diff options
| -rw-r--r-- | archival/libunarchive/rangecoder.h | 38 |
1 files changed, 29 insertions, 9 deletions
diff --git a/archival/libunarchive/rangecoder.h b/archival/libunarchive/rangecoder.h index bb4159112..43f752257 100644 --- a/archival/libunarchive/rangecoder.h +++ b/archival/libunarchive/rangecoder.h @@ -56,7 +56,8 @@ typedef struct { #define RC_MODEL_TOTAL_BITS 11 -static speed_inline void rc_read(rc_t * rc) +/* Called twice: once at startup and once in rc_normalize() */ +static void rc_read(rc_t * rc) { rc->buffer_size = read(rc->fd, rc->buffer, rc->buffer_size); if (rc->buffer_size <= 0) @@ -65,6 +66,7 @@ static speed_inline void rc_read(rc_t * rc) rc->buffer_end = rc->buffer + rc->buffer_size; } +/* Called once */ static always_inline void rc_init(rc_t * rc, int fd, int buffer_size) { int i; @@ -84,35 +86,50 @@ static always_inline void rc_init(rc_t * rc, int fd, int buffer_size) } } +/* Called once. TODO: bb_maybe_free() */ static always_inline void rc_free(rc_t * rc) { if (ENABLE_FEATURE_CLEAN_UP) free(rc->buffer); } +/* Called twice, but one callsite is in speed_inline'd rc_is_bit_0_helper() */ +static void rc_do_normalize(rc_t * rc) +{ + if (rc->ptr >= rc->buffer_end) + rc_read(rc); + rc->range <<= 8; + rc->code = (rc->code << 8) | *rc->ptr++; +} static always_inline void rc_normalize(rc_t * rc) { if (rc->range < (1 << RC_TOP_BITS)) { - if (rc->ptr >= rc->buffer_end) - rc_read(rc); - rc->range <<= 8; - rc->code = (rc->code << 8) | *rc->ptr++; + rc_do_normalize(rc); } } -static speed_inline int rc_is_bit_0(rc_t * rc, uint16_t * p) +/* Called 9 times */ +/* Why rc_is_bit_0_helper exists? + * Because we want to always expose (rc->code < rc->bound) to optimizer + */ +static speed_inline uint32_t rc_is_bit_0_helper(rc_t * rc, uint16_t * p) { rc_normalize(rc); rc->bound = *p * (rc->range >> RC_MODEL_TOTAL_BITS); - return rc->code < rc->bound; + return rc->bound; +} +static always_inline int rc_is_bit_0(rc_t * rc, uint16_t * p) +{ + uint32_t t = rc_is_bit_0_helper(rc, p); + return rc->code < t; } +/* Called ~10 times, but very small, thus inlined */ static speed_inline void rc_update_bit_0(rc_t * rc, uint16_t * p) { rc->range = rc->bound; *p += ((1 << RC_MODEL_TOTAL_BITS) - *p) >> RC_MOVE_BITS; } - static speed_inline void rc_update_bit_1(rc_t * rc, uint16_t * p) { rc->range -= rc->bound; @@ -120,7 +137,8 @@ static speed_inline void rc_update_bit_1(rc_t * rc, uint16_t * p) *p -= *p >> RC_MOVE_BITS; } -static speed_inline int rc_get_bit(rc_t * rc, uint16_t * p, int *symbol) +/* Called 4 times in unlzma loop */ +static int rc_get_bit(rc_t * rc, uint16_t * p, int *symbol) { if (rc_is_bit_0(rc, p)) { rc_update_bit_0(rc, p); @@ -133,6 +151,7 @@ static speed_inline int rc_get_bit(rc_t * rc, uint16_t * p, int *symbol) } } +/* Called once */ static always_inline int rc_direct_bit(rc_t * rc) { rc_normalize(rc); @@ -144,6 +163,7 @@ static always_inline int rc_direct_bit(rc_t * rc) return 0; } +/* Called twice */ static speed_inline void rc_bit_tree_decode(rc_t * rc, uint16_t * p, int num_levels, int *symbol) { |