pan/bi: Add ISA parser

This Python script parses the ISA.xml file to produce a normalized
in-memory representation suitable for the disassembly and packing
scripts to consume. In particular, it papers over details about
duplicate encodings and default fields.

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6749>

diff --git a/src/panfrost/bifrost/isa_parse.py b/src/panfrost/bifrost/isa_parse.py
new file mode 100644 (file)
index 0000000..9b4e8a6
--- /dev/null
+++ b/src/panfrost/bifrost/isa_parse.py
@@ -0,0 +1,178 @@
+#
+# 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.
+
+# Parse instruction set XML into a normalized form for processing
+
+import xml.etree.ElementTree as ET
+import copy
+
+def parse_cond(cond, aliased = False):
+    if cond.tag == 'reserved':
+        return None
+    
+    if cond.attrib.get('alias', False) and not aliased:
+        return ['alias', parse_cond(cond, True)]
+
+    if 'left' in cond.attrib:
+        return [cond.tag, cond.attrib['left'], cond.attrib['right']]
+    else:
+        return [cond.tag] + [parse_cond(x) for x in cond.findall('*')]
+
+def parse_exact(obj):
+    return [int(obj.attrib['mask'], 0), int(obj.attrib['exact'], 0)]
+
+def parse_derived(obj):
+    out = []
+
+    for deriv in obj.findall('derived'):
+        loc = [int(deriv.attrib['start']), int(deriv.attrib['size'])]
+        count = 1 << loc[1]
+
+        opts = [parse_cond(d) for d in deriv.findall('*')]
+        default = [None] * count
+        opts_fit = (opts + default)[0:count]
+
+        out.append([loc, opts_fit])
+
+    return out
+
+def parse_modifiers(obj):
+    out = []
+
+    for mod in obj.findall('mod'):
+        name = mod.attrib['name']
+        start = mod.attrib.get('start', None)
+        size = int(mod.attrib['size'])
+
+        if start is not None:
+            start = int(start)
+
+        opts = [x.text if x.tag == 'opt' else x.tag for x in mod.findall('*')]
+
+        if len(opts) == 0:
+            assert('opt' in mod.attrib)
+            opts = ['none', mod.attrib['opt']]
+
+        # Find suitable default
+        default = mod.attrib.get('default', 'none' if 'none' in opts else None)
+
+        # Pad out as reserved
+        count = (1 << size)
+        opts = (opts + (['reserved'] * count))[0:count]
+        out.append([[name, start, size], default, opts])
+
+    return out
+
+def parse_copy(enc, existing):
+    for node in enc.findall('copy'):
+        name = node.get('name')
+        for ex in existing:
+            if ex[0][0] == name:
+                ex[0][1] = node.get('start')
+
+def parse_instruction(ins):
+    common = {
+            'srcs': [],
+            'modifiers': [],
+            'immediates': [],
+            'swaps': [],
+            'derived': [],
+            'staging': ins.attrib.get('staging', '')
+    }
+
+    if 'exact' in ins.attrib:
+        common['exact'] = parse_exact(ins)
+
+    for src in ins.findall('src'):
+        mask = int(src.attrib['mask'], 0) if ('mask' in src.attrib) else 0xFF
+        common['srcs'].append([int(src.attrib['start'], 0), mask])
+
+    for imm in ins.findall('immediate'):
+        common['immediates'].append([imm.attrib['name'], int(imm.attrib['start']), int(imm.attrib['size'])])
+
+    common['derived'] = parse_derived(ins)
+    common['modifiers'] = parse_modifiers(ins)
+
+    for swap in ins.findall('swap'):
+        lr = [int(swap.get('left')), int(swap.get('right'))]
+        cond = parse_cond(swap.findall('*')[0])
+        rewrites = {}
+
+        for rw in swap.findall('rewrite'):
+            mp = {}
+
+            for m in rw.findall('map'):
+                mp[m.attrib['from']] = m.attrib['to']
+
+            rewrites[rw.attrib['name']] = mp
+
+        common['swaps'].append([lr, cond, rewrites])
+
+    encodings = ins.findall('encoding')
+    variants = []
+
+    if len(encodings) == 0:
+        variants = [[None, common]]
+    else:
+        for enc in encodings:
+            variant = copy.deepcopy(common)
+            assert(len(variant['derived']) == 0)
+
+            variant['exact'] = parse_exact(enc)
+            variant['derived'] = parse_derived(enc)
+            parse_copy(enc, variant['modifiers'])
+
+            cond = parse_cond(enc.findall('*')[0])
+            variants.append([cond, variant])
+
+    return variants
+
+def parse_instructions(xml):
+    final = {}
+    instructions = ET.parse(xml).getroot().findall('ins')
+
+    for ins in instructions:
+        final[ins.attrib['name']] = parse_instruction(ins)
+
+    return final
+
+# Expand out an opcode name to something C-escaped
+
+def opname_to_c(name):
+    return name.lower().replace('*', 'fma_').replace('+', 'add_').replace('.', '_')
+
+# Expand out distinct states to distrinct instructions, with a placeholder
+# condition for instructions with a single state
+
+def expand_states(instructions):
+    out = {}
+
+    for ins in instructions:
+        c = instructions[ins]
+
+        for ((test, desc), i) in zip(c, range(len(c))):
+            # Construct a name for the state
+            name = ins + (('.' + str(i)) if len(c) > 1 else '')
+
+            out[name] = (ins, test if test is not None else [], desc)
+
+    return out