pb_common: small performance optimizations
diff --git a/pb_common.c b/pb_common.c
index 911ae4c..ae3e9b6 100644
--- a/pb_common.c
+++ b/pb_common.c
@@ -9,62 +9,66 @@
{
uint32_t word0;
uint32_t data_offset;
- uint_least8_t format;
int_least8_t size_offset;
if (iter->index >= iter->descriptor->field_count)
return false;
word0 = PB_PROGMEM_READU32(iter->descriptor->field_info[iter->field_info_index]);
- format = word0 & 3;
- iter->tag = (pb_size_t)((word0 >> 2) & 0x3F);
iter->type = (pb_type_t)((word0 >> 8) & 0xFF);
- if (format == 0)
+ switch(word0 & 3)
{
- /* 1-word format */
- iter->array_size = 1;
- size_offset = (int_least8_t)((word0 >> 24) & 0x0F);
- data_offset = (word0 >> 16) & 0xFF;
- iter->data_size = (pb_size_t)((word0 >> 28) & 0x0F);
- }
- else if (format == 1)
- {
- /* 2-word format */
- uint32_t word1 = PB_PROGMEM_READU32(iter->descriptor->field_info[iter->field_info_index + 1]);
+ case 0: {
+ /* 1-word format */
+ iter->array_size = 1;
+ iter->tag = (pb_size_t)((word0 >> 2) & 0x3F);
+ size_offset = (int_least8_t)((word0 >> 24) & 0x0F);
+ data_offset = (word0 >> 16) & 0xFF;
+ iter->data_size = (pb_size_t)((word0 >> 28) & 0x0F);
+ break;
+ }
- iter->array_size = (pb_size_t)((word0 >> 16) & 0x0FFF);
- iter->tag = (pb_size_t)(iter->tag | ((word1 >> 28) << 6));
- size_offset = (int_least8_t)((word0 >> 28) & 0x0F);
- data_offset = word1 & 0xFFFF;
- iter->data_size = (pb_size_t)((word1 >> 16) & 0x0FFF);
- }
- else if (format == 2)
- {
- /* 4-word format */
- uint32_t word1 = PB_PROGMEM_READU32(iter->descriptor->field_info[iter->field_info_index + 1]);
- uint32_t word2 = PB_PROGMEM_READU32(iter->descriptor->field_info[iter->field_info_index + 2]);
- uint32_t word3 = PB_PROGMEM_READU32(iter->descriptor->field_info[iter->field_info_index + 3]);
+ case 1: {
+ /* 2-word format */
+ uint32_t word1 = PB_PROGMEM_READU32(iter->descriptor->field_info[iter->field_info_index + 1]);
- iter->array_size = (pb_size_t)(word0 >> 16);
- iter->tag = (pb_size_t)(iter->tag | ((word1 >> 8) << 6));
- size_offset = (int_least8_t)(word1 & 0xFF);
- data_offset = word2;
- iter->data_size = (pb_size_t)word3;
- }
- else
- {
- /* 8-word format */
- uint32_t word1 = PB_PROGMEM_READU32(iter->descriptor->field_info[iter->field_info_index + 1]);
- uint32_t word2 = PB_PROGMEM_READU32(iter->descriptor->field_info[iter->field_info_index + 2]);
- uint32_t word3 = PB_PROGMEM_READU32(iter->descriptor->field_info[iter->field_info_index + 3]);
- uint32_t word4 = PB_PROGMEM_READU32(iter->descriptor->field_info[iter->field_info_index + 4]);
+ iter->array_size = (pb_size_t)((word0 >> 16) & 0x0FFF);
+ iter->tag = (pb_size_t)(((word0 >> 2) & 0x3F) | ((word1 >> 28) << 6));
+ size_offset = (int_least8_t)((word0 >> 28) & 0x0F);
+ data_offset = word1 & 0xFFFF;
+ iter->data_size = (pb_size_t)((word1 >> 16) & 0x0FFF);
+ break;
+ }
- iter->array_size = (pb_size_t)word4;
- iter->tag = (pb_size_t)(iter->tag | ((word1 >> 8) << 6));
- size_offset = (int_least8_t)(word1 & 0xFF);
- data_offset = word2;
- iter->data_size = (pb_size_t)word3;
+ case 2: {
+ /* 4-word format */
+ uint32_t word1 = PB_PROGMEM_READU32(iter->descriptor->field_info[iter->field_info_index + 1]);
+ uint32_t word2 = PB_PROGMEM_READU32(iter->descriptor->field_info[iter->field_info_index + 2]);
+ uint32_t word3 = PB_PROGMEM_READU32(iter->descriptor->field_info[iter->field_info_index + 3]);
+
+ iter->array_size = (pb_size_t)(word0 >> 16);
+ iter->tag = (pb_size_t)(((word0 >> 2) & 0x3F) | ((word1 >> 8) << 6));
+ size_offset = (int_least8_t)(word1 & 0xFF);
+ data_offset = word2;
+ iter->data_size = (pb_size_t)word3;
+ break;
+ }
+
+ default: {
+ /* 8-word format */
+ uint32_t word1 = PB_PROGMEM_READU32(iter->descriptor->field_info[iter->field_info_index + 1]);
+ uint32_t word2 = PB_PROGMEM_READU32(iter->descriptor->field_info[iter->field_info_index + 2]);
+ uint32_t word3 = PB_PROGMEM_READU32(iter->descriptor->field_info[iter->field_info_index + 3]);
+ uint32_t word4 = PB_PROGMEM_READU32(iter->descriptor->field_info[iter->field_info_index + 4]);
+
+ iter->array_size = (pb_size_t)word4;
+ iter->tag = (pb_size_t)(((word0 >> 2) & 0x3F) | ((word1 >> 8) << 6));
+ size_offset = (int_least8_t)(word1 & 0xFF);
+ data_offset = word2;
+ iter->data_size = (pb_size_t)word3;
+ break;
+ }
}
if (!iter->message)
@@ -139,17 +143,13 @@
pb_type_t prev_type = (prev_descriptor >> 8) & 0xFF;
pb_size_t descriptor_len = (pb_size_t)(1 << (prev_descriptor & 3));
+ /* Add to fields.
+ * The cast to pb_size_t is needed to avoid -Wconversion warning.
+ * Because the data is is constants from generator, there is no danger of overflow.
+ */
iter->field_info_index = (pb_size_t)(iter->field_info_index + descriptor_len);
-
- if (PB_HTYPE(prev_type) == PB_HTYPE_REQUIRED)
- {
- iter->required_field_index++;
- }
-
- if (PB_LTYPE_IS_SUBMSG(prev_type))
- {
- iter->submessage_index++;
- }
+ iter->required_field_index = (pb_size_t)(iter->required_field_index + (PB_HTYPE(prev_type) == PB_HTYPE_REQUIRED));
+ iter->submessage_index = (pb_size_t)(iter->submessage_index + PB_LTYPE_IS_SUBMSG(prev_type));
}
}
@@ -203,6 +203,14 @@
pb_size_t start = iter->index;
uint32_t fieldinfo;
+ if (tag < iter->tag)
+ {
+ /* Fields are in tag number order, so we know that tag is between
+ * 0 and our start position. Setting index to end forces
+ * advance_iterator() call below to restart from beginning. */
+ iter->index = iter->descriptor->field_count;
+ }
+
do
{
/* Advance iterator but don't load values yet */
