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tiny optimization to diff-delta 

This is my assembly freak side looking at generated code again.  And
since create_delta() is certainly pretty high on the radar every bits
count.  In this case shorter code is generated if hash_mask is not
copied to a local variable.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
maint
Nicolas Pitre 2006-05-02 23:46:51 -04:00 committed by Junio C Hamano
parent 3dc5a9e4cd
commit 2d08e5dd73
1 changed files with 2 additions and 3 deletions
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5
diff-delta.c
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@ -239,7 +239,7 @@ create_delta(const struct delta_index *index,
const void *trg_buf, unsigned long trg_size, const void *trg_buf, unsigned long trg_size,
unsigned long *delta_size, unsigned long max_size) unsigned long *delta_size, unsigned long max_size)
{ {
unsigned int i, outpos, outsize, hash_mask, val; unsigned int i, outpos, outsize, val;
int inscnt; int inscnt;
const unsigned char *ref_data, *ref_top, *data, *top; const unsigned char *ref_data, *ref_top, *data, *top;
unsigned char *out; unsigned char *out;
@ -275,7 +275,6 @@ create_delta(const struct delta_index *index,
ref_top = ref_data + index->src_size; ref_top = ref_data + index->src_size;
data = trg_buf; data = trg_buf;
top = trg_buf + trg_size; top = trg_buf + trg_size;
hash_mask = index->hash_mask;


outpos++; outpos++;
val = 0; val = 0;
@ -290,7 +289,7 @@ create_delta(const struct delta_index *index,
struct index_entry *entry; struct index_entry *entry;
val ^= U[data[-RABIN_WINDOW]]; val ^= U[data[-RABIN_WINDOW]];
val = ((val << 8) | *data) ^ T[val >> RABIN_SHIFT]; val = ((val << 8) | *data) ^ T[val >> RABIN_SHIFT];
i = val & hash_mask; i = val & index->hash_mask;
for (entry = index->hash[i]; entry; entry = entry->next) { for (entry = index->hash[i]; entry; entry = entry->next) {
const unsigned char *ref = entry->ptr; const unsigned char *ref = entry->ptr;
const unsigned char *src = data; const unsigned char *src = data;