Re: [Qemu-devel] [PATCH v21 4/7] target/avr: Add instruction translation

[Richard Henderson <richard.henderson@linaro.org>]

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On 6/11/19 2:02 PM, Michael Rolnik wrote:
> I am using this
> one https://github.com/seharris/qemu-avr-tests/blob/master/free-rtos/Demo/AVR_ATMega2560_GCC/demo.elf
> <https://github.com/seharris/qemu-avr-tests/blob/master/free-rtos/Demo/AVR_ATMega2560_GCC/demo.elf> 
> it fails within __divmodsi4 function, there is rcall right after sbrc.
> 
> Thanks for helping.

Two separate bugs, fixed thus.


r~

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>From 7be2c4dfcbdca59f6b5b52f65f3fc1df6923db50 Mon Sep 17 00:00:00 2001
From: Richard Henderson <richard.henderson@linaro.org>
Date: Wed, 12 Jun 2019 09:31:14 -0700
Subject: [PATCH] !fixup target/avr: Add instruction translation

When skipping, the skipped NORETURN must chain to the next.
Avoid double-allocating goto_tb indexes.  Choose index 1 to
be the end of TB, which means all other branches use 0.
---
 target/avr/translate.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/target/avr/translate.c b/target/avr/translate.c
index 4d9e2afa26..abb838b53f 100644
--- a/target/avr/translate.c
+++ b/target/avr/translate.c
@@ -622,7 +622,7 @@ static bool trans_BRBC(DisasContext *ctx, arg_BRBC *a)
     }
 
     tcg_gen_brcondi_i32(tcg_invert_cond(cond), var, 0, not_taken);
-    gen_goto_tb(ctx, 1, ctx->npc + a->imm);
+    gen_goto_tb(ctx, 0, ctx->npc + a->imm);
     gen_set_label(not_taken);
 
     ctx->bstate = DISAS_CHAIN;
@@ -672,7 +672,7 @@ static bool trans_BRBS(DisasContext *ctx, arg_BRBS *a)
     }
 
     tcg_gen_brcondi_i32(tcg_invert_cond(cond), var, 0, not_taken);
-    gen_goto_tb(ctx, 1, ctx->npc + a->imm);
+    gen_goto_tb(ctx, 0, ctx->npc + a->imm);
     gen_set_label(not_taken);
 
     ctx->bstate = DISAS_CHAIN;
@@ -2855,6 +2855,9 @@ void gen_intermediate_code(CPUState *cs, TranslationBlock *tb, int max_insns)
         if (skip_label) {
             canonicalize_skip(&ctx);
             gen_set_label(skip_label);
+            if (ctx.bstate == DISAS_NORETURN) {
+                ctx.bstate = DISAS_CHAIN;
+            }
         }
     } while (ctx.bstate == DISAS_NEXT
              && num_insns < max_insns
@@ -2876,7 +2879,7 @@ void gen_intermediate_code(CPUState *cs, TranslationBlock *tb, int max_insns)
     case DISAS_CHAIN:
         if (!nonconst_skip) {
             /* Note gen_goto_tb checks singlestep.  */
-            gen_goto_tb(&ctx, 0, ctx.npc);
+            gen_goto_tb(&ctx, 1, ctx.npc);
             break;
         }
         tcg_gen_movi_tl(cpu_pc, ctx.npc);
-- 
2.17.1