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7016474: string compare intrinsic improvements

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Reviewed-by: kvn
This commit is contained in:
Tom Rodriguez 2011-02-09 15:02:23 -08:00
parent 477cbff4b6
commit 4b3ada699d
4 changed files with 99 additions and 49 deletions
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123
hotspot/src/cpu/x86/vm/assembler_x86.cpp
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@ -2349,6 +2349,17 @@ void Assembler::prefix(Prefix p) {
a_byte(p);
}
void Assembler::por(XMMRegister dst, XMMRegister src) {
NOT_LP64(assert(VM_Version::supports_sse2(), ""));
emit_byte(0x66);
int encode = prefix_and_encode(dst->encoding(), src->encoding());
emit_byte(0x0F);
emit_byte(0xEB);
emit_byte(0xC0 | encode);
}
void Assembler::pshufd(XMMRegister dst, XMMRegister src, int mode) {
assert(isByte(mode), "invalid value");
NOT_LP64(assert(VM_Version::supports_sse2(), ""));
@ -8655,7 +8666,7 @@ void MacroAssembler::string_indexof(Register str1, Register str2,
// Compare strings.
void MacroAssembler::string_compare(Register str1, Register str2,
Register cnt1, Register cnt2, Register result,
XMMRegister vec1, XMMRegister vec2) {
XMMRegister vec1) {
Label LENGTH_DIFF_LABEL, POP_LABEL, DONE_LABEL, WHILE_HEAD_LABEL;
// Compute the minimum of the string lengths and the
@ -8702,62 +8713,85 @@ void MacroAssembler::string_compare(Register str1, Register str2,
bind(LSkip2);
}
// Advance to next character
addptr(str1, 2);
addptr(str2, 2);
Address::ScaleFactor scale = Address::times_2;
int stride = 8;
// Advance to next element
addptr(str1, 16/stride);
addptr(str2, 16/stride);
if (UseSSE42Intrinsics) {
// With SSE4.2, use double quad vector compare
Label COMPARE_VECTORS, VECTOR_NOT_EQUAL, COMPARE_TAIL;
Label COMPARE_WIDE_VECTORS, VECTOR_NOT_EQUAL, COMPARE_TAIL;
int pcmpmask = 0x19;
// Setup to compare 16-byte vectors
movl(cnt1, cnt2);
andl(cnt2, 0xfffffff8); // cnt2 holds the vector count
andl(cnt1, 0x00000007); // cnt1 holds the tail count
testl(cnt2, cnt2);
movl(result, cnt2);
andl(cnt2, ~(stride - 1)); // cnt2 holds the vector count
jccb(Assembler::zero, COMPARE_TAIL);
lea(str2, Address(str2, cnt2, Address::times_2));
lea(str1, Address(str1, cnt2, Address::times_2));
negptr(cnt2);
lea(str1, Address(str1, result, scale));
lea(str2, Address(str2, result, scale));
negptr(result);
bind(COMPARE_VECTORS);
movdqu(vec1, Address(str1, cnt2, Address::times_2));
movdqu(vec2, Address(str2, cnt2, Address::times_2));
pxor(vec1, vec2);
ptest(vec1, vec1);
jccb(Assembler::notZero, VECTOR_NOT_EQUAL);
addptr(cnt2, 8);
jcc(Assembler::notZero, COMPARE_VECTORS);
jmpb(COMPARE_TAIL);
// pcmpestri
// inputs:
// vec1- substring
// rax - negative string length (elements count)
// mem - scaned string
// rdx - string length (elements count)
// pcmpmask - cmp mode: 11000 (string compare with negated result)
// + 00 (unsigned bytes) or + 01 (unsigned shorts)
// outputs:
// rcx - first mismatched element index
assert(result == rax && cnt2 == rdx && cnt1 == rcx, "pcmpestri");
bind(COMPARE_WIDE_VECTORS);
movdqu(vec1, Address(str1, result, scale));
pcmpestri(vec1, Address(str2, result, scale), pcmpmask);
// After pcmpestri cnt1(rcx) contains mismatched element index
jccb(Assembler::below, VECTOR_NOT_EQUAL); // CF==1
addptr(result, stride);
subptr(cnt2, stride);
jccb(Assembler::notZero, COMPARE_WIDE_VECTORS);
// compare wide vectors tail
testl(result, result);
jccb(Assembler::zero, LENGTH_DIFF_LABEL);
movl(cnt2, stride);
movl(result, stride);
negptr(result);
movdqu(vec1, Address(str1, result, scale));
pcmpestri(vec1, Address(str2, result, scale), pcmpmask);
jccb(Assembler::aboveEqual, LENGTH_DIFF_LABEL);
// Mismatched characters in the vectors
bind(VECTOR_NOT_EQUAL);
lea(str1, Address(str1, cnt2, Address::times_2));
lea(str2, Address(str2, cnt2, Address::times_2));
movl(cnt1, 8);
addptr(result, cnt1);
movptr(cnt2, result);
load_unsigned_short(result, Address(str1, cnt2, scale));
load_unsigned_short(cnt1, Address(str2, cnt2, scale));
subl(result, cnt1);
jmpb(POP_LABEL);
// Compare tail (< 8 chars), or rescan last vectors to
// find 1st mismatched characters
bind(COMPARE_TAIL);
testl(cnt1, cnt1);
jccb(Assembler::zero, LENGTH_DIFF_LABEL);
movl(cnt2, cnt1);
bind(COMPARE_TAIL); // limit is zero
movl(cnt2, result);
// Fallthru to tail compare
}
// Shift str2 and str1 to the end of the arrays, negate min
lea(str1, Address(str1, cnt2, Address::times_2, 0));
lea(str2, Address(str2, cnt2, Address::times_2, 0));
lea(str1, Address(str1, cnt2, scale, 0));
lea(str2, Address(str2, cnt2, scale, 0));
negptr(cnt2);
// Compare the rest of the characters
// Compare the rest of the elements
bind(WHILE_HEAD_LABEL);
load_unsigned_short(result, Address(str1, cnt2, Address::times_2, 0));
load_unsigned_short(cnt1, Address(str2, cnt2, Address::times_2, 0));
load_unsigned_short(result, Address(str1, cnt2, scale, 0));
load_unsigned_short(cnt1, Address(str2, cnt2, scale, 0));
subl(result, cnt1);
jccb(Assembler::notZero, POP_LABEL);
increment(cnt2);
jcc(Assembler::notZero, WHILE_HEAD_LABEL);
jccb(Assembler::notZero, WHILE_HEAD_LABEL);
// Strings are equal up to min length. Return the length difference.
bind(LENGTH_DIFF_LABEL);
@ -8766,7 +8800,7 @@ void MacroAssembler::string_compare(Register str1, Register str2,
// Discard the stored length difference
bind(POP_LABEL);
addptr(rsp, wordSize);
pop(cnt1);
// That's it
bind(DONE_LABEL);
@ -8814,6 +8848,7 @@ void MacroAssembler::char_arrays_equals(bool is_array_equ, Register ary1, Regist
if (UseSSE42Intrinsics) {
// With SSE4.2, use double quad vector compare
Label COMPARE_WIDE_VECTORS, COMPARE_TAIL;
// Compare 16-byte vectors
andl(result, 0x0000000e); // tail count (in bytes)
andl(limit, 0xfffffff0); // vector count (in bytes)
@ -8827,11 +8862,23 @@ void MacroAssembler::char_arrays_equals(bool is_array_equ, Register ary1, Regist
movdqu(vec1, Address(ary1, limit, Address::times_1));
movdqu(vec2, Address(ary2, limit, Address::times_1));
pxor(vec1, vec2);
ptest(vec1, vec1);
jccb(Assembler::notZero, FALSE_LABEL);
addptr(limit, 16);
jcc(Assembler::notZero, COMPARE_WIDE_VECTORS);
testl(result, result);
jccb(Assembler::zero, TRUE_LABEL);
movdqu(vec1, Address(ary1, result, Address::times_1, -16));
movdqu(vec2, Address(ary2, result, Address::times_1, -16));
pxor(vec1, vec2);
ptest(vec1, vec1);
jccb(Assembler::notZero, FALSE_LABEL);
jmpb(TRUE_LABEL);
bind(COMPARE_TAIL); // limit is zero
movl(limit, result);
// Fallthru to tail compare