zig libc: export fdiml and fdimf (#31759)

Exports `fdiml` and `fdimf` in zig libc and removes from from musl and mingw libc.

Contributes to: https://codeberg.org/ziglang/zig/issues/30978

Reviewed-on: https://codeberg.org/ziglang/zig/pulls/31759
Reviewed-by: Andrew Kelley <andrew@ziglang.org>
Co-authored-by: badayvedat <badayvedat@gmail.com>
Co-committed-by: badayvedat <badayvedat@gmail.com>

lib/c/math.zig

@@ -45,6 +45,7 @@ comptime {
     if ((builtin.target.isMinGW() and @sizeOf(f64) != @sizeOf(c_longdouble)) or builtin.target.isMuslLibC() or builtin.target.isWasiLibC()) {
         symbol(&atanl, "atanl");
         symbol(&copysignl, "copysignl");
+        symbol(&fdiml, "fdiml");
         symbol(&nanl, "nanl");
     }
 
@@ -67,6 +68,7 @@ comptime {
         symbol(&exp10, "exp10");
         symbol(&exp10f, "exp10f");
         symbol(&fdim, "fdim");
+        symbol(&fdimf, "fdimf");
         symbol(&finite, "finite");
         symbol(&finitef, "finitef");
         symbol(&frexp, "frexp");
@@ -160,19 +162,30 @@ fn exp10f(x: f32) callconv(.c) f32 {
     return math.pow(f32, 10.0, x);
 }
 
-fn fdim(x: f64, y: f64) callconv(.c) f64 {
-    if (math.isNan(x)) {
+fn fdimGeneric(comptime T: type, x: T, y: T) T {
+    if (math.isNan(x))
         return x;
-    }
-    if (math.isNan(y)) {
+
+    if (math.isNan(y))
         return y;
-    }
-    if (x > y) {
+
+    if (x > y)
         return x - y;
-    }
     return 0;
 }
 
+fn fdim(x: f64, y: f64) callconv(.c) f64 {
+    return fdimGeneric(f64, x, y);
+}
+
+fn fdimf(x: f32, y: f32) callconv(.c) f32 {
+    return fdimGeneric(f32, x, y);
+}
+
+fn fdiml(x: c_longdouble, y: c_longdouble) callconv(.c) c_longdouble {
+    return fdimGeneric(c_longdouble, x, y);
+}
+
 fn finite(x: f64) callconv(.c) c_int {
     return if (math.isFinite(x)) 1 else 0;
 }

lib/libc/mingw/math/fdiml.c

@@ -1,24 +0,0 @@
-/**
- * This file has no copyright assigned and is placed in the Public Domain.
- * This file is part of the mingw-w64 runtime package.
- * No warranty is given; refer to the file DISCLAIMER.PD within this package.
- */
-#include <errno.h>
-#include <math.h>
-
-long double
-fdiml (long double x, long double y)
-{
-  int cx = fpclassify (x), cy = fpclassify (y);
-  long double r;
-
-  if (cx == FP_NAN || cy == FP_NAN
-      || (y < 0 && cx == FP_INFINITE && cy == FP_INFINITE))
-    return x - y;  /* Take care invalid flag is raised.  */
-  if (x <= y)
-    return 0.0;
-  r = x - y;
-  if (fpclassify (r) == FP_INFINITE)
-    errno = ERANGE;
-  return r;
-}

lib/libc/musl/src/math/fdimf.c

@@ -1,10 +0,0 @@
-#include <math.h>
-
-float fdimf(float x, float y)
-{
-	if (isnan(x))
-		return x;
-	if (isnan(y))
-		return y;
-	return x > y ? x - y : 0;
-}

lib/libc/musl/src/math/fdiml.c

@@ -1,18 +0,0 @@
-#include <math.h>
-#include <float.h>
-
-#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
-long double fdiml(long double x, long double y)
-{
-	return fdim(x, y);
-}
-#else
-long double fdiml(long double x, long double y)
-{
-	if (isnan(x))
-		return x;
-	if (isnan(y))
-		return y;
-	return x > y ? x - y : 0;
-}
-#endif

src/libs/mingw.zig

@@ -850,7 +850,6 @@ const mingw32_x86_src = [_][]const u8{
     "complex" ++ path.sep_str ++ "ctanl.c",
     "math" ++ path.sep_str ++ "cbrtl.c",
     "math" ++ path.sep_str ++ "erfl.c",
-    "math" ++ path.sep_str ++ "fdiml.c",
     "math" ++ path.sep_str ++ "fmal.c",
     "math" ++ path.sep_str ++ "llrintl.c",
     "math" ++ path.sep_str ++ "llroundl.c",

src/libs/musl.zig

@@ -823,8 +823,6 @@ const src_files = [_][]const u8{
     "musl/src/math/expm1l.c",
     "musl/src/math/__expo2.c",
     "musl/src/math/__expo2f.c",
-    "musl/src/math/fdimf.c",
-    "musl/src/math/fdiml.c",
     "musl/src/math/fma.c",
     "musl/src/math/fmaf.c",
     "musl/src/math/fmal.c",

src/libs/wasi_libc.zig

@@ -692,8 +692,6 @@ const libc_top_half_src_files = [_][]const u8{
     "musl/src/math/expm1.c",
     "musl/src/math/expm1f.c",
     "musl/src/math/expm1l.c",
-    "musl/src/math/fdimf.c",
-    "musl/src/math/fdiml.c",
     "musl/src/math/fma.c",
     "musl/src/math/fmaf.c",
     "musl/src/math/ilogb.c",

test/libc.zig

@@ -198,8 +198,8 @@ pub fn addCases(cases: *tests.LibcContext) void {
     cases.addLibcTestCase("math/fabsf.c", true, .{});
     cases.addLibcTestCase("math/fabsl.c", true, .{});
     cases.addLibcTestCase("math/fdim.c", true, .{});
-    // cases.addLibcTestCase("math/fdimf.c", true, .{});
-    // cases.addLibcTestCase("math/fdiml.c", true, .{});
+    cases.addLibcTestCase("math/fdimf.c", true, .{});
+    cases.addLibcTestCase("math/fdiml.c", true, .{});
     cases.addLibcTestCase("math/fenv.c", true, .{});
     cases.addLibcTestCase("math/floor.c", true, .{});
     cases.addLibcTestCase("math/floorf.c", true, .{});