Ensure the other compilers consistently handle both get_IsHardwareAccelerated and get_IsSupported

[tannergooding]

These checks frequently appear in generic and other code allowing early dead code elimination. They should be consistently handled to avoid pessimizing things.

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[Copilot]

Pull request overview

This PR updates multiple runtime backends (Mono mini JIT, Mono interpreter, and CoreCLR interpreter) to recognize and fold both get_IsHardwareAccelerated and get_IsSupported for vector APIs, and refactors CoreLib’s Vector*<T>.IsSupported implementations to delegate to Scalar<T>.IsSupported.

Changes:

• Mono mini JIT: return a constant false for Vector256/Vector512.*.get_IsHardwareAccelerated instead of falling back to managed.
• Mono interpreter + CoreCLR interpreter: add/extend intrinsic recognition to fold get_IsSupported (and keep folding get_IsHardwareAccelerated).
• CoreLib: replace per-type typeof(T) == ... chains in Vector64/128/256/512<T>.IsSupported with Scalar<T>.IsSupported.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/mono/mono/mini/simd-intrinsics.c	Adds constant-folding for get_IsHardwareAccelerated on unsupported vector sizes (256/512).
src/mono/mono/mini/interp/transform.c	Extends interpreter intrinsic handling to fold get_IsSupported for relevant Vector APIs.
src/mono/mono/mini/interp/transform-simd.c	Expands SIMD intrinsic handling across Vector sizes and adds get_IsSupported handling.
src/libraries/System.Private.CoreLib/src/System/Runtime/Intrinsics/Vector64_1.cs	Refactors IsSupported to use Scalar<T>.IsSupported.
src/libraries/System.Private.CoreLib/src/System/Runtime/Intrinsics/Vector128_1.cs	Refactors IsSupported to use Scalar<T>.IsSupported.
src/libraries/System.Private.CoreLib/src/System/Runtime/Intrinsics/Vector256_1.cs	Refactors IsSupported to use Scalar<T>.IsSupported.
src/libraries/System.Private.CoreLib/src/System/Runtime/Intrinsics/Vector512_1.cs	Refactors IsSupported to use Scalar<T>.IsSupported.
src/coreclr/interpreter/intrinsics.cpp	Adds recognition for get_IsSupported on System.Runtime.Intrinsics.Vector* types.
src/coreclr/interpreter/compiler.cpp	Implements NI_IsSupported_Type expansion to a constant based on the generic type argument.

Comments suppressed due to low confidence (1)

src/mono/mono/mini/interp/transform-simd.c:552

• emit_sri_vector only identifies the vector type from a generic-inst return or first parameter. For explicit ISimdVector<...,T>.get_IsHardwareAccelerated (and other vector-less members), the signature has no MONO_TYPE_GENERICINST, so this returns FALSE and the interpreter won't constant-fold the check. If the intent is to fold these calls, consider also using cmethod->klass when it's a SIMD generic instance (or special-casing SN_get_IsHardwareAccelerated/SN_get_IsSupported before the vector_klass inference).

	gint16 simd_opcode = -1;
	gint16 simd_intrins = -1;

	if (csignature->ret->type == MONO_TYPE_GENERICINST) {
		vector_klass = mono_class_from_mono_type_internal (csignature->ret);
	} else if (csignature->param_count && csignature->params [0]->type == MONO_TYPE_GENERICINST) {
		vector_klass = mono_class_from_mono_type_internal (csignature->params [0]);
	} else {
		return FALSE;
	}

[Copilot]

Pull request overview

Copilot reviewed 10 out of 10 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 10 out of 10 changed files in this pull request and generated 2 comments.

Comments suppressed due to low confidence (1)

src/mono/mono/mini/interp/transform-simd.c:552

• emit_sri_vector() no longer successfully handles Vector64/Vector128/Vector256/Vector512.get_IsHardwareAccelerated: those APIs return bool and have no genericinst return/arg, so the current vector_klass discovery falls into the final return FALSE; (lines 546-552). As a result, the SIMD path won’t fold IsHardwareAccelerated to true when SIMD intrinsics are enabled (it will fall back to interp_handle_intrinsics, which folds it to false), and the later if (id == SN_get_IsHardwareAccelerated) { ... MINT_LDC_I4_1 ... } becomes effectively unreachable. Consider restoring an early special-case for SN_get_IsHardwareAccelerated (before requiring a genericinst) that bases the result on the declaring Vector* type/size (e.g., true for supported sizes, false for unsupported ones).

	const char *cmethod_name = strip_explicit_isimd_prefix (cmethod->name);

	int id = lookup_intrins (sri_vector_methods, sizeof (sri_vector_methods), cmethod_name);
	if (id == -1)
		return FALSE;

	MonoClass *vector_klass = NULL;
	int vector_size = 0;

	gint16 simd_opcode = -1;
	gint16 simd_intrins = -1;

	if (csignature->ret->type == MONO_TYPE_GENERICINST) {
		vector_klass = mono_class_from_mono_type_internal (csignature->ret);
	} else if (csignature->param_count && csignature->params [0]->type == MONO_TYPE_GENERICINST) {
		vector_klass = mono_class_from_mono_type_internal (csignature->params [0]);
	} else {
		return FALSE;
	}

[Copilot]

Pull request overview

Copilot reviewed 10 out of 10 changed files in this pull request and generated no new comments.

[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 2 comments.