Rollup merge of rust-lang#133395 - calebzulawski:simd_relaxed_fma, r=workingjubilee

matthiaskrgr · web-flow · commit c5acac93fd6d · 2024-12-03T07:48:33.000+01:00
Add simd_relaxed_fma intrinsic Adds compiler support for rust-lang/portable-simd#387 (comment) r? `@workingjubilee` cc `@RalfJung` is this kind of nondeterminism a problem for miri/opsem?
diff --git a/src/intrinsics/simd.rs b/src/intrinsics/simd.rs
@@ -415,7 +415,8 @@ pub(super) fn codegen_simd_intrinsic_call<'tcx>(
             });
         }
 
-        sym::simd_fma => {
+        // FIXME: simd_relaxed_fma doesn't relax to non-fused multiply-add
+        sym::simd_fma | sym::simd_relaxed_fma => {
             intrinsic_args!(fx, args => (a, b, c); intrinsic);
 
             if !a.layout().ty.is_simd() {

Original file line number	Diff line number	Diff line change
`@@ -415,7 +415,8 @@ pub(super) fn codegen_simd_intrinsic_call<'tcx>(`
`415`	`415`	`});`
`416`	`416`	`}`
`417`	`417`
`418`		`- sym::simd_fma => {`
	`418`	`+ // FIXME: simd_relaxed_fma doesn't relax to non-fused multiply-add`
	`419`	`+ sym::simd_fma \| sym::simd_relaxed_fma => {`
`419`	`420`	`intrinsic_args!(fx, args => (a, b, c); intrinsic);`
`420`	`421`
`421`	`422`	`if !a.layout().ty.is_simd() {`