Small speedup to inflate [psumbera].
Seeing a few percent speedup by using a pointer instead of an
assigned structure. This seems to help the compiler to optimize
better.
diff --git a/inffast.c b/inffast.c
index 0dbd1db..1fec7f3 100644
--- a/inffast.c
+++ b/inffast.c
@@ -70,7 +70,7 @@
code const FAR *dcode; /* local strm->distcode */
unsigned lmask; /* mask for first level of length codes */
unsigned dmask; /* mask for first level of distance codes */
- code here; /* retrieved table entry */
+ code const *here; /* retrieved table entry */
unsigned op; /* code bits, operation, extra bits, or */
/* window position, window bytes to copy */
unsigned len; /* match length, unused bytes */
@@ -107,20 +107,20 @@
hold += (unsigned long)(*in++) << bits;
bits += 8;
}
- here = lcode[hold & lmask];
+ here = lcode + (hold & lmask);
dolen:
- op = (unsigned)(here.bits);
+ op = (unsigned)(here->bits);
hold >>= op;
bits -= op;
- op = (unsigned)(here.op);
+ op = (unsigned)(here->op);
if (op == 0) { /* literal */
- Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
+ Tracevv((stderr, here->val >= 0x20 && here->val < 0x7f ?
"inflate: literal '%c'\n" :
- "inflate: literal 0x%02x\n", here.val));
- *out++ = (unsigned char)(here.val);
+ "inflate: literal 0x%02x\n", here->val));
+ *out++ = (unsigned char)(here->val);
}
else if (op & 16) { /* length base */
- len = (unsigned)(here.val);
+ len = (unsigned)(here->val);
op &= 15; /* number of extra bits */
if (op) {
if (bits < op) {
@@ -138,14 +138,14 @@
hold += (unsigned long)(*in++) << bits;
bits += 8;
}
- here = dcode[hold & dmask];
+ here = dcode + (hold & dmask);
dodist:
- op = (unsigned)(here.bits);
+ op = (unsigned)(here->bits);
hold >>= op;
bits -= op;
- op = (unsigned)(here.op);
+ op = (unsigned)(here->op);
if (op & 16) { /* distance base */
- dist = (unsigned)(here.val);
+ dist = (unsigned)(here->val);
op &= 15; /* number of extra bits */
if (bits < op) {
hold += (unsigned long)(*in++) << bits;
@@ -264,7 +264,7 @@
}
}
else if ((op & 64) == 0) { /* 2nd level distance code */
- here = dcode[here.val + (hold & ((1U << op) - 1))];
+ here = dcode + here->val + (hold & ((1U << op) - 1));
goto dodist;
}
else {
@@ -274,7 +274,7 @@
}
}
else if ((op & 64) == 0) { /* 2nd level length code */
- here = lcode[here.val + (hold & ((1U << op) - 1))];
+ here = lcode + here->val + (hold & ((1U << op) - 1));
goto dolen;
}
else if (op & 32) { /* end-of-block */
