changeset de679a068dd8 in /z/repo/m5
details: http://repo.m5sim.org/m5?cmd=changeset;node=de679a068dd8
description:
X86: When decoding a memory only inst, fault on reg encodings, don't
assert.
This change makes the decoder figure out if an instruction that only
supports
memory is using a register encoding and decodes directly to "Unknown"
which will
behave appropriately. This prevents other parts of the instruction
creation
process from seeing the mismatch and asserting.
diffstat:
src/arch/x86/isa/specialize.isa | 13 ++++++++++++-
1 files changed, 12 insertions(+), 1 deletions(-)
diffs (30 lines):
diff -r 6e368a935ac0 -r de679a068dd8 src/arch/x86/isa/specialize.isa
--- a/src/arch/x86/isa/specialize.isa Fri Apr 22 10:18:51 2011 -0700
+++ b/src/arch/x86/isa/specialize.isa Sat Apr 23 15:02:29 2011 -0700
@@ -96,6 +96,15 @@
}};
let {{
+ def doBadInstDecode():
+ blocks = OutputBlocks()
+ blocks.decode_block = '''
+ return new Unknown(machInst);
+ '''
+ return blocks
+}};
+
+let {{
class OpType(object):
parser =
re.compile(r"(?P<tag>[A-Z]+)(?P<size>[a-z]*)|(r(?P<reg>[A-Z0-9]+)(?P<rsize>[a-z]*))")
def __init__(self, opTypeString):
@@ -146,7 +155,9 @@
# This refers to memory. The macroop constructor sets up modrm
# addressing. Non memory modrm settings should cause an error.
env.doModRM = True
- return doRipRelativeDecode(Name, opTypes, env)
+ return doSplitDecode("MODRM_MOD",
+ {"3" : (doBadInstDecode,) },
+ (doRipRelativeDecode, Name, opTypes, env))
elif opType.tag == None or opType.size == None:
raise Exception, "Problem parsing operand tag: %s" % opType.tag
elif opType.tag == "C":
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