Commit d4217e21191d66fd62fed980a2429a6eddd7ca7a | zig

author	Pivok <pivoc@protonmail.com> 2026-02-11 19:39:40+01:00
committer	Andrew Kelley <andrew@ziglang.org> 2026-02-11 19:39:40+01:00
log	d4217e21191d66fd62fed980a2429a6eddd7ca7a
tree	8fdd79a30f4493281bde5eb0757b4b284a61badf
parent	96bd268c8c07b8aae0372317bfea60ef2fb3f257

zig libc: exp10, exp10f, pow10, pow10f (#31163)

See #30978.

Commands i run:
```
$ stage3/bin/zig build -p stage4 -Denable-llvm -Dno-lib

$ stage4/bin/zig build test-libc -Dlibc-test-path=../../libc-test -Dtest-filter=exp10 -fqemu -fwasmtime --summary line
Build Summary: 725/737 steps succeeded (12 skipped)
```

Reviewed-on: https://codeberg.org/ziglang/zig/pulls/31163
Reviewed-by: Andrew Kelley <andrew@ziglang.org>
Co-authored-by: Pivok <pivoc@protonmail.com>
Co-committed-by: Pivok <pivoc@protonmail.com>

5 files changed, 20 insertions(+), 50 deletions(-)

lib
- c
  - math.zig
- libc
  - musl
    src
    math
    exp10.c
    exp10f.c
src
- libs
  - musl.zig
  - wasi_libc.zig

lib/c/math.zig+20

...	@@ -45,8 +45,12 @@ comptime {	...	@@ -45,8 +45,12 @@ comptime {
45	symbol(&atanl, "atanl");	45	symbol(&atanl, "atanl");
46	symbol(&cbrt, "cbrt");	46	symbol(&cbrt, "cbrt");
47	symbol(&cbrtf, "cbrtf");	47	symbol(&cbrtf, "cbrtf");
		48	symbol(&exp10, "exp10");
		49	symbol(&exp10f, "exp10f");
48	symbol(&hypot, "hypot");	50	symbol(&hypot, "hypot");
49	symbol(&pow, "pow");	51	symbol(&pow, "pow");
		52	symbol(&pow10, "pow10");
		53	symbol(&pow10f, "pow10f");
50	}	54	}
51		55
52	if (builtin.target.isMuslLibC()) {	56	if (builtin.target.isMuslLibC()) {
...	@@ -123,6 +127,14 @@ fn cbrtf(x: f32) callconv(.c) f32 {	...	@@ -123,6 +127,14 @@ fn cbrtf(x: f32) callconv(.c) f32 {
123	return math.cbrt(x);	127	return math.cbrt(x);
124	}	128	}
125		129
		130	fn exp10(x: f64) callconv(.c) f64 {
		131	return math.pow(f64, 10.0, x);
		132	}
		133
		134	fn exp10f(x: f32) callconv(.c) f32 {
		135	return math.pow(f32, 10.0, x);
		136	}
		137
126	fn hypot(x: f64, y: f64) callconv(.c) f64 {	138	fn hypot(x: f64, y: f64) callconv(.c) f64 {
127	return math.hypot(x, y);	139	return math.hypot(x, y);
128	}	140	}
...	@@ -138,3 +150,11 @@ fn hypotl(x: c_longdouble, y: c_longdouble) callconv(.c) c_longdouble {	...	@@ -138,3 +150,11 @@ fn hypotl(x: c_longdouble, y: c_longdouble) callconv(.c) c_longdouble {
138	fn pow(x: f64, y: f64) callconv(.c) f64 {	150	fn pow(x: f64, y: f64) callconv(.c) f64 {
139	return math.pow(f64, x, y);	151	return math.pow(f64, x, y);
140	}	152	}
		153
		154	fn pow10(x: f64) callconv(.c) f64 {
		155	return exp10(x);
		156	}
		157
		158	fn pow10f(x: f32) callconv(.c) f32 {
		159	return exp10f(x);
		160	}

lib/libc/musl/src/math/exp10.c deleted-24

...	@@ -1,24 +0,0 @@
1	#define _GNU_SOURCE
2	#include <math.h>
3	#include <stdint.h>
4
5	double exp10(double x)
6	{
7	static const double p10[] = {
8	1e-15, 1e-14, 1e-13, 1e-12, 1e-11, 1e-10,
9	1e-9, 1e-8, 1e-7, 1e-6, 1e-5, 1e-4, 1e-3, 1e-2, 1e-1,
10	1, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9,
11	1e10, 1e11, 1e12, 1e13, 1e14, 1e15
12	};
13	double n, y = modf(x, &n);
14	union {double f; uint64_t i;} u = {n};
15	/* fabs(n) < 16 without raising invalid on nan */
16	if ((u.i>>52 & 0x7ff) < 0x3ff+4) {
17	if (!y) return p10[(int)n+15];
18	y = exp2(3.32192809488736234787031942948939 * y);
19	return y * p10[(int)n+15];
20	}
21	return pow(10.0, x);
22	}
23
24	weak_alias(exp10, pow10);

lib/libc/musl/src/math/exp10f.c deleted-22

...	@@ -1,22 +0,0 @@
1	#define _GNU_SOURCE
2	#include <math.h>
3	#include <stdint.h>
4
5	float exp10f(float x)
6	{
7	static const float p10[] = {
8	1e-7f, 1e-6f, 1e-5f, 1e-4f, 1e-3f, 1e-2f, 1e-1f,
9	1, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7
10	};
11	float n, y = modff(x, &n);
12	union {float f; uint32_t i;} u = {n};
13	/* fabsf(n) < 8 without raising invalid on nan */
14	if ((u.i>>23 & 0xff) < 0x7f+3) {
15	if (!y) return p10[(int)n+7];
16	y = exp2f(3.32192809488736234787031942948939f * y);
17	return y * p10[(int)n+7];
18	}
19	return exp2(3.32192809488736234787031942948939 * x);
20	}
21
22	weak_alias(exp10f, pow10f);

src/libs/musl.zig-2

...	@@ -848,8 +848,6 @@ const src_files = [_][]const u8{	...	@@ -848,8 +848,6 @@ const src_files = [_][]const u8{
848	"musl/src/math/erf.c",	848	"musl/src/math/erf.c",
849	"musl/src/math/erff.c",	849	"musl/src/math/erff.c",
850	"musl/src/math/erfl.c",	850	"musl/src/math/erfl.c",
851	"musl/src/math/exp10.c",
852	"musl/src/math/exp10f.c",
853	"musl/src/math/exp10l.c",	851	"musl/src/math/exp10l.c",
854	"musl/src/math/exp2f_data.c",	852	"musl/src/math/exp2f_data.c",
855	"musl/src/math/exp2l.c",	853	"musl/src/math/exp2l.c",

src/libs/wasi_libc.zig-2

...	@@ -710,8 +710,6 @@ const libc_top_half_src_files = [_][]const u8{	...	@@ -710,8 +710,6 @@ const libc_top_half_src_files = [_][]const u8{
710	"musl/src/math/erf.c",	710	"musl/src/math/erf.c",
711	"musl/src/math/erff.c",	711	"musl/src/math/erff.c",
712	"musl/src/math/erfl.c",	712	"musl/src/math/erfl.c",
713	"musl/src/math/exp10.c",
714	"musl/src/math/exp10f.c",
715	"musl/src/math/exp10l.c",	713	"musl/src/math/exp10l.c",
716	"musl/src/math/exp2f_data.c",	714	"musl/src/math/exp2f_data.c",
717	"musl/src/math/exp2l.c",	715	"musl/src/math/exp2l.c",