pound-emu_pound/scripts/generate_jit_assets.py
Ronald Caesar 0d957968df
jit/interpreter: Organize ifdefs
Signed-off-by: Ronald Caesar <github43132@proton.me>
2025-12-06 01:55:55 -04:00

241 lines
8.6 KiB
Python

#!/usr/bin/env python3
import re
import sys
import argparse
# Increased bucket size to handle overlapping wildcards
MAX_BUCKET_SIZE = 64
TABLE_SIZE = 4096
# Bits [27:20] and [7:4]
HASH_BITS_MASK = 0x0FF000F0
class Instruction:
def __init__(self, name, mnemonic, bitstring, array_index):
self.name = name
self.mnemonic = mnemonic
self.bitstring = bitstring
self.array_index = array_index
self.mask = 0
self.expected = 0
self.parse_bits()
def parse_bits(self):
if len(self.bitstring) != 32:
print(
f"Error: Bitstring length {len(self.bitstring)} invalid for {self.name}"
)
sys.exit(1)
for i, char in enumerate(self.bitstring):
bit_pos = 31 - i
if char == "0":
self.mask |= 1 << bit_pos
elif char == "1":
self.mask |= 1 << bit_pos
self.expected |= 1 << bit_pos
# Variable bits (c, n, d, m, etc) leave mask as 0
def parse_inc_file(input_path):
instructions = []
regex = re.compile(r'INST\(\s*([A-Za-z0-9_]+),\s*"(.*?)",\s*"(.*?)"\s*\)')
try:
with open(input_path, "r") as f:
lines = f.readlines()
except FileNotFoundError:
print(f"Error: Could not find input file: {input_path}")
sys.exit(1)
index_counter = 0
for line in lines:
line = line.strip()
if not line or line.startswith("//"):
continue
match = regex.search(line)
if match:
inst = Instruction(
match.group(1), match.group(2), match.group(3), index_counter
)
instructions.append(inst)
index_counter += 1
return instructions
def generate_lookup_table(instructions):
buckets = {i: [] for i in range(TABLE_SIZE)}
# Iterate over every possible hash index to determine which instructions belong in it
for i in range(TABLE_SIZE):
# Reconstruct the 32-bit value that would generate this hash index
# Hash algorithm: (Major << 4) | Minor
# Major is bits [27:20], Minor is bits [7:4]
major_val = (i >> 4) & 0xFF
minor_val = i & 0x0F
# Create a "Probe" value with the hash bits set
probe_val = (major_val << 20) | (minor_val << 4)
for inst in instructions:
# Check if this instruction matches this hash index.
# An instruction matches if its FIXED bits (mask) match the Probe bits
# for the specific positions used by the hash.
relevant_mask = inst.mask & HASH_BITS_MASK
relevant_expected = inst.expected & HASH_BITS_MASK
if (probe_val & relevant_mask) == relevant_expected:
buckets[i].append(inst)
if len(buckets[i]) > MAX_BUCKET_SIZE:
print(
f"FATAL ERROR: Bucket {i:#05x} overflowed! Size: {len(buckets[i])}"
)
print(
"This means too many instructions map to the same hash index."
)
sys.exit(1)
return buckets
def write_decoder_table_h_file(path):
print(f"Generating decoder table header file: {path}")
with open(path, "w") as f:
f.write("/* GENERATED FILE - DO NOT EDIT */\n")
f.write("/* This file is generated by scripts/generate_jit_assets.py */\n")
f.write("#ifndef POUND_JIT_DECODER_ARM32_GENERATED_H\n")
f.write("#define POUND_JIT_DECODER_ARM32_GENERATED_H\n\n")
f.write('#include "arm32.h"\n')
f.write("#include <stddef.h>\n\n")
f.write(f"#define LOOKUP_TABLE_MAX_BUCKET_SIZE {MAX_BUCKET_SIZE}U\n\n")
f.write("typedef struct {\n")
f.write(
" const pvm_jit_decoder_arm32_instruction_info_t *instructions[LOOKUP_TABLE_MAX_BUCKET_SIZE];\n"
)
f.write(" size_t count;\n")
f.write("} decode_bucket_t;\n\n")
f.write(
f"extern const decode_bucket_t g_decoder_lookup_table[{TABLE_SIZE}];\n\n"
)
f.write("#endif\n")
def write_opcodes_header(path, instructions):
"""Generates the arm32_opcodes.h file with a unique enum for each mnemonic."""
print(f"Generating opcode header file: {path}")
seen = set()
with open(path, "w") as f:
f.write("/* GENERATED FILE - DO NOT EDIT */\n")
f.write("/* This file is generated by scripts/generate_jit_assets.py */\n")
f.write("#ifndef POUND_JIT_DECODER_ARM32_OPCODES_H\n")
f.write("#define POUND_JIT_DECODER_ARM32_OPCODES_H\n\n")
f.write("typedef enum {\n")
for inst in instructions:
enum_name = f" PVM_A32_OP_{inst.name.upper()},\n"
if enum_name not in seen:
f.write(enum_name)
seen.add(enum_name)
f.write(" PVM_A32_OP_STOP,\n")
f.write("} pvm_jit_decoder_arm32_opcode_t;\n\n")
f.write("#endif // POUND_JIT_DECODER_ARM32_OPCODES_H\n")
def write_decoder_table_c_file(path, instructions, buckets):
"""Writes the decoder C file, now including the opcode enum."""
print(f"Generating decoder table source file: {path}")
with open(path, "w") as f:
f.write("/* GENERATED FILE - DO NOT EDIT */\n")
f.write("/* This file is generated by scripts/generate_jit_assets.py */\n")
f.write('#include "arm32.h"\n')
f.write('#include "arm32_table.h"\n\n')
f.write(
f"static const pvm_jit_decoder_arm32_instruction_info_t g_instructions[{len(instructions)}] = {{\n"
)
for inst in instructions:
f.write(
f' {{ "{inst.mnemonic}", "{inst.bitstring}", PVM_A32_OP_{inst.name.upper()}, {inst.mask:#010x}U, {inst.expected:#010x}U }},\n'
)
f.write("};\n")
f.write(f"const decode_bucket_t g_decoder_lookup_table[{TABLE_SIZE}] = {{\n")
for i in range(TABLE_SIZE):
if len(buckets[i]) > 0:
f.write(f" [{i:#05x}] = {{ .instructions = {{ ")
for inst in buckets[i]:
f.write(f"&g_instructions[{inst.array_index}], ")
f.write(f"}}, .count = {len(buckets[i])}U }},\n")
f.write("};\n")
def write_interpreter_handler_table(path, instructions):
"""Generates the dispatch table."""
print(f"Generating interpreter handler table: {path}")
seen = set()
with open(path, "w") as f:
for inst in instructions:
enum_name = f"PVM_A32_OP_{inst.name.upper()}"
if enum_name not in seen:
f.write(f" [{enum_name}] = &&{enum_name},\n")
seen.add(enum_name)
f.write(f" [PVM_A32_OP_STOP] = &&PVM_A32_OP_STOP,\n")
def write_interpreter_handler_skeletons(path, instructions):
"""Generates a skeleton file for handlers."""
print(f"Generating new skeleton file: {path}")
seen = set()
with open(path, "w") as f:
f.write("/*\n")
f.write(" * GENERATED FILE - DO NOT EDIT\n")
f.write(" * This file is generated by scripts/generate_jit_assets.py \n")
f.write(
" * This file contains pre-generated, empty handler blocks for the every instruction.\n"
)
f.write(" */\n\n")
for inst in instructions:
enum_name = f"HANDLER(PVM_A32_OP_{inst.name.upper()}): {{\n"
if enum_name not in seen:
f.write(enum_name)
seen.add(enum_name)
f.write(f" // TODO: Implement handler for {inst.mnemonic}\n")
f.write(" DISPATCH();\n")
f.write("}\n\n")
f.write(f"HANDLER(PVM_A32_OP_STOP): {{\n")
f.write(f" // TODO: Implement handler for PVM_A32_OP_STOP\n")
f.write(" DISPATCH();\n")
f.write("}\n\n")
def main():
parser = argparse.ArgumentParser(description="Generate ARM32 Decoder Tables")
parser.add_argument("input")
parser.add_argument("--out-opcodes-h")
parser.add_argument("--out-decoder-c")
parser.add_argument("--out-decoder-h")
parser.add_argument("--out-handler-table-inc")
parser.add_argument("--out-handler-skeletons-inc")
args = parser.parse_args()
instructions = parse_inc_file(args.input)
buckets = generate_lookup_table(instructions)
# Generate all necessary files
write_opcodes_header(args.out_opcodes_h, instructions)
write_decoder_table_c_file(args.out_decoder_c, instructions, buckets)
write_decoder_table_h_file(args.out_decoder_h)
write_interpreter_handler_table(args.out_handler_table_inc, instructions)
write_interpreter_handler_skeletons(args.out_handler_skeletons_inc, instructions)
if __name__ == "__main__":
main()