From: Peter Maydell <peter.maydell@linaro.org>
To: qemu-arm@nongnu.org, qemu-devel@nongnu.org
Cc: Richard Henderson <richard.henderson@linaro.org>
Subject: [PATCH v2 01/10] decodetree: Fix codegen for non-overlapping group inside overlapping group
Date: Mon, 19 Oct 2020 16:12:52 +0100 [thread overview]
Message-ID: <20201019151301.2046-2-peter.maydell@linaro.org> (raw)
In-Reply-To: <20201019151301.2046-1-peter.maydell@linaro.org>
For nested groups like:
{
[
pattern 1
pattern 2
]
pattern 3
}
the intended behaviour is that patterns 1 and 2 must not
overlap with each other; if the insn matches neither then
we fall through to pattern 3 as the next thing in the
outer overlapping group.
Currently we generate incorrect code for this situation,
because in the code path for a failed match inside the
inner non-overlapping group we generate a "return" statement,
which causes decode to stop entirely rather than continuing
to the next thing in the outer group.
Generate a "break" instead, so that decode flow behaves
as required for this nested group case.
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
scripts/decodetree.py | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/scripts/decodetree.py b/scripts/decodetree.py
index 60fd3b5e5f6..c1bf3cfa85f 100644
--- a/scripts/decodetree.py
+++ b/scripts/decodetree.py
@@ -548,7 +548,7 @@ class Tree:
output(ind, ' /* ',
str_match_bits(innerbits, innermask), ' */\n')
s.output_code(i + 4, extracted, innerbits, innermask)
- output(ind, ' return false;\n')
+ output(ind, ' break;\n')
output(ind, '}\n')
# end Tree
--
2.20.1
next prev parent reply other threads:[~2020-10-19 15:16 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-19 15:12 [PATCH v2 00/10] target/arm: Various v8.1M minor features Peter Maydell
2020-10-19 15:12 ` Peter Maydell [this message]
2020-10-19 15:12 ` [PATCH v2 02/10] target/arm: Implement v8.1M NOCP handling Peter Maydell
2020-10-19 16:11 ` Richard Henderson
2020-10-19 15:12 ` [PATCH v2 03/10] target/arm: Implement v8.1M conditional-select insns Peter Maydell
2020-10-19 15:12 ` [PATCH v2 04/10] target/arm: Make the t32 insn[25:23]=111 group non-overlapping Peter Maydell
2020-10-19 15:12 ` [PATCH v2 05/10] target/arm: Don't allow BLX imm for M-profile Peter Maydell
2020-10-19 15:12 ` [PATCH v2 06/10] target/arm: Implement v8.1M branch-future insns (as NOPs) Peter Maydell
2020-10-19 15:12 ` [PATCH v2 07/10] target/arm: Implement v8.1M low-overhead-loop instructions Peter Maydell
2020-10-19 15:39 ` Richard Henderson
2020-10-19 15:12 ` [PATCH v2 08/10] target/arm: Fix has_vfp/has_neon ID reg squashing for M-profile Peter Maydell
2020-10-19 15:13 ` [PATCH v2 09/10] target/arm: Allow M-profile CPUs with FP16 to set FPSCR.FP16 Peter Maydell
2020-10-19 15:57 ` Richard Henderson
2020-10-19 15:13 ` [PATCH v2 10/10] target/arm: Implement FPSCR.LTPSIZE for M-profile LOB extension Peter Maydell
2020-10-19 16:00 ` Richard Henderson
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