diff mbox

[09/10] target-avr: updating translate.c to use instructions translation

Message ID 1464898022-97990-9-git-send-email-rolnik@amazon.com (mailing list archive)
State New, archived
Headers show

Commit Message

Michael Rolnik June 2, 2016, 8:07 p.m. UTC
Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
---
 target-avr/Makefile.objs |   4 +-
 target-avr/translate.c   | 148 ++++++++++++++++++++++-------------------------
 2 files changed, 72 insertions(+), 80 deletions(-)

Comments

Richard Henderson June 5, 2016, 3:33 a.m. UTC | #1
On 06/02/2016 01:07 PM, Michael Rolnik wrote:
> +uint32_t    get_opcode(
> +                                    uint8_t const      *code,
> +                                    unsigned            bitBase,
> +                                    unsigned            bitSize)
> +{
> +    return  *(uint16_t *)code;
> +}

Unused.  And what was this supposed to do?

> +        /*  decode next instruction */
> +        ctx.inst[1].cpc = ctx.inst[0].npc;
> +        decode_opc(cpu, &ctx, &ctx.inst[1]);

Why are you decoding one instruction ahead?

While I can see that this might be keen for some of the skip-next instructions, 
I don't see that you're using that just now.  So perhaps delay this until it's 
actually used?


r~
Michael Rolnik June 5, 2016, 9:49 p.m. UTC | #2
get_opcode no longer present.

I use it for the sake of skip instruction. I do not know a priori the
length of the next instruction as it can be either 16 or 32 bits.

On Sun, Jun 5, 2016 at 6:33 AM, Richard Henderson <rth@twiddle.net> wrote:

> On 06/02/2016 01:07 PM, Michael Rolnik wrote:
>
>> +uint32_t    get_opcode(
>> +                                    uint8_t const      *code,
>> +                                    unsigned            bitBase,
>> +                                    unsigned            bitSize)
>> +{
>> +    return  *(uint16_t *)code;
>> +}
>>
>
> Unused.  And what was this supposed to do?
>
> +        /*  decode next instruction */
>> +        ctx.inst[1].cpc = ctx.inst[0].npc;
>> +        decode_opc(cpu, &ctx, &ctx.inst[1]);
>>
>
> Why are you decoding one instruction ahead?
>
> While I can see that this might be keen for some of the skip-next
> instructions, I don't see that you're using that just now.  So perhaps
> delay this until it's actually used?
>
>
> r~
>
diff mbox

Patch

diff --git a/target-avr/Makefile.objs b/target-avr/Makefile.objs
index c503546..8d06d54 100644
--- a/target-avr/Makefile.objs
+++ b/target-avr/Makefile.objs
@@ -1,3 +1,5 @@ 
-obj-y   += translate.o cpu.o helper.o
+obj-y   += translate.o helper.o cpu.o translate-inst.o
 obj-y   += gdbstub.o
 obj-$(CONFIG_SOFTMMU) += machine.o
+
+obj-y   += decode.o
diff --git a/target-avr/translate.c b/target-avr/translate.c
index e98aaef..0df0184 100644
--- a/target-avr/translate.c
+++ b/target-avr/translate.c
@@ -18,60 +18,31 @@ 
  *  <http://www.gnu.org/licenses/lgpl-2.1.html>
  */
 
-#include "qemu/osdep.h"
-
-#include "cpu.h"
-#include "exec/exec-all.h"
-#include "disas/disas.h"
-#include "tcg-op.h"
-#include "exec/cpu_ldst.h"
-
-#include "exec/helper-proto.h"
-#include "exec/helper-gen.h"
-#include "exec/log.h"
-
-typedef struct DisasContext DisasContext;
-typedef struct InstInfo     InstInfo;
-
-/*This is the state at translation time.  */
-struct DisasContext {
-    struct TranslationBlock    *tb;
-
-    /*Routine used to access memory */
-    int                         memidx;
-    int                         bstate;
-    int                         singlestep;
-};
-
-enum {
-    BS_NONE     = 0,    /*  Nothing special (none of the below          */
-    BS_STOP     = 1,    /*  We want to stop translation for any reason  */
-    BS_BRANCH   = 2,    /*  A branch condition is reached               */
-    BS_EXCP     = 3,    /*  An exception condition is reached           */
-};
-
-static TCGv_env cpu_env;
-
-static TCGv     cpu_pc;
-
-static TCGv     cpu_Cf;
-static TCGv     cpu_Zf;
-static TCGv     cpu_Nf;
-static TCGv     cpu_Vf;
-static TCGv     cpu_Sf;
-static TCGv     cpu_Hf;
-static TCGv     cpu_Tf;
-static TCGv     cpu_If;
-
-static TCGv     cpu_rampD;
-static TCGv     cpu_rampX;
-static TCGv     cpu_rampY;
-static TCGv     cpu_rampZ;
-
-static TCGv     cpu_io[64];
-static TCGv     cpu_r[32];
-static TCGv     cpu_eind;
-static TCGv     cpu_sp;
+#include "translate.h"
+
+
+TCGv_env cpu_env;
+
+TCGv     cpu_pc;
+
+TCGv     cpu_Cf;
+TCGv     cpu_Zf;
+TCGv     cpu_Nf;
+TCGv     cpu_Vf;
+TCGv     cpu_Sf;
+TCGv     cpu_Hf;
+TCGv     cpu_Tf;
+TCGv     cpu_If;
+
+TCGv     cpu_rampD;
+TCGv     cpu_rampX;
+TCGv     cpu_rampY;
+TCGv     cpu_rampZ;
+
+TCGv     cpu_io[64];
+TCGv     cpu_r[32];
+TCGv     cpu_eind;
+TCGv     cpu_sp;
 
 #include "exec/gen-icount.h"
 #define REG(x)  (cpu_r[x])
@@ -120,30 +91,42 @@  void                avr_translate_init(void)
     done_init = 1;
 }
 
-static inline void  gen_goto_tb(CPUAVRState        *env,
-                                DisasContext       *ctx,
-                                int                 n,
-                                target_ulong        dest)
+static void         decode_opc(
+                                    AVRCPU             *cpu,
+                                    DisasContext       *ctx,
+                                    InstInfo           *inst)
 {
-    TranslationBlock   *tb;
+    CPUAVRState        *env     = &cpu->env;
 
-    tb      = ctx->tb;
+    inst->opcode    = cpu_ldl_code(env, inst->cpc * 2);   /*  pc points to words    */
+    inst->length    = 16;
+    inst->translate = NULL;
 
-    if ((tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK)
-        &&  (ctx->singlestep == 0)) {
-        tcg_gen_goto_tb(n);
-        tcg_gen_movi_i32(cpu_pc, dest);
-        tcg_gen_exit_tb((uintptr_t)tb + n);
-    } else {
-        tcg_gen_movi_i32(cpu_pc, dest);
+    /*  the following function looks onto the opcode as a string of bytes   */
+    avr_decode(inst->cpc, &inst->length, inst->opcode, &inst->translate);
 
-        if (ctx->singlestep) {
-            gen_helper_debug(cpu_env);
-        }
-        tcg_gen_exit_tb(0);
+    if (inst->length == 16) {
+        inst->npc    = inst->cpc + 1;
+        /*  get opcode as 16bit value   */
+        inst->opcode = inst->opcode & 0x0000ffff;
+    }
+    if (inst->length == 32) {
+        inst->npc    = inst->cpc + 2;
+        /*  get opcode as 32bit value   */
+        inst->opcode = (inst->opcode << 16)
+                     | (inst->opcode >> 16);
     }
 }
 
+uint32_t    get_opcode(
+                                    uint8_t const      *code,
+                                    unsigned            bitBase,
+                                    unsigned            bitSize)
+{
+    return  *(uint16_t *)code;
+}
+
+
 /*generate intermediate code for basic block 'tb'.  */
 void                gen_intermediate_code(
                                 CPUAVRState        *env,
@@ -176,18 +159,21 @@  void                gen_intermediate_code(
     gen_tb_start(tb);
 
     /*  decode first instruction    */
-    cpc = pc_start;
-    npc = cpc + 1;
+    ctx.inst[0].cpc     = pc_start;
+    decode_opc(cpu, &ctx, &ctx.inst[0]);
     do {
-        /*  translate current instruction   */
+        /*  set curr/next PCs   */
+        cpc = ctx.inst[0].cpc;
+        npc = ctx.inst[0].npc;
+
+        /*  decode next instruction */
+        ctx.inst[1].cpc = ctx.inst[0].npc;
+        decode_opc(cpu, &ctx, &ctx.inst[1]);
+
+        /*  translate current instruction */
         tcg_gen_insn_start(cpc);
         num_insns++;
 
-        /*  just skip to next instruction   */
-        cpc++;
-        npc++;
-        ctx.bstate  = BS_NONE;
-
         if (unlikely(cpu_breakpoint_test(cs, cpc * 2, BP_ANY))) {
             tcg_gen_movi_i32(cpu_pc, cpc);
             gen_helper_debug(cpu_env);
@@ -199,6 +185,8 @@  void                gen_intermediate_code(
             goto done_generating;
         }
 
+        ctx.bstate  = ctx.inst[0].translate(env, &ctx, ctx.inst[0].opcode);
+
         if (num_insns >= max_insns) {
             break;      /* max translated instructions limit reached */
         }
@@ -208,6 +196,8 @@  void                gen_intermediate_code(
         if ((cpc & (TARGET_PAGE_SIZE - 1)) == 0) {
             break;      /* page boundary */
         }
+
+        ctx.inst[0] = ctx.inst[1];  /*  make next inst curr */
     } while (ctx.bstate == BS_NONE && !tcg_op_buf_full());
 
     if (tb->cflags & CF_LAST_IO) {