[mono] Fix a regression caused by 9ddd58a.

Fixes dotnet#63079.

src/mono/mono/metadata/jit-icall-reg.h

@@ -98,6 +98,7 @@ MONO_JIT_ICALL (__emul_ldiv_un) \
 MONO_JIT_ICALL (__emul_lmul) \
 MONO_JIT_ICALL (__emul_lmul_ovf) \
 MONO_JIT_ICALL (__emul_lmul_ovf_un) \
+MONO_JIT_ICALL (__emul_lmul_ovf_un_oom) \
 MONO_JIT_ICALL (__emul_lrem) \
 MONO_JIT_ICALL (__emul_lrem_un) \
 MONO_JIT_ICALL (__emul_lshl) \
@@ -108,6 +109,7 @@ MONO_JIT_ICALL (__emul_op_idiv_un) \
 MONO_JIT_ICALL (__emul_op_imul) \
 MONO_JIT_ICALL (__emul_op_imul_ovf) \
 MONO_JIT_ICALL (__emul_op_imul_ovf_un) \
+MONO_JIT_ICALL (__emul_op_imul_ovf_un_oom) \
 MONO_JIT_ICALL (__emul_op_irem) \
 MONO_JIT_ICALL (__emul_op_irem_un) \
 MONO_JIT_ICALL (__emul_rconv_to_i8) \

src/mono/mono/mini/jit-icalls.c

@@ -195,6 +195,40 @@ mono_llmult_ovf_un (guint64 a, guint64 b)
 	return 0;
 }
 
+guint64
+mono_llmult_ovf_un_oom (guint64 a, guint64 b)
+{
+	guint32 al = a;
+	guint32 ah = a >> 32;
+	guint32 bl = b;
+	guint32 bh = b >> 32;
+	guint64 res, t1;
+
+	// fixme: this is incredible slow
+
+	if (ah && bh)
+		goto raise_exception;
+
+	res = (guint64)al * (guint64)bl;
+
+	t1 = (guint64)ah * (guint64)bl + (guint64)al * (guint64)bh;
+
+	if (t1 > 0xffffffff)
+		goto raise_exception;
+
+	res += ((guint64)t1) << 32;
+
+	return res;
+
+ raise_exception:
+	{
+		ERROR_DECL (error);
+		mono_error_set_out_of_memory (error, "");
+		mono_error_set_pending_exception (error);
+	}
+	return 0;
+}
+
 guint64
 mono_llmult_ovf (gint64 a, gint64 b)
 {
@@ -521,6 +555,21 @@ mono_imul_ovf_un (guint32 a, guint32 b)
 
 	return res;
 }
+
+gint32
+mono_imul_ovf_un_oom (guint32 a, guint32 b)
+{
+	const guint64 res = (guint64)a * (guint64)b;
+
+	if (res >> 32) {
+		ERROR_DECL (error);
+		mono_error_set_out_of_memory (error, "");
+		mono_error_set_pending_exception (error);
+		return 0;
+	}
+
+	return res;
+}
 #endif
 
 #if defined(MONO_ARCH_EMULATE_MUL_DIV) || defined(MONO_ARCH_SOFT_FLOAT_FALLBACK)

src/mono/mono/mini/jit-icalls.h

@@ -21,6 +21,8 @@ ICALL_EXPORT gint64 mono_llmult (gint64 a, gint64 b);
 
 ICALL_EXPORT guint64 mono_llmult_ovf_un (guint64 a, guint64 b);
 
+ICALL_EXPORT guint64 mono_llmult_ovf_un_oom (guint64 a, guint64 b);
+
 ICALL_EXPORT guint64 mono_llmult_ovf (gint64 a, gint64 b);
 
 ICALL_EXPORT gint32 mono_idiv (gint32 a, gint32 b);
@@ -37,6 +39,8 @@ ICALL_EXPORT gint32 mono_imul_ovf (gint32 a, gint32 b);
 
 ICALL_EXPORT gint32 mono_imul_ovf_un (guint32 a, guint32 b);
 
+ICALL_EXPORT gint32 mono_imul_ovf_un_oom (guint32 a, guint32 b);
+
 ICALL_EXPORT double mono_fdiv (double a, double b);
 
 ICALL_EXPORT gint64 mono_lldiv (gint64 a, gint64 b);

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

@@ -517,21 +517,6 @@ add_widen_op (MonoCompile *cfg, MonoInst *ins, MonoInst **arg1_ref, MonoInst **a
 #endif
 }
 
-#define ADD_BINOP(op) do {	\
-		MONO_INST_NEW (cfg, ins, (op));	\
-		sp -= 2;	\
-		ins->sreg1 = sp [0]->dreg;	\
-		ins->sreg2 = sp [1]->dreg;	\
-		type_from_op (cfg, ins, sp [0], sp [1]);	\
-		CHECK_TYPE (ins);	\
-		if (ovf_exc) ins->inst_exc_name = ovf_exc; else ins->inst_exc_name = "OverflowException"; ovf_exc = NULL; \
-		/* Have to insert a widening op */		 \
-        add_widen_op (cfg, ins, &sp [0], &sp [1]);		 \
-        ins->dreg = alloc_dreg ((cfg), (MonoStackType)(ins)->type); \
-        MONO_ADD_INS ((cfg)->cbb, (ins)); \
-        *sp++ = mono_decompose_opcode ((cfg), (ins));	\
-	} while (0)
-
 #define ADD_UNOP(op) do {	\
 		MONO_INST_NEW (cfg, ins, (op));	\
 		sp--;	\
@@ -8674,7 +8659,37 @@ mono_method_to_ir (MonoCompile *cfg, MonoMethod *method, MonoBasicBlock *start_b
 		case MONO_CEE_MUL_OVF_UN:
 		case MONO_CEE_SUB_OVF:
 		case MONO_CEE_SUB_OVF_UN:
-			ADD_BINOP (il_op);
+			MONO_INST_NEW (cfg, ins, il_op);
+			sp -= 2;
+			ins->sreg1 = sp [0]->dreg;
+			ins->sreg2 = sp [1]->dreg;
+			type_from_op (cfg, ins, sp [0], sp [1]);
+			CHECK_TYPE (ins);
+			if (ovf_exc)
+				ins->inst_exc_name = ovf_exc;
+			else
+				ins->inst_exc_name = "OverflowException";
+			/* Have to insert a widening op */
+			add_widen_op (cfg, ins, &sp [0], &sp [1]);
+			ins->dreg = alloc_dreg (cfg, (MonoStackType)(ins)->type);
+			MONO_ADD_INS ((cfg)->cbb, ins);
+			/* The opcode might be emulated, so need to special case this */
+			if (ovf_exc && mono_find_jit_opcode_emulation (ins->opcode)) {
+				switch (ins->opcode) {
+				case OP_IMUL_OVF_UN:
+					/* This opcode is just a placeholder, it will be emulated also */
+					ins->opcode = OP_IMUL_OVF_UN_OOM;
+					break;
+				case OP_LMUL_OVF_UN:
+					/* This opcode is just a placeholder, it will be emulated also */
+					ins->opcode = OP_LMUL_OVF_UN_OOM;
+					break;
+				default:
+					g_assert_not_reached ();
+				}
+			}
+			ovf_exc = NULL;
+			*sp++ = mono_decompose_opcode (cfg, ins);
 			break;
 		case MONO_CEE_CPOBJ:
 			GSHAREDVT_FAILURE (il_op);

src/mono/mono/mini/mini-ops.h

@@ -639,6 +639,11 @@ MINI_OP(OP_FGETHIGH32, "float_gethigh32", IREG, FREG, NONE)
 
 MINI_OP(OP_JUMP_TABLE, "jump_table", IREG, NONE, NONE)
 
+/* Same as OP_IMUL_OVF_UN, but throws an OutOfMemoryException */
+/* Emulated */
+MINI_OP(OP_IMUL_OVF_UN_OOM,   "int_mul_ovf_un_oom", IREG, IREG, IREG)
+MINI_OP(OP_LMUL_OVF_UN_OOM,   "long_mul_ovf_un_oom", LREG, LREG, LREG)
+
 /* aot compiler */
 MINI_OP(OP_AOTCONST, "aotconst", IREG, NONE, NONE)
 MINI_OP(OP_PATCH_INFO, "patch_info", NONE, NONE, NONE)

src/mono/mono/mini/mini-runtime.c

@@ -4729,6 +4729,7 @@ register_icalls (void)
 #if !defined(MONO_ARCH_NO_EMULATE_LONG_MUL_OPTS) || defined(MONO_ARCH_EMULATE_LONG_MUL_OVF_OPTS)
 	register_opcode_emulation (OP_LMUL_OVF_UN, __emul_lmul_ovf_un, mono_icall_sig_long_long_long, mono_llmult_ovf_un, FALSE);
 	register_opcode_emulation (OP_LMUL_OVF, __emul_lmul_ovf, mono_icall_sig_long_long_long, mono_llmult_ovf, FALSE);
+	register_opcode_emulation (OP_LMUL_OVF_UN_OOM, __emul_lmul_ovf_un_oom, mono_icall_sig_long_long_long, mono_llmult_ovf_un_oom, FALSE);
 #endif
 
 #ifndef MONO_ARCH_NO_EMULATE_LONG_SHIFT_OPS
@@ -4751,6 +4752,7 @@ register_icalls (void)
 #if defined(MONO_ARCH_EMULATE_MUL_DIV) || defined(MONO_ARCH_EMULATE_MUL_OVF)
 	register_opcode_emulation (OP_IMUL_OVF, __emul_op_imul_ovf, mono_icall_sig_int32_int32_int32, mono_imul_ovf, FALSE);
 	register_opcode_emulation (OP_IMUL_OVF_UN, __emul_op_imul_ovf_un, mono_icall_sig_int32_int32_int32, mono_imul_ovf_un, FALSE);
+	register_opcode_emulation (OP_IMUL_OVF_UN_OOM, __emul_op_imul_ovf_un_oom, mono_icall_sig_int32_int32_int32, mono_imul_ovf_un_oom, FALSE);
 #endif
 
 #if defined(MONO_ARCH_EMULATE_MUL_DIV) || defined(MONO_ARCH_SOFT_FLOAT_FALLBACK)

src/mono/mono/mini/mini-x86.c

@@ -2992,7 +2992,7 @@ mono_arch_output_basic_block (MonoCompile *cfg, MonoBasicBlock *bb)
 			break;
 		case OP_IMUL_OVF:
 			x86_imul_reg_reg (code, ins->sreg1, ins->sreg2);
-			EMIT_COND_SYSTEM_EXCEPTION (X86_CC_O, FALSE, "OverflowException");
+			EMIT_COND_SYSTEM_EXCEPTION (X86_CC_O, FALSE, ins->inst_exc_name);
 			break;
 		case OP_IMUL_OVF_UN: {
 			/* the mul operation and the exception check should most likely be split */
@@ -3028,7 +3028,7 @@ mono_arch_output_basic_block (MonoCompile *cfg, MonoBasicBlock *bb)
 				x86_pop_reg (code, X86_EDX);
 			if (saved_eax)
 				x86_pop_reg (code, X86_EAX);
-			EMIT_COND_SYSTEM_EXCEPTION (X86_CC_O, FALSE, "OverflowException");
+			EMIT_COND_SYSTEM_EXCEPTION (X86_CC_O, FALSE, ins->inst_exc_name);
 			break;
 		}
 		case OP_ICONST: