[Qemu-devel] [RFC 04/28] target-xtensa: implement narrow instructions

[Max Filippov <jcmvbkbc@gmail.com>]

Instructions with op0 >= 8 are 2 bytes long, others are 3 bytes long.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 target-xtensa/translate.c |   57 +++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 57 insertions(+), 0 deletions(-)

diff --git a/target-xtensa/translate.c b/target-xtensa/translate.c
index 16efcfd..26fc28b 100644
--- a/target-xtensa/translate.c
+++ b/target-xtensa/translate.c
@@ -301,22 +301,79 @@ static void disas_xtensa_insn(DisasContext *dc)
     case 7: /*B*/
         break;
 
+#define gen_narrow_load_store(type) do { \
+            TCGv_i32 addr = tcg_temp_new_i32(); \
+            tcg_gen_addi_i32(addr, cpu_R[RRRN_S], RRRN_R << 2); \
+            tcg_gen_qemu_##type(cpu_R[RRRN_T], addr, 0); \
+            tcg_temp_free(addr); \
+        } while (0)
+
     case 8: /*L32I.Nn*/
+        gen_narrow_load_store(ld32u);
         break;
 
     case 9: /*S32I.Nn*/
+        gen_narrow_load_store(st32);
         break;
+#undef gen_narrow_load_store
 
     case 10: /*ADD.Nn*/
+        tcg_gen_add_i32(cpu_R[RRRN_R], cpu_R[RRRN_S], cpu_R[RRRN_T]);
         break;
 
     case 11: /*ADDI.Nn*/
+        tcg_gen_addi_i32(cpu_R[RRRN_R], cpu_R[RRRN_S], RRRN_T ? RRRN_T : -1);
         break;
 
     case 12: /*ST2n*/
+        if (RRRN_T < 8) { /*MOVI.Nn*/
+            tcg_gen_movi_i32(cpu_R[RRRN_S],
+                    RRRN_R | (RRRN_T << 4) |
+                    ((RRRN_T & 6) == 6 ? 0xffffff80 : 0));
+        } else { /*BEQZ.Nn*/ /*BNEZ.Nn*/
+            int label = gen_new_label();
+            int inv = RRRN_T & 4;
+
+            tcg_gen_brcondi_i32(inv ? TCG_COND_EQ : TCG_COND_NE,
+                    cpu_R[RRRN_S], 0, label);
+            gen_jumpi(dc, dc->pc + 4 + (RRRN_R | ((RRRN_T & 3) << 4)));
+            gen_set_label(label);
+            gen_jumpi(dc, dc->pc + 2);
+        }
         break;
 
     case 13: /*ST3n*/
+        switch (RRRN_R) {
+        case 0: /*MOV.Nn*/
+            tcg_gen_mov_i32(cpu_R[RRRN_T], cpu_R[RRRN_S]);
+            break;
+
+        case 15: /*S3*/
+            switch (RRRN_T) {
+            case 0: /*RET.Nn*/
+                gen_jump(dc, cpu_R[0]);
+                break;
+
+            case 1: /*RETW.Nn*/
+                break;
+
+            case 2: /*BREAK.Nn*/
+                break;
+
+            case 3: /*NOP.Nn*/
+                break;
+
+            case 6: /*ILL.Nn*/
+                break;
+
+            default: /*reserved*/
+                break;
+            }
+            break;
+
+        default: /*reserved*/
+            break;
+        }
         break;
 
     default: /*reserved*/
-- 
1.7.3.4