update

Author: tgross35

libm/configure.rs

@@ -35,7 +35,8 @@ impl Config {
 
         let target_arch = env::var("CARGO_CFG_TARGET_ARCH").unwrap();
         // Symbols are missing so we can't test until they get to nightly
-        let bootstrapping_f128 = target_arch == "x86" || target_arch == "s390x";
+        let bootstrapping_f16 = target_arch == "s390x";
+        let bootstrapping_f128 = target_arch == "x86";
 
         Self {
             target_triple,
@@ -52,8 +53,8 @@ impl Config {
             target_features,
             // Note that these are unstable options, so only show up with the nightly compiler or
             // with `RUSTC_BOOTSTRAP=1` (which is required to use the types anyway).
-            // reliable_f16: env::var_os("CARGO_CFG_TARGET_HAS_RELIABLE_F16").is_some(),
-            reliable_f16: true,
+            reliable_f16: env::var_os("CARGO_CFG_TARGET_HAS_RELIABLE_F16").is_some()
+                && !bootstrapping_f16,
             reliable_f128: env::var_os("CARGO_CFG_TARGET_HAS_RELIABLE_F128").is_some()
                 && !bootstrapping_f128,
         }