From 5e04706b91ca90d6befd4da24a588a55e631d4a9 Mon Sep 17 00:00:00 2001 From: Lasse Collin Date: Mon, 12 Feb 2024 17:09:10 +0200 Subject: liblzma: LZMA decoder: Optimize loop comparison. But now it needs one more local variable. --- src/liblzma/rangecoder/range_decoder.h | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'src/liblzma/rangecoder') diff --git a/src/liblzma/rangecoder/range_decoder.h b/src/liblzma/rangecoder/range_decoder.h index 40de80c0..8cc78e6a 100644 --- a/src/liblzma/rangecoder/range_decoder.h +++ b/src/liblzma/rangecoder/range_decoder.h @@ -61,13 +61,21 @@ rc_read_init(lzma_range_decoder *rc, const uint8_t *restrict in, /// Makes local copies of range decoder and *in_pos variables. Doing this /// improves speed significantly. The range decoder macros expect also /// variables 'in' and 'in_size' to be defined. -#define rc_to_local(range_decoder, in_pos) \ +#define rc_to_local(range_decoder, in_pos, fast_mode_in_required) \ lzma_range_decoder rc = range_decoder; \ const uint8_t *rc_in_ptr = in + (in_pos); \ const uint8_t *rc_in_end = in + in_size; \ + const uint8_t *rc_in_fast_end \ + = (rc_in_end - rc_in_ptr) <= (fast_mode_in_required) \ + ? rc_in_ptr \ + : rc_in_end - (fast_mode_in_required); \ uint32_t rc_bound +/// Evaluates to true if there is enough input remaining to use fast mode. +#define rc_is_fast_allowed() (rc_in_ptr < rc_in_fast_end) + + /// Stores the local copes back to the range decoder structure. #define rc_from_local(range_decoder, in_pos) \ do { \ -- cgit v1.2.3