Commit abb7f827 authored by Alyssa Rosenzweig's avatar Alyssa Rosenzweig 💜
Browse files

pan/va: Add Valhall assembler



This Python script acts as a standalone assembler. It takes Valhall
instructions with Mesa-flavour syntax, parses them, errors out if there
are syntax errors, and writes out an assembled binary if there are not.
It also is available as a programmatic interface for automated testing.

While this attempts to handle syntax errors, it does not check
semantics. It will happily compile programs that fault, provided each
instruction locally 'looks' plausible.

The code itself is quite small, despite supporting most of the known
ISA, because the syntax is regular and the heavylifting is done by
ISA.xml and valhall.py.
Signed-off-by: Alyssa Rosenzweig's avatarAlyssa Rosenzweig <alyssa@collabora.com>
parent 9e0a4037
#encoding=utf-8
# Copyright (C) 2020 Collabora, Ltd.
#
# Permission is hereby granted, free of charge, to any person obtaining a
# copy of this software and associated documentation files (the "Software"),
# to deal in the Software without restriction, including without limitation
# the rights to use, copy, modify, merge, publish, distribute, sublicense,
# and/or sell copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice (including the next
# paragraph) shall be included in all copies or substantial portions of the
# Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
# IN THE SOFTWARE.
import argparse
import sys
import struct
from valhall import instructions, enums, immediates, typesize
LINE = ''
class ParseError(Exception):
def __init__(self, error):
self.error = error
# When running standalone, exit with the error since we're dealing with a
# human. Otherwise raise a Python exception so the test harness can handle it.
def die(s):
if __name__ == "__main__":
print(LINE)
print(s)
sys.exit(1)
else:
raise ParseError(s)
def die_if(cond, s):
if cond:
die(s)
def parse_int(s, minimum, maximum):
try:
number = int(s, base = 0)
except ValueError:
die(f"Expected number {s}")
if number > maximum or number < minimum:
die(f"Range error on {s}")
return number
def encode_source(op, immediate_mode = 'none'):
if op == 'atest_datum':
die_if(immediate_mode != 'none', 'Expected no modifier with atest datum')
return 0x2A | 0xC0
elif op.startswith('blend_descriptor_'):
die_if(immediate_mode != 'none', 'Expected no modifier with blend descriptor')
fin = op[len('blend_descriptor_'):]
die_if(len(fin) != 3, 'Bad syntax')
die_if(fin[1] != '_', 'Bad syntax')
die_if(fin[2] not in ['x', 'y'], 'Bad component')
rt = parse_int(fin[0], 0, 7)
hi = 1 if (fin[2] == 'y') else 0
return (0x30 | (2*rt) + hi) | 0xC0
elif op[0] == '`':
die_if(op[1] != 'r', f"Expected register after discard {op}")
return parse_int(op[2:], 0, 63) | 0x40
elif op[0] == 'r':
return parse_int(op[1:], 0, 63)
elif op[0] == 'u':
return parse_int(op[1:], 0, 63) | 0x80
elif op[0] == 'i':
return int(op[3:]) | 0xC0
elif op in enums['thread_storage_pointers'].bare_values:
die_if(immediate_mode != 'ts',
f'Expected .ts with thread pointer, got {immediate_mode}')
idx = 32 + enums['thread_storage_pointers'].bare_values.index(op)
return idx | 0xC0
elif op in enums['thread_identification'].bare_values:
die_if(immediate_mode != 'id',
'Expected .id modifier with thread storage pointer')
idx = 32 + enums['thread_identification'].bare_values.index(op)
return idx | 0xC0
elif op.startswith('0x'):
try:
val = int(op, base=0)
except ValueError:
die('Expected value')
die_if(val not in immediates, 'Unexpected immediate value')
return immediates.index(val) | 0xC0
else:
die('Invalid operand')
def encode_dest(op):
die_if(op[0] != 'r', f"Expected register destination {op}")
parts = op.split(".")
reg = parts[0]
# Default to writing in full
wrmask = 0x3
if len(parts) > 1:
WMASKS = ["h0", "h1"]
die_if(len(parts) > 2, "Too many modifiers")
mask = parts[1];
die_if(mask not in WMASKS, "Expected a write mask")
wrmask = 1 << WMASKS.index(mask)
return parse_int(reg[1:], 0, 63) | (wrmask << 6)
def parse_asm(line):
global LINE
LINE = line # For better errors
encoded = 0
# Figure out mnemonic
head = line.split(" ")[0]
opts = [ins for ins in instructions if head.startswith(ins.name)]
opts = sorted(opts, key=lambda x: len(x.name), reverse=True)
if len(opts) == 0:
die(f"No known mnemonic for {head}")
if len(opts) > 1 and len(opts[0].name) == len(opts[1].name):
print(f"Ambiguous mnemonic for {head}")
print(f"Options:")
for ins in opts:
print(f" {ins}")
sys.exit(1)
ins = opts[0]
# Split off modifiers
if len(head) > len(ins.name) and head[len(ins.name)] != '.':
die(f"Expected . after instruction in {head}")
mods = head[len(ins.name) + 1:].split(".")
modifier_map = {}
immediate_mode = 'none'
for mod in mods:
if mod in enums['immediate_mode'].bare_values:
die_if(immediate_mode != 'none', 'Multiple immediate modes specified')
immediate_mode = mod
tail = line[(len(head) + 1):]
operands = [x.strip() for x in tail.split(",") if len(x.strip()) > 0]
expected_op_count = len(ins.srcs) + len(ins.dests) + len(ins.immediates) + len(ins.staging)
if len(operands) != expected_op_count:
die(f"Wrong number of operands in {line}, expected {expected_op_count}, got {len(operands)} {operands}")
# Encode each operand
for i, (op, sr) in enumerate(zip(operands, ins.staging)):
die_if(op[0] != '@', f'Expected staging register, got {op}')
parts = op[1:].split(':')
die_if(any([x[0] != 'r' for x in parts]), f'Expected registers, got {op}')
regs = [parse_int(x[1:], 0, 63) for x in parts]
sr_count = len(regs)
die_if(sr_count < 1, f'Expected staging register, got {op}')
die_if(sr_count > 7, f'Too many staging registers {sr_count}')
base = regs[0]
die_if(any([reg != (base + i) for i, reg in enumerate(regs)]),
'Expected consecutive staging registers, got {op}')
if sr.count == 0:
modifier_map["staging_register_count"] = sr_count
else:
die_if(sr_count != sr.count, f"Expected 4 staging registers, got {sr_count}")
encoded |= ((sr.encoded_flags | base) << sr.start)
operands = operands[len(ins.staging):]
for op, dest in zip(operands, ins.dests):
encoded |= encode_dest(op) << 40
operands = operands[len(ins.dests):]
if len(ins.dests) == 0 and len(ins.staging) == 0:
# Set a placeholder writemask to prevent encoding faults
encoded |= (0xC0 << 40)
for i, (op, src) in enumerate(zip(operands, ins.srcs)):
parts = op.split('.')
encoded |= encode_source(parts[0], immediate_mode) << (i * 8)
# Has a swizzle been applied yet?
swizzled = False
tsize = typesize(ins.name)
for mod in parts[1:]:
# Encode the modifier
if mod in src.offset and src.bits[mod] == 1:
encoded |= (1 << src.offset[mod])
elif mod in enums[f'swizzles_{tsize}_bit'].bare_values and (src.widen or src.lanes):
die_if(swizzled, "Multiple swizzles specified")
swizzled = True
val = enums[f'swizzles_{tsize}_bit'].bare_values.index(mod)
encoded |= (val << src.offset['widen'])
elif src.lane and mod in enums[f'lane_{src.size}_bit'].bare_values:
die_if(swizzled, "Multiple swizzles specified")
swizzled = True
val = enums[f'lane_{src.size}_bit'].bare_values.index(mod)
encoded |= (val << src.offset['lane'])
elif tsize == 32 and mod in enums['widen'].bare_values:
die_if(not src.swizzle, "Instruction doesn't take widens")
die_if(swizzled, "Multiple swizzles specified")
swizzled = True
val = enums['widen'].bare_values.index(mod)
encoded |= (val << src.offset['swizzle'])
elif tsize == 16 and mod in enums['swizzles_16_bit'].bare_values:
die_if(not src.swizzle, "Instruction doesn't take swizzles")
die_if(swizzled, "Multiple swizzles specified")
swizzled = True
val = enums['swizzles_16_bit'].bare_values.index(mod)
encoded |= (val << src.offset['swizzle'])
elif mod in enums['lane_8_bit'].bare_values:
die_if(not src.lane, "Instruction doesn't take a lane")
die_if(swizzled, "Multiple swizzles specified")
swizzled = True
val = enums['lane_8_bit'].bare_values.index(mod)
encoded |= (val << src.lane)
else:
die(f"Unknown modifier {mod}")
# Encode the identity if a swizzle is required but not specified
if src.swizzle and not swizzled and tsize == 16:
mod = enums['swizzles_16_bit'].default
val = enums['swizzles_16_bit'].bare_values.index(mod)
encoded |= (val << src.offset['swizzle'])
elif src.widen and not swizzled and tsize == 16:
die_if(swizzled, "Multiple swizzles specified")
mod = enums['swizzles_16_bit'].default
val = enums['swizzles_16_bit'].bare_values.index(mod)
encoded |= (val << src.offset['widen'])
operands = operands[len(ins.srcs):]
for i, (op, imm) in enumerate(zip(operands, ins.immediates)):
if op[0] == '#':
die_if(imm.name != 'constant', "Wrong syntax for immediate")
parts = [imm.name, op[1:]]
else:
parts = op.split(':')
die_if(len(parts) != 2, f"Wrong syntax for immediate, wrong number of colons in {op}")
die_if(parts[0] != imm.name, f"Wrong immediate, expected {imm.name}, got {parts[0]}")
if imm.signed:
minimum = -(1 << (imm.size - 1))
maximum = +(1 << (imm.size - 1)) - 1
else:
minimum = 0
maximum = (1 << imm.size) - 1
val = parse_int(parts[1], minimum, maximum)
if val < 0:
# Sign extends
val = (1 << imm.size) + val
encoded |= (val << imm.start)
operands = operands[len(ins.immediates):]
# Encode the operation itself
encoded |= (ins.opcode << 48)
encoded |= (ins.opcode2 << ins.secondary_shift)
# Encode modifiers
has_action = False
for mod in mods:
if len(mod) == 0:
continue
if mod in enums['action'].bare_values:
die_if(has_action, "Multiple actions specified")
has_action = True
encoded |= (enums['action'].bare_values.index(mod) << 59)
encoded |= (1 << 62) # Action, not wait
elif mod.startswith('wait'):
die_if(has_action, "Multiple actions specified")
has_action = True
slots = mod[len('wait'):]
try:
slots = set([int(x) for x in slots])
except ValueError:
die(f"Expected slots in {mod}")
known_slots = set([0, 1, 2])
die_if(not slots.issubset(known_slots), f"Unknown slots in {mod}")
if 0 in slots:
encoded |= (1 << 59)
if 1 in slots:
encoded |= (1 << 60)
if 2 in slots:
encoded |= (1 << 61)
elif mod in enums['immediate_mode'].bare_values:
pass # handled specially
else:
candidates = [c for c in ins.modifiers if mod in c.bare_values]
die_if(len(candidates) == 0, f"Invalid modifier {mod} used")
assert(len(candidates) == 1) # No ambiguous modifiers
opts = candidates[0]
value = opts.bare_values.index(mod)
assert(value is not None)
die_if(opts.name in modifier_map, f"{opts.name} specified twice")
modifier_map[opts.name] = value
for mod in ins.modifiers:
value = modifier_map.get(mod.name, mod.default)
die_if(value is None, f"Missing required modifier {mod.name}")
assert(value < (1 << mod.size))
encoded |= (value << mod.start)
encoded |= (enums['immediate_mode'].bare_values.index(immediate_mode) << 57)
return encoded
if __name__ == "__main__":
# Provide commandline interface
parser = argparse.ArgumentParser(description='Assemble Valhall shaders')
parser.add_argument('infile', nargs='?', type=argparse.FileType('r'),
default=sys.stdin)
parser.add_argument('outfile', type=argparse.FileType('wb'))
args = parser.parse_args()
lines = args.infile.read().strip().split('\n')
lines = [l for l in lines if len(l) > 0 and l[0] != '#']
packed = b''.join([struct.pack('<Q', parse_asm(ln)) for ln in lines])
args.outfile.write(packed)
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment