8258946: Fix optimization-unstable code involving signed integer over…

…flow Backport-of: dd8996c
openjdk · Jul 28, 2022 · c61acb5 · c61acb5 · openjdk-notifier · Jul 28, 2022
1 parent 5d20cb6
commit c61acb5
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Showing 3 changed files with 10 additions and 10 deletions.
diff --git a/src/hotspot/share/opto/ifnode.cpp b/src/hotspot/share/opto/ifnode.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2021, Oracle and/or its affiliates. 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
@@ -633,15 +633,15 @@ const TypeInt* IfNode::filtered_int_type(PhaseGVN* gvn, Node *val, Node* if_proj
               return cmp2_t;
             case BoolTest::lt:
               lo = TypeInt::INT->_lo;
-              if (hi - 1 < hi) {
+              if (hi != min_jint) {
                 hi = hi - 1;
               }
               break;
             case BoolTest::le:
               lo = TypeInt::INT->_lo;
               break;
             case BoolTest::gt:
-              if (lo + 1 > lo) {
+              if (lo != max_jint) {
                 lo = lo + 1;
               }
               hi = TypeInt::INT->_hi;

diff --git a/src/hotspot/share/opto/loopTransform.cpp b/src/hotspot/share/opto/loopTransform.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2021, Oracle and/or its affiliates. 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
@@ -824,12 +824,12 @@ bool IdealLoopTree::policy_unroll(PhaseIdealLoop *phase) {
       const TypeInt* iv_type = phase->_igvn.type(phi)->is_int();
       int next_stride = stride_con * 2; // stride after this unroll
       if (next_stride > 0) {
-        if (iv_type->_lo + next_stride <= iv_type->_lo || // overflow
+        if (iv_type->_lo > max_jint - next_stride || // overflow
             iv_type->_lo + next_stride >  iv_type->_hi) {
           return false;  // over-unrolling
         }
       } else if (next_stride < 0) {
-        if (iv_type->_hi + next_stride >= iv_type->_hi || // overflow
+        if (iv_type->_hi < min_jint - next_stride || // overflow
             iv_type->_hi + next_stride <  iv_type->_lo) {
           return false;  // over-unrolling
         }
@@ -840,8 +840,8 @@ bool IdealLoopTree::policy_unroll(PhaseIdealLoop *phase) {
   // After unroll limit will be adjusted: new_limit = limit-stride.
   // Bailout if adjustment overflow.
   const TypeInt* limit_type = phase->_igvn.type(limit_n)->is_int();
-  if ((stride_con > 0 && ((limit_type->_hi - stride_con) >= limit_type->_hi)) ||
-      (stride_con < 0 && ((limit_type->_lo - stride_con) <= limit_type->_lo)))
+  if ((stride_con > 0 && ((min_jint + stride_con) > limit_type->_hi)) ||
+      (stride_con < 0 && ((max_jint + stride_con) < limit_type->_lo)))
     return false;  // overflow
 
   // Adjust body_size to determine if we unroll or not

diff --git a/src/hotspot/share/opto/parse2.cpp b/src/hotspot/share/opto/parse2.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2021, Oracle and/or its affiliates. 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
@@ -548,7 +548,7 @@ void Parse::do_lookupswitch() {
     }
     prev = match_int+1;
   }
-  if (prev-1 != max_jint) {
+  if (prev != min_jint) {
     defaults += (float)max_jint - prev + 1;
   }
   float default_cnt = 1;