Update (2025.02.24, 2nd)

35673: LA port of 8344026: Ubsan: prevent potential integer overflow in c1_LIRGenerator_.cpp file

src/hotspot/cpu/loongarch/c1_LIRGenerator_loongarch_64.cpp

@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2005, 2021, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2021, 2024, Loongson Technology. All rights reserved.
+ * Copyright (c) 2021, 2025, Loongson Technology. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -274,17 +274,20 @@ void LIRGenerator::cmp_reg_mem(LIR_Condition condition, LIR_Opr reg, LIR_Opr bas
 }
 
 bool LIRGenerator::strength_reduce_multiply(LIR_Opr left, jint c, LIR_Opr result, LIR_Opr tmp) {
-  if (is_power_of_2(c - 1)) {
-    __ shift_left(left, exact_log2(c - 1), tmp);
+  juint u_value = (juint)c;
+  if (is_power_of_2(u_value - 1)) {
+    __ shift_left(left, exact_log2(u_value - 1), tmp);
     __ add(tmp, left, result);
     return true;
-  } else if (is_power_of_2(c + 1)) {
-    __ shift_left(left, exact_log2(c + 1), tmp);
+  } else if (is_power_of_2(u_value + 1)) {
+    __ shift_left(left, exact_log2(u_value + 1), tmp);
     __ sub(tmp, left, result);
     return true;
-  } else {
-    return false;
+  } else if (c == -1) {
+    __ negate(left, result);
+    return true;
   }
+  return false;
 }
 
 void LIRGenerator::store_stack_parameter (LIR_Opr item, ByteSize offset_from_sp) {