[mono][jit] Fuse SIMD extract and insert on arm64 (#92714)

* Fuse extract and insert into arm64 ins.

* Extending to vector4.

* Ins index is now a function. Removed newline.

* Refactoring.

* SIMD extract ops have no side offects (to facilitate their elimination). Fixed bug.

* Fixed arm32 build.

Author: jandupej

src/mono/mono/mini/method-to-ir.c

@@ -12746,6 +12746,14 @@ mono_op_no_side_effects (int opcode)
 	case OP_NOT_NULL:
 	case OP_IL_SEQ_POINT:
 	case OP_RTTYPE:
+#if defined(TARGET_X86) || defined(TARGET_AMD64) || defined(TARGET_WASM) || defined(TARGET_ARM64)
+	case OP_EXTRACT_I1:
+	case OP_EXTRACT_I2:
+	case OP_EXTRACT_I4:
+	case OP_EXTRACT_I8:
+	case OP_EXTRACT_R4:
+	case OP_EXTRACT_R8:
+#endif
 		return TRUE;
 	default:
 		return FALSE;

src/mono/mono/mini/mini-arm64.c

@@ -4061,18 +4061,20 @@ mono_arch_output_basic_block (MonoCompile *cfg, MonoBasicBlock *bb)
 				break;
 			}
 
+			int idx_to = GTMREG_TO_UINT32 (ins->inst_c0) & 0xff;
+			int idx_from = GTMREG_TO_UINT32 (ins->inst_c0) >> 8;
 			if (dreg != sreg1) {
 				if (dreg != sreg2) {
 					arm_neon_mov (code, dreg, sreg1);
-					arm_neon_ins_e(code, t, dreg, sreg2, GTMREG_TO_UINT32 (ins->inst_c0), 0);
+					arm_neon_ins_e(code, t, dreg, sreg2, idx_to, idx_from);
 				} else {
 					arm_neon_mov (code, NEON_TMP_REG, sreg1);
-					arm_neon_ins_e(code, t, NEON_TMP_REG, sreg2, GTMREG_TO_UINT32 (ins->inst_c0), 0);
+					arm_neon_ins_e(code, t, NEON_TMP_REG, sreg2, idx_to, idx_from);
 					arm_neon_mov (code, dreg, NEON_TMP_REG);
 				}
 			} else {
 				g_assert (dreg != sreg2);
-				arm_neon_ins_e(code, t, dreg, sreg2, GTMREG_TO_UINT32 (ins->inst_c0), 0);
+				arm_neon_ins_e(code, t, dreg, sreg2, idx_to, idx_from);
 			}
 			break;
 		}

src/mono/mono/mini/simd-intrinsics.c

@@ -1068,21 +1068,42 @@ emit_hardware_intrinsics (
 	return custom_emit (cfg, fsig, args, klass, intrin_group, info, id, arg0_type, is_64bit);
 }
 
+static MonoInst*
+emit_vector_insert_element (
+	MonoCompile* cfg, MonoClass* vklass, MonoInst* ins, MonoTypeEnum type, MonoInst* element, 
+	int index, gboolean is_zero_inited)
+{
+	int op = type_to_insert_op (type);
+
+	if (is_zero_inited && is_zero_const (element)) {
+			// element already set to zero
+#ifdef TARGET_ARM64
+	} else if (!COMPILE_LLVM (cfg) && element->opcode == type_to_extract_op (type) && 
+		(type == MONO_TYPE_R4 || type == MONO_TYPE_R8)) {
+		// OP_INSERT_Ix inserts from GP reg, not SIMD. Cannot optimize for int types.
+		ins = emit_simd_ins (cfg, vklass, op, ins->dreg, element->sreg1);
+		ins->inst_c0 = index | ((element->inst_c0) << 8);
+		ins->inst_c1 = type;
+#endif
+	} else {
+		ins = emit_simd_ins (cfg, vklass, op, ins->dreg, element->dreg);
+		ins->inst_c0 = index;
+		ins->inst_c1 = type;
+	}
+
+	return ins;
+}
+
 static MonoInst *
 emit_vector_create_elementwise (
 	MonoCompile *cfg, MonoMethodSignature *fsig, MonoType *vtype,
 	MonoTypeEnum type, MonoInst **args)
 {
-	int op = type_to_insert_op (type);
 	MonoClass *vklass = mono_class_from_mono_type_internal (vtype);
 	MonoInst *ins = emit_xzero (cfg, vklass);
-	for (int i = 0; i < fsig->param_count; ++i) {
-		if (!is_zero_const (args [i])) {
-			ins = emit_simd_ins (cfg, vklass, op, ins->dreg, args [i]->dreg);
-			ins->inst_c0 = i;
-			ins->inst_c1 = type;
-		}
-	}
+	for (int i = 0; i < fsig->param_count; ++i)
+		ins = emit_vector_insert_element (cfg, vklass, ins, type, args[i], i, TRUE);
+
 	return ins;
 }
 
@@ -2282,17 +2303,12 @@ emit_sri_vector (MonoCompile *cfg, MonoMethod *cmethod, MonoMethodSignature *fsi
 		if (args [1]->opcode == OP_ICONST) {
 			// If the index is provably a constant, we can generate vastly better code.
 			int index = GTMREG_TO_INT (args[1]->inst_c0);
-
 			if (index < 0 || index >= elems) {
 					MONO_EMIT_NEW_BIALU_IMM (cfg, OP_COMPARE_IMM, -1, args [1]->dreg, elems);
 					MONO_EMIT_NEW_COND_EXC (cfg, GE_UN, "ArgumentOutOfRangeException");
 			}
 
-			int insert_op = type_to_insert_op (arg0_type);
-			MonoInst *ins = emit_simd_ins (cfg, klass, insert_op, args [0]->dreg, args [2]->dreg);
-			ins->inst_c0 = index;
-			ins->inst_c1 = arg0_type;
-			return ins;
+			return emit_vector_insert_element (cfg, klass, args [0], arg0_type, args [2], index, FALSE);
 		} 
 
 		if (!COMPILE_LLVM (cfg) && fsig->params [0]->type != MONO_TYPE_GENERICINST)
@@ -2690,11 +2706,9 @@ emit_vector_2_3_4 (MonoCompile *cfg, MonoMethod *cmethod, MonoMethodSignature *f
 			ins->dreg = dreg;
 			ins->inst_c1 = MONO_TYPE_R4;
 
-			for (int i = 1; i < fsig->param_count; ++i) {
-				ins = emit_simd_ins (cfg, klass, OP_INSERT_R4, ins->dreg, args [i + 1]->dreg);
-				ins->inst_c0 = i;
-				ins->inst_c1 = MONO_TYPE_R4;
-			}
+			for (int i = 1; i < fsig->param_count; ++i)
+				ins = emit_vector_insert_element (cfg, klass, ins, MONO_TYPE_R4, args [i + 1], i, FALSE);
+
 			ins->dreg = dreg;
 
 			if (indirect) {
@@ -2835,10 +2849,14 @@ emit_vector_2_3_4 (MonoCompile *cfg, MonoMethod *cmethod, MonoMethodSignature *f
 				MONO_EMIT_NEW_COND_EXC (cfg, GE_UN, "ArgumentOutOfRangeException");
 			}
 
-			ins = emit_simd_ins (cfg, klass, OP_INSERT_R4, dreg, args [2]->dreg);
-			ins->inst_c0 = index;
-			ins->inst_c1 = MONO_TYPE_R4;
-			ins->dreg = dreg;
+			if (args [0]->dreg == dreg) {
+				ins = emit_vector_insert_element (cfg, klass, args [0], MONO_TYPE_R4, args [2], index, FALSE);
+			} else {
+				ins = emit_simd_ins (cfg, klass, OP_INSERT_R4, dreg, args [2]->dreg);
+				ins->inst_c0 = index;
+				ins->inst_c1 = MONO_TYPE_R4;
+				ins->dreg = dreg;
+			}
 
 			if (indirect) {
 				EMIT_NEW_STORE_MEMBASE (cfg, ins, OP_STOREX_MEMBASE, args [0]->dreg, 0, dreg);