From 3f290ab44d31263637053c3c1ef47ad89d2c4c07 Mon Sep 17 00:00:00 2001
From: Trevor Gross <tmgross@umich.edu>
Date: Tue, 4 Mar 2025 17:46:50 -0500
Subject: [PATCH] Simplify test crate build features

Since we have a handful of different float-related configuration in
testcrate, track a list of which are implied by others rather than
repeating the config.
---
 testcrate/benches/float_conv.rs |  2 +-
 testcrate/build.rs              | 31 ++++++++++++++++++++++++-------
 2 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/testcrate/benches/float_conv.rs b/testcrate/benches/float_conv.rs
index 0625a1ae5..7d8549b43 100644
--- a/testcrate/benches/float_conv.rs
+++ b/testcrate/benches/float_conv.rs
@@ -665,7 +665,7 @@ pub fn float_conv() {
     conv_f64_i64(&mut criterion);
     conv_f64_i128(&mut criterion);
 
-    #[cfg(all(f128_enabled))]
+    #[cfg(f128_enabled)]
     // FIXME: ppc64le has a sporadic overflow panic in the crate functions
     // <https://github.com/rust-lang/compiler-builtins/issues/617#issuecomment-2125914639>
     #[cfg(not(all(target_arch = "powerpc64", target_endian = "little")))]
diff --git a/testcrate/build.rs b/testcrate/build.rs
index 3e5f780ac..427fa799b 100644
--- a/testcrate/build.rs
+++ b/testcrate/build.rs
@@ -1,7 +1,11 @@
 use std::collections::HashSet;
 
+mod builtins_configure {
+    include!("../configure.rs");
+}
+
 /// Features to enable
-#[derive(Debug, PartialEq, Eq, Hash)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 enum Feature {
     NoSysF128,
     NoSysF128IntConvert,
@@ -10,8 +14,16 @@ enum Feature {
     NoSysF16F128Convert,
 }
 
-mod builtins_configure {
-    include!("../configure.rs");
+impl Feature {
+    fn implies(self) -> &'static [Self] {
+        match self {
+            Self::NoSysF128 => [Self::NoSysF128IntConvert, Self::NoSysF16F128Convert].as_slice(),
+            Self::NoSysF128IntConvert => [].as_slice(),
+            Self::NoSysF16 => [Self::NoSysF16F64Convert, Self::NoSysF16F128Convert].as_slice(),
+            Self::NoSysF16F64Convert => [].as_slice(),
+            Self::NoSysF16F128Convert => [].as_slice(),
+        }
+    }
 }
 
 fn main() {
@@ -40,8 +52,6 @@ fn main() {
         || target.arch == "powerpc64"
     {
         features.insert(Feature::NoSysF128);
-        features.insert(Feature::NoSysF128IntConvert);
-        features.insert(Feature::NoSysF16F128Convert);
     }
 
     if target.arch == "x86" {
@@ -67,8 +77,6 @@ fn main() {
         || target.arch == "wasm64"
     {
         features.insert(Feature::NoSysF16);
-        features.insert(Feature::NoSysF16F64Convert);
-        features.insert(Feature::NoSysF16F128Convert);
     }
 
     // These platforms are missing either `__extendhfdf2` or `__truncdfhf2`.
@@ -76,6 +84,15 @@ fn main() {
         features.insert(Feature::NoSysF16F64Convert);
     }
 
+    // Add implied features. Collection is required for borrows.
+    features.extend(
+        features
+            .iter()
+            .flat_map(|x| x.implies())
+            .copied()
+            .collect::<Vec<_>>(),
+    );
+
     for feature in features {
         let (name, warning) = match feature {
             Feature::NoSysF128 => ("no-sys-f128", "using apfloat fallback for f128"),