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src/share/vm/opto/mulnode.cpp
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rev 9644 : 8145096: Undefined behaviour in HotSpot
Summary: Fix some integer overflows
Reviewed-by: duke
@@ -243,17 +243,17 @@
double c = (double)lo1;
int32_t hi1 = r1->_hi;
double d = (double)hi1;
// Compute all endpoints & check for overflow
- int32_t A = lo0*lo1;
+ int32_t A = java_multiply(lo0, lo1);
if( (double)A != a*c ) return TypeInt::INT; // Overflow?
- int32_t B = lo0*hi1;
+ int32_t B = java_multiply(lo0, hi1);
if( (double)B != a*d ) return TypeInt::INT; // Overflow?
- int32_t C = hi0*lo1;
+ int32_t C = java_multiply(hi0, lo1);
if( (double)C != b*c ) return TypeInt::INT; // Overflow?
- int32_t D = hi0*hi1;
+ int32_t D = java_multiply(hi0, hi1);
if( (double)D != b*d ) return TypeInt::INT; // Overflow?
if( A < B ) { lo0 = A; hi0 = B; } // Sort range endpoints
else { lo0 = B; hi0 = A; }
if( C < D ) {
@@ -339,17 +339,17 @@
double c = (double)lo1;
jlong hi1 = r1->_hi;
double d = (double)hi1;
// Compute all endpoints & check for overflow
- jlong A = lo0*lo1;
+ jlong A = java_multiply(lo0, lo1);
if( (double)A != a*c ) return TypeLong::LONG; // Overflow?
- jlong B = lo0*hi1;
+ jlong B = java_multiply(lo0, hi1);
if( (double)B != a*d ) return TypeLong::LONG; // Overflow?
- jlong C = hi0*lo1;
+ jlong C = java_multiply(hi0, lo1);
if( (double)C != b*c ) return TypeLong::LONG; // Overflow?
- jlong D = hi0*hi1;
+ jlong D = java_multiply(hi0, hi1);
if( (double)D != b*d ) return TypeLong::LONG; // Overflow?
if( A < B ) { lo0 = A; hi0 = B; } // Sort range endpoints
else { lo0 = B; hi0 = A; }
if( C < D ) {
@@ -572,11 +572,11 @@
if( t2 && t2->is_con() ) {
jlong con = t2->get_con();
// Masking off high bits which are always zero is useless.
const TypeLong* t1 = phase->type( in(1) )->isa_long();
if (t1 != NULL && t1->_lo >= 0) {
- jlong t1_support = ((jlong)1 << (1 + log2_long(t1->_hi))) - 1;
+ jlong t1_support = java_subtract(((jlong)1 << (1 + log2_long(t1->_hi))), (jlong)1);
if ((t1_support & con) == t1_support)
return usr;
}
uint lop = usr->Opcode();
// Masking off the high bits of a unsigned-shift-right is not
@@ -800,11 +800,11 @@
}
}
// Check for ((x & ((CONST64(1)<<(64-c0))-1)) << c0) which ANDs off high bits
// before shifting them away.
- const jlong bits_mask = ((jlong)CONST64(1) << (jlong)(BitsPerJavaLong - con)) - CONST64(1);
+ const jlong bits_mask = jlong((~ UCONST64(0)) >> con);
if( add1_op == Op_AndL &&
phase->type(add1->in(2)) == TypeLong::make( bits_mask ) )
return new LShiftLNode( add1->in(1), in(2) );
return NULL;
@@ -1252,11 +1252,11 @@
if( !t2 || !t2->is_con() ) return NULL; // Right input is a constant
const int con = t2->get_con() & ( BitsPerLong - 1 ); // Shift count is always masked
if ( con == 0 ) return NULL; // let Identity() handle a 0 shift count
// note: mask computation below does not work for 0 shift count
// We'll be wanting the right-shift amount as a mask of that many bits
- const jlong mask = (((jlong)CONST64(1) << (jlong)(BitsPerJavaLong - con)) -1);
+ const jlong mask = jlong((~ UCONST64(0)) >> con);
// Check for ((x << z) + Y) >>> z. Replace with x + con>>>z
// The idiom for rounding to a power of 2 is "(Q+(2^z-1)) >>> z".
// If Q is "X << z" the rounding is useless. Look for patterns like
// ((X<<Z) + Y) >>> Z and replace with (X + Y>>>Z) & Z-mask.
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