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6823354: Add intrinsics for {Integer,Long}.{numberOfLeadingZeros,numberOfTrailingZeros}()

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These methods can be instrinsified by using bit scan, bit test, and population count instructions.

Reviewed-by: kvn, never
This commit is contained in:
Christian Thalinger 2009-05-06 00:27:52 -07:00
parent 716c78f080
commit 6a270f9f19
15 changed files with 997 additions and 17 deletions
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90
hotspot/src/share/vm/opto/connode.cpp
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@ -1255,3 +1255,93 @@ const Type *MoveD2LNode::Value( PhaseTransform *phase ) const {
v.set_jdouble(td->getd());
return TypeLong::make( v.get_jlong() );
}
//------------------------------Value------------------------------------------
const Type* CountLeadingZerosINode::Value(PhaseTransform* phase) const {
const Type* t = phase->type(in(1));
if (t == Type::TOP) return Type::TOP;
const TypeInt* ti = t->isa_int();
if (ti && ti->is_con()) {
jint i = ti->get_con();
// HD, Figure 5-6
if (i == 0)
return TypeInt::make(BitsPerInt);
int n = 1;
unsigned int x = i;
if (x >> 16 == 0) { n += 16; x <<= 16; }
if (x >> 24 == 0) { n += 8; x <<= 8; }
if (x >> 28 == 0) { n += 4; x <<= 4; }
if (x >> 30 == 0) { n += 2; x <<= 2; }
n -= x >> 31;
return TypeInt::make(n);
}
return TypeInt::INT;
}
//------------------------------Value------------------------------------------
const Type* CountLeadingZerosLNode::Value(PhaseTransform* phase) const {
const Type* t = phase->type(in(1));
if (t == Type::TOP) return Type::TOP;
const TypeLong* tl = t->isa_long();
if (tl && tl->is_con()) {
jlong l = tl->get_con();
// HD, Figure 5-6
if (l == 0)
return TypeInt::make(BitsPerLong);
int n = 1;
unsigned int x = (((julong) l) >> 32);
if (x == 0) { n += 32; x = (int) l; }
if (x >> 16 == 0) { n += 16; x <<= 16; }
if (x >> 24 == 0) { n += 8; x <<= 8; }
if (x >> 28 == 0) { n += 4; x <<= 4; }
if (x >> 30 == 0) { n += 2; x <<= 2; }
n -= x >> 31;
return TypeInt::make(n);
}
return TypeInt::INT;
}
//------------------------------Value------------------------------------------
const Type* CountTrailingZerosINode::Value(PhaseTransform* phase) const {
const Type* t = phase->type(in(1));
if (t == Type::TOP) return Type::TOP;
const TypeInt* ti = t->isa_int();
if (ti && ti->is_con()) {
jint i = ti->get_con();
// HD, Figure 5-14
int y;
if (i == 0)
return TypeInt::make(BitsPerInt);
int n = 31;
y = i << 16; if (y != 0) { n = n - 16; i = y; }
y = i << 8; if (y != 0) { n = n - 8; i = y; }
y = i << 4; if (y != 0) { n = n - 4; i = y; }
y = i << 2; if (y != 0) { n = n - 2; i = y; }
y = i << 1; if (y != 0) { n = n - 1; }
return TypeInt::make(n);
}
return TypeInt::INT;
}
//------------------------------Value------------------------------------------
const Type* CountTrailingZerosLNode::Value(PhaseTransform* phase) const {
const Type* t = phase->type(in(1));
if (t == Type::TOP) return Type::TOP;
const TypeLong* tl = t->isa_long();
if (tl && tl->is_con()) {
jlong l = tl->get_con();
// HD, Figure 5-14
int x, y;
if (l == 0)
return TypeInt::make(BitsPerLong);
int n = 63;
y = (int) l; if (y != 0) { n = n - 32; x = y; } else x = (((julong) l) >> 32);
y = x << 16; if (y != 0) { n = n - 16; x = y; }
y = x << 8; if (y != 0) { n = n - 8; x = y; }
y = x << 4; if (y != 0) { n = n - 4; x = y; }
y = x << 2; if (y != 0) { n = n - 2; x = y; }
y = x << 1; if (y != 0) { n = n - 1; }
return TypeInt::make(n);
}
return TypeInt::INT;
}