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authorRasmus Villemoes <linux@rasmusvillemoes.dk>2015-02-10 13:12:21 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-03-25 17:04:57 +0300
commitbea2b592fd18eb8ffa3fc4ad380610632d03a38f (patch)
tree82a139e42a1812111dacc5a23b8b5fcb39058396 /lib/lz4/lz4_decompress.c
parent7085a7401ba54e92bbb5aa24d6f428071e18e509 (diff)
downloadlinux-bea2b592fd18eb8ffa3fc4ad380610632d03a38f.tar.xz
lib/lz4: Pull out constant tables
There's no reason to allocate the dec{32,64}table on the stack; it just wastes a bunch of instructions setting them up and, of course, also consumes quite a bit of stack. Using size_t for such small integers is a little excessive. $ scripts/bloat-o-meter /tmp/built-in.o lib/built-in.o add/remove: 2/2 grow/shrink: 2/0 up/down: 1304/-1548 (-244) function old new delta lz4_decompress_unknownoutputsize 55 718 +663 lz4_decompress 55 632 +577 dec64table - 32 +32 dec32table - 32 +32 lz4_uncompress 747 - -747 lz4_uncompress_unknownoutputsize 801 - -801 The now inlined lz4_uncompress functions used to have a stack footprint of 176 bytes (according to -fstack-usage); their inlinees have increased their stack use from 32 bytes to 48 and 80 bytes, respectively. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'lib/lz4/lz4_decompress.c')
-rw-r--r--lib/lz4/lz4_decompress.c18
1 files changed, 7 insertions, 11 deletions
diff --git a/lib/lz4/lz4_decompress.c b/lib/lz4/lz4_decompress.c
index f0f5c5c3de12..26cc6029b280 100644
--- a/lib/lz4/lz4_decompress.c
+++ b/lib/lz4/lz4_decompress.c
@@ -47,6 +47,11 @@
#include "lz4defs.h"
+static const int dec32table[] = {0, 3, 2, 3, 0, 0, 0, 0};
+#if LZ4_ARCH64
+static const int dec64table[] = {0, 0, 0, -1, 0, 1, 2, 3};
+#endif
+
static int lz4_uncompress(const char *source, char *dest, int osize)
{
const BYTE *ip = (const BYTE *) source;
@@ -56,10 +61,6 @@ static int lz4_uncompress(const char *source, char *dest, int osize)
BYTE *cpy;
unsigned token;
size_t length;
- size_t dec32table[] = {0, 3, 2, 3, 0, 0, 0, 0};
-#if LZ4_ARCH64
- size_t dec64table[] = {0, 0, 0, -1, 0, 1, 2, 3};
-#endif
while (1) {
@@ -116,7 +117,7 @@ static int lz4_uncompress(const char *source, char *dest, int osize)
/* copy repeated sequence */
if (unlikely((op - ref) < STEPSIZE)) {
#if LZ4_ARCH64
- size_t dec64 = dec64table[op - ref];
+ int dec64 = dec64table[op - ref];
#else
const int dec64 = 0;
#endif
@@ -177,11 +178,6 @@ static int lz4_uncompress_unknownoutputsize(const char *source, char *dest,
BYTE * const oend = op + maxoutputsize;
BYTE *cpy;
- size_t dec32table[] = {0, 3, 2, 3, 0, 0, 0, 0};
-#if LZ4_ARCH64
- size_t dec64table[] = {0, 0, 0, -1, 0, 1, 2, 3};
-#endif
-
/* Main Loop */
while (ip < iend) {
@@ -249,7 +245,7 @@ static int lz4_uncompress_unknownoutputsize(const char *source, char *dest,
/* copy repeated sequence */
if (unlikely((op - ref) < STEPSIZE)) {
#if LZ4_ARCH64
- size_t dec64 = dec64table[op - ref];
+ int dec64 = dec64table[op - ref];
#else
const int dec64 = 0;
#endif