Rustup to rustc 1.54.0-nightly (881c1ac40 2021-05-08)

[rust.git] / src / lib.rs

diff --git a/src/lib.rs b/src/lib.rs
index 5a75b9be0cb690d96e6b5866a81cf938f82f9be5..61b6316b973df261b52d50f89e7600a1a9385364 100644 (file)
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -272,10 +272,30 @@ fn build_isa(sess: &Session, backend_config: &BackendConfig) -> Box<dyn isa::Tar
     let flags = settings::Flags::new(flags_builder);
 
     let variant = cranelift_codegen::isa::BackendVariant::MachInst;
-    let mut isa_builder = cranelift_codegen::isa::lookup_variant(target_triple, variant).unwrap();
-    // Don't use "haswell", as it implies `has_lzcnt`.macOS CI is still at Ivy Bridge EP, so `lzcnt`
-    // is interpreted as `bsr`.
-    isa_builder.enable("nehalem").unwrap();
+
+    let isa_builder = match sess.opts.cg.target_cpu.as_deref() {
+        Some("native") => {
+            let builder = cranelift_native::builder_with_options(variant, true).unwrap();
+            builder
+        }
+        Some(value) => {
+            let mut builder =
+                cranelift_codegen::isa::lookup_variant(target_triple, variant).unwrap();
+            if let Err(_) = builder.enable(value) {
+                sess.fatal("The specified target cpu isn't currently supported by Cranelift.");
+            }
+            builder
+        }
+        None => {
+            let mut builder =
+                cranelift_codegen::isa::lookup_variant(target_triple, variant).unwrap();
+            // Don't use "haswell" as the default, as it implies `has_lzcnt`.
+            // macOS CI is still at Ivy Bridge EP, so `lzcnt` is interpreted as `bsr`.
+            builder.enable("nehalem").unwrap();
+            builder
+        }
+    };
+
     isa_builder.finish(flags)
 }