*
**************************************************************************/
+/*
+ * Functions for fast bitwise access to multiple probably unaligned input buffers
+ */
+
#ifndef vl_vlc_h
#define vl_vlc_h
-#include <assert.h>
-
-#include <pipe/p_compiler.h>
+#include "pipe/p_compiler.h"
-#include <util/u_math.h>
+#include "util/u_math.h"
#include "util/u_pointer.h"
+#include "util/u_debug.h"
struct vl_vlc
{
uint64_t buffer;
- unsigned valid_bits;
- uint32_t *data;
- uint32_t *end;
+ signed invalid_bits;
+ const uint8_t *data;
+ const uint8_t *end;
+
+ unsigned num_inputs;
+ const void *const *inputs;
+ const unsigned *sizes;
+ unsigned bytes_left;
};
struct vl_vlc_entry
struct vl_vlc_entry entry;
};
+/**
+ * initalize and decompress a lookup table
+ */
static INLINE void
vl_vlc_init_table(struct vl_vlc_entry *dst, unsigned dst_size, const struct vl_vlc_compressed *src, unsigned src_size)
{
unsigned i, bits = util_logbase2(dst_size);
+ assert(dst && dst_size);
+ assert(src && src_size);
+
for (i=0;i<dst_size;++i) {
dst[i].length = 0;
dst[i].value = 0;
}
}
+/**
+ * switch over to next input buffer
+ */
+static INLINE void
+vl_vlc_next_input(struct vl_vlc *vlc)
+{
+ unsigned len = vlc->sizes[0];
+
+ assert(vlc);
+ assert(vlc->num_inputs);
+
+ vlc->bytes_left -= len;
+
+ vlc->data = vlc->inputs[0];
+ vlc->end = vlc->data + len;
+
+ --vlc->num_inputs;
+ ++vlc->inputs;
+ ++vlc->sizes;
+}
+
+/**
+ * align the data pointer to the next dword
+ */
+static INLINE void
+vl_vlc_align_data_ptr(struct vl_vlc *vlc)
+{
+ /* align the data pointer */
+ while (vlc->data != vlc->end && pointer_to_uintptr(vlc->data) & 3) {
+ vlc->buffer |= (uint64_t)*vlc->data << (24 + vlc->invalid_bits);
+ ++vlc->data;
+ vlc->invalid_bits -= 8;
+ }
+}
+
+/**
+ * fill the bit buffer, so that at least 32 bits are valid
+ */
static INLINE void
vl_vlc_fillbits(struct vl_vlc *vlc)
{
- if (vlc->valid_bits < 32) {
- uint32_t value = *vlc->data;
+ assert(vlc);
+
+ /* as long as the buffer needs to be filled */
+ while (vlc->invalid_bits > 0) {
+ unsigned bytes_left = vlc->end - vlc->data;
+
+ /* if this input is depleted */
+ if (bytes_left == 0) {
+
+ if (vlc->num_inputs)
+ /* go on to next input */
+ vl_vlc_next_input(vlc);
+ else
+ /* or give up since we don't have anymore inputs */
+ return;
+
+ } else if (bytes_left >= 4) {
- //assert(vlc->data <= vlc->end);
+ /* enough bytes in buffer, read in a whole dword */
+ uint64_t value = *(const uint32_t*)vlc->data;
#ifndef PIPE_ARCH_BIG_ENDIAN
- value = util_bswap32(value);
+ value = util_bswap32(value);
#endif
- vlc->buffer |= (uint64_t)value << (32 - vlc->valid_bits);
- ++vlc->data;
- vlc->valid_bits += 32;
+ vlc->buffer |= value << vlc->invalid_bits;
+ vlc->data += 4;
+ vlc->invalid_bits -= 32;
+
+ /* buffer is now definitely filled up avoid the loop test */
+ break;
+
+ } else while (vlc->data < vlc->end) {
+
+ /* not enough bytes left in buffer, read single bytes */
+ vlc->buffer |= (uint64_t)*vlc->data << (24 + vlc->invalid_bits);
+ ++vlc->data;
+ vlc->invalid_bits -= 8;
+ }
}
}
+/**
+ * initialize vlc structure and start reading from first input buffer
+ */
static INLINE void
-vl_vlc_init(struct vl_vlc *vlc, const uint8_t *data, unsigned len)
+vl_vlc_init(struct vl_vlc *vlc, unsigned num_inputs,
+ const void *const *inputs, const unsigned *sizes)
{
+ unsigned i;
+
assert(vlc);
- assert(data && len);
+ assert(num_inputs);
vlc->buffer = 0;
- vlc->valid_bits = 0;
+ vlc->invalid_bits = 32;
+ vlc->num_inputs = num_inputs;
+ vlc->inputs = inputs;
+ vlc->sizes = sizes;
+ vlc->bytes_left = 0;
- /* align the data pointer */
- while (pointer_to_uintptr(data) & 3) {
- vlc->buffer |= (uint64_t)*data << (56 - vlc->valid_bits);
- ++data;
- --len;
- vlc->valid_bits += 8;
- }
- vlc->data = (uint32_t*)data;
- vlc->end = (uint32_t*)(data + len);
+ for (i = 0; i < num_inputs; ++i)
+ vlc->bytes_left += sizes[i];
+ vl_vlc_next_input(vlc);
+ vl_vlc_align_data_ptr(vlc);
vl_vlc_fillbits(vlc);
vl_vlc_fillbits(vlc);
}
+/**
+ * number of bits still valid in bit buffer
+ */
+static INLINE unsigned
+vl_vlc_valid_bits(struct vl_vlc *vlc)
+{
+ return 32 - vlc->invalid_bits;
+}
+
+/**
+ * number of bits left over all inbut buffers
+ */
static INLINE unsigned
vl_vlc_bits_left(struct vl_vlc *vlc)
{
- signed bytes_left = ((uint8_t*)vlc->end)-((uint8_t*)vlc->data);
- return bytes_left * 8 + vlc->valid_bits;
+ signed bytes_left = vlc->end - vlc->data;
+ bytes_left += vlc->bytes_left;
+ return bytes_left * 8 + vl_vlc_valid_bits(vlc);
}
+/**
+ * get num_bits from bit buffer without removing them
+ */
static INLINE unsigned
vl_vlc_peekbits(struct vl_vlc *vlc, unsigned num_bits)
{
- //assert(vlc->valid_bits >= num_bits);
-
+ assert(vl_vlc_valid_bits(vlc) >= num_bits || vlc->data >= vlc->end);
return vlc->buffer >> (64 - num_bits);
}
+/**
+ * remove num_bits from bit buffer
+ */
static INLINE void
vl_vlc_eatbits(struct vl_vlc *vlc, unsigned num_bits)
{
- //assert(vlc->valid_bits > num_bits);
+ assert(vl_vlc_valid_bits(vlc) >= num_bits);
vlc->buffer <<= num_bits;
- vlc->valid_bits -= num_bits;
+ vlc->invalid_bits += num_bits;
}
+/**
+ * get num_bits from bit buffer with removing them
+ */
static INLINE unsigned
vl_vlc_get_uimsbf(struct vl_vlc *vlc, unsigned num_bits)
{
unsigned value;
- //assert(vlc->valid_bits >= num_bits);
+ assert(vl_vlc_valid_bits(vlc) >= num_bits);
value = vlc->buffer >> (64 - num_bits);
vl_vlc_eatbits(vlc, num_bits);
return value;
}
+/**
+ * treat num_bits as signed value and remove them from bit buffer
+ */
static INLINE signed
vl_vlc_get_simsbf(struct vl_vlc *vlc, unsigned num_bits)
{
signed value;
- //assert(vlc->valid_bits >= num_bits);
+ assert(vl_vlc_valid_bits(vlc) >= num_bits);
value = ((int64_t)vlc->buffer) >> (64 - num_bits);
vl_vlc_eatbits(vlc, num_bits);
return value;
}
+/**
+ * lookup a value and length in a decompressed table
+ */
static INLINE int8_t
vl_vlc_get_vlclbf(struct vl_vlc *vlc, const struct vl_vlc_entry *tbl, unsigned num_bits)
{
return tbl->value;
}
+/**
+ * fast forward search for a specific byte value
+ */
+static INLINE boolean
+vl_vlc_search_byte(struct vl_vlc *vlc, unsigned num_bits, uint8_t value)
+{
+ /* make sure we are on a byte boundary */
+ assert((vl_vlc_valid_bits(vlc) % 8) == 0);
+ assert(num_bits == ~0 || (num_bits % 8) == 0);
+
+ /* deplete the bit buffer */
+ while (vl_vlc_valid_bits(vlc) > 0) {
+
+ if (vl_vlc_peekbits(vlc, 8) == value) {
+ vl_vlc_fillbits(vlc);
+ return TRUE;
+ }
+
+ vl_vlc_eatbits(vlc, 8);
+
+ if (num_bits != ~0) {
+ num_bits -= 8;
+ if (num_bits == 0)
+ return FALSE;
+ }
+ }
+
+ /* deplete the byte buffers */
+ while (1) {
+
+ /* if this input is depleted */
+ if (vlc->data == vlc->end) {
+ if (vlc->num_inputs)
+ /* go on to next input */
+ vl_vlc_next_input(vlc);
+ else
+ /* or give up since we don't have anymore inputs */
+ return FALSE;
+ }
+
+ if (*vlc->data == value) {
+ vl_vlc_align_data_ptr(vlc);
+ vl_vlc_fillbits(vlc);
+ return TRUE;
+ }
+
+ ++vlc->data;
+ if (num_bits != ~0) {
+ num_bits -= 8;
+ if (num_bits == 0) {
+ vl_vlc_align_data_ptr(vlc);
+ return FALSE;
+ }
+ }
+ }
+}
+
#endif /* vl_vlc_h */
projects / mesa.git / blobdiff