From 0fab77e8d72cf232af4977642b52544f0e4ab521 Mon Sep 17 00:00:00 2001
From: Amjad Alsharafi <26300843+Amjad50@users.noreply.github.com>
Date: Tue, 27 Aug 2024 12:55:05 +0800
Subject: [PATCH] Don't include `math` for `unix` and `wasi` targets

This fixes such as (https://github.com/rust-lang/rust/issues/128386)
where, our implementation is being used on systems where there is
already `math` library and its more performant and accurate.

So with this change, linux will go back to the previous behavior and not
include these functions, windows and apple were generally not affected.

Looking at the targets we have builtin now in rust, everything else is
probably good to have the math symbols.

> A note on the above, the `hermit` os uses `libm` directly for itself,
> but I think its Ok to keep providing math in `compiler_builtin` for it,
> its technically the same implementation either from `compiler_builtin`
> or `hermit-builtins`.

Signed-off-by: Amjad Alsharafi <26300843+Amjad50@users.noreply.github.com>
---
 src/lib.rs  | 13 ++++++++++---
 src/math.rs |  3 ++-
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index 0d44fdf9..b85f789f 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -47,9 +47,16 @@ mod macros;
 pub mod float;
 pub mod int;
 
-// Disabled on x86 without sse2 due to ABI issues
-// <https://github.com/rust-lang/rust/issues/114479>
-#[cfg(not(all(target_arch = "x86", not(target_feature = "sse2"))))]
+// Disable for any of the following:
+// - x86 without sse2 due to ABI issues
+//   - <https://github.com/rust-lang/rust/issues/114479>
+// - All unix targets (linux, macos, freebsd, android, etc)
+// - wasm with known target_os
+#[cfg(not(any(
+    all(target_arch = "x86", not(target_feature = "sse2")),
+    unix,
+    all(target_family = "wasm", not(target_os = "unknown"))
+)))]
 pub mod math;
 pub mod mem;
 
diff --git a/src/math.rs b/src/math.rs
index 7d4d1787..477dfe36 100644
--- a/src/math.rs
+++ b/src/math.rs
@@ -17,7 +17,7 @@ macro_rules! no_mangle {
     }
 }
 
-#[cfg(all(not(windows), not(target_vendor = "apple")))]
+#[cfg(not(windows))]
 no_mangle! {
     fn acos(x: f64) -> f64;
     fn asin(x: f64) -> f64;
@@ -92,6 +92,7 @@ no_mangle! {
     fn fmodf(x: f32, y: f32) -> f32;
 }
 
+// allow for windows (and other targets)
 intrinsics! {
     pub extern "C" fn lgamma_r(x: f64, s: &mut i32) -> f64 {
         let r = self::libm::lgamma_r(x);