diff mbox

[for-2.5,24/30] m68k: add DBcc and Scc (memory operand)

Message ID 1439151229-27747-25-git-send-email-laurent@vivier.eu
State New
Headers show

Commit Message

Laurent Vivier Aug. 9, 2015, 8:13 p.m. UTC
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---
 target-m68k/translate.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

Comments

Richard Henderson Aug. 12, 2015, 5:49 p.m. UTC | #1
On 08/09/2015 01:13 PM, Laurent Vivier wrote:
> +DISAS_INSN(scc_mem)
> +{
> +    TCGLabel *l1;
> +    int cond;
> +    TCGv dest;
> +
> +    l1 = gen_new_label();
> +    cond = (insn >> 8) & 0xf;
> +    dest = tcg_temp_local_new();
> +    tcg_gen_movi_i32(dest, 0);
> +    gen_jmpcc(s, cond ^ 1, l1);
> +    tcg_gen_movi_i32(dest, 0xff);
> +    gen_set_label(l1);
> +    DEST_EA(env, insn, OS_BYTE, dest, NULL);
> +    tcg_temp_free(dest);
> +}

It seems like this could just as easily be shared with scc?
DEST_EA handles a byte store into a register just fine.

I suppose the real ugliness at the moment is the tcg branch;
if you were using setcond instead that would help matters.
Adjusting the code surrounding gen_jmpcc is a larger task,
but it really would help a lot.  There are several examples
of how to organize such a thing...

> +DISAS_INSN(dbcc)
> +{
> +    TCGLabel *l1;
> +    TCGv reg;
> +    TCGv tmp;
> +    int16_t offset;
> +    uint32_t base;
> +
> +    reg = DREG(insn, 0);
> +    base = s->pc;
> +    offset = cpu_ldsw_code(env, s->pc);
> +    s->pc += 2;

read_im16?

> +    l1 = gen_new_label();
> +    gen_jmpcc(s, (insn >> 8) & 0xf, l1);
> +
> +    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, -1, l1);
> +    update_cc_op(s);
> +    gen_jmp_tb(s, 1, base + offset);
> +    gen_set_label(l1);
> +    update_cc_op(s);

Move the update_cc_op calls before the first branch.


r~
diff mbox

Patch

diff --git a/target-m68k/translate.c b/target-m68k/translate.c
index 95d58d1..cb746d7 100644
--- a/target-m68k/translate.c
+++ b/target-m68k/translate.c
@@ -994,6 +994,50 @@  static void gen_jmp_tb(DisasContext *s, int n, uint32_t dest)
     s->is_jmp = DISAS_TB_JUMP;
 }
 
+DISAS_INSN(scc_mem)
+{
+    TCGLabel *l1;
+    int cond;
+    TCGv dest;
+
+    l1 = gen_new_label();
+    cond = (insn >> 8) & 0xf;
+    dest = tcg_temp_local_new();
+    tcg_gen_movi_i32(dest, 0);
+    gen_jmpcc(s, cond ^ 1, l1);
+    tcg_gen_movi_i32(dest, 0xff);
+    gen_set_label(l1);
+    DEST_EA(env, insn, OS_BYTE, dest, NULL);
+    tcg_temp_free(dest);
+}
+
+DISAS_INSN(dbcc)
+{
+    TCGLabel *l1;
+    TCGv reg;
+    TCGv tmp;
+    int16_t offset;
+    uint32_t base;
+
+    reg = DREG(insn, 0);
+    base = s->pc;
+    offset = cpu_ldsw_code(env, s->pc);
+    s->pc += 2;
+    l1 = gen_new_label();
+    gen_jmpcc(s, (insn >> 8) & 0xf, l1);
+
+    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, -1, l1);
+    update_cc_op(s);
+    gen_jmp_tb(s, 1, base + offset);
+    gen_set_label(l1);
+    update_cc_op(s);
+    gen_jmp_tb(s, 0, s->pc);
+}
+
 DISAS_INSN(undef_mac)
 {
     gen_exception(s, s->pc - 2, EXCP_LINEA);
@@ -3248,6 +3292,9 @@  void register_m68k_insns (CPUM68KState *env)
     INSN(addsubq,   5080, f0c0, M68000);
     INSN(scc,       50c0, f0f8, CF_ISA_A);
     INSN(addsubq,   5080, f1c0, CF_ISA_A);
+    INSN(scc_mem,   50c0, f0c0, M68000);
+    INSN(scc,       50c0, f0f8, M68000);
+    INSN(dbcc,      50c8, f0f8, M68000);
     INSN(tpf,       51f8, fff8, CF_ISA_A);
 
     /* Branch instructions.  */