Auto merge of #143405 - tgross35:update-builtins, r=tgross35

Update the `compiler-builtins` subtree

Update the Josh subtree to rust-lang/compiler-builtins@ed17b95715dd.

r? `@ghost`

Author: bors

library/compiler-builtins/builtins-test-intrinsics/build.rs

@@ -6,6 +6,5 @@ fn main() {
     println!("cargo::rerun-if-changed=../configure.rs");
 
     let target = builtins_configure::Target::from_env();
-    builtins_configure::configure_f16_f128(&target);
     builtins_configure::configure_aliases(&target);
 }

library/compiler-builtins/builtins-test/benches/float_cmp.rs

@@ -177,6 +177,7 @@ float_bench! {
     ],
 }
 
+#[cfg(f128_enabled)]
 float_bench! {
     name: cmp_f128_gt,
     sig: (a: f128, b: f128) -> CmpResult,
@@ -189,6 +190,7 @@ float_bench! {
     asm: []
 }
 
+#[cfg(f128_enabled)]
 float_bench! {
     name: cmp_f128_unord,
     sig: (a: f128, b: f128) -> CmpResult,

library/compiler-builtins/builtins-test/build.rs

@@ -116,5 +116,4 @@ fn main() {
     }
 
     builtins_configure::configure_aliases(&target);
-    builtins_configure::configure_f16_f128(&target);
 }

library/compiler-builtins/builtins-test/tests/conv.rs

@@ -118,7 +118,7 @@ mod i_to_f {
         i128, __floattidf;
     }
 
-    #[cfg(not(feature = "no-f16-f128"))]
+    #[cfg(f128_enabled)]
     #[cfg(not(any(target_arch = "powerpc", target_arch = "powerpc64")))]
     i_to_f! { f128, Quad, not(feature = "no-sys-f128-int-convert"),
         u32, __floatunsitf;
@@ -129,7 +129,7 @@ mod i_to_f {
         i128, __floattitf;
     }
 
-    #[cfg(not(feature = "no-f16-f128"))]
+    #[cfg(f128_enabled)]
     #[cfg(any(target_arch = "powerpc", target_arch = "powerpc64"))]
     i_to_f! { f128, Quad, not(feature = "no-sys-f128-int-convert"),
         u32, __floatunsikf;

library/compiler-builtins/builtins-test/tests/div_rem.rs

@@ -147,7 +147,7 @@ mod float_div {
         f64, __divdf3, Double, all();
     }
 
-    #[cfg(not(feature = "no-f16-f128"))]
+    #[cfg(f128_enabled)]
     #[cfg(not(any(target_arch = "powerpc", target_arch = "powerpc64")))]
     float! {
         f128, __divtf3, Quad,
@@ -156,7 +156,7 @@ mod float_div {
         not(any(feature = "no-sys-f128", all(target_arch = "aarch64", target_os = "linux")));
     }
 
-    #[cfg(not(feature = "no-f16-f128"))]
+    #[cfg(f128_enabled)]
     #[cfg(any(target_arch = "powerpc", target_arch = "powerpc64"))]
     float! {
         f128, __divkf3, Quad, not(feature = "no-sys-f128");

library/compiler-builtins/compiler-builtins/build.rs

@@ -2,7 +2,7 @@ mod configure;
 
 use std::env;
 
-use configure::{Target, configure_aliases, configure_f16_f128};
+use configure::{Target, configure_aliases};
 
 fn main() {
     println!("cargo::rerun-if-changed=build.rs");
@@ -12,7 +12,6 @@ fn main() {
     let cwd = env::current_dir().unwrap();
 
     configure_check_cfg();
-    configure_f16_f128(&target);
     configure_aliases(&target);
 
     configure_libm(&target);

library/compiler-builtins/compiler-builtins/configure.rs

@@ -1,6 +1,7 @@
 // Configuration that is shared between `compiler_builtins` and `builtins_test`.
 
-use std::env;
+use std::process::{Command, Stdio};
+use std::{env, str};
 
 #[derive(Debug)]
 #[allow(dead_code)]
@@ -16,6 +17,8 @@ pub struct Target {
     pub pointer_width: u8,
     pub little_endian: bool,
     pub features: Vec<String>,
+    pub reliable_f128: bool,
+    pub reliable_f16: bool,
 }
 
 impl Target {
@@ -32,6 +35,19 @@ impl Target {
             .map(|s| s.to_lowercase().replace("_", "-"))
             .collect();
 
+        // Query rustc for options that Cargo does not provide env for. The bootstrap hack is used
+        // to get consistent output regardless of channel (`f16`/`f128` config options are hidden
+        // on stable otherwise).
+        let mut cmd = Command::new(env::var("RUSTC").unwrap());
+        cmd.args(["--print=cfg", "--target", &triple])
+            .env("RUSTC_BOOTSTRAP", "1")
+            .stderr(Stdio::inherit());
+        let out = cmd
+            .output()
+            .unwrap_or_else(|e| panic!("failed to run `{cmd:?}`: {e}"));
+        assert!(out.status.success(), "failed to run `{cmd:?}`");
+        let rustc_cfg = str::from_utf8(&out.stdout).unwrap();
+
         Self {
             triple,
             triple_split,
@@ -51,6 +67,8 @@ impl Target {
                 .split(",")
                 .map(ToOwned::to_owned)
                 .collect(),
+            reliable_f128: rustc_cfg.lines().any(|l| l == "target_has_reliable_f128"),
+            reliable_f16: rustc_cfg.lines().any(|l| l == "target_has_reliable_f16"),
         }
     }
 
@@ -74,63 +92,24 @@ pub fn configure_aliases(target: &Target) {
     if target.triple_split[0] == "thumbv6m" || target.triple_split[0] == "thumbv8m.base" {
         println!("cargo:rustc-cfg=thumb_1")
     }
-}
-
-/// Configure whether or not `f16` and `f128` support should be enabled.
-pub fn configure_f16_f128(target: &Target) {
-    // Set whether or not `f16` and `f128` are supported at a basic level by LLVM. This only means
-    // that the backend will not crash when using these types and generates code that can be called
-    // without crashing (no infinite recursion). This does not mean that the platform doesn't have
-    // ABI or other bugs.
-    //
-    // We do this here rather than in `rust-lang/rust` because configuring via cargo features is
-    // not straightforward.
-    //
-    // Original source of this list:
-    // <https://github.com/rust-lang/compiler-builtins/pull/652#issuecomment-2266151350>
-    let f16_enabled = match target.arch.as_str() {
-        // Unsupported <https://github.com/llvm/llvm-project/issues/94434>
-        "arm64ec" => false,
-        // Selection failure <https://github.com/llvm/llvm-project/issues/50374>
-        "s390x" => false,
-        // Infinite recursion <https://github.com/llvm/llvm-project/issues/97981>
-        "csky" => false,
-        "hexagon" => false,
-        "powerpc" | "powerpc64" => false,
-        "sparc" | "sparc64" => false,
-        "wasm32" | "wasm64" => false,
-        // Most everything else works as of LLVM 19
-        _ => true,
-    };
 
-    let f128_enabled = match target.arch.as_str() {
-        // Unsupported (libcall is not supported) <https://github.com/llvm/llvm-project/issues/121122>
-        "amdgpu" => false,
-        // Unsupported <https://github.com/llvm/llvm-project/issues/94434>
-        "arm64ec" => false,
-        // FIXME(llvm20): fixed by <https://github.com/llvm/llvm-project/pull/117525>
-        "mips64" | "mips64r6" => false,
-        // Selection failure <https://github.com/llvm/llvm-project/issues/95471>
-        "nvptx64" => false,
-        // Selection failure <https://github.com/llvm/llvm-project/issues/101545>
-        "powerpc64" if &target.os == "aix" => false,
-        // Selection failure <https://github.com/llvm/llvm-project/issues/41838>
-        "sparc" => false,
-        // Most everything else works as of LLVM 19
-        _ => true,
-    };
+    /* Not all backends support `f16` and `f128` to the same level on all architectures, so we
+     * need to disable things if the compiler may crash. See configuration at:
+     * * https://github.com/rust-lang/rust/blob/c65dccabacdfd6c8a7f7439eba13422fdd89b91e/compiler/rustc_codegen_llvm/src/llvm_util.rs#L367-L432
+     * * https://github.com/rust-lang/rustc_codegen_gcc/blob/4b5c44b14166083eef8d71f15f5ea1f53fc976a0/src/lib.rs#L496-L507
+     * * https://github.com/rust-lang/rustc_codegen_cranelift/blob/c713ffab3c6e28ab4b4dd4e392330f786ea657ad/src/lib.rs#L196-L226
+     */
 
-    // If the feature is set, disable these types.
-    let disable_both = env::var_os("CARGO_FEATURE_NO_F16_F128").is_some();
+    // If the feature is set, disable both of these types.
+    let no_f16_f128 = target.cargo_features.iter().any(|s| s == "no-f16-f128");
 
     println!("cargo::rustc-check-cfg=cfg(f16_enabled)");
-    println!("cargo::rustc-check-cfg=cfg(f128_enabled)");
-
-    if f16_enabled && !disable_both {
+    if target.reliable_f16 && !no_f16_f128 {
         println!("cargo::rustc-cfg=f16_enabled");
     }
 
-    if f128_enabled && !disable_both {
+    println!("cargo::rustc-check-cfg=cfg(f128_enabled)");
+    if target.reliable_f128 && !no_f16_f128 {
         println!("cargo::rustc-cfg=f128_enabled");
     }
 }

library/compiler-builtins/compiler-builtins/src/aarch64.rs

@@ -5,7 +5,7 @@ use core::intrinsics;
 intrinsics! {
     #[unsafe(naked)]
     #[cfg(all(target_os = "uefi", not(feature = "no-asm")))]
-    pub unsafe extern "C" fn __chkstk() {
+    pub unsafe extern "custom" fn __chkstk() {
         core::arch::naked_asm!(
             ".p2align 2",
             "lsl    x16, x15, #4",

library/compiler-builtins/compiler-builtins/src/arm.rs

@@ -9,19 +9,18 @@ unsafe extern "C" {
 }
 
 // SAFETY: these are defined in compiler-builtins
-// FIXME(extern_custom), this isn't always the correct ABI
-unsafe extern "aapcs" {
+unsafe extern "custom" {
     // AAPCS is not always the correct ABI for these intrinsics, but we only use this to
     // forward another `__aeabi_` call so it doesn't matter.
-    fn __aeabi_idiv(a: i32, b: i32) -> i32;
+    fn __aeabi_idiv();
 }
 
 intrinsics! {
     // NOTE This function and the ones below are implemented using assembly because they are using a
     // custom calling convention which can't be implemented using a normal Rust function.
     #[unsafe(naked)]
     #[cfg(not(target_env = "msvc"))]
-    pub unsafe extern "C" fn __aeabi_uidivmod() {
+    pub unsafe extern "custom" fn __aeabi_uidivmod() {
         core::arch::naked_asm!(
             "push {{lr}}",
             "sub sp, sp, #4",
@@ -35,7 +34,7 @@ intrinsics! {
     }
 
     #[unsafe(naked)]
-    pub unsafe extern "C" fn __aeabi_uldivmod() {
+    pub unsafe extern "custom" fn __aeabi_uldivmod() {
         core::arch::naked_asm!(
             "push {{r4, lr}}",
             "sub sp, sp, #16",
@@ -51,7 +50,7 @@ intrinsics! {
     }
 
     #[unsafe(naked)]
-    pub unsafe extern "C" fn __aeabi_idivmod() {
+    pub unsafe extern "custom" fn __aeabi_idivmod() {
         core::arch::naked_asm!(
             "push {{r0, r1, r4, lr}}",
             "bl {trampoline}",
@@ -64,7 +63,7 @@ intrinsics! {
     }
 
     #[unsafe(naked)]
-    pub unsafe extern "C" fn __aeabi_ldivmod() {
+    pub unsafe extern "custom" fn __aeabi_ldivmod() {
         core::arch::naked_asm!(
             "push {{r4, lr}}",
             "sub sp, sp, #16",
@@ -135,8 +134,8 @@ intrinsics! {
     /// eight bytes.
     #[cfg(not(target_vendor = "apple"))]
     pub unsafe extern "aapcs" fn __aeabi_memcpy8(dst: *mut u8, src: *const u8, n: usize) {
-        debug_assert!(dst.addr() & 7 == 0);
-        debug_assert!(src.addr() & 7 == 0);
+        debug_assert!(dst.addr().is_multiple_of(8));
+        debug_assert!(src.addr().is_multiple_of(8));
 
         // SAFETY: memcpy preconditions apply, less strict alignment.
         unsafe { __aeabi_memcpy4(dst, src, n) };
@@ -161,8 +160,8 @@ intrinsics! {
     /// four bytes.
     #[cfg(not(any(target_vendor = "apple", target_env = "msvc")))]
     pub unsafe extern "aapcs" fn __aeabi_memmove4(dst: *mut u8, src: *const u8, n: usize) {
-        debug_assert!(dst.addr() & 3 == 0);
-        debug_assert!(src.addr() & 3 == 0);
+        debug_assert!(dst.addr().is_multiple_of(4));
+        debug_assert!(src.addr().is_multiple_of(4));
 
         // SAFETY: same preconditions, less strict aligment.
         unsafe { __aeabi_memmove(dst, src, n) };
@@ -176,8 +175,8 @@ intrinsics! {
     /// eight bytes.
     #[cfg(not(any(target_vendor = "apple", target_env = "msvc")))]
     pub unsafe extern "aapcs" fn __aeabi_memmove8(dst: *mut u8, src: *const u8, n: usize) {
-        debug_assert!(dst.addr() & 7 == 0);
-        debug_assert!(src.addr() & 7 == 0);
+        debug_assert!(dst.addr().is_multiple_of(8));
+        debug_assert!(src.addr().is_multiple_of(8));
 
         // SAFETY: memmove preconditions apply, less strict alignment.
         unsafe { __aeabi_memmove(dst, src, n) };
@@ -236,7 +235,7 @@ intrinsics! {
     /// eight bytes.
     #[cfg(not(target_vendor = "apple"))]
     pub unsafe extern "aapcs" fn __aeabi_memset8(dst: *mut u8, n: usize, c: i32) {
-        debug_assert!(dst.addr() & 7 == 0);
+        debug_assert!(dst.addr().is_multiple_of(8));
 
         // SAFETY: memset preconditions apply, less strict alignment.
         unsafe { __aeabi_memset4(dst, n, c) };
@@ -261,7 +260,7 @@ intrinsics! {
     /// four bytes.
     #[cfg(not(any(target_vendor = "apple", target_env = "msvc")))]
     pub unsafe extern "aapcs" fn __aeabi_memclr4(dst: *mut u8, n: usize) {
-        debug_assert!(dst.addr() & 3 == 0);
+        debug_assert!(dst.addr().is_multiple_of(4));
 
         // SAFETY: memclr preconditions apply, less strict alignment.
         unsafe { __aeabi_memset4(dst, n, 0) };
@@ -275,7 +274,7 @@ intrinsics! {
     /// eight bytes.
     #[cfg(not(any(target_vendor = "apple", target_env = "msvc")))]
     pub unsafe extern "aapcs" fn __aeabi_memclr8(dst: *mut u8, n: usize) {
-        debug_assert!(dst.addr() & 7 == 0);
+        debug_assert!(dst.addr().is_multiple_of(8));
 
         // SAFETY: memclr preconditions apply, less strict alignment.
         unsafe { __aeabi_memset4(dst, n, 0) };

library/compiler-builtins/compiler-builtins/src/int/udiv.rs

@@ -44,7 +44,7 @@ intrinsics! {
     }
 
     #[unsafe(naked)]
-    pub unsafe extern "C" fn __udivmodqi4() {
+    pub unsafe extern "custom" fn __udivmodqi4() {
         // compute unsigned 8-bit `n / d` and `n % d`.
         //
         // Note: GCC implements a [non-standard calling convention](https://gcc.gnu.org/wiki/avr-gcc#Exceptions_to_the_Calling_Convention) for this function.