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target/arm: Fix handling of LDAPR/STLR with negative offset

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When we converted the LDAPR/STLR instructions to decodetree we
accidentally introduced a regression where the offset is negative.
The 9-bit immediate field is signed, and the old hand decoder
correctly used sextract32() to get it out of the insn word,
but the ldapr_stlr_i pattern in the decode file used "imm:9"
instead of "imm:s9", so it treated the field as unsigned.

Fix the pattern to treat the field as a signed immediate.

Cc: qemu-stable@nongnu.org
Fixes: 2521b6073b ("target/arm: Convert LDAPR/STLR (imm) to decodetree")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2419
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20240709134504.3500007-2-peter.maydell@linaro.org
(cherry picked from commit 5669d26ec6)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
This commit is contained in:
Peter Maydell 2024-07-16 11:30:32 +01:00 committed by Michael Tokarev
parent ab32beaa8e
commit c68b380b62
1 changed files with 1 additions and 1 deletions
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2
target/arm/tcg/a64.decode
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@ -467,7 +467,7 @@ LDAPR sz:2 111 0 00 1 0 1 11111 1100 00 rn:5 rt:5
LDRA 11 111 0 00 m:1 . 1 ......... w:1 1 rn:5 rt:5 imm=%ldra_imm
&ldapr_stlr_i rn rt imm sz sign ext
@ldapr_stlr_i .. ...... .. . imm:9 .. rn:5 rt:5 &ldapr_stlr_i
@ldapr_stlr_i .. ...... .. . imm:s9 .. rn:5 rt:5 &ldapr_stlr_i
STLR_i sz:2 011001 00 0 ......... 00 ..... ..... @ldapr_stlr_i sign=0 ext=0
LDAPR_i sz:2 011001 01 0 ......... 00 ..... ..... @ldapr_stlr_i sign=0 ext=0
LDAPR_i 00 011001 10 0 ......... 00 ..... ..... @ldapr_stlr_i sign=1 ext=0 sz=0