mirrors/pound-emu_pound
0
0
Fork 0
mirror of https://github.com/pound-emu/pound.git synced 2025-12-16 04:36:57 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

temp commit

Browse source 
Signed-off-by: Ronald Caesar <github43132@proton.me>
This commit is contained in:
Ronald Caesar 2025-10-19 00:33:42 -04:00
parent 2e2b5df20c
commit cabf8ee15d
No known key found for this signature in database
GPG key ID: 04307C401999C596
5 changed files with 76 additions and 34 deletions
Download patch file Download diff file Expand all files Collapse all files

84
src/jit/decoder/arm32.cpp
View file

@ -9,7 +9,15 @@ namespace pound::jit::decoder
{
/* Increase value as more instructions get implemented */
#define INSTRUCTION_ARRAY_CAPACITY 4
arm32_decoder_t g_arm32_decoder = {};
typedef struct
{
uint16_t* hash_table;
uint8_t* collision_map;
uint16_t hash_shift;
uint16_t hash_mask;
uint16_t table_size;
} arm32_perfect_hash_t;
/*
* ============================================================================
@ -18,6 +26,7 @@ arm32_decoder_t g_arm32_decoder = {};
*/
void arm32_add_instruction(arm32_decoder_t* decoder, const char* name, const char* bitstring, arm32_handler_fn handler);
void arm32_ADD_imm_handler(arm32_decoder_t* decoder, arm32_instruction_t instruction);
void arm32_SUB_imm_handler(arm32_decoder_t* decoder, arm32_instruction_t instruction);
void arm32_parse_bitstring(const char* bitstring, uint32_t* mask, uint32_t* expected);
void arm32_grow_instructions_array(arm32_decoder_t* decoder, size_t new_capacity);
@ -50,8 +59,66 @@ void arm32_init(pound::host::memory::arena_t allocator, arm32_decoder_t* decoder
#define INST(fn, name, bitstring) arm32_add_instruction(decoder, name, bitstring, &arm32_##fn##_handler);
#include "./arm32.inc"
#undef INST
LOG_TRACE("Initializing perfect hash parameters for %zu instructions", decoder->instruction_count);
/* Start with table size as next power of 2 >= count * 2 */
uint16_t table_size = 1U;
while (table_size < decoder->instruction_count * 2)
{
table_size <<= 1U;
}
uint16_t mask = table_size - 1;
size_t slots_used_size = table_size * sizeof(bool);
bool* slots_used = (bool*)pound::host::memory::arena_allocate(&decoder->allocator, slots_used_size);
PVM_ASSERT(nullptr != slots_used);
LOG_TRACE("Growing perfevt hash slots used array to %d bytes", slots_used_size);
uint16_t shift = 0;
bool perfect_hash_generated = false;
for (; shift < 16; ++shift)
{
bool collision_free = true;
(void)memset(slots_used, false, slots_used_size);
for (size_t i = 0; i < decoder->instruction_count; ++i)
{
uint32_t value = decoder->instructions[i].mask ^ decoder->instructions[i].expected;
value = ((value >> 16) ^ value) * 0x45d9f3b;
value = ((value >> 16) ^ value) * 0x45d9f3b;
value = (value >> 16) ^ value;
uint32_t hash_seed = value;
uint16_t hash = ((hash_seed >> shift) & mask);
if (true == slots_used[hash])
{
LOG_TRACE("COLLISION DETECTED at slot %u for shift %u", hash, shift);
collision_free = false;
break;
}
slots_used[hash] = true;
}
if (true == collision_free)
{
LOG_TRACE("COLLISION-FREE HASH found for shift %u", shift);
perfect_hash_generated = true;
break;
}
}
PVM_ASSERT_MSG(true == perfect_hash_generated, "Failed to generate perfect hash - no collision-free hash found");
LOG_TRACE("Perfect hash parameters: shift=%u, mask=0x%04x, table_size=%u", shift, mask, table_size);
/* TODO(GloriousTacoo:jit): Generate hash table. */
}
/*
* ============================================================================
* Private Functions
* ============================================================================
*/
void arm32_add_instruction(arm32_decoder_t* decoder, const char* name, const char* bitstring, arm32_handler_fn handler)
{
PVM_ASSERT(nullptr != decoder);
@ -81,23 +148,13 @@ void arm32_add_instruction(arm32_decoder_t* decoder, const char* name, const cha
}
++decoder->instruction_count;
LOG_TRACE("========================================");
LOG_TRACE("Instruction Registered: %s", info->name);
LOG_TRACE("Mask: 0x%08X", info->mask);
LOG_TRACE("Expected: 0x%08X", info->expected);
LOG_TRACE("Priority: %d", info->priority);
LOG_TRACE("========================================");
/* TODO(GloriousTacoo:jit): Add instruction to lookup table. */
}
void arm32_ADD_imm_handler(arm32_decoder_t* decoder, arm32_instruction_t instruction) {}
/*
* ============================================================================
* Private Functions
* ============================================================================
*/
void arm32_SUB_imm_handler(arm32_decoder_t* decoder, arm32_instruction_t instruction) {}
void arm32_parse_bitstring(const char* bitstring, uint32_t* mask, uint32_t* expected)
{
@ -109,7 +166,7 @@ void arm32_parse_bitstring(const char* bitstring, uint32_t* mask, uint32_t* expe
*mask = 0;
*expected = 0;
uint8_t instruction_size_bits = 32;
for (int i = 0; (i < instruction_size_bits) && (bitstring[i] != '\0'); ++i)
for (unsigned int i = 0; (i < instruction_size_bits) && (bitstring[i] != '\0'); ++i)
{
uint32_t bit_position = 31 - i;
switch (bitstring[i])
@ -134,5 +191,4 @@ void arm32_parse_bitstring(const char* bitstring, uint32_t* mask, uint32_t* expe
}
}
}
} // namespace pound::jit::decoder