Rollup merge of rust-lang#101381 - Urgau:target-mixup-homogenous-floats, r=Amanieu

Test that target feature mix up with homogeneous floats is sound

This pull-request adds a test in `src/test/abi/` that test that target feature mix up with homogeneous floats is sound.

This is basically is ripoff of [src/test/ui/simd/target-feature-mixup.rs](https://github.com/rust-lang/rust/blob/47d1cdb0bcac8e417071ce1929d261efe2399ae2/src/test/ui/simd/target-feature-mixup.rs) but for floats and without `#[repr(simd)]`.

*Extracted from rust-lang#97559 since I don't yet know what to do with that PR.*

Author: Manishearth

src/test/ui/abi/homogenous-floats-target-feature-mixup.rs

@@ -0,0 +1,192 @@
+// This test check that even if we mixup target feature of function with homogenous floats,
+// the abi is sound and still produce the right answer.
+//
+// This is basically the same test as src/test/ui/simd/target-feature-mixup.rs but for floats and
+// without #[repr(simd)]
+
+// run-pass
+// ignore-emscripten
+// ignore-sgx no processes
+
+#![feature(avx512_target_feature)]
+
+#![allow(overflowing_literals)]
+#![allow(unused_variables)]
+
+use std::process::{Command, ExitStatus};
+use std::env;
+
+fn main() {
+    if let Some(level) = env::args().nth(1) {
+        return test::main(&level)
+    }
+
+    match std::env::var("TARGET") {
+        Ok(s) => {
+            // Skip this tests on i586-unknown-linux-gnu where sse2 is disabled
+            if s.contains("i586") {
+                return
+            }
+        }
+        Err(_) => return,
+    }
+
+    let me = env::current_exe().unwrap();
+    for level in ["sse", "avx", "avx512"].iter() {
+        let status = Command::new(&me).arg(level).status().unwrap();
+        if status.success() {
+            println!("success with {}", level);
+            continue
+        }
+
+        // We don't actually know if our computer has the requisite target features
+        // for the test below. Testing for that will get added to libstd later so
+        // for now just assume sigill means this is a machine that can't run this test.
+        if is_sigill(status) {
+            println!("sigill with {}, assuming spurious", level);
+            continue
+        }
+        panic!("invalid status at {}: {}", level, status);
+    }
+}
+
+#[cfg(unix)]
+fn is_sigill(status: ExitStatus) -> bool {
+    use std::os::unix::prelude::*;
+    status.signal() == Some(4)
+}
+
+#[cfg(windows)]
+fn is_sigill(status: ExitStatus) -> bool {
+    status.code() == Some(0xc000001d)
+}
+
+#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+#[allow(nonstandard_style)]
+mod test {
+    #[derive(PartialEq, Debug, Clone, Copy)]
+    struct f32x2(f32, f32);
+
+    #[derive(PartialEq, Debug, Clone, Copy)]
+    struct f32x4(f32, f32, f32, f32);
+
+    #[derive(PartialEq, Debug, Clone, Copy)]
+    struct f32x8(f32, f32, f32, f32, f32, f32, f32, f32);
+
+    pub fn main(level: &str) {
+        unsafe {
+            main_normal(level);
+            main_sse(level);
+            if level == "sse" {
+                return
+            }
+            main_avx(level);
+            if level == "avx" {
+                return
+            }
+            main_avx512(level);
+        }
+    }
+
+    macro_rules! mains {
+        ($(
+            $(#[$attr:meta])*
+            unsafe fn $main:ident(level: &str) {
+                ...
+            }
+        )*) => ($(
+            $(#[$attr])*
+            unsafe fn $main(level: &str) {
+                let m128 = f32x2(1., 2.);
+                let m256 = f32x4(3., 4., 5., 6.);
+                let m512 = f32x8(7., 8., 9., 10., 11., 12., 13., 14.);
+                assert_eq!(id_sse_128(m128), m128);
+                assert_eq!(id_sse_256(m256), m256);
+                assert_eq!(id_sse_512(m512), m512);
+
+                if level == "sse" {
+                    return
+                }
+                assert_eq!(id_avx_128(m128), m128);
+                assert_eq!(id_avx_256(m256), m256);
+                assert_eq!(id_avx_512(m512), m512);
+
+                if level == "avx" {
+                    return
+                }
+                assert_eq!(id_avx512_128(m128), m128);
+                assert_eq!(id_avx512_256(m256), m256);
+                assert_eq!(id_avx512_512(m512), m512);
+            }
+        )*)
+    }
+
+    mains! {
+        unsafe fn main_normal(level: &str) { ... }
+        #[target_feature(enable = "sse2")]
+        unsafe fn main_sse(level: &str) { ... }
+        #[target_feature(enable = "avx")]
+        unsafe fn main_avx(level: &str) { ... }
+        #[target_feature(enable = "avx512bw")]
+        unsafe fn main_avx512(level: &str) { ... }
+    }
+
+    #[target_feature(enable = "sse2")]
+    unsafe fn id_sse_128(a: f32x2) -> f32x2 {
+        assert_eq!(a, f32x2(1., 2.));
+        a.clone()
+    }
+
+    #[target_feature(enable = "sse2")]
+    unsafe fn id_sse_256(a: f32x4) -> f32x4 {
+        assert_eq!(a, f32x4(3., 4., 5., 6.));
+        a.clone()
+    }
+
+    #[target_feature(enable = "sse2")]
+    unsafe fn id_sse_512(a: f32x8) -> f32x8 {
+        assert_eq!(a, f32x8(7., 8., 9., 10., 11., 12., 13., 14.));
+        a.clone()
+    }
+
+    #[target_feature(enable = "avx")]
+    unsafe fn id_avx_128(a: f32x2) -> f32x2 {
+        assert_eq!(a, f32x2(1., 2.));
+        a.clone()
+    }
+
+    #[target_feature(enable = "avx")]
+    unsafe fn id_avx_256(a: f32x4) -> f32x4 {
+        assert_eq!(a, f32x4(3., 4., 5., 6.));
+        a.clone()
+    }
+
+    #[target_feature(enable = "avx")]
+    unsafe fn id_avx_512(a: f32x8) -> f32x8 {
+        assert_eq!(a, f32x8(7., 8., 9., 10., 11., 12., 13., 14.));
+        a.clone()
+    }
+
+    #[target_feature(enable = "avx512bw")]
+    unsafe fn id_avx512_128(a: f32x2) -> f32x2 {
+        assert_eq!(a, f32x2(1., 2.));
+        a.clone()
+    }
+
+    #[target_feature(enable = "avx512bw")]
+    unsafe fn id_avx512_256(a: f32x4) -> f32x4 {
+        assert_eq!(a, f32x4(3., 4., 5., 6.));
+        a.clone()
+    }
+
+    #[target_feature(enable = "avx512bw")]
+    unsafe fn id_avx512_512(a: f32x8) -> f32x8 {
+        assert_eq!(a, f32x8(7., 8., 9., 10., 11., 12., 13., 14.));
+        a.clone()
+    }
+}
+
+#[cfg(not(any(target_arch = "x86", target_arch = "x86_64")))]
+mod test {
+    pub fn main(level: &str) {}
+}