From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: peter.maydell@linaro.org
Subject: [PULL 4/9] decodetree: Allow group covering the entire insn space
Date: Tue, 9 Jun 2020 09:24:59 -0700 [thread overview]
Message-ID: <20200609162504.780080-5-richard.henderson@linaro.org> (raw)
In-Reply-To: <20200609162504.780080-1-richard.henderson@linaro.org>
This is an edge case for sure, but the logic that disallowed
this case was faulty. Further, a few fixes scattered about
can allow this to work.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
...est1.decode => succ_pattern_group_nest2.decode} | 2 +-
scripts/decodetree.py | 14 +++++++++++---
2 files changed, 12 insertions(+), 4 deletions(-)
rename tests/decode/{err_pattern_group_nest1.decode => succ_pattern_group_nest2.decode} (85%)
diff --git a/tests/decode/err_pattern_group_nest1.decode b/tests/decode/succ_pattern_group_nest2.decode
similarity index 85%
rename from tests/decode/err_pattern_group_nest1.decode
rename to tests/decode/succ_pattern_group_nest2.decode
index 92e971c3c5..8d5ab4b2d3 100644
--- a/tests/decode/err_pattern_group_nest1.decode
+++ b/tests/decode/succ_pattern_group_nest2.decode
@@ -6,7 +6,7 @@
%sub3 16:8
%sub4 24:8
-# Groups with no overlap are supposed to fail
+# Group with complete overlap of the two patterns
{
top 00000000 00000000 00000000 00000000
sub4 ........ ........ ........ ........ %sub1 %sub2 %sub3 %sub4
diff --git a/scripts/decodetree.py b/scripts/decodetree.py
index ea313bcdea..3307c74c30 100755
--- a/scripts/decodetree.py
+++ b/scripts/decodetree.py
@@ -124,6 +124,7 @@ def is_pow2(x):
def ctz(x):
"""Return the number of times 2 factors into X."""
+ assert x != 0
r = 0
while ((x >> r) & 1) == 0:
r += 1
@@ -131,6 +132,8 @@ def ctz(x):
def is_contiguous(bits):
+ if bits == 0:
+ return -1
shift = ctz(bits)
if is_pow2((bits >> shift) + 1):
return shift
@@ -793,9 +796,8 @@ def build_incmulti_pattern(lineno, pats):
error(lineno, 'width mismatch in patterns within braces')
repeat = True
- while repeat:
- if fixedmask == 0:
- error(lineno, 'no overlap in patterns within braces')
+ fixedbits = 0
+ while repeat and fixedmask != 0:
fixedbits = None
for p in pats:
thisbits = p.fixedbits & fixedmask
@@ -978,6 +980,12 @@ def build_tree(pats, outerbits, outermask):
innermask &= i.fixedmask
if innermask == 0:
+ # Edge condition: One pattern covers the entire insnmask
+ if len(pats) == 1:
+ t = Tree(outermask, innermask)
+ t.subs.append((0, pats[0]))
+ return t
+
text = 'overlapping patterns:'
for p in pats:
text += '\n' + p.file + ':' + str(p.lineno) + ': ' + str(p)
--
2.25.1
next prev parent reply other threads:[~2020-06-09 16:28 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-09 16:24 [PULL 0/9] decodetree: Add non-overlapping groups Richard Henderson
2020-06-09 16:24 ` [PULL 1/9] decodetree: Tidy error_with_file Richard Henderson
2020-06-09 16:24 ` [PULL 2/9] decodetree: Rename MultiPattern to IncMultiPattern Richard Henderson
2020-06-09 16:24 ` [PULL 3/9] decodetree: Split out MultiPattern from IncMultiPattern Richard Henderson
2020-06-09 16:24 ` Richard Henderson [this message]
2020-06-09 16:25 ` [PULL 5/9] decodetree: Move semantic propagation into classes Richard Henderson
2020-06-09 16:25 ` [PULL 6/9] decodetree: Implement non-overlapping groups Richard Henderson
2020-06-09 16:25 ` [PULL 7/9] tests/decode: Test " Richard Henderson
2020-06-09 16:25 ` [PULL 8/9] decodetree: Drop check for less than 2 patterns in a group Richard Henderson
2020-06-09 16:25 ` [PULL 9/9] target/arm: Use a non-overlapping group for misc control Richard Henderson
2020-06-11 12:07 ` [PULL 0/9] decodetree: Add non-overlapping groups Peter Maydell
2020-08-01 17:42 ` Peter Maydell
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200609162504.780080-5-richard.henderson@linaro.org \
--to=richard.henderson@linaro.org \
--cc=peter.maydell@linaro.org \
--cc=qemu-devel@nongnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).