From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: laurent.desnogues@gmail.com, peter.maydell@linaro.org
Subject: [Qemu-devel] [PATCH] target/arm: Fix sign-extension for SMLAL*
Date: Thu, 12 Sep 2019 14:30:58 -0400 [thread overview]
Message-ID: <20190912183058.17947-1-richard.henderson@linaro.org> (raw)
The 32-bit product should be sign-extended, not zero-extended.
Fixes: ea96b374641b
Reported-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
target/arm/translate.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/target/arm/translate.c b/target/arm/translate.c
index 34bb280e3d..fd2f0e3048 100644
--- a/target/arm/translate.c
+++ b/target/arm/translate.c
@@ -8045,7 +8045,9 @@ static bool op_smlaxxx(DisasContext *s, arg_rrrr *a,
case 2:
tl = load_reg(s, a->ra);
th = load_reg(s, a->rd);
- t1 = tcg_const_i32(0);
+ /* Sign-extend the 32-bit product to 64 bits. */
+ t1 = tcg_temp_new_i32();
+ tcg_gen_sari_i32(t1, t0, 31);
tcg_gen_add2_i32(tl, th, tl, th, t0, t1);
tcg_temp_free_i32(t0);
tcg_temp_free_i32(t1);
--
2.17.1
next reply other threads:[~2019-09-12 18:33 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-12 18:30 Richard Henderson [this message]
2019-09-13 6:03 ` [Qemu-devel] [PATCH] target/arm: Fix sign-extension for SMLAL* Laurent Desnogues
2019-09-13 11:01 ` Philippe Mathieu-Daudé
2019-10-14 23:42 ` Richard Henderson
2019-10-17 13:52 ` Peter Maydell
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