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Use int as index to reduce cast operations 

Decreases the number of instructions per block by almost 1
This commit is contained in:
John Keiser 2020-04-22 09:40:44 -07:00
parent d4a37f6ef5
commit a198abc485
1 changed files with 4 additions and 5 deletions
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9
src/generic/json_structural_indexer.h
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@ -22,11 +22,10 @@ public:
// it helps tremendously.
if (bits == 0)
return;
auto cnt = count_ones(bits);
int cnt = static_cast<int>(count_ones(bits));
// Do the first 8 all together
decltype(cnt) i;
for (i=0; i<8; i++) {
for (int i=0; i<8; i++) {
this->tail[i] = idx + trailing_zeroes(bits);
bits = clear_lowest_bit(bits);
}
@ -34,7 +33,7 @@ public:
// Do the next 8 all together (we hope in most cases it won't happen at all
// and the branch is easily predicted).
if (unlikely(cnt > 8)) {
for (i=8; i<16; i++) {
for (int i=8; i<16; i++) {
this->tail[i] = idx + trailing_zeroes(bits);
bits = clear_lowest_bit(bits);
}
@ -43,7 +42,7 @@ public:
// branch mispredictions here. 16+ structurals per block means either punctuation ({} [] , :)
// or the start of a value ("abc" true 123) every four characters.
if (unlikely(cnt > 16)) {
i = 16;
int i = 16;
do {
this->tail[i] = idx + trailing_zeroes(bits);
bits = clear_lowest_bit(bits);