From: Vladimir Isaev <vladimir.isaev@syntacore.com>
To: richard.henderson@linaro.org, palmer@dabbelt.com,
alistair.francis@wdc.com, bin.meng@windriver.com,
qemu-riscv@nongnu.org
Cc: qemu-devel@nongnu.org, Vladimir Isaev <vladimir.isaev@syntacore.com>
Subject: [PATCH] target/riscv: fix ctzw behavior
Date: Fri, 3 Feb 2023 17:00:59 +0300 [thread overview]
Message-ID: <20230203140059.13068-1-vladimir.isaev@syntacore.com> (raw)
According to spec, ctzw should work with 32-bit register, not 64.
For example, previous implementation returns 33 for (1<<33) input
when the new one returns 32.
Signed-off-by: Vladimir Isaev <vladimir.isaev@syntacore.com>
---
target/riscv/insn_trans/trans_rvb.c.inc | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/target/riscv/insn_trans/trans_rvb.c.inc b/target/riscv/insn_trans/trans_rvb.c.inc
index e2b8329f1e5b..42c6ded13de8 100644
--- a/target/riscv/insn_trans/trans_rvb.c.inc
+++ b/target/riscv/insn_trans/trans_rvb.c.inc
@@ -80,7 +80,14 @@ static void gen_ctz(TCGv ret, TCGv arg1)
static void gen_ctzw(TCGv ret, TCGv arg1)
{
- tcg_gen_ctzi_tl(ret, arg1, 32);
+ TCGv_i32 t = tcg_temp_new_i32();
+
+ tcg_gen_trunc_tl_i32(t, arg1);
+ tcg_gen_ctzi_i32(t, t, 32);
+
+ tcg_gen_extu_i32_tl(ret, t);
+
+ tcg_temp_free_i32(t);
}
static bool trans_ctz(DisasContext *ctx, arg_ctz *a)
--
2.39.1
next reply other threads:[~2023-02-03 14:02 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-03 14:00 Vladimir Isaev [this message]
2023-02-03 16:56 ` [PATCH] target/riscv: fix ctzw behavior Richard Henderson
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