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src/cpu/sparc/vm/macroAssembler_sparc.cpp
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@@ -4514,22 +4514,14 @@
if (ae == StrIntrinsicNode::LU || ae == StrIntrinsicNode::UL) {
neg(chr2, limit2); // limit2 = -(limit2-stride2)
}
// Compare the rest of the characters
- if (ae == StrIntrinsicNode::UU) {
- lduh(str1, limit1, chr1);
- } else {
- ldub(str1, limit1, chr1);
- }
+ load_sized_value(Address(str1, limit1), chr1, (ae == StrIntrinsicNode::UU) ? 2 : 1, false);
bind(Lloop);
- if (ae == StrIntrinsicNode::LL) {
- ldub(str2, limit2, chr2);
- } else {
- lduh(str2, limit2, chr2);
- }
+ load_sized_value(Address(str2, limit2), chr2, (ae == StrIntrinsicNode::LL) ? 1 : 2, false);
subcc(chr1, chr2, chr1);
br(Assembler::notZero, false, Assembler::pt, Ldone);
assert(chr1 == result, "result must be pre-placed");
delayed()->inccc(limit1, stride1);
@@ -4537,15 +4529,11 @@
inccc(limit2, stride2);
}
// annul LDUB if branch is not taken to prevent access past end of string
br(Assembler::notZero, true, Assembler::pt, Lloop);
- if (ae == StrIntrinsicNode::UU) {
- delayed()->lduh(str1, limit2, chr1);
- } else {
- delayed()->ldub(str1, limit1, chr1);
- }
+ delayed()->load_sized_value(Address(str1, limit1), chr1, (ae == StrIntrinsicNode::UU) ? 2 : 1, false);
// If strings are equal up to min length, return the length difference.
if (ae == StrIntrinsicNode::UU) {
// Divide by 2 to get number of chars
sra(diff, 1, result);
@@ -4561,111 +4549,122 @@
}
}
void MacroAssembler::array_equals(bool is_array_equ, Register ary1, Register ary2,
Register limit, Register tmp, Register result, bool is_byte) {
- Label Ldone, Lvector, Lloop;
+ Label Ldone, Lslow;
assert_different_registers(ary1, ary2, limit, tmp, result);
int length_offset = arrayOopDesc::length_offset_in_bytes();
int base_offset = arrayOopDesc::base_offset_in_bytes(is_byte ? T_BYTE : T_CHAR);
if (is_array_equ) {
// return true if the same array
cmp(ary1, ary2);
brx(Assembler::equal, true, Assembler::pn, Ldone);
- delayed()->add(G0, 1, result); // equal
+ delayed()->mov(1, result); // equal
br_null(ary1, true, Assembler::pn, Ldone);
- delayed()->mov(G0, result); // not equal
+ delayed()->clr(result); // not equal
br_null(ary2, true, Assembler::pn, Ldone);
- delayed()->mov(G0, result); // not equal
+ delayed()->clr(result); // not equal
// load the lengths of arrays
ld(Address(ary1, length_offset), limit);
ld(Address(ary2, length_offset), tmp);
// return false if the two arrays are not equal length
cmp(limit, tmp);
br(Assembler::notEqual, true, Assembler::pn, Ldone);
- delayed()->mov(G0, result); // not equal
+ delayed()->clr(result); // not equal
}
cmp_zero_and_br(Assembler::zero, limit, Ldone, true, Assembler::pn);
- delayed()->add(G0, 1, result); // zero-length arrays are equal
+ delayed()->mov(1, result); // zero-length arrays are equal
if (is_array_equ) {
// load array addresses
add(ary1, base_offset, ary1);
add(ary2, base_offset, ary2);
+ // set byte count
+ if (!is_byte) {
+ sll(limit, exact_log2(sizeof(jchar)), limit);
+ }
} else {
// We have no guarantee that on 64 bit the higher half of limit is 0
signx(limit);
}
- if (is_byte) {
- Label Lskip;
- // check for trailing byte
- andcc(limit, 0x1, tmp);
- br(Assembler::zero, false, Assembler::pt, Lskip);
- delayed()->nop();
-
- // compare the trailing byte
- sub(limit, sizeof(jbyte), limit);
- ldub(ary1, limit, result);
- ldub(ary2, limit, tmp);
- cmp(result, tmp);
- br(Assembler::notEqual, true, Assembler::pt, Ldone);
- delayed()->mov(G0, result); // not equal
-
- // only one byte?
- cmp_zero_and_br(zero, limit, Ldone, true, Assembler::pn);
- delayed()->add(G0, 1, result); // zero-length arrays are equal
- bind(Lskip);
- } else if (is_array_equ) {
- // set byte count
- sll(limit, exact_log2(sizeof(jchar)), limit);
- }
+ // Prefetch beginning of arrays
+ prefetch(ary1, 0, Assembler::severalReads);
+ prefetch(ary2, 0, Assembler::severalReads);
+
+ // Check for doubleword (8 byte) alignment of ary1 and ary2
+ or3(ary1, ary2, tmp);
+ andcc(tmp, 7, tmp);
+ br_notnull_short(tmp, Assembler::pn, Lslow);
+
+ // Aligned, perform doubleword comparison
+ array_equals_loop(ary1, ary2, limit, tmp, result, 8, Ldone);
+ ba(Ldone);
+ delayed()->movcc(Assembler::equal, false, xcc, 1, result);
+
+ bind(Lslow);
+ // Unaligned, perform word comparison (word alignment is guaranteed)
+ array_equals_loop(ary1, ary2, limit, tmp, result, 4, Ldone);
+ movcc(Assembler::equal, false, icc, 1, result);
- // check for trailing character
- andcc(limit, 0x2, tmp);
- br(Assembler::zero, false, Assembler::pt, Lvector);
- delayed()->nop();
-
- // compare the trailing char
- sub(limit, sizeof(jchar), limit);
- lduh(ary1, limit, result);
- lduh(ary2, limit, tmp);
- cmp(result, tmp);
- br(Assembler::notEqual, true, Assembler::pt, Ldone);
- delayed()->mov(G0, result); // not equal
+ bind(Ldone);
+}
- // only one char?
- cmp_zero_and_br(zero, limit, Ldone, true, Assembler::pn);
- delayed()->add(G0, 1, result); // zero-length arrays are equal
+// Compares two arrays in chunks of size 'byte_width'. The addresses must be aligned accordingly.
+void MacroAssembler::array_equals_loop(Register ary1, Register ary2, Register limit, Register tmp,
+ Register result, size_t byte_width, Label& Ldone) {
+ Label Lloop, Lremaining;
+ // Use appropriate CC register depending on byte_width
+ Assembler::CC cc = (byte_width == 8) ? xcc : icc;
- // word by word compare, dont't need alignment check
- bind(Lvector);
// Shift ary1 and ary2 to the end of the arrays, negate limit
add(ary1, limit, ary1);
add(ary2, limit, ary2);
neg(limit, limit);
- lduw(ary1, limit, result);
+ // MAIN LOOP
+ // Load and compare array elements of size 'byte_width' until the elements are not
+ // equal or we reached the end of the arrays. If the size of the arrays is not a
+ // multiple of 'byte_width', we simply read over the end of the array, bail out and
+ // compare the remaining bytes below by skipping the garbage bytes.
+ load_sized_value(Address(ary1, limit), result, byte_width, false);
bind(Lloop);
- lduw(ary2, limit, tmp);
+ load_sized_value(Address(ary2, limit), tmp, byte_width, false);
+ inccc(limit, byte_width);
+ // Bail out if we reached the end (but still do the comparison)
+ br(Assembler::positive, false, Assembler::pn, Lremaining);
+ delayed()->cmp(result, tmp);
+ // Check equality of elements
+ bp(Assembler::equal, false, cc, Assembler::pt, target(Lloop));
+ delayed()->load_sized_value(Address(ary1, limit), result, byte_width, false);
+
+ ba(Ldone);
+ delayed()->clr(result); // not equal
+
+ // TAIL COMPARISON
+ // We got here because we reached the end of the arrays. 'limit' is the number of
+ // garbage bytes we may have compared by reading over the end of the arrays. Shift
+ // out the garbage and compare the remaining elements.
+ bind(Lremaining);
+ // Optimistic shortcut: elements potentially including garbage are equal
+ bp(Assembler::equal, true, cc, Assembler::pt, target(Ldone));
+ delayed()->mov(1, result); // equal
+ // Shift 'limit' bytes to the right and compare
+ sll(limit, 3, limit); // bytes to bits
+ srlx(result, limit, result);
+ srlx(tmp, limit, tmp);
cmp(result, tmp);
- br(Assembler::notEqual, true, Assembler::pt, Ldone);
- delayed()->mov(G0, result); // not equal
- inccc(limit, 2*sizeof(jchar));
- // annul LDUW if branch is not taken to prevent access past end of array
- br(Assembler::notZero, true, Assembler::pt, Lloop);
- delayed()->lduw(ary1, limit, result); // hoisted
-
- add(G0, 1, result); // equals
- bind(Ldone);
+ clr(result);
+ // CC register contains result
}
void MacroAssembler::has_negatives(Register inp, Register size, Register result, Register t2, Register t3, Register t4, Register t5) {
// test for negative bytes in input string of a given size
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