Unpin compiler-builtins

Co-authored-by: Antoni Boucher <bouanto@zoho.com>

Author: GuillaumeGomez

.github/workflows/m68k.yml

@@ -85,14 +85,14 @@ jobs:
     - name: Build sample project with target defined as JSON spec
       run: |
         ./y.sh prepare --only-libcore --cross
-        ./y.sh build --sysroot --target-triple m68k-unknown-linux-gnu --target ${{ github.workspace }}/target_specs/m68k-unknown-linux-gnu.json
+        ./y.sh build --sysroot --features compiler_builtins/no-f16-f128 --target-triple m68k-unknown-linux-gnu --target ${{ github.workspace }}/target_specs/m68k-unknown-linux-gnu.json
         ./y.sh cargo build --manifest-path=./tests/hello-world/Cargo.toml --target ${{ github.workspace }}/target_specs/m68k-unknown-linux-gnu.json
         ./y.sh clean all
 
     - name: Build
       run: |
         ./y.sh prepare --only-libcore --cross
-        ./y.sh build --sysroot --target-triple m68k-unknown-linux-gnu
+        ./y.sh build --sysroot --features compiler_builtins/no-f16-f128 --target-triple m68k-unknown-linux-gnu
         CG_GCC_TEST_TARGET=m68k-unknown-linux-gnu cargo test
         ./y.sh clean all
 
@@ -107,4 +107,4 @@ jobs:
 
     - name: Run tests
       run: |
-        ./y.sh test --release --clean --build-sysroot ${{ matrix.commands }}
+        ./y.sh test --release --clean --build-sysroot --sysroot-features compiler_builtins/no-f16-f128 ${{ matrix.commands }}

build_system/build_sysroot/Cargo.toml

@@ -17,6 +17,22 @@ rustc-std-workspace-core = { path = "./sysroot_src/library/rustc-std-workspace-c
 rustc-std-workspace-alloc = { path = "./sysroot_src/library/rustc-std-workspace-alloc" }
 rustc-std-workspace-std = { path = "./sysroot_src/library/rustc-std-workspace-std" }
 
+# For compiler-builtins we always use a high number of codegen units.
+# The goal here is to place every single intrinsic into its own object
+# file to avoid symbol clashes with the system libgcc if possible. Note
+# that this number doesn't actually produce this many object files, we
+# just don't create more than this number of object files.
+#
+# It's a bit of a bummer that we have to pass this here, unfortunately.
+# Ideally this would be specified through an env var to Cargo so Cargo
+# knows how many CGUs are for this specific crate, but for now
+# per-crate configuration isn't specifiable in the environment.
+[profile.dev.package.compiler_builtins]
+codegen-units = 10000
+
+[profile.release.package.compiler_builtins]
+codegen-units = 10000
+
 [profile.release]
 debug = "limited"
 #lto = "fat" # TODO(antoyo): re-enable when the failing LTO tests regarding proc-macros are fixed.

build_system/src/build.rs

@@ -24,16 +24,6 @@ impl BuildArg {
 
         while let Some(arg) = args.next() {
             match arg.as_str() {
-                "--features" => {
-                    if let Some(arg) = args.next() {
-                        build_arg.flags.push("--features".to_string());
-                        build_arg.flags.push(arg.as_str().into());
-                    } else {
-                        return Err(
-                            "Expected a value after `--features`, found nothing".to_string()
-                        );
-                    }
-                }
                 "--sysroot" => {
                     build_arg.build_sysroot = true;
                 }
@@ -56,7 +46,6 @@ impl BuildArg {
             r#"
 `build` command help:
 
-    --features [arg]       : Add a new feature [arg]
     --sysroot              : Build with sysroot"#
         );
         ConfigInfo::show_usage();
@@ -150,6 +139,10 @@ pub fn build_sysroot(env: &HashMap<String, String>, config: &ConfigInfo) -> Resu
         &"--features",
         &"std/compiler-builtins-no-f16-f128",
     ];
+    for feature in &config.features {
+        args.push(&"--features");
+        args.push(feature);
+    }
 
     if config.no_default_features {
         rustflags.push_str(" -Csymbol-mangling-version=v0");

build_system/src/config.rs

@@ -98,7 +98,7 @@ impl ConfigFile {
     }
 }
 
-#[derive(Default, Debug)]
+#[derive(Default, Debug, Clone)]
 pub struct ConfigInfo {
     pub target: String,
     pub target_triple: String,
@@ -123,6 +123,7 @@ pub struct ConfigInfo {
     pub no_download: bool,
     pub no_default_features: bool,
     pub backend: Option<String>,
+    pub features: Vec<String>,
 }
 
 impl ConfigInfo {
@@ -133,6 +134,13 @@ impl ConfigInfo {
         args: &mut impl Iterator<Item = String>,
     ) -> Result<bool, String> {
         match arg {
+            "--features" => {
+                if let Some(arg) = args.next() {
+                    self.features.push(arg);
+                } else {
+                    return Err("Expected a value after `--features`, found nothing".to_string());
+                }
+            }
             "--target" => {
                 if let Some(arg) = args.next() {
                     self.target = arg;
@@ -443,6 +451,7 @@ impl ConfigInfo {
     pub fn show_usage() {
         println!(
             "\
+    --features [arg]       : Add a new feature [arg]
     --target-triple [arg]  : Set the target triple to [arg]
     --target [arg]         : Set the target to [arg]
     --out-dir              : Location where the files will be generated

build_system/src/test.rs

@@ -92,6 +92,7 @@ struct TestArg {
     current_part: Option<usize>,
     sysroot_panic_abort: bool,
     config_info: ConfigInfo,
+    sysroot_features: Vec<String>,
 }
 
 impl TestArg {
@@ -127,6 +128,14 @@ impl TestArg {
                 "--sysroot-panic-abort" => {
                     test_arg.sysroot_panic_abort = true;
                 }
+                "--sysroot-features" => match args.next() {
+                    Some(feature) if !feature.is_empty() => {
+                        test_arg.sysroot_features.push(feature);
+                    }
+                    _ => {
+                        return Err(format!("Expected an argument after `{}`, found nothing", arg))
+                    }
+                },
                 "--help" => {
                     show_usage();
                     return Ok(None);
@@ -250,7 +259,9 @@ fn mini_tests(env: &Env, args: &TestArg) -> Result<(), String> {
 fn build_sysroot(env: &Env, args: &TestArg) -> Result<(), String> {
     // FIXME: create a function "display_if_not_quiet" or something along the line.
     println!("[BUILD] sysroot");
-    build::build_sysroot(env, &args.config_info)?;
+    let mut config = args.config_info.clone();
+    config.features.extend(args.sysroot_features.iter().cloned());
+    build::build_sysroot(env, &config)?;
     Ok(())
 }
 

src/context.rs

@@ -227,48 +227,14 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
             "__builtin_umul_overflow",
             "__builtin_usubll_overflow",
             "__builtin_usub_overflow",
-            "sqrtf",
-            "sqrt",
             "__builtin_powif",
             "__builtin_powi",
-            "sinf",
-            "sin",
-            "cosf",
-            "cos",
-            "powf",
-            "pow",
-            "expf",
-            "exp",
-            "exp2f",
-            "exp2",
-            "logf",
-            "log",
-            "log10f",
-            "log10",
-            "log2f",
-            "log2",
-            "fmaf",
-            "fma",
             "fabsf",
             "fabs",
-            "fminf",
-            "fmin",
-            "fmaxf",
-            "fmax",
             "copysignf",
             "copysign",
-            "floorf",
-            "floor",
-            "ceilf",
-            "ceil",
-            "truncf",
-            "trunc",
-            "rintf",
-            "rint",
             "nearbyintf",
             "nearbyint",
-            "roundf",
-            "round",
         ];
 
         for builtin in builtins.iter() {

src/intrinsic/mod.rs

@@ -127,20 +127,13 @@ impl<'a, 'gcc, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
         // https://github.com/rust-lang/rust-clippy/issues/12497
         // and leave `else if use_integer_compare` to be placed "as is".
         #[allow(clippy::suspicious_else_formatting)]
-        let llval = match name {
+        let value = match name {
             _ if simple.is_some() => {
-                // FIXME(antoyo): remove this cast when the API supports function.
-                let func = unsafe {
-                    std::mem::transmute::<Function<'gcc>, RValue<'gcc>>(simple.expect("simple"))
-                };
-                self.call(
-                    self.type_void(),
-                    None,
-                    None,
+                let func = simple.expect("simple function");
+                self.cx.context.new_call(
+                    self.location,
                     func,
                     &args.iter().map(|arg| arg.immediate()).collect::<Vec<_>>(),
-                    None,
-                    None,
                 )
             }
             sym::likely => self.expect(args[0].immediate(), true),
@@ -383,7 +376,7 @@ impl<'a, 'gcc, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
 
             _ if name_str.starts_with("simd_") => {
                 match generic_simd_intrinsic(self, name, callee_ty, args, ret_ty, llret_ty, span) {
-                    Ok(llval) => llval,
+                    Ok(value) => value,
                     Err(()) => return Ok(()),
                 }
             }
@@ -396,9 +389,9 @@ impl<'a, 'gcc, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
             if let PassMode::Cast { cast: ref ty, .. } = fn_abi.ret.mode {
                 let ptr_llty = self.type_ptr_to(ty.gcc_type(self));
                 let ptr = self.pointercast(result.val.llval, ptr_llty);
-                self.store(llval, ptr, result.val.align);
+                self.store(value, ptr, result.val.align);
             } else {
-                OperandRef::from_immediate_or_packed_pair(self, llval, result.layout)
+                OperandRef::from_immediate_or_packed_pair(self, value, result.layout)
                     .val
                     .store(self, result);
             }

src/intrinsic/simd.rs

@@ -763,10 +763,7 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
             _ => return_error!(InvalidMonomorphization::UnrecognizedIntrinsic { span, name }),
         };
         let builtin_name = format!("{}{}", intr_name, elem_ty_str);
-        let funcs = bx.cx.functions.borrow();
-        let function = funcs
-            .get(&builtin_name)
-            .unwrap_or_else(|| panic!("unable to find builtin function {}", builtin_name));
+        let function = bx.context.get_builtin_function(builtin_name);
 
         // TODO(antoyo): add platform-specific behavior here for architectures that have these
         // intrinsics as instructions (for instance, gpus)
@@ -784,7 +781,7 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
                     .map(|arg| bx.extract_element(arg.immediate(), index).to_rvalue())
                     .collect()
             };
-            vector_elements.push(bx.context.new_call(None, *function, &arguments));
+            vector_elements.push(bx.context.new_call(None, function, &arguments));
         }
         let c = bx.context.new_rvalue_from_vector(None, vec_ty, &vector_elements);
         Ok(c)