x64: Fix has_native_fma (#11794)

alexcrichton · web-flow · commit 0ac154bdd065 · 2025-10-06T19:21:58.000Z
This commit synchronizes the implementation of lowering and
`has_native_fma` where lowering requires both AVX + FMA but
`has_native_fma` was just testing FMA, meaning that if `has_fma` was
enabled but `has_avx` was disabled it would be possible to generate a
link-time error with Wasmtime.
diff --git a/cranelift/codegen/src/isa/x64/mod.rs b/cranelift/codegen/src/isa/x64/mod.rs
@@ -177,7 +177,7 @@ impl TargetIsa for X64Backend {
     }
 
     fn has_native_fma(&self) -> bool {
-        self.x64_flags.has_fma()
+        self.x64_flags.has_avx() && self.x64_flags.has_fma()
     }
 
     fn has_round(&self) -> bool {

Original file line number	Diff line number	Diff line change
`@@ -177,7 +177,7 @@ impl TargetIsa for X64Backend {`
`177`	`177`	`}`
`178`	`178`
`179`	`179`	`fn has_native_fma(&self) -> bool {`
`180`		`- self.x64_flags.has_fma()`
	`180`	`+ self.x64_flags.has_avx() && self.x64_flags.has_fma()`
`181`	`181`	`}`
`182`	`182`
`183`	`183`	`fn has_round(&self) -> bool {`