From e4c4e6ddc365d8e9b5409e2f929116624c932c1d Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Tue, 30 Jan 2018 22:37:06 +0100 Subject: [PATCH] gzip: code shrink function old new delta send_bits 92 70 -22 Signed-off-by: Denys Vlasenko --- archival/gzip.c | 31 ++++++++++++++++++------------- 1 file changed, 18 insertions(+), 13 deletions(-) diff --git a/archival/gzip.c b/archival/gzip.c index 8ef66390a..efc5a0eea 100644 --- a/archival/gzip.c +++ b/archival/gzip.c @@ -358,7 +358,7 @@ struct globals { unsigned short bi_buf; #undef BUF_SIZE -#define BUF_SIZE (8 * sizeof(G1.bi_buf)) +#define BUF_SIZE (int)(8 * sizeof(G1.bi_buf)) /* Number of bits used within bi_buf. (bi_buf might be implemented on * more than 16 bits on some systems.) @@ -522,24 +522,29 @@ static unsigned file_read(void *buf, unsigned size) */ static void send_bits(int value, int length) { + unsigned new_buf; + int remain; + #ifdef DEBUG Tracev((stderr, " l %2d v %4x ", length, value)); Assert(length > 0 && length <= 15, "invalid length"); G1.bits_sent += length; #endif - /* If not enough room in bi_buf, use (valid) bits from bi_buf and - * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid)) - * unused bits in value. - */ - if (G1.bi_valid > (int) BUF_SIZE - length) { - G1.bi_buf |= (value << G1.bi_valid); - put_16bit(G1.bi_buf); - G1.bi_buf = (ush) value >> (BUF_SIZE - G1.bi_valid); - G1.bi_valid += length - BUF_SIZE; - } else { - G1.bi_buf |= value << G1.bi_valid; - G1.bi_valid += length; + + new_buf = G1.bi_buf | (value << G1.bi_valid); + remain = BUF_SIZE - G1.bi_valid; + /* If not enough room in bi_buf */ + if (length > remain) { + /* ...use (valid) bits from bi_buf and + * (16 - bi_valid) bits from value, + * leaving (width - (16-bi_valid)) unused bits in value. + */ + put_16bit(new_buf); + new_buf = (ush) value >> remain; + length -= BUF_SIZE; } + G1.bi_buf = new_buf; + G1.bi_valid += length; } -- 2.25.1