From bea2b592fd18eb8ffa3fc4ad380610632d03a38f Mon Sep 17 00:00:00 2001 From: Rasmus Villemoes Date: Tue, 10 Feb 2015 11:12:21 +0100 Subject: 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 Signed-off-by: Greg Kroah-Hartman --- lib/lz4/lz4_decompress.c | 18 +++++++----------- 1 file changed, 7 insertions(+), 11 deletions(-) (limited to 'lib') 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 -- cgit