more bootstrapping

Author: tgross35

builtins-test/src/lib.rs

@@ -407,11 +407,20 @@ macro_rules! apfloat_fallback {
 
 mod bootstrap {
     // Needed for testing other symbols,
-    #[linkage = "weak"]
-    #[unsafe(no_mangle)]
     #[cfg(f16_enabled)]
     #[cfg(target_arch = "s390x")]
+    #[linkage = "weak"]
+    #[unsafe(no_mangle)]
     pub extern "C" fn __extendhfsf2(a: f16) -> f32 {
         compiler_builtins::float::extend::__extendhfsf2(a)
     }
+
+    #[cfg(f16_enabled)]
+    #[cfg(f128_enabled)]
+    #[cfg(target_arch = "x86")]
+    #[linkage = "weak"]
+    #[unsafe(no_mangle)]
+    pub extern "C" fn __extenddftf2(a: f64) -> f128 {
+        compiler_builtins::float::extend::__extenddftf2(a)
+    }
 }

libm/configure.rs

@@ -34,7 +34,7 @@ impl Config {
             .collect();
 
         let target_arch = env::var("CARGO_CFG_TARGET_ARCH").unwrap();
-        let bootstrapping_f16 = target_arch == "x86";
+        let bootstrapping_f128 = target_arch == "x86";
 
         Self {
             target_triple,
@@ -53,8 +53,8 @@ impl Config {
             // with `RUSTC_BOOTSTRAP=1` (which is required to use the types anyway).
             // reliable_f128: env::var_os("CARGO_CFG_TARGET_HAS_RELIABLE_F128").is_some(),
             // reliable_f16: env::var_os("CARGO_CFG_TARGET_HAS_RELIABLE_F16").is_some(),
-            reliable_f16: !bootstrapping_f16,
-            reliable_f128: true,
+            reliable_f16: true,
+            reliable_f128: bootstrapping_f128,
         }
     }
 }