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[97.126.115.157]) by smtp.gmail.com with ESMTPSA id z62sm11924391pfl.33.2019.01.31.13.08.53 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 31 Jan 2019 13:08:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=S31DKu0mZOkrs3M7J/A2evOJI3LY5m9uL/909EEUJnk=; b=PT8Y2a19lT5AK0P11rkVrHIFFBrWOw96FAjGPhD5yBhHG9SHX0DvKXXgYnzsXzW45x VaMqthq9wRoAY0JQsxUTA4hHkl/fDeimDz+ez1PYjEWfLlxEncLgzqwP2kjFtht64tzj o0x5DSYE/wB+IJ4hM2h+/OjmDtzFHYVfMihR8= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=S31DKu0mZOkrs3M7J/A2evOJI3LY5m9uL/909EEUJnk=; b=XP9pP6Dcxx4J6IDITNWeY13KlLVWCkggFfbtw7Oz8B56zgUDDJ8h/VlUuAfdifCVZL c6NfRT4Q/XG8sOkDheMwDtJz4vBxf5b0v24mieA/it4GKTS62VDwz1/igyWRe/PwjFZc CgB/zCk0Fc4Ed06df4V++dGLcX/wG8oTT78yInIls42qod8HIEcCXRHxPv5IBOPhI724 RJ+M3CNaESP0yIDXHprwlyXibaqiNKxeTUXAc/jogr9Q6MIV5apX9xp3XdCE3op0JYcL PpYbLr5Kj3AB270e17MkHJx/H06/WsSAIX7FNqM1BIUMdBjn3JOCpA60t4jaGUGxDSG+ ICDg== X-Gm-Message-State: AJcUukc9EcJqvaxiX8iZR6NcPi40nhAxmSj7bs792C5YA0Wlw3oi2zNK gxWDbrc1DQ3wiFa1wyH5DYhbZPgWe8U= X-Google-Smtp-Source: ALg8bN6a/uRCFgXdKgoR8A7uOYA8lw/IfMYVMEsCC7AJhd2IeCb/id/H5op3B+vkuZytV09pOlPo0w== X-Received: by 2002:aa7:8758:: with SMTP id g24mr35653343pfo.250.1548968934896; Thu, 31 Jan 2019 13:08:54 -0800 (PST) From: Richard Henderson To: qemu-devel@nongnu.org Date: Thu, 31 Jan 2019 13:08:50 -0800 Message-Id: <20190131210851.9842-2-richard.henderson@linaro.org> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20190131210851.9842-1-richard.henderson@linaro.org> References: <20190131210851.9842-1-richard.henderson@linaro.org> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2607:f8b0:4864:20::531 Subject: [Qemu-devel] [PATCH 1/2] decodetree: Initial support for variable-length ISAs X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: ysato@users.sourceforge.jp Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Assuming that the ISA clearly describes how to determine the length of the instruction, and the ISA has a reasonable maximum instruction length, the input to the decoder can be right-justified in an appropriate insn word. This is not 100% convenient, as out-of-line %fields are numbered relative to the maximum instruction length, but this appears to still be usable. Signed-off-by: Richard Henderson --- scripts/decodetree.py | 38 ++++++++++++++++++++++++++++---------- 1 file changed, 28 insertions(+), 10 deletions(-) diff --git a/scripts/decodetree.py b/scripts/decodetree.py index 2f8b5a1c92..5fb0acaa15 100755 --- a/scripts/decodetree.py +++ b/scripts/decodetree.py @@ -159,6 +159,7 @@ import getopt =20 insnwidth =3D 32 insnmask =3D 0xffffffff +variablewidth =3D False fields =3D {} arguments =3D {} formats =3D {} @@ -420,7 +421,7 @@ class Arguments: =20 class General: """Common code between instruction formats and instruction patterns""" - def __init__(self, name, lineno, base, fixb, fixm, udfm, fldm, flds): + def __init__(self, name, lineno, base, fixb, fixm, udfm, fldm, flds, w= ): self.name =3D name self.file =3D input_file self.lineno =3D lineno @@ -430,6 +431,7 @@ class General: self.undefmask =3D udfm self.fieldmask =3D fldm self.fields =3D flds + self.width =3D w =20 def __str__(self): r =3D self.name @@ -597,7 +599,7 @@ def infer_argument_set(flds): return arg =20 =20 -def infer_format(arg, fieldmask, flds): +def infer_format(arg, fieldmask, flds, width): global arguments global formats global decode_function @@ -616,6 +618,8 @@ def infer_format(arg, fieldmask, flds): continue if fieldmask !=3D fmt.fieldmask: continue + if width !=3D fmt.width: + continue if not eq_fields_for_fmts(flds, fmt.fields): continue return (fmt, const_flds) @@ -624,7 +628,7 @@ def infer_format(arg, fieldmask, flds): if not arg: arg =3D infer_argument_set(flds) =20 - fmt =3D Format(name, 0, arg, 0, 0, 0, fieldmask, var_flds) + fmt =3D Format(name, 0, arg, 0, 0, 0, fieldmask, var_flds, width) formats[name] =3D fmt =20 return (fmt, const_flds) @@ -640,6 +644,7 @@ def parse_generic(lineno, is_format, name, toks): global re_ident global insnwidth global insnmask + global variablewidth =20 fixedmask =3D 0 fixedbits =3D 0 @@ -725,8 +730,15 @@ def parse_generic(lineno, is_format, name, toks): error(lineno, 'invalid token "{0}"'.format(t)) width +=3D shift =20 + if variablewidth and width < insnwidth and width % 8 =3D=3D 0: + shift =3D insnwidth - width + fixedbits <<=3D shift + fixedmask <<=3D shift + undefmask <<=3D shift + undefmask |=3D (1 << shift) - 1 + # We should have filled in all of the bits of the instruction. - if not (is_format and width =3D=3D 0) and width !=3D insnwidth: + elif not (is_format and width =3D=3D 0) and width !=3D insnwidth: error(lineno, 'definition has {0} bits'.format(width)) =20 # Do not check for fields overlaping fields; one valid usage @@ -752,7 +764,7 @@ def parse_generic(lineno, is_format, name, toks): if name in formats: error(lineno, 'duplicate format name', name) fmt =3D Format(name, lineno, arg, fixedbits, fixedmask, - undefmask, fieldmask, flds) + undefmask, fieldmask, flds, width) formats[name] =3D fmt else: # Patterns can reference a format ... @@ -762,12 +774,14 @@ def parse_generic(lineno, is_format, name, toks): error(lineno, 'pattern specifies both format and argument = set') if fixedmask & fmt.fixedmask: error(lineno, 'pattern fixed bits overlap format fixed bit= s') + if width !=3D fmt.width: + error(lineno, 'pattern uses format of different width') fieldmask |=3D fmt.fieldmask fixedbits |=3D fmt.fixedbits fixedmask |=3D fmt.fixedmask undefmask |=3D fmt.undefmask else: - (fmt, flds) =3D infer_format(arg, fieldmask, flds) + (fmt, flds) =3D infer_format(arg, fieldmask, flds, width) arg =3D fmt.base for f in flds.keys(): if f not in arg.fields: @@ -779,7 +793,7 @@ def parse_generic(lineno, is_format, name, toks): if f not in flds.keys() and f not in fmt.fields.keys(): error(lineno, 'field {0} not initialized'.format(f)) pat =3D Pattern(name, lineno, fmt, fixedbits, fixedmask, - undefmask, fieldmask, flds) + undefmask, fieldmask, flds, width) patterns.append(pat) =20 # Validate the masks that we have assembled. @@ -987,12 +1001,14 @@ def main(): global insntype global insnmask global decode_function + global variablewidth =20 decode_scope =3D 'static ' =20 - long_opts =3D ['decode=3D', 'translate=3D', 'output=3D', 'insnwidth=3D= '] + long_opts =3D ['decode=3D', 'translate=3D', + 'output=3D', 'insnwidth=3D', 'varinsnwidth=3D'] try: - (opts, args) =3D getopt.getopt(sys.argv[1:], 'o:w:', long_opts) + (opts, args) =3D getopt.getopt(sys.argv[1:], 'o:vw:', long_opts) except getopt.GetoptError as err: error(0, err) for o, a in opts: @@ -1004,7 +1020,9 @@ def main(): elif o =3D=3D '--translate': translate_prefix =3D a translate_scope =3D '' - elif o in ('-w', '--insnwidth'): + elif o in ('-w', '--insnwidth', '--varinsnwidth'): + if o =3D=3D '--varinsnwidth': + variablewidth =3D True insnwidth =3D int(a) if insnwidth =3D=3D 16: insntype =3D 'uint16_t' --=20 2.17.2