musl/src/math/__tan.c",
795	795	"musl/src/math/__tandf.c",
796		"musl/src/math/tanhf.c",
797	796	"musl/src/math/tanhl.c",
798	797	"musl/src/math/__tanl.c",
799	798	"musl/src/math/tanl.c",