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| author | Richard Henderson <richard.henderson@linaro.org> | 2020-05-16 13:15:02 -0700 |
|---|---|---|
| committer | Richard Henderson <richard.henderson@linaro.org> | 2020-06-08 10:36:47 -0700 |
| commit | b44b3449a08818f0eb25b93faaf535e9c9a85e50 (patch) | |
| tree | 0aac860b3f61062e251a8c6108eef4254c895756 | |
| parent | df63044d02bf79241257bafe282d966c86933b68 (diff) | |
| download | qemu-b44b3449a08818f0eb25b93faaf535e9c9a85e50.zip | |
decodetree: Allow group covering the entire insn space
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>
| -rwxr-xr-x | scripts/decodetree.py | 14 | ||||
| -rw-r--r-- | tests/decode/succ_pattern_group_nest2.decode (renamed from tests/decode/err_pattern_group_nest1.decode) | 2 |
2 files changed, 12 insertions, 4 deletions
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) diff --git a/tests/decode/err_pattern_group_nest1.decode b/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 |