[mono] Remove some of the restrictions on constrained calls from gsharevt methods. (#21470)

This is a backport of https://github.com/dotnet/runtime/pull/59182.

3 files changed, 43 insertions, 24 deletions

diff --git a/mono/mini/jit-icalls.c b/mono/mini/jit-icalls.c
index 3104418350c..dd63bc68ed7 100644
--- a/mono/mini/jit-icalls.c
+++ b/mono/mini/jit-icalls.c
@@ -1412,7 +1412,7 @@ constrained_gsharedvt_call_setup (gpointer mp, MonoMethod *cmethod, MonoClass *k
  * the arguments to the method in the format used by mono_runtime_invoke_checked ().
  */
 MonoObject*
-mono_gsharedvt_constrained_call (gpointer mp, MonoMethod *cmethod, MonoClass *klass, gboolean deref_arg, gpointer *args)
+mono_gsharedvt_constrained_call (gpointer mp, MonoMethod *cmethod, MonoClass *klass, guint8 *deref_args, gpointer *args)
 {
 	ERROR_DECL (error);
 	MonoObject *o;
@@ -1429,8 +1429,15 @@ mono_gsharedvt_constrained_call (gpointer mp, MonoMethod *cmethod, MonoClass *kl
 
 	if (!m)
 		return NULL;
-	if (args && deref_arg) {
-		new_args [0] = *(gpointer*)args [0];
+	if (deref_args) {
+		/* Have to deref gsharedvt ref arguments since the runtime invoke expects it */
+		MonoMethodSignature *fsig = mono_method_signature_internal (m);
+		g_assert (fsig->param_count < 16);
+		memcpy (new_args, args, fsig->param_count * sizeof (gpointer));
+		for (int i = 0; i < fsig->param_count; ++i) {
+			if (deref_args [i])
+				new_args [i] = *(gpointer*)new_args [i];
+		}
 		args = new_args;
 	}
 	if (m->wrapper_type == MONO_WRAPPER_MANAGED_TO_NATIVE) {
diff --git a/mono/mini/jit-icalls.h b/mono/mini/jit-icalls.h
index 7de1133c0e4..72af13f2640 100644
--- a/mono/mini/jit-icalls.h
+++ b/mono/mini/jit-icalls.h
@@ -205,7 +205,7 @@ ICALL_EXPORT
 void
 ves_icall_mono_delegate_ctor_interp (MonoObject *this_obj, MonoObject *target, gpointer addr);
 
-ICALL_EXTERN_C MonoObject* mono_gsharedvt_constrained_call (gpointer mp, MonoMethod *cmethod, MonoClass *klass, gboolean deref_arg, gpointer *args);
+ICALL_EXTERN_C MonoObject* mono_gsharedvt_constrained_call (gpointer mp, MonoMethod *cmethod, MonoClass *klass, guint8 *deref_args, gpointer *args);
 
 ICALL_EXTERN_C void mono_gsharedvt_value_copy (gpointer dest, gpointer src, MonoClass *klass);
 
diff --git a/mono/mini/method-to-ir.c b/mono/mini/method-to-ir.c
index 0944915708b..6e3a4860ded 100644
--- a/mono/mini/method-to-ir.c
+++ b/mono/mini/method-to-ir.c
@@ -3729,13 +3729,10 @@ handle_constrained_gsharedvt_call (MonoCompile *cfg, MonoMethod *cmethod, MonoMe
 		if (fsig->param_count == 0 || (!fsig->hasthis && fsig->param_count == 1)) {
 			supported = TRUE;
 		} else {
-			/* Allow scalar parameters and a gsharedvt first parameter */
-			supported = MONO_TYPE_IS_PRIMITIVE (fsig->params [0]) || MONO_TYPE_IS_REFERENCE (fsig->params [0]) || fsig->params [0]->byref || mini_is_gsharedvt_type (fsig->params [0]);
-			if (supported) {
-				for (int i = 1; i < fsig->param_count; ++i) {
-					if (!(fsig->params [i]->byref || MONO_TYPE_IS_PRIMITIVE (fsig->params [i]) || MONO_TYPE_IS_REFERENCE (fsig->params [i]) || MONO_TYPE_ISSTRUCT (fsig->params [i])))
-						supported = FALSE;
-				}
+			supported = TRUE;
+			for (int i = 0; i < fsig->param_count; ++i) {
+				if (!(fsig->params [i]->byref || MONO_TYPE_IS_PRIMITIVE (fsig->params [i]) || MONO_TYPE_IS_REFERENCE (fsig->params [i]) || MONO_TYPE_ISSTRUCT (fsig->params [i]) || mini_is_gsharedvt_type (fsig->params [i])))
+					supported = FALSE;
 			}
 		}
 	}
@@ -3756,7 +3753,22 @@ handle_constrained_gsharedvt_call (MonoCompile *cfg, MonoMethod *cmethod, MonoMe
 
 		/* !fsig->hasthis is for the wrapper for the Object.GetType () icall */
 		if (fsig->hasthis && fsig->param_count) {
-			/* Call mono_gsharedvt_constrained_call (gpointer mp, MonoMethod *cmethod, MonoClass *klass, gboolean deref_arg, gpointer *args) */
+			/* Call mono_gsharedvt_constrained_call (gpointer mp, MonoMethod *cmethod, MonoClass *klass, gboolean *deref_args, gpointer *args) */
+			gboolean has_gsharedvt = FALSE;
+			for (int i = 0; i < fsig->param_count; ++i) {
+				if (mini_is_gsharedvt_type (fsig->params [i]))
+					has_gsharedvt = TRUE;
+			}
+			/* Pass an array of bools which signal whenever the corresponding argument is a gsharedvt ref type */
+			if (has_gsharedvt) {
+				MONO_INST_NEW (cfg, ins, OP_LOCALLOC_IMM);
+				ins->dreg = alloc_preg (cfg);
+				ins->inst_imm = fsig->param_count;
+				MONO_ADD_INS (cfg->cbb, ins);
+				args [3] = ins;
+			} else {
+				EMIT_NEW_PCONST (cfg, args [3], 0);
+			}
 			/* Pass the arguments using a localloc-ed array using the format expected by runtime_invoke () */
 			MONO_INST_NEW (cfg, ins, OP_LOCALLOC_IMM);
 			ins->dreg = alloc_preg (cfg);
@@ -3764,21 +3776,21 @@ handle_constrained_gsharedvt_call (MonoCompile *cfg, MonoMethod *cmethod, MonoMe
 			MONO_ADD_INS (cfg->cbb, ins);
 			args [4] = ins;
 
-			/* Only the first argument is allowed to be gsharedvt */
-			/* args [3] = deref_arg */
-			if (mini_is_gsharedvt_type (fsig->params [0])) {
-				int deref_arg_reg;
-				ins = mini_emit_get_gsharedvt_info_klass (cfg, mono_class_from_mono_type_internal (fsig->params [0]), MONO_RGCTX_INFO_CLASS_BOX_TYPE);
-				deref_arg_reg = alloc_preg (cfg);
-				/* deref_arg = BOX_TYPE != MONO_GSHAREDVT_BOX_TYPE_VTYPE */
-				EMIT_NEW_BIALU_IMM (cfg, args [3], OP_ISUB_IMM, deref_arg_reg, ins->dreg, 1);
-			} else {
-				EMIT_NEW_ICONST (cfg, args [3], 0);
-			}
-
 			for (int i = 0; i < fsig->param_count; ++i) {
 				int addr_reg;
 
+				if (mini_is_gsharedvt_type (fsig->params [i])) {
+					MonoInst *is_deref;
+					int deref_arg_reg;
+					ins = mini_emit_get_gsharedvt_info_klass (cfg, mono_class_from_mono_type_internal (fsig->params [i]), MONO_RGCTX_INFO_CLASS_BOX_TYPE);
+					deref_arg_reg = alloc_preg (cfg);
+					/* deref_arg = BOX_TYPE != MONO_GSHAREDVT_BOX_TYPE_VTYPE */
+					EMIT_NEW_BIALU_IMM (cfg, is_deref, OP_ISUB_IMM, deref_arg_reg, ins->dreg, 1);
+					MONO_EMIT_NEW_STORE_MEMBASE (cfg, OP_STOREI1_MEMBASE_REG, args [3]->dreg, i, is_deref->dreg);
+				} else if (has_gsharedvt) {
+					MONO_EMIT_NEW_STORE_MEMBASE_IMM (cfg, OP_STOREI1_MEMBASE_IMM, args [3]->dreg, i, 0);
+				}
+
 				if (mini_is_gsharedvt_type (fsig->params [i]) || MONO_TYPE_IS_PRIMITIVE (fsig->params [i]) || MONO_TYPE_ISSTRUCT (fsig->params [i])) {
 					EMIT_NEW_VARLOADA_VREG (cfg, ins, sp [i + 1]->dreg, fsig->params [i]);
 					addr_reg = ins->dreg;