authorgravatar for hi@mihaelm.commihael <hi@mihaelm.com> 2026-03-15 21:22:01+01:00
committergravatar for hi@mihaelm.commihael <hi@mihaelm.com> 2026-03-17 23:33:10+01:00
log4cad6f5372f6f17e249c24fba4d23466fa853fc0
tree570937b9a319f0e31af630229fe507275379b590
parent014178725744eda46db04ccfe44187ef616ceaf7
signaturebadge-check Signed by SSH key SHA256:aoFoShdYLdrqMichqKXSSieTKUfACUIDJHsKc4V2tQg

`libzigc`: Implement `modfl`

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=modfl -fqemu -fwasmtime --summary line Build Summary: 369/369 steps succeeded ```

6 files changed, 9 insertions(+), 99 deletions(-)

lib/c/math.zig+9-2
......@@ -39,6 +39,7 @@ comptime {
3939 symbol(&hypotf, "hypotf");
4040 symbol(&hypotl, "hypotl");
4141 symbol(&modff, "modff");
42 symbol(&modfl, "modfl");
4243 symbol(&nan, "nan");
4344 symbol(&nanf, "nanf");
4445 symbol(&nanl, "nanl");
......@@ -201,11 +202,16 @@ fn modff(x: f32, iptr: *f32) callconv(.c) f32 {
201202 return modfGeneric(f32, x, iptr);
202203}
203204
205fn modfl(x: c_longdouble, iptr: *c_longdouble) callconv(.c) c_longdouble {
206 return modfGeneric(c_longdouble, x, iptr);
207}
208
204209fn testModf(comptime T: type) !void {
205210 // Choose the appropriate `modf` impl to test based on type
206211 const f = switch (T) {
207 f64 => modf,
208212 f32 => modff,
213 f64 => modf,
214 c_longdouble => modfl,
209215 else => @compileError("modf not implemented for " ++ @typeName(T)),
210216 };
211217
......@@ -248,8 +254,9 @@ fn testModf(comptime T: type) !void {
248254}
249255
250256test "modf" {
251 try testModf(f64);
252257 try testModf(f32);
258 try testModf(f64);
259 try testModf(c_longdouble);
253260}
254261
255262fn nan(_: [*:0]const c_char) callconv(.c) f64 {
lib/libc/mingw/math/modfl.c deleted-41
......@@ -1,41 +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 <fenv.h>
7#include <math.h>
8#include <errno.h>
9
10long double
11modfl (long double value, long double* iptr)
12{
13 long double int_part = 0.0L;
14 /* truncate */
15#if (defined(_AMD64_) && !defined(_ARM64EC_)) || (defined(__x86_64__) && !defined(__arm64ec__))
16 asm volatile ("subq $8, %%rsp\n"
17 "fnstcw 4(%%rsp)\n"
18 "movzwl 4(%%rsp), %%eax\n"
19 "orb $12, %%ah\n"
20 "movw %%ax, (%%rsp)\n"
21 "fldcw (%%rsp)\n"
22 "frndint\n"
23 "fldcw 4(%%rsp)\n"
24 "addq $8, %%rsp\n" : "=t" (int_part) : "0" (value) : "eax"); /* round */
25#elif defined(_X86_) || defined(__i386__)
26 asm volatile ("push %%eax\n\tsubl $8, %%esp\n"
27 "fnstcw 4(%%esp)\n"
28 "movzwl 4(%%esp), %%eax\n"
29 "orb $12, %%ah\n"
30 "movw %%ax, (%%esp)\n"
31 "fldcw (%%esp)\n"
32 "frndint\n"
33 "fldcw 4(%%esp)\n"
34 "addl $8, %%esp\n\tpop %%eax\n" : "=t" (int_part) : "0" (value) : "eax"); /* round */
35#else
36 int_part = truncl(value);
37#endif
38 if (iptr)
39 *iptr = int_part;
40 return (isinf (value) ? 0.0L : value - int_part);
41}
lib/libc/musl/src/math/modfl.c deleted-53
......@@ -1,53 +0,0 @@
1#include "libm.h"
2
3#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
4long double modfl(long double x, long double *iptr)
5{
6 double d;
7 long double r;
8
9 r = modf(x, &d);
10 *iptr = d;
11 return r;
12}
13#elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
14
15static const long double toint = 1/LDBL_EPSILON;
16
17long double modfl(long double x, long double *iptr)
18{
19 union ldshape u = {x};
20 int e = (u.i.se & 0x7fff) - 0x3fff;
21 int s = u.i.se >> 15;
22 long double absx;
23 long double y;
24
25 /* no fractional part */
26 if (e >= LDBL_MANT_DIG-1) {
27 *iptr = x;
28 if (isnan(x))
29 return x;
30 return s ? -0.0 : 0.0;
31 }
32
33 /* no integral part*/
34 if (e < 0) {
35 *iptr = s ? -0.0 : 0.0;
36 return x;
37 }
38
39 /* raises spurious inexact */
40 absx = s ? -x : x;
41 y = absx + toint - toint - absx;
42 if (y == 0) {
43 *iptr = x;
44 return s ? -0.0 : 0.0;
45 }
46 if (y > 0)
47 y -= 1;
48 if (s)
49 y = -y;
50 *iptr = x + y;
51 return -y;
52}
53#endif
src/libs/mingw.zig-1
......@@ -619,7 +619,6 @@ const mingw32_generic_src = [_][]const u8{
619619 "math" ++ path.sep_str ++ "lgamma.c",
620620 "math" ++ path.sep_str ++ "lgammaf.c",
621621 "math" ++ path.sep_str ++ "lgammal.c",
622 "math" ++ path.sep_str ++ "modfl.c",
623622 "math" ++ path.sep_str ++ "powi.c",
624623 "math" ++ path.sep_str ++ "powif.c",
625624 "math" ++ path.sep_str ++ "powil.c",
src/libs/musl.zig-1
......@@ -934,7 +934,6 @@ const src_files = [_][]const u8{
934934 "musl/src/math/__math_uflowf.c",
935935 "musl/src/math/__math_xflow.c",
936936 "musl/src/math/__math_xflowf.c",
937 "musl/src/math/modfl.c",
938937 "musl/src/math/nearbyint.c",
939938 "musl/src/math/nearbyintf.c",
940939 "musl/src/math/nearbyintl.c",
src/libs/wasi_libc.zig-1
......@@ -755,7 +755,6 @@ const libc_top_half_src_files = [_][]const u8{
755755 "musl/src/math/__math_uflowf.c",
756756 "musl/src/math/__math_xflow.c",
757757 "musl/src/math/__math_xflowf.c",
758 "musl/src/math/modfl.c",
759758 "musl/src/math/nearbyintl.c",
760759 "musl/src/math/nextafter.c",
761760 "musl/src/math/nextafterf.c",