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-sta...@nongnu.org
Fixes: 2521b6073b7 ("target/arm: Convert LDAPR/STLR (imm) to decodetree")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2419
Signed-off-by: Peter Maydell <peter.mayd...@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <phi...@linaro.org>
Reviewed-by: Richard Henderson <richard.hender...@linaro.org>
Message-id: 20240709134504.3500007-2-peter.mayd...@linaro.org
---
target/arm/tcg/a64.decode | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/target/arm/tcg/a64.decode b/target/arm/tcg/a64.decode
index 2922de700ca..62df4c4ceb4 100644
--- a/target/arm/tcg/a64.decode
+++ b/target/arm/tcg/a64.decode
@@ -520,7 +520,7 @@ 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
--
2.34.1
