[Qemu-devel] Re: [PATCH 07/17] m68k: add DBcc instruction.

[Andreas Schwab <schwab@linux-m68k.org>]

Laurent Vivier <laurent@vivier.eu> writes:

> +    tmp = tcg_temp_new();
> +    tcg_gen_ext16s_i32(tmp, reg);
> +    tcg_gen_addi_i32(tmp, tmp, -1);
> +    gen_partset_reg(OS_WORD, reg, tmp);
> +    tcg_gen_brcondi_i32(TCG_COND_EQ, tmp, 0, l1);

The counter needs to be compared with -1, not 0.

Andreas.
---
>From 07f10a1b4a4aa4a54468e1106a4bbc28c5ada45e Mon Sep 17 00:00:00 2001
From: Andreas Schwab <schwab@linux-m68k.org>
Date: Sat, 30 May 2009 23:52:11 +0200
Subject: [PATCH] m68k: fix decoding of dbcc

The counter needs to be compared with -1, not 0.

Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
---
 target-m68k/translate.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/target-m68k/translate.c b/target-m68k/translate.c
index 9d68b02..ea6b34b 100644
--- a/target-m68k/translate.c
+++ b/target-m68k/translate.c
@@ -942,7 +942,7 @@ DISAS_INSN(dbcc)
     tcg_gen_ext16s_i32(tmp, reg);
     tcg_gen_addi_i32(tmp, tmp, -1);
     gen_partset_reg(OS_WORD, reg, tmp);
-    tcg_gen_brcondi_i32(TCG_COND_EQ, tmp, 0, l1);
+    tcg_gen_brcondi_i32(TCG_COND_EQ, tmp, -1, l1);
     gen_jmp_tb(s, 1, base + offset);
     gen_set_label(l1);
     gen_jmp_tb(s, 0, s->pc);
-- 
1.6.3.1

-- 
Andreas Schwab, schwab@linux-m68k.org
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