8258946: Fix optimization-unstable code involving signed integer overflow
Reviewed-by: thartmann, kvn
diff --git a/src/hotspot/share/opto/ifnode.cpp b/src/hotspot/share/opto/ifnode.cpp
index 4d1ef3c..9f4c7f7 100644
--- 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
@@ -631,7 +631,7 @@
return cmp2_t;
case BoolTest::lt:
lo = TypeInt::INT->_lo;
- if (hi - 1 < hi) {
+ if (hi != min_jint) {
hi = hi - 1;
}
break;
@@ -639,7 +639,7 @@
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
index e43b1a1..a4486df 100644
--- a/src/hotspot/share/opto/loopTransform.cpp
+++ b/src/hotspot/share/opto/loopTransform.cpp
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2000, 2020, 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
@@ -912,12 +912,12 @@
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
}
@@ -928,8 +928,8 @@
// 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
index 17dee70..4258c22 100644
--- 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
@@ -536,7 +536,7 @@
}
prev = match_int+1;
}
- if (prev-1 != max_jint) {
+ if (prev != min_jint) {
defaults += (float)max_jint - prev + 1;
}
float default_cnt = 1;
