tcg: Put opcodes in a linked list

The previous setup required ops and args to be completely sequential,
and was error prone when it came to both iteration and optimization.

Reviewed-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Signed-off-by: Richard Henderson <rth@twiddle.net>

5 files changed, 431 insertions, 501 deletions

diff --git a/include/exec/gen-icount.h b/include/exec/gen-icount.h
index a37a61d038..6e5b01239b 100644
--- a/include/exec/gen-icount.h
+++ b/include/exec/gen-icount.h
@@ -11,8 +11,8 @@ static int exitreq_label;
 
 static inline void gen_tb_start(TranslationBlock *tb)
 {
-    TCGv_i32 count;
-    TCGv_i32 flag;
+    TCGv_i32 count, flag, imm;
+    int i;
 
     exitreq_label = gen_new_label();
     flag = tcg_temp_new_i32();
@@ -21,16 +21,25 @@ static inline void gen_tb_start(TranslationBlock *tb)
     tcg_gen_brcondi_i32(TCG_COND_NE, flag, 0, exitreq_label);
     tcg_temp_free_i32(flag);
 
-    if (!(tb->cflags & CF_USE_ICOUNT))
+    if (!(tb->cflags & CF_USE_ICOUNT)) {
         return;
+    }
 
     icount_label = gen_new_label();
     count = tcg_temp_local_new_i32();
     tcg_gen_ld_i32(count, cpu_env,
                    -ENV_OFFSET + offsetof(CPUState, icount_decr.u32));
+
+    imm = tcg_temp_new_i32();
+    tcg_gen_movi_i32(imm, 0xdeadbeef);
+
     /* This is a horrid hack to allow fixing up the value later.  */
-    icount_arg = tcg_ctx.gen_opparam_ptr + 1;
-    tcg_gen_subi_i32(count, count, 0xdeadbeef);
+    i = tcg_ctx.gen_last_op_idx;
+    i = tcg_ctx.gen_op_buf[i].args;
+    icount_arg = &tcg_ctx.gen_opparam_buf[i + 1];
+
+    tcg_gen_sub_i32(count, count, imm);
+    tcg_temp_free_i32(imm);
 
     tcg_gen_brcondi_i32(TCG_COND_LT, count, 0, icount_label);
     tcg_gen_st16_i32(count, cpu_env,
@@ -49,7 +58,8 @@ static void gen_tb_end(TranslationBlock *tb, int num_insns)
         tcg_gen_exit_tb((uintptr_t)tb + TB_EXIT_ICOUNT_EXPIRED);
     }
 
-    *tcg_ctx.gen_opc_ptr = INDEX_op_end;
+    /* Terminate the linked list.  */
+    tcg_ctx.gen_op_buf[tcg_ctx.gen_last_op_idx].next = -1;
 }
 
 static inline void gen_io_start(void)
diff --git a/tcg/optimize.c b/tcg/optimize.c
index 34ae3c2857..f2b8acf1e0 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -162,13 +162,13 @@ static bool temps_are_copies(TCGArg arg1, TCGArg arg2)
     return false;
 }
 
-static void tcg_opt_gen_mov(TCGContext *s, int op_index, TCGArg *gen_args,
+static void tcg_opt_gen_mov(TCGContext *s, TCGOp *op, TCGArg *args,
                             TCGOpcode old_op, TCGArg dst, TCGArg src)
 {
     TCGOpcode new_op = op_to_mov(old_op);
     tcg_target_ulong mask;
 
-    s->gen_opc_buf[op_index] = new_op;
+    op->opc = new_op;
 
     reset_temp(dst);
     mask = temps[src].mask;
@@ -193,17 +193,17 @@ static void tcg_opt_gen_mov(TCGContext *s, int op_index, TCGArg *gen_args,
         temps[src].next_copy = dst;
     }
 
-    gen_args[0] = dst;
-    gen_args[1] = src;
+    args[0] = dst;
+    args[1] = src;
 }
 
-static void tcg_opt_gen_movi(TCGContext *s, int op_index, TCGArg *gen_args,
+static void tcg_opt_gen_movi(TCGContext *s, TCGOp *op, TCGArg *args,
                              TCGOpcode old_op, TCGArg dst, TCGArg val)
 {
     TCGOpcode new_op = op_to_movi(old_op);
     tcg_target_ulong mask;
 
-    s->gen_opc_buf[op_index] = new_op;
+    op->opc = new_op;
 
     reset_temp(dst);
     temps[dst].state = TCG_TEMP_CONST;
@@ -215,8 +215,8 @@ static void tcg_opt_gen_movi(TCGContext *s, int op_index, TCGArg *gen_args,
     }
     temps[dst].mask = mask;
 
-    gen_args[0] = dst;
-    gen_args[1] = val;
+    args[0] = dst;
+    args[1] = val;
 }
 
 static TCGArg do_constant_folding_2(TCGOpcode op, TCGArg x, TCGArg y)
@@ -533,11 +533,9 @@ static bool swap_commutative2(TCGArg *p1, TCGArg *p2)
 }
 
 /* Propagate constants and copies, fold constant expressions. */
-static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
-                                    TCGArg *args, TCGOpDef *tcg_op_defs)
+static void tcg_constant_folding(TCGContext *s)
 {
-    int nb_ops, op_index, nb_temps, nb_globals;
-    TCGArg *gen_args;
+    int oi, oi_next, nb_temps, nb_globals;
 
     /* Array VALS has an element for each temp.
        If this temp holds a constant then its value is kept in VALS' element.
@@ -548,24 +546,23 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
     nb_globals = s->nb_globals;
     reset_all_temps(nb_temps);
 
-    nb_ops = tcg_opc_ptr - s->gen_opc_buf;
-    gen_args = args;
-    for (op_index = 0; op_index < nb_ops; op_index++) {
-        TCGOpcode op = s->gen_opc_buf[op_index];
-        const TCGOpDef *def = &tcg_op_defs[op];
+    for (oi = s->gen_first_op_idx; oi >= 0; oi = oi_next) {
         tcg_target_ulong mask, partmask, affected;
-        int nb_oargs, nb_iargs, nb_args, i;
+        int nb_oargs, nb_iargs, i;
         TCGArg tmp;
 
-        if (op == INDEX_op_call) {
-            *gen_args++ = tmp = *args++;
-            nb_oargs = tmp >> 16;
-            nb_iargs = tmp & 0xffff;
-            nb_args = nb_oargs + nb_iargs + def->nb_cargs;
+        TCGOp * const op = &s->gen_op_buf[oi];
+        TCGArg * const args = &s->gen_opparam_buf[op->args];
+        TCGOpcode opc = op->opc;
+        const TCGOpDef *def = &tcg_op_defs[opc];
+
+        oi_next = op->next;
+        if (opc == INDEX_op_call) {
+            nb_oargs = op->callo;
+            nb_iargs = op->calli;
         } else {
             nb_oargs = def->nb_oargs;
             nb_iargs = def->nb_iargs;
-            nb_args = def->nb_args;
         }
 
         /* Do copy propagation */
@@ -576,7 +573,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
         }
 
         /* For commutative operations make constant second argument */
-        switch (op) {
+        switch (opc) {
         CASE_OP_32_64(add):
         CASE_OP_32_64(mul):
         CASE_OP_32_64(and):
@@ -634,7 +631,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
 
         /* Simplify expressions for "shift/rot r, 0, a => movi r, 0",
            and "sub r, 0, a => neg r, a" case.  */
-        switch (op) {
+        switch (opc) {
         CASE_OP_32_64(shl):
         CASE_OP_32_64(shr):
         CASE_OP_32_64(sar):
@@ -642,9 +639,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
         CASE_OP_32_64(rotr):
             if (temps[args[1]].state == TCG_TEMP_CONST
                 && temps[args[1]].val == 0) {
-                tcg_opt_gen_movi(s, op_index, gen_args, op, args[0], 0);
-                args += 3;
-                gen_args += 2;
+                tcg_opt_gen_movi(s, op, args, opc, args[0], 0);
                 continue;
             }
             break;
@@ -657,7 +652,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
                     /* Proceed with possible constant folding. */
                     break;
                 }
-                if (op == INDEX_op_sub_i32) {
+                if (opc == INDEX_op_sub_i32) {
                     neg_op = INDEX_op_neg_i32;
                     have_neg = TCG_TARGET_HAS_neg_i32;
                 } else {
@@ -669,12 +664,9 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
                 }
                 if (temps[args[1]].state == TCG_TEMP_CONST
                     && temps[args[1]].val == 0) {
-                    s->gen_opc_buf[op_index] = neg_op;
+                    op->opc = neg_op;
                     reset_temp(args[0]);
-                    gen_args[0] = args[0];
-                    gen_args[1] = args[2];
-                    args += 3;
-                    gen_args += 2;
+                    args[1] = args[2];
                     continue;
                 }
             }
@@ -728,12 +720,9 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
                 if (!have_not) {
                     break;
                 }
-                s->gen_opc_buf[op_index] = not_op;
+                op->opc = not_op;
                 reset_temp(args[0]);
-                gen_args[0] = args[0];
-                gen_args[1] = args[i];
-                args += 3;
-                gen_args += 2;
+                args[1] = args[i];
                 continue;
             }
         default:
@@ -741,7 +730,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
         }
 
         /* Simplify expression for "op r, a, const => mov r, a" cases */
-        switch (op) {
+        switch (opc) {
         CASE_OP_32_64(add):
         CASE_OP_32_64(sub):
         CASE_OP_32_64(shl):
@@ -769,12 +758,10 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
             break;
         do_mov3:
             if (temps_are_copies(args[0], args[1])) {
-                s->gen_opc_buf[op_index] = INDEX_op_nop;
+                op->opc = INDEX_op_nop;
             } else {
-                tcg_opt_gen_mov(s, op_index, gen_args, op, args[0], args[1]);
-                gen_args += 2;
+                tcg_opt_gen_mov(s, op, args, opc, args[0], args[1]);
             }
-            args += 3;
             continue;
         default:
             break;
@@ -784,7 +771,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
            output argument is supported. */
         mask = -1;
         affected = -1;
-        switch (op) {
+        switch (opc) {
         CASE_OP_32_64(ext8s):
             if ((temps[args[1]].mask & 0x80) != 0) {
                 break;
@@ -923,38 +910,31 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
 
         if (partmask == 0) {
             assert(nb_oargs == 1);
-            tcg_opt_gen_movi(s, op_index, gen_args, op, args[0], 0);
-            args += nb_args;
-            gen_args += 2;
+            tcg_opt_gen_movi(s, op, args, opc, args[0], 0);
             continue;
         }
         if (affected == 0) {
             assert(nb_oargs == 1);
             if (temps_are_copies(args[0], args[1])) {
-                s->gen_opc_buf[op_index] = INDEX_op_nop;
+                op->opc = INDEX_op_nop;
             } else if (temps[args[1]].state != TCG_TEMP_CONST) {
-                tcg_opt_gen_mov(s, op_index, gen_args, op, args[0], args[1]);
-                gen_args += 2;
+                tcg_opt_gen_mov(s, op, args, opc, args[0], args[1]);
             } else {
-                tcg_opt_gen_movi(s, op_index, gen_args, op,
+                tcg_opt_gen_movi(s, op, args, opc,
                                  args[0], temps[args[1]].val);
-                gen_args += 2;
             }
-            args += nb_args;
             continue;
         }
 
         /* Simplify expression for "op r, a, 0 => movi r, 0" cases */
-        switch (op) {
+        switch (opc) {
         CASE_OP_32_64(and):
         CASE_OP_32_64(mul):
         CASE_OP_32_64(muluh):
         CASE_OP_32_64(mulsh):
             if ((temps[args[2]].state == TCG_TEMP_CONST
                 && temps[args[2]].val == 0)) {
-                tcg_opt_gen_movi(s, op_index, gen_args, op, args[0], 0);
-                args += 3;
-                gen_args += 2;
+                tcg_opt_gen_movi(s, op, args, opc, args[0], 0);
                 continue;
             }
             break;
@@ -963,18 +943,15 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
         }
 
         /* Simplify expression for "op r, a, a => mov r, a" cases */
-        switch (op) {
+        switch (opc) {
         CASE_OP_32_64(or):
         CASE_OP_32_64(and):
             if (temps_are_copies(args[1], args[2])) {
                 if (temps_are_copies(args[0], args[1])) {
-                    s->gen_opc_buf[op_index] = INDEX_op_nop;
+                    op->opc = INDEX_op_nop;
                 } else {
-                    tcg_opt_gen_mov(s, op_index, gen_args, op,
-                                    args[0], args[1]);
-                    gen_args += 2;
+                    tcg_opt_gen_mov(s, op, args, opc, args[0], args[1]);
                 }
-                args += 3;
                 continue;
             }
             break;
@@ -983,14 +960,12 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
         }
 
         /* Simplify expression for "op r, a, a => movi r, 0" cases */
-        switch (op) {
+        switch (opc) {
         CASE_OP_32_64(andc):
         CASE_OP_32_64(sub):
         CASE_OP_32_64(xor):
             if (temps_are_copies(args[1], args[2])) {
-                tcg_opt_gen_movi(s, op_index, gen_args, op, args[0], 0);
-                gen_args += 2;
-                args += 3;
+                tcg_opt_gen_movi(s, op, args, opc, args[0], 0);
                 continue;
             }
             break;
@@ -1001,17 +976,14 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
         /* Propagate constants through copy operations and do constant
            folding.  Constants will be substituted to arguments by register
            allocator where needed and possible.  Also detect copies. */
-        switch (op) {
+        switch (opc) {
         CASE_OP_32_64(mov):
             if (temps_are_copies(args[0], args[1])) {
-                args += 2;
-                s->gen_opc_buf[op_index] = INDEX_op_nop;
+                op->opc = INDEX_op_nop;
                 break;
             }
             if (temps[args[1]].state != TCG_TEMP_CONST) {
-                tcg_opt_gen_mov(s, op_index, gen_args, op, args[0], args[1]);
-                gen_args += 2;
-                args += 2;
+                tcg_opt_gen_mov(s, op, args, opc, args[0], args[1]);
                 break;
             }
             /* Source argument is constant.  Rewrite the operation and
@@ -1019,9 +991,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
             args[1] = temps[args[1]].val;
             /* fallthrough */
         CASE_OP_32_64(movi):
-            tcg_opt_gen_movi(s, op_index, gen_args, op, args[0], args[1]);
-            gen_args += 2;
-            args += 2;
+            tcg_opt_gen_movi(s, op, args, opc, args[0], args[1]);
             break;
 
         CASE_OP_32_64(not):
@@ -1033,20 +1003,16 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
         case INDEX_op_ext32s_i64:
         case INDEX_op_ext32u_i64:
             if (temps[args[1]].state == TCG_TEMP_CONST) {
-                tmp = do_constant_folding(op, temps[args[1]].val, 0);
-                tcg_opt_gen_movi(s, op_index, gen_args, op, args[0], tmp);
-                gen_args += 2;
-                args += 2;
+                tmp = do_constant_folding(opc, temps[args[1]].val, 0);
+                tcg_opt_gen_movi(s, op, args, opc, args[0], tmp);
                 break;
             }
             goto do_default;
 
         case INDEX_op_trunc_shr_i32:
             if (temps[args[1]].state == TCG_TEMP_CONST) {
-                tmp = do_constant_folding(op, temps[args[1]].val, args[2]);
-                tcg_opt_gen_movi(s, op_index, gen_args, op, args[0], tmp);
-                gen_args += 2;
-                args += 3;
+                tmp = do_constant_folding(opc, temps[args[1]].val, args[2]);
+                tcg_opt_gen_movi(s, op, args, opc, args[0], tmp);
                 break;
             }
             goto do_default;
@@ -1075,11 +1041,9 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
         CASE_OP_32_64(remu):
             if (temps[args[1]].state == TCG_TEMP_CONST
                 && temps[args[2]].state == TCG_TEMP_CONST) {
-                tmp = do_constant_folding(op, temps[args[1]].val,
+                tmp = do_constant_folding(opc, temps[args[1]].val,
                                           temps[args[2]].val);
-                tcg_opt_gen_movi(s, op_index, gen_args, op, args[0], tmp);
-                gen_args += 2;
-                args += 3;
+                tcg_opt_gen_movi(s, op, args, opc, args[0], tmp);
                 break;
             }
             goto do_default;
@@ -1089,54 +1053,44 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
                 && temps[args[2]].state == TCG_TEMP_CONST) {
                 tmp = deposit64(temps[args[1]].val, args[3], args[4],
                                 temps[args[2]].val);
-                tcg_opt_gen_movi(s, op_index, gen_args, op, args[0], tmp);
-                gen_args += 2;
-                args += 5;
+                tcg_opt_gen_movi(s, op, args, opc, args[0], tmp);
                 break;
             }
             goto do_default;
 
         CASE_OP_32_64(setcond):
-            tmp = do_constant_folding_cond(op, args[1], args[2], args[3]);
+            tmp = do_constant_folding_cond(opc, args[1], args[2], args[3]);
             if (tmp != 2) {
-                tcg_opt_gen_movi(s, op_index, gen_args, op, args[0], tmp);
-                gen_args += 2;
-                args += 4;
+                tcg_opt_gen_movi(s, op, args, opc, args[0], tmp);
                 break;
             }
             goto do_default;
 
         CASE_OP_32_64(brcond):
-            tmp = do_constant_folding_cond(op, args[0], args[1], args[2]);
+            tmp = do_constant_folding_cond(opc, args[0], args[1], args[2]);
             if (tmp != 2) {
                 if (tmp) {
                     reset_all_temps(nb_temps);
-                    s->gen_opc_buf[op_index] = INDEX_op_br;
-                    gen_args[0] = args[3];
-                    gen_args += 1;
+                    op->opc = INDEX_op_br;
+                    args[0] = args[3];
                 } else {
-                    s->gen_opc_buf[op_index] = INDEX_op_nop;
+                    op->opc = INDEX_op_nop;
                 }
-                args += 4;
                 break;
             }
             goto do_default;
 
         CASE_OP_32_64(movcond):
-            tmp = do_constant_folding_cond(op, args[1], args[2], args[5]);
+            tmp = do_constant_folding_cond(opc, args[1], args[2], args[5]);
             if (tmp != 2) {
                 if (temps_are_copies(args[0], args[4-tmp])) {
-                    s->gen_opc_buf[op_index] = INDEX_op_nop;
+                    op->opc = INDEX_op_nop;
                 } else if (temps[args[4-tmp]].state == TCG_TEMP_CONST) {
-                    tcg_opt_gen_movi(s, op_index, gen_args, op,
+                    tcg_opt_gen_movi(s, op, args, opc,
                                      args[0], temps[args[4-tmp]].val);
-                    gen_args += 2;
                 } else {
-                    tcg_opt_gen_mov(s, op_index, gen_args, op,
-                                    args[0], args[4-tmp]);
-                    gen_args += 2;
+                    tcg_opt_gen_mov(s, op, args, opc, args[0], args[4-tmp]);
                 }
-                args += 6;
                 break;
             }
             goto do_default;
@@ -1154,24 +1108,31 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
                 uint64_t a = ((uint64_t)ah << 32) | al;
                 uint64_t b = ((uint64_t)bh << 32) | bl;
                 TCGArg rl, rh;
+                TCGOp *op2;
+                TCGArg *args2;
 
-                if (op == INDEX_op_add2_i32) {
+                if (opc == INDEX_op_add2_i32) {
                     a += b;
                 } else {
                     a -= b;
                 }
 
                 /* We emit the extra nop when we emit the add2/sub2.  */
-                assert(s->gen_opc_buf[op_index + 1] == INDEX_op_nop);
+                op2 = &s->gen_op_buf[oi_next];
+                assert(op2->opc == INDEX_op_nop);
+
+                /* But we still have to allocate args for the op.  */
+                op2->args = s->gen_next_parm_idx;
+                s->gen_next_parm_idx += 2;
+                args2 = &s->gen_opparam_buf[op2->args];
 
                 rl = args[0];
                 rh = args[1];
-                tcg_opt_gen_movi(s, op_index, &gen_args[0],
-                                 op, rl, (uint32_t)a);
-                tcg_opt_gen_movi(s, ++op_index, &gen_args[2],
-                                 op, rh, (uint32_t)(a >> 32));
-                gen_args += 4;
-                args += 6;
+                tcg_opt_gen_movi(s, op, args, opc, rl, (uint32_t)a);
+                tcg_opt_gen_movi(s, op2, args2, opc, rh, (uint32_t)(a >> 32));
+
+                /* We've done all we need to do with the movi.  Skip it.  */
+                oi_next = op2->next;
                 break;
             }
             goto do_default;
@@ -1183,18 +1144,25 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
                 uint32_t b = temps[args[3]].val;
                 uint64_t r = (uint64_t)a * b;
                 TCGArg rl, rh;
+                TCGOp *op2;
+                TCGArg *args2;
 
                 /* We emit the extra nop when we emit the mulu2.  */
-                assert(s->gen_opc_buf[op_index + 1] == INDEX_op_nop);
+                op2 = &s->gen_op_buf[oi_next];
+                assert(op2->opc == INDEX_op_nop);
+
+                /* But we still have to allocate args for the op.  */
+                op2->args = s->gen_next_parm_idx;
+                s->gen_next_parm_idx += 2;
+                args2 = &s->gen_opparam_buf[op2->args];
 
                 rl = args[0];
                 rh = args[1];
-                tcg_opt_gen_movi(s, op_index, &gen_args[0],
-                                 op, rl, (uint32_t)r);
-                tcg_opt_gen_movi(s, ++op_index, &gen_args[2],
-                                 op, rh, (uint32_t)(r >> 32));
-                gen_args += 4;
-                args += 4;
+                tcg_opt_gen_movi(s, op, args, opc, rl, (uint32_t)r);
+                tcg_opt_gen_movi(s, op2, args2, opc, rh, (uint32_t)(r >> 32));
+
+                /* We've done all we need to do with the movi.  Skip it.  */
+                oi_next = op2->next;
                 break;
             }
             goto do_default;
@@ -1205,12 +1173,11 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
                 if (tmp) {
             do_brcond_true:
                     reset_all_temps(nb_temps);
-                    s->gen_opc_buf[op_index] = INDEX_op_br;
-                    gen_args[0] = args[5];
-                    gen_args += 1;
+                    op->opc = INDEX_op_br;
+                    args[0] = args[5];
                 } else {
             do_brcond_false:
-                    s->gen_opc_buf[op_index] = INDEX_op_nop;
+                    op->opc = INDEX_op_nop;
                 }
             } else if ((args[4] == TCG_COND_LT || args[4] == TCG_COND_GE)
                        && temps[args[2]].state == TCG_TEMP_CONST
@@ -1221,12 +1188,11 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
                    vs the high word of the input.  */
             do_brcond_high:
                 reset_all_temps(nb_temps);
-                s->gen_opc_buf[op_index] = INDEX_op_brcond_i32;
-                gen_args[0] = args[1];
-                gen_args[1] = args[3];
-                gen_args[2] = args[4];
-                gen_args[3] = args[5];
-                gen_args += 4;
+                op->opc = INDEX_op_brcond_i32;
+                args[0] = args[1];
+                args[1] = args[3];
+                args[2] = args[4];
+                args[3] = args[5];
             } else if (args[4] == TCG_COND_EQ) {
                 /* Simplify EQ comparisons where one of the pairs
                    can be simplified.  */
@@ -1246,12 +1212,10 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
                 }
             do_brcond_low:
                 reset_all_temps(nb_temps);
-                s->gen_opc_buf[op_index] = INDEX_op_brcond_i32;
-                gen_args[0] = args[0];
-                gen_args[1] = args[2];
-                gen_args[2] = args[4];
-                gen_args[3] = args[5];
-                gen_args += 4;
+                op->opc = INDEX_op_brcond_i32;
+                args[1] = args[2];
+                args[2] = args[4];
+                args[3] = args[5];
             } else if (args[4] == TCG_COND_NE) {
                 /* Simplify NE comparisons where one of the pairs
                    can be simplified.  */
@@ -1273,15 +1237,13 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
             } else {
                 goto do_default;
             }
-            args += 6;
             break;
 
         case INDEX_op_setcond2_i32:
             tmp = do_constant_folding_cond2(&args[1], &args[3], args[5]);
             if (tmp != 2) {
             do_setcond_const:
-                tcg_opt_gen_movi(s, op_index, gen_args, op, args[0], tmp);
-                gen_args += 2;
+                tcg_opt_gen_movi(s, op, args, opc, args[0], tmp);
             } else if ((args[5] == TCG_COND_LT || args[5] == TCG_COND_GE)
                        && temps[args[3]].state == TCG_TEMP_CONST
                        && temps[args[4]].state == TCG_TEMP_CONST
@@ -1290,14 +1252,12 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
                 /* Simplify LT/GE comparisons vs zero to a single compare
                    vs the high word of the input.  */
             do_setcond_high:
-                s->gen_opc_buf[op_index] = INDEX_op_setcond_i32;
                 reset_temp(args[0]);
                 temps[args[0]].mask = 1;
-                gen_args[0] = args[0];
-                gen_args[1] = args[2];
-                gen_args[2] = args[4];
-                gen_args[3] = args[5];
-                gen_args += 4;
+                op->opc = INDEX_op_setcond_i32;
+                args[1] = args[2];
+                args[2] = args[4];
+                args[3] = args[5];
             } else if (args[5] == TCG_COND_EQ) {
                 /* Simplify EQ comparisons where one of the pairs
                    can be simplified.  */
@@ -1318,12 +1278,9 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
             do_setcond_low:
                 reset_temp(args[0]);
                 temps[args[0]].mask = 1;
-                s->gen_opc_buf[op_index] = INDEX_op_setcond_i32;
-                gen_args[0] = args[0];
-                gen_args[1] = args[1];
-                gen_args[2] = args[3];
-                gen_args[3] = args[5];
-                gen_args += 4;
+                op->opc = INDEX_op_setcond_i32;
+                args[2] = args[3];
+                args[3] = args[5];
             } else if (args[5] == TCG_COND_NE) {
                 /* Simplify NE comparisons where one of the pairs
                    can be simplified.  */
@@ -1345,7 +1302,6 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
             } else {
                 goto do_default;
             }
-            args += 6;
             break;
 
         case INDEX_op_call:
@@ -1377,22 +1333,12 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
                     }
                 }
             }
-            for (i = 0; i < nb_args; i++) {
-                gen_args[i] = args[i];
-            }
-            args += nb_args;
-            gen_args += nb_args;
             break;
         }
     }
-
-    return gen_args;
 }
 
-TCGArg *tcg_optimize(TCGContext *s, uint16_t *tcg_opc_ptr,
-        TCGArg *args, TCGOpDef *tcg_op_defs)
+void tcg_optimize(TCGContext *s)
 {
-    TCGArg *res;
-    res = tcg_constant_folding(s, tcg_opc_ptr, args, tcg_op_defs);
-    return res;
+    tcg_constant_folding(s);
 }
diff --git a/tcg/tcg-op.c b/tcg/tcg-op.c
index 5305f1d34a..cbaa15ccb9 100644
--- a/tcg/tcg-op.c
+++ b/tcg/tcg-op.c
@@ -35,100 +35,116 @@ extern TCGv_i32 TCGV_HIGH_link_error(TCGv_i64);
 #define TCGV_HIGH TCGV_HIGH_link_error
 #endif
 
+/* Note that this is optimized for sequential allocation during translate.
+   Up to and including filling in the forward link immediately.  We'll do
+   proper termination of the end of the list after we finish translation.  */
+
+static void tcg_emit_op(TCGContext *ctx, TCGOpcode opc, int args)
+{
+    int oi = ctx->gen_next_op_idx;
+    int ni = oi + 1;
+    int pi = oi - 1;
+
+    tcg_debug_assert(oi < OPC_BUF_SIZE);
+    ctx->gen_last_op_idx = oi;
+    ctx->gen_next_op_idx = ni;
+
+    ctx->gen_op_buf[oi] = (TCGOp){
+        .opc = opc,
+        .args = args,
+        .prev = pi,
+        .next = ni
+    };
+}
+
 void tcg_gen_op0(TCGContext *ctx, TCGOpcode opc)
 {
-    *ctx->gen_opc_ptr++ = opc;
+    tcg_emit_op(ctx, opc, -1);
 }
 
 void tcg_gen_op1(TCGContext *ctx, TCGOpcode opc, TCGArg a1)
 {
-    uint16_t *op = ctx->gen_opc_ptr;
-    TCGArg *opp = ctx->gen_opparam_ptr;
+    int pi = ctx->gen_next_parm_idx;
 
-    op[0] = opc;
-    opp[0] = a1;
+    tcg_debug_assert(pi + 1 <= OPPARAM_BUF_SIZE);
+    ctx->gen_next_parm_idx = pi + 1;
+    ctx->gen_opparam_buf[pi] = a1;
 
-    ctx->gen_opc_ptr = op + 1;
-    ctx->gen_opparam_ptr = opp + 1;
+    tcg_emit_op(ctx, opc, pi);
 }
 
 void tcg_gen_op2(TCGContext *ctx, TCGOpcode opc, TCGArg a1, TCGArg a2)
 {
-    uint16_t *op = ctx->gen_opc_ptr;
-    TCGArg *opp = ctx->gen_opparam_ptr;
+    int pi = ctx->gen_next_parm_idx;
 
-    op[0] = opc;
-    opp[0] = a1;
-    opp[1] = a2;
+    tcg_debug_assert(pi + 2 <= OPPARAM_BUF_SIZE);
+    ctx->gen_next_parm_idx = pi + 2;
+    ctx->gen_opparam_buf[pi + 0] = a1;
+    ctx->gen_opparam_buf[pi + 1] = a2;
 
-    ctx->gen_opc_ptr = op + 1;
-    ctx->gen_opparam_ptr = opp + 2;
+    tcg_emit_op(ctx, opc, pi);
 }
 
 void tcg_gen_op3(TCGContext *ctx, TCGOpcode opc, TCGArg a1,
                  TCGArg a2, TCGArg a3)
 {
-    uint16_t *op = ctx->gen_opc_ptr;
-    TCGArg *opp = ctx->gen_opparam_ptr;
+    int pi = ctx->gen_next_parm_idx;
 
-    op[0] = opc;
-    opp[0] = a1;
-    opp[1] = a2;
-    opp[2] = a3;
+    tcg_debug_assert(pi + 3 <= OPPARAM_BUF_SIZE);
+    ctx->gen_next_parm_idx = pi + 3;
+    ctx->gen_opparam_buf[pi + 0] = a1;
+    ctx->gen_opparam_buf[pi + 1] = a2;
+    ctx->gen_opparam_buf[pi + 2] = a3;
 
-    ctx->gen_opc_ptr = op + 1;
-    ctx->gen_opparam_ptr = opp + 3;
+    tcg_emit_op(ctx, opc, pi);
 }
 
 void tcg_gen_op4(TCGContext *ctx, TCGOpcode opc, TCGArg a1,
                  TCGArg a2, TCGArg a3, TCGArg a4)
 {
-    uint16_t *op = ctx->gen_opc_ptr;
-    TCGArg *opp = ctx->gen_opparam_ptr;
+    int pi = ctx->gen_next_parm_idx;
 
-    op[0] = opc;
-    opp[0] = a1;
-    opp[1] = a2;
-    opp[2] = a3;
-    opp[3] = a4;
+    tcg_debug_assert(pi + 4 <= OPPARAM_BUF_SIZE);
+    ctx->gen_next_parm_idx = pi + 4;
+    ctx->gen_opparam_buf[pi + 0] = a1;
+    ctx->gen_opparam_buf[pi + 1] = a2;
+    ctx->gen_opparam_buf[pi + 2] = a3;
+    ctx->gen_opparam_buf[pi + 3] = a4;
 
-    ctx->gen_opc_ptr = op + 1;
-    ctx->gen_opparam_ptr = opp + 4;
+    tcg_emit_op(ctx, opc, pi);
 }
 
 void tcg_gen_op5(TCGContext *ctx, TCGOpcode opc, TCGArg a1,
                  TCGArg a2, TCGArg a3, TCGArg a4, TCGArg a5)
 {
-    uint16_t *op = ctx->gen_opc_ptr;
-    TCGArg *opp = ctx->gen_opparam_ptr;
+    int pi = ctx->gen_next_parm_idx;
 
-    op[0] = opc;
-    opp[0] = a1;
-    opp[1] = a2;
-    opp[2] = a3;
-    opp[3] = a4;
-    opp[4] = a5;
+    tcg_debug_assert(pi + 5 <= OPPARAM_BUF_SIZE);
+    ctx->gen_next_parm_idx = pi + 5;
+    ctx->gen_opparam_buf[pi + 0] = a1;
+    ctx->gen_opparam_buf[pi + 1] = a2;
+    ctx->gen_opparam_buf[pi + 2] = a3;
+    ctx->gen_opparam_buf[pi + 3] = a4;
+    ctx->gen_opparam_buf[pi + 4] = a5;
 
-    ctx->gen_opc_ptr = op + 1;
-    ctx->gen_opparam_ptr = opp + 5;
+    tcg_emit_op(ctx, opc, pi);
 }
 
 void tcg_gen_op6(TCGContext *ctx, TCGOpcode opc, TCGArg a1, TCGArg a2,
                  TCGArg a3, TCGArg a4, TCGArg a5, TCGArg a6)
 {
-    uint16_t *op = ctx->gen_opc_ptr;
-    TCGArg *opp = ctx->gen_opparam_ptr;
+    int pi = ctx->gen_next_parm_idx;
 
-    op[0] = opc;
-    opp[0] = a1;
-    opp[1] = a2;
-    opp[2] = a3;
-    opp[3] = a4;
-    opp[4] = a5;
-    opp[5] = a6;
+    tcg_debug_assert(pi + 6 <= OPPARAM_BUF_SIZE);
+    ctx->gen_next_parm_idx = pi + 6;
+    ctx->gen_opparam_buf[pi + 0] = a1;
+    ctx->gen_opparam_buf[pi + 1] = a2;
+    ctx->gen_opparam_buf[pi + 2] = a3;
+    ctx->gen_opparam_buf[pi + 3] = a4;
+    ctx->gen_opparam_buf[pi + 4] = a5;
+    ctx->gen_opparam_buf[pi + 5] = a6;
 
-    ctx->gen_opc_ptr = op + 1;
-    ctx->gen_opparam_ptr = opp + 6;
+    tcg_emit_op(ctx, opc, pi);
 }
 
 /* 32 bit ops */
@@ -1862,53 +1878,57 @@ static inline TCGMemOp tcg_canonicalize_memop(TCGMemOp op, bool is64, bool st)
     return op;
 }
 
-static inline void tcg_add_param_i32(TCGv_i32 val)
-{
-    *tcg_ctx.gen_opparam_ptr++ = GET_TCGV_I32(val);
-}
-
-static inline void tcg_add_param_i64(TCGv_i64 val)
+static void gen_ldst_i32(TCGOpcode opc, TCGv_i32 val, TCGv addr,
+                         TCGMemOp memop, TCGArg idx)
 {
+#if TARGET_LONG_BITS == 32
+    tcg_gen_op4ii_i32(opc, val, addr, memop, idx);
+#else
     if (TCG_TARGET_REG_BITS == 32) {
-        *tcg_ctx.gen_opparam_ptr++ = GET_TCGV_I32(TCGV_LOW(val));
-        *tcg_ctx.gen_opparam_ptr++ = GET_TCGV_I32(TCGV_HIGH(val));
+        tcg_gen_op5ii_i32(opc, val, TCGV_LOW(addr), TCGV_HIGH(addr),
+                          memop, idx);
     } else {
-        *tcg_ctx.gen_opparam_ptr++ = GET_TCGV_I64(val);
+        tcg_gen_op4(&tcg_ctx, opc, GET_TCGV_I32(val), GET_TCGV_I64(addr),
+                    memop, idx);
     }
+#endif
 }
 
+static void gen_ldst_i64(TCGOpcode opc, TCGv_i64 val, TCGv addr,
+                         TCGMemOp memop, TCGArg idx)
+{
 #if TARGET_LONG_BITS == 32
-# define tcg_add_param_tl  tcg_add_param_i32
+    if (TCG_TARGET_REG_BITS == 32) {
+        tcg_gen_op5ii_i32(opc, TCGV_LOW(val), TCGV_HIGH(val),
+                          addr, memop, idx);
+    } else {
+        tcg_gen_op4(&tcg_ctx, opc, GET_TCGV_I64(val), GET_TCGV_I32(addr),
+                    memop, idx);
+    }
 #else
-# define tcg_add_param_tl  tcg_add_param_i64
+    if (TCG_TARGET_REG_BITS == 32) {
+        tcg_gen_op6ii_i32(opc, TCGV_LOW(val), TCGV_HIGH(val),
+                          TCGV_LOW(addr), TCGV_HIGH(addr), memop, idx);
+    } else {
+        tcg_gen_op4ii_i64(opc, val, addr, memop, idx);
+    }
 #endif
+}
 
 void tcg_gen_qemu_ld_i32(TCGv_i32 val, TCGv addr, TCGArg idx, TCGMemOp memop)
 {
     memop = tcg_canonicalize_memop(memop, 0, 0);
-
-    *tcg_ctx.gen_opc_ptr++ = INDEX_op_qemu_ld_i32;
-    tcg_add_param_i32(val);
-    tcg_add_param_tl(addr);
-    *tcg_ctx.gen_opparam_ptr++ = memop;
-    *tcg_ctx.gen_opparam_ptr++ = idx;
+    gen_ldst_i32(INDEX_op_qemu_ld_i32, val, addr, memop, idx);
 }
 
 void tcg_gen_qemu_st_i32(TCGv_i32 val, TCGv addr, TCGArg idx, TCGMemOp memop)
 {
     memop = tcg_canonicalize_memop(memop, 0, 1);
-
-    *tcg_ctx.gen_opc_ptr++ = INDEX_op_qemu_st_i32;
-    tcg_add_param_i32(val);
-    tcg_add_param_tl(addr);
-    *tcg_ctx.gen_opparam_ptr++ = memop;
-    *tcg_ctx.gen_opparam_ptr++ = idx;
+    gen_ldst_i32(INDEX_op_qemu_st_i32, val, addr, memop, idx);
 }
 
 void tcg_gen_qemu_ld_i64(TCGv_i64 val, TCGv addr, TCGArg idx, TCGMemOp memop)
 {
-    memop = tcg_canonicalize_memop(memop, 1, 0);
-
     if (TCG_TARGET_REG_BITS == 32 && (memop & MO_SIZE) < MO_64) {
         tcg_gen_qemu_ld_i32(TCGV_LOW(val), addr, idx, memop);
         if (memop & MO_SIGN) {
@@ -1919,25 +1939,17 @@ void tcg_gen_qemu_ld_i64(TCGv_i64 val, TCGv addr, TCGArg idx, TCGMemOp memop)
         return;
     }
 
-    *tcg_ctx.gen_opc_ptr++ = INDEX_op_qemu_ld_i64;
-    tcg_add_param_i64(val);
-    tcg_add_param_tl(addr);
-    *tcg_ctx.gen_opparam_ptr++ = memop;
-    *tcg_ctx.gen_opparam_ptr++ = idx;
+    memop = tcg_canonicalize_memop(memop, 1, 0);
+    gen_ldst_i64(INDEX_op_qemu_ld_i64, val, addr, memop, idx);
 }
 
 void tcg_gen_qemu_st_i64(TCGv_i64 val, TCGv addr, TCGArg idx, TCGMemOp memop)
 {
-    memop = tcg_canonicalize_memop(memop, 1, 1);
-
     if (TCG_TARGET_REG_BITS == 32 && (memop & MO_SIZE) < MO_64) {
         tcg_gen_qemu_st_i32(TCGV_LOW(val), addr, idx, memop);
         return;
     }
 
-    *tcg_ctx.gen_opc_ptr++ = INDEX_op_qemu_st_i64;
-    tcg_add_param_i64(val);
-    tcg_add_param_tl(addr);
-    *tcg_ctx.gen_opparam_ptr++ = memop;
-    *tcg_ctx.gen_opparam_ptr++ = idx;
+    memop = tcg_canonicalize_memop(memop, 1, 1);
+    gen_ldst_i64(INDEX_op_qemu_st_i64, val, addr, memop, idx);
 }
diff --git a/tcg/tcg.c b/tcg/tcg.c
index 3470500a7a..ee041b9405 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -407,7 +407,6 @@ void tcg_func_start(TCGContext *s)
     /* No temps have been previously allocated for size or locality.  */
     memset(s->free_temps, 0, sizeof(s->free_temps));
 
-    s->labels = tcg_malloc(sizeof(TCGLabel) * TCG_MAX_LABELS);
     s->nb_labels = 0;
     s->current_frame_offset = s->frame_start;
 
@@ -415,8 +414,10 @@ void tcg_func_start(TCGContext *s)
     s->goto_tb_issue_mask = 0;
 #endif
 
-    s->gen_opc_ptr = s->gen_opc_buf;
-    s->gen_opparam_ptr = s->gen_opparam_buf;
+    s->gen_first_op_idx = 0;
+    s->gen_last_op_idx = -1;
+    s->gen_next_op_idx = 0;
+    s->gen_next_parm_idx = 0;
 
     s->be = tcg_malloc(sizeof(TCGBackendData));
 }
@@ -703,9 +704,8 @@ int tcg_check_temp_count(void)
 void tcg_gen_callN(TCGContext *s, void *func, TCGArg ret,
                    int nargs, TCGArg *args)
 {
-    int i, real_args, nb_rets;
+    int i, real_args, nb_rets, pi, pi_first;
     unsigned sizemask, flags;
-    TCGArg *nparam;
     TCGHelperInfo *info;
 
     info = g_hash_table_lookup(s->helpers, (gpointer)func);
@@ -758,8 +758,7 @@ void tcg_gen_callN(TCGContext *s, void *func, TCGArg ret,
     }
 #endif /* TCG_TARGET_EXTEND_ARGS */
 
-    *s->gen_opc_ptr++ = INDEX_op_call;
-    nparam = s->gen_opparam_ptr++;
+    pi_first = pi = s->gen_next_parm_idx;
     if (ret != TCG_CALL_DUMMY_ARG) {
 #if defined(__sparc__) && !defined(__arch64__) \
     && !defined(CONFIG_TCG_INTERPRETER)
@@ -769,25 +768,25 @@ void tcg_gen_callN(TCGContext *s, void *func, TCGArg ret,
                two return temporaries, and reassemble below.  */
             retl = tcg_temp_new_i64();
             reth = tcg_temp_new_i64();
-            *s->gen_opparam_ptr++ = GET_TCGV_I64(reth);
-            *s->gen_opparam_ptr++ = GET_TCGV_I64(retl);
+            s->gen_opparam_buf[pi++] = GET_TCGV_I64(reth);
+            s->gen_opparam_buf[pi++] = GET_TCGV_I64(retl);
             nb_rets = 2;
         } else {
-            *s->gen_opparam_ptr++ = ret;
+            s->gen_opparam_buf[pi++] = ret;
             nb_rets = 1;
         }
 #else
         if (TCG_TARGET_REG_BITS < 64 && (sizemask & 1)) {
 #ifdef HOST_WORDS_BIGENDIAN
-            *s->gen_opparam_ptr++ = ret + 1;
-            *s->gen_opparam_ptr++ = ret;
+            s->gen_opparam_buf[pi++] = ret + 1;
+            s->gen_opparam_buf[pi++] = ret;
 #else
-            *s->gen_opparam_ptr++ = ret;
-            *s->gen_opparam_ptr++ = ret + 1;
+            s->gen_opparam_buf[pi++] = ret;
+            s->gen_opparam_buf[pi++] = ret + 1;
 #endif
             nb_rets = 2;
         } else {
-            *s->gen_opparam_ptr++ = ret;
+            s->gen_opparam_buf[pi++] = ret;
             nb_rets = 1;
         }
 #endif
@@ -801,7 +800,7 @@ void tcg_gen_callN(TCGContext *s, void *func, TCGArg ret,
 #ifdef TCG_TARGET_CALL_ALIGN_ARGS
             /* some targets want aligned 64 bit args */
             if (real_args & 1) {
-                *s->gen_opparam_ptr++ = TCG_CALL_DUMMY_ARG;
+                s->gen_opparam_buf[pi++] = TCG_CALL_DUMMY_ARG;
                 real_args++;
             }
 #endif
@@ -816,26 +815,42 @@ void tcg_gen_callN(TCGContext *s, void *func, TCGArg ret,
 	       have to get more complicated to differentiate between
 	       stack arguments and register arguments.  */
 #if defined(HOST_WORDS_BIGENDIAN) != defined(TCG_TARGET_STACK_GROWSUP)
-            *s->gen_opparam_ptr++ = args[i] + 1;
-            *s->gen_opparam_ptr++ = args[i];
+            s->gen_opparam_buf[pi++] = args[i] + 1;
+            s->gen_opparam_buf[pi++] = args[i];
 #else
-            *s->gen_opparam_ptr++ = args[i];
-            *s->gen_opparam_ptr++ = args[i] + 1;
+            s->gen_opparam_buf[pi++] = args[i];
+            s->gen_opparam_buf[pi++] = args[i] + 1;
 #endif
             real_args += 2;
             continue;
         }
 
-        *s->gen_opparam_ptr++ = args[i];
+        s->gen_opparam_buf[pi++] = args[i];
         real_args++;
     }
-    *s->gen_opparam_ptr++ = (uintptr_t)func;
-    *s->gen_opparam_ptr++ = flags;
+    s->gen_opparam_buf[pi++] = (uintptr_t)func;
+    s->gen_opparam_buf[pi++] = flags;
+
+    i = s->gen_next_op_idx;
+    tcg_debug_assert(i < OPC_BUF_SIZE);
+    tcg_debug_assert(pi <= OPPARAM_BUF_SIZE);
+
+    /* Set links for sequential allocation during translation.  */
+    s->gen_op_buf[i] = (TCGOp){
+        .opc = INDEX_op_call,
+        .callo = nb_rets,
+        .calli = real_args,
+        .args = pi_first,
+        .prev = i - 1,
+        .next = i + 1
+    };
 
-    *nparam = (nb_rets << 16) | real_args;
+    /* Make sure the calli field didn't overflow.  */
+    tcg_debug_assert(s->gen_op_buf[i].calli == real_args);
 
-    /* total parameters, needed to go backward in the instruction stream */
-    *s->gen_opparam_ptr++ = 1 + nb_rets + real_args + 3;
+    s->gen_last_op_idx = i;
+    s->gen_next_op_idx = i + 1;
+    s->gen_next_parm_idx = pi;
 
 #if defined(__sparc__) && !defined(__arch64__) \
     && !defined(CONFIG_TCG_INTERPRETER)
@@ -972,20 +987,21 @@ static const char * const ldst_name[] =
 
 void tcg_dump_ops(TCGContext *s)
 {
-    const uint16_t *opc_ptr;
-    const TCGArg *args;
-    TCGArg arg;
-    TCGOpcode c;
-    int i, k, nb_oargs, nb_iargs, nb_cargs, first_insn;
-    const TCGOpDef *def;
     char buf[128];
+    TCGOp *op;
+    int oi;
 
-    first_insn = 1;
-    opc_ptr = s->gen_opc_buf;
-    args = s->gen_opparam_buf;
-    while (opc_ptr < s->gen_opc_ptr) {
-        c = *opc_ptr++;
+    for (oi = s->gen_first_op_idx; oi >= 0; oi = op->next) {
+        int i, k, nb_oargs, nb_iargs, nb_cargs;
+        const TCGOpDef *def;
+        const TCGArg *args;
+        TCGOpcode c;
+
+        op = &s->gen_op_buf[oi];
+        c = op->opc;
         def = &tcg_op_defs[c];
+        args = &s->gen_opparam_buf[op->args];
+
         if (c == INDEX_op_debug_insn_start) {
             uint64_t pc;
 #if TARGET_LONG_BITS > TCG_TARGET_REG_BITS
@@ -993,21 +1009,14 @@ void tcg_dump_ops(TCGContext *s)
 #else
             pc = args[0];
 #endif
-            if (!first_insn) {
+            if (oi != s->gen_first_op_idx) {
                 qemu_log("\n");
             }
             qemu_log(" ---- 0x%" PRIx64, pc);
-            first_insn = 0;
-            nb_oargs = def->nb_oargs;
-            nb_iargs = def->nb_iargs;
-            nb_cargs = def->nb_cargs;
         } else if (c == INDEX_op_call) {
-            TCGArg arg;
-
             /* variable number of arguments */
-            arg = *args++;
-            nb_oargs = arg >> 16;
-            nb_iargs = arg & 0xffff;
+            nb_oargs = op->callo;
+            nb_iargs = op->calli;
             nb_cargs = def->nb_cargs;
 
             /* function name, flags, out args */
@@ -1028,26 +1037,20 @@ void tcg_dump_ops(TCGContext *s)
             }
         } else {
             qemu_log(" %s ", def->name);
-            if (c == INDEX_op_nopn) {
-                /* variable number of arguments */
-                nb_cargs = *args;
-                nb_oargs = 0;
-                nb_iargs = 0;
-            } else {
-                nb_oargs = def->nb_oargs;
-                nb_iargs = def->nb_iargs;
-                nb_cargs = def->nb_cargs;
-            }
-            
+
+            nb_oargs = def->nb_oargs;
+            nb_iargs = def->nb_iargs;
+            nb_cargs = def->nb_cargs;
+
             k = 0;
-            for(i = 0; i < nb_oargs; i++) {
+            for (i = 0; i < nb_oargs; i++) {
                 if (k != 0) {
                     qemu_log(",");
                 }
                 qemu_log("%s", tcg_get_arg_str_idx(s, buf, sizeof(buf),
                                                    args[k++]));
             }
-            for(i = 0; i < nb_iargs; i++) {
+            for (i = 0; i < nb_iargs; i++) {
                 if (k != 0) {
                     qemu_log(",");
                 }
@@ -1085,16 +1088,14 @@ void tcg_dump_ops(TCGContext *s)
                 i = 0;
                 break;
             }
-            for(; i < nb_cargs; i++) {
+            for (; i < nb_cargs; i++) {
                 if (k != 0) {
                     qemu_log(",");
                 }
-                arg = args[k++];
-                qemu_log("$0x%" TCG_PRIlx, arg);
+                qemu_log("$0x%" TCG_PRIlx, args[k++]);
             }
         }
         qemu_log("\n");
-        args += nb_iargs + nb_oargs + nb_cargs;
     }
 }
 
@@ -1244,20 +1245,6 @@ void tcg_add_target_add_op_defs(const TCGTargetOpDef *tdefs)
 }
 
 #ifdef USE_LIVENESS_ANALYSIS
-
-/* set a nop for an operation using 'nb_args' */
-static inline void tcg_set_nop(TCGContext *s, uint16_t *opc_ptr, 
-                               TCGArg *args, int nb_args)
-{
-    if (nb_args == 0) {
-        *opc_ptr = INDEX_op_nop;
-    } else {
-        *opc_ptr = INDEX_op_nopn;
-        args[0] = nb_args;
-        args[nb_args - 1] = nb_args;
-    }
-}
-
 /* liveness analysis: end of function: all temps are dead, and globals
    should be in memory. */
 static inline void tcg_la_func_end(TCGContext *s, uint8_t *dead_temps,
@@ -1287,19 +1274,10 @@ static inline void tcg_la_bb_end(TCGContext *s, uint8_t *dead_temps,
    temporaries are removed. */
 static void tcg_liveness_analysis(TCGContext *s)
 {
-    int i, op_index, nb_args, nb_iargs, nb_oargs, nb_ops;
-    TCGOpcode op, op_new, op_new2;
-    TCGArg *args, arg;
-    const TCGOpDef *def;
     uint8_t *dead_temps, *mem_temps;
-    uint16_t dead_args;
-    uint8_t sync_args;
-    bool have_op_new2;
-    
-    s->gen_opc_ptr++; /* skip end */
-
-    nb_ops = s->gen_opc_ptr - s->gen_opc_buf;
+    int oi, oi_prev, nb_ops;
 
+    nb_ops = s->gen_next_op_idx;
     s->op_dead_args = tcg_malloc(nb_ops * sizeof(uint16_t));
     s->op_sync_args = tcg_malloc(nb_ops * sizeof(uint8_t));
     
@@ -1307,25 +1285,31 @@ static void tcg_liveness_analysis(TCGContext *s)
     mem_temps = tcg_malloc(s->nb_temps);
     tcg_la_func_end(s, dead_temps, mem_temps);
 
-    args = s->gen_opparam_ptr;
-    op_index = nb_ops - 1;
-    while (op_index >= 0) {
-        op = s->gen_opc_buf[op_index];
-        def = &tcg_op_defs[op];
-        switch(op) {
+    for (oi = s->gen_last_op_idx; oi >= 0; oi = oi_prev) {
+        int i, nb_iargs, nb_oargs;
+        TCGOpcode opc_new, opc_new2;
+        bool have_opc_new2;
+        uint16_t dead_args;
+        uint8_t sync_args;
+        TCGArg arg;
+
+        TCGOp * const op = &s->gen_op_buf[oi];
+        TCGArg * const args = &s->gen_opparam_buf[op->args];
+        TCGOpcode opc = op->opc;
+        const TCGOpDef *def = &tcg_op_defs[opc];
+
+        oi_prev = op->prev;
+
+        switch (opc) {
         case INDEX_op_call:
             {
                 int call_flags;
 
-                nb_args = args[-1];
-                args -= nb_args;
-                arg = *args++;
-                nb_iargs = arg & 0xffff;
-                nb_oargs = arg >> 16;
+                nb_oargs = op->callo;
+                nb_iargs = op->calli;
                 call_flags = args[nb_oargs + nb_iargs + 1];
 
-                /* pure functions can be removed if their result is not
-                   used */
+                /* pure functions can be removed if their result is unused */
                 if (call_flags & TCG_CALL_NO_SIDE_EFFECTS) {
                     for (i = 0; i < nb_oargs; i++) {
                         arg = args[i];
@@ -1333,8 +1317,7 @@ static void tcg_liveness_analysis(TCGContext *s)
                             goto do_not_remove_call;
                         }
                     }
-                    tcg_set_nop(s, s->gen_opc_buf + op_index,
-                                args - 1, nb_args);
+                    goto do_remove;
                 } else {
                 do_not_remove_call:
 
@@ -1373,41 +1356,33 @@ static void tcg_liveness_analysis(TCGContext *s)
                             dead_temps[arg] = 0;
                         }
                     }
-                    s->op_dead_args[op_index] = dead_args;
-                    s->op_sync_args[op_index] = sync_args;
+                    s->op_dead_args[oi] = dead_args;
+                    s->op_sync_args[oi] = sync_args;
                 }
-                args--;
             }
             break;
         case INDEX_op_debug_insn_start:
-            args -= def->nb_args;
-            break;
-        case INDEX_op_nopn:
-            nb_args = args[-1];
-            args -= nb_args;
+        case INDEX_op_nop:
+        case INDEX_op_end:
             break;
         case INDEX_op_discard:
-            args--;
             /* mark the temporary as dead */
             dead_temps[args[0]] = 1;
             mem_temps[args[0]] = 0;
             break;
-        case INDEX_op_end:
-            break;
 
         case INDEX_op_add2_i32:
-            op_new = INDEX_op_add_i32;
+            opc_new = INDEX_op_add_i32;
             goto do_addsub2;
         case INDEX_op_sub2_i32:
-            op_new = INDEX_op_sub_i32;
+            opc_new = INDEX_op_sub_i32;
             goto do_addsub2;
         case INDEX_op_add2_i64:
-            op_new = INDEX_op_add_i64;
+            opc_new = INDEX_op_add_i64;
             goto do_addsub2;
         case INDEX_op_sub2_i64:
-            op_new = INDEX_op_sub_i64;
+            opc_new = INDEX_op_sub_i64;
         do_addsub2:
-            args -= 6;
             nb_iargs = 4;
             nb_oargs = 2;
             /* Test if the high part of the operation is dead, but not
@@ -1418,12 +1393,11 @@ static void tcg_liveness_analysis(TCGContext *s)
                 if (dead_temps[args[0]] && !mem_temps[args[0]]) {
                     goto do_remove;
                 }
-                /* Create the single operation plus nop.  */
-                s->gen_opc_buf[op_index] = op = op_new;
+                /* Replace the opcode and adjust the args in place,
+                   leaving 3 unused args at the end.  */
+                op->opc = opc = opc_new;
                 args[1] = args[2];
                 args[2] = args[4];
-                assert(s->gen_opc_buf[op_index + 1] == INDEX_op_nop);
-                tcg_set_nop(s, s->gen_opc_buf + op_index + 1, args + 3, 3);
                 /* Fall through and mark the single-word operation live.  */
                 nb_iargs = 2;
                 nb_oargs = 1;
@@ -1431,27 +1405,26 @@ static void tcg_liveness_analysis(TCGContext *s)
             goto do_not_remove;
 
         case INDEX_op_mulu2_i32:
-            op_new = INDEX_op_mul_i32;
-            op_new2 = INDEX_op_muluh_i32;
-            have_op_new2 = TCG_TARGET_HAS_muluh_i32;
+            opc_new = INDEX_op_mul_i32;
+            opc_new2 = INDEX_op_muluh_i32;
+            have_opc_new2 = TCG_TARGET_HAS_muluh_i32;
             goto do_mul2;
         case INDEX_op_muls2_i32:
-            op_new = INDEX_op_mul_i32;
-            op_new2 = INDEX_op_mulsh_i32;
-            have_op_new2 = TCG_TARGET_HAS_mulsh_i32;
+            opc_new = INDEX_op_mul_i32;
+            opc_new2 = INDEX_op_mulsh_i32;
+            have_opc_new2 = TCG_TARGET_HAS_mulsh_i32;
             goto do_mul2;
         case INDEX_op_mulu2_i64:
-            op_new = INDEX_op_mul_i64;
-            op_new2 = INDEX_op_muluh_i64;
-            have_op_new2 = TCG_TARGET_HAS_muluh_i64;
+            opc_new = INDEX_op_mul_i64;
+            opc_new2 = INDEX_op_muluh_i64;
+            have_opc_new2 = TCG_TARGET_HAS_muluh_i64;
             goto do_mul2;
         case INDEX_op_muls2_i64:
-            op_new = INDEX_op_mul_i64;
-            op_new2 = INDEX_op_mulsh_i64;
-            have_op_new2 = TCG_TARGET_HAS_mulsh_i64;
+            opc_new = INDEX_op_mul_i64;
+            opc_new2 = INDEX_op_mulsh_i64;
+            have_opc_new2 = TCG_TARGET_HAS_mulsh_i64;
             goto do_mul2;
         do_mul2:
-            args -= 4;
             nb_iargs = 2;
             nb_oargs = 2;
             if (dead_temps[args[1]] && !mem_temps[args[1]]) {
@@ -1460,28 +1433,25 @@ static void tcg_liveness_analysis(TCGContext *s)
                     goto do_remove;
                 }
                 /* The high part of the operation is dead; generate the low. */
-                s->gen_opc_buf[op_index] = op = op_new;
+                op->opc = opc = opc_new;
                 args[1] = args[2];
                 args[2] = args[3];
-            } else if (have_op_new2 && dead_temps[args[0]]
+            } else if (have_opc_new2 && dead_temps[args[0]]
                        && !mem_temps[args[0]]) {
-                /* The low part of the operation is dead; generate the high.  */
-                s->gen_opc_buf[op_index] = op = op_new2;
+                /* The low part of the operation is dead; generate the high. */
+                op->opc = opc = opc_new2;
                 args[0] = args[1];
                 args[1] = args[2];
                 args[2] = args[3];
             } else {
                 goto do_not_remove;
             }
-            assert(s->gen_opc_buf[op_index + 1] == INDEX_op_nop);
-            tcg_set_nop(s, s->gen_opc_buf + op_index + 1, args + 3, 1);
             /* Mark the single-word operation live.  */
             nb_oargs = 1;
             goto do_not_remove;
 
         default:
             /* XXX: optimize by hardcoding common cases (e.g. triadic ops) */
-            args -= def->nb_args;
             nb_iargs = def->nb_iargs;
             nb_oargs = def->nb_oargs;
 
@@ -1489,24 +1459,23 @@ static void tcg_liveness_analysis(TCGContext *s)
                its outputs are dead. We assume that nb_oargs == 0
                implies side effects */
             if (!(def->flags & TCG_OPF_SIDE_EFFECTS) && nb_oargs != 0) {
-                for(i = 0; i < nb_oargs; i++) {
+                for (i = 0; i < nb_oargs; i++) {
                     arg = args[i];
                     if (!dead_temps[arg] || mem_temps[arg]) {
                         goto do_not_remove;
                     }
                 }
             do_remove:
-                tcg_set_nop(s, s->gen_opc_buf + op_index, args, def->nb_args);
+                op->opc = INDEX_op_nop;
 #ifdef CONFIG_PROFILER
                 s->del_op_count++;
 #endif
             } else {
             do_not_remove:
-
                 /* output args are dead */
                 dead_args = 0;
                 sync_args = 0;
-                for(i = 0; i < nb_oargs; i++) {
+                for (i = 0; i < nb_oargs; i++) {
                     arg = args[i];
                     if (dead_temps[arg]) {
                         dead_args |= (1 << i);
@@ -1527,23 +1496,18 @@ static void tcg_liveness_analysis(TCGContext *s)
                 }
 
                 /* input args are live */
-                for(i = nb_oargs; i < nb_oargs + nb_iargs; i++) {
+                for (i = nb_oargs; i < nb_oargs + nb_iargs; i++) {
                     arg = args[i];
                     if (dead_temps[arg]) {
                         dead_args |= (1 << i);
                     }
                     dead_temps[arg] = 0;
                 }
-                s->op_dead_args[op_index] = dead_args;
-                s->op_sync_args[op_index] = sync_args;
+                s->op_dead_args[oi] = dead_args;
+                s->op_sync_args[oi] = sync_args;
             }
             break;
         }
-        op_index--;
-    }
-
-    if (args != s->gen_opparam_buf) {
-        tcg_abort();
     }
 }
 #else
@@ -2110,11 +2074,11 @@ static void tcg_reg_alloc_op(TCGContext *s,
 #define STACK_DIR(x) (x)
 #endif
 
-static int tcg_reg_alloc_call(TCGContext *s, const TCGOpDef *def,
-                              TCGOpcode opc, const TCGArg *args,
-                              uint16_t dead_args, uint8_t sync_args)
+static void tcg_reg_alloc_call(TCGContext *s, int nb_oargs, int nb_iargs,
+                               const TCGArg * const args, uint16_t dead_args,
+                               uint8_t sync_args)
 {
-    int nb_iargs, nb_oargs, flags, nb_regs, i, reg, nb_params;
+    int flags, nb_regs, i, reg;
     TCGArg arg;
     TCGTemp *ts;
     intptr_t stack_offset;
@@ -2123,22 +2087,16 @@ static int tcg_reg_alloc_call(TCGContext *s, const TCGOpDef *def,
     int allocate_args;
     TCGRegSet allocated_regs;
 
-    arg = *args++;
-
-    nb_oargs = arg >> 16;
-    nb_iargs = arg & 0xffff;
-    nb_params = nb_iargs;
-
     func_addr = (tcg_insn_unit *)(intptr_t)args[nb_oargs + nb_iargs];
     flags = args[nb_oargs + nb_iargs + 1];
 
     nb_regs = ARRAY_SIZE(tcg_target_call_iarg_regs);
-    if (nb_regs > nb_params) {
-        nb_regs = nb_params;
+    if (nb_regs > nb_iargs) {
+        nb_regs = nb_iargs;
     }
 
     /* assign stack slots first */
-    call_stack_size = (nb_params - nb_regs) * sizeof(tcg_target_long);
+    call_stack_size = (nb_iargs - nb_regs) * sizeof(tcg_target_long);
     call_stack_size = (call_stack_size + TCG_TARGET_STACK_ALIGN - 1) & 
         ~(TCG_TARGET_STACK_ALIGN - 1);
     allocate_args = (call_stack_size > TCG_STATIC_CALL_ARGS_SIZE);
@@ -2149,7 +2107,7 @@ static int tcg_reg_alloc_call(TCGContext *s, const TCGOpDef *def,
     }
 
     stack_offset = TCG_TARGET_CALL_STACK_OFFSET;
-    for(i = nb_regs; i < nb_params; i++) {
+    for(i = nb_regs; i < nb_iargs; i++) {
         arg = args[nb_oargs + i];
 #ifdef TCG_TARGET_STACK_GROWSUP
         stack_offset -= sizeof(tcg_target_long);
@@ -2256,8 +2214,6 @@ static int tcg_reg_alloc_call(TCGContext *s, const TCGOpDef *def,
             }
         }
     }
-    
-    return nb_iargs + nb_oargs + def->nb_cargs + 1;
 }
 
 #ifdef CONFIG_PROFILER
@@ -2285,10 +2241,7 @@ static inline int tcg_gen_code_common(TCGContext *s,
                                       tcg_insn_unit *gen_code_buf,
                                       long search_pc)
 {
-    TCGOpcode opc;
-    int op_index;
-    const TCGOpDef *def;
-    const TCGArg *args;
+    int oi, oi_next;
 
 #ifdef DEBUG_DISAS
     if (unlikely(qemu_loglevel_mask(CPU_LOG_TB_OP))) {
@@ -2303,8 +2256,7 @@ static inline int tcg_gen_code_common(TCGContext *s,
 #endif
 
 #ifdef USE_TCG_OPTIMIZATIONS
-    s->gen_opparam_ptr =
-        tcg_optimize(s, s->gen_opc_ptr, s->gen_opparam_buf, tcg_op_defs);
+    tcg_optimize(s);
 #endif
 
 #ifdef CONFIG_PROFILER
@@ -2333,42 +2285,31 @@ static inline int tcg_gen_code_common(TCGContext *s,
 
     tcg_out_tb_init(s);
 
-    args = s->gen_opparam_buf;
-    op_index = 0;
+    for (oi = s->gen_first_op_idx; oi >= 0; oi = oi_next) {
+        TCGOp * const op = &s->gen_op_buf[oi];
+        TCGArg * const args = &s->gen_opparam_buf[op->args];
+        TCGOpcode opc = op->opc;
+        const TCGOpDef *def = &tcg_op_defs[opc];
+        uint16_t dead_args = s->op_dead_args[oi];
+        uint8_t sync_args = s->op_sync_args[oi];
 
-    for(;;) {
-        opc = s->gen_opc_buf[op_index];
+        oi_next = op->next;
 #ifdef CONFIG_PROFILER
         tcg_table_op_count[opc]++;
 #endif
-        def = &tcg_op_defs[opc];
-#if 0
-        printf("%s: %d %d %d\n", def->name,
-               def->nb_oargs, def->nb_iargs, def->nb_cargs);
-        //        dump_regs(s);
-#endif
-        switch(opc) {
+
+        switch (opc) {
         case INDEX_op_mov_i32:
         case INDEX_op_mov_i64:
-            tcg_reg_alloc_mov(s, def, args, s->op_dead_args[op_index],
-                              s->op_sync_args[op_index]);
+            tcg_reg_alloc_mov(s, def, args, dead_args, sync_args);
             break;
         case INDEX_op_movi_i32:
         case INDEX_op_movi_i64:
-            tcg_reg_alloc_movi(s, args, s->op_dead_args[op_index],
-                               s->op_sync_args[op_index]);
+            tcg_reg_alloc_movi(s, args, dead_args, sync_args);
             break;
         case INDEX_op_debug_insn_start:
-            /* debug instruction */
-            break;
         case INDEX_op_nop:
-        case INDEX_op_nop1:
-        case INDEX_op_nop2:
-        case INDEX_op_nop3:
             break;
-        case INDEX_op_nopn:
-            args += args[0];
-            goto next;
         case INDEX_op_discard:
             temp_dead(s, args[0]);
             break;
@@ -2377,12 +2318,9 @@ static inline int tcg_gen_code_common(TCGContext *s,
             tcg_out_label(s, args[0], s->code_ptr);
             break;
         case INDEX_op_call:
-            args += tcg_reg_alloc_call(s, def, opc, args,
-                                       s->op_dead_args[op_index],
-                                       s->op_sync_args[op_index]);
-            goto next;
-        case INDEX_op_end:
-            goto the_end;
+            tcg_reg_alloc_call(s, op->callo, op->calli, args,
+                               dead_args, sync_args);
+            break;
         default:
             /* Sanity check that we've not introduced any unhandled opcodes. */
             if (def->flags & TCG_OPF_NOT_PRESENT) {
@@ -2391,21 +2329,17 @@ static inline int tcg_gen_code_common(TCGContext *s,
             /* Note: in order to speed up the code, it would be much
                faster to have specialized register allocator functions for
                some common argument patterns */
-            tcg_reg_alloc_op(s, def, opc, args, s->op_dead_args[op_index],
-                             s->op_sync_args[op_index]);
+            tcg_reg_alloc_op(s, def, opc, args, dead_args, sync_args);
             break;
         }
-        args += def->nb_args;
-    next:
         if (search_pc >= 0 && search_pc < tcg_current_code_size(s)) {
-            return op_index;
+            return oi;
         }
-        op_index++;
 #ifndef NDEBUG
         check_regs(s);
 #endif
     }
- the_end:
+
     /* Generate TB finalization at the end of block */
     tcg_out_tb_finalize(s);
     return -1;
@@ -2416,14 +2350,18 @@ int tcg_gen_code(TCGContext *s, tcg_insn_unit *gen_code_buf)
 #ifdef CONFIG_PROFILER
     {
         int n;
-        n = (s->gen_opc_ptr - s->gen_opc_buf);
+
+        n = s->gen_last_op_idx + 1;
         s->op_count += n;
-        if (n > s->op_count_max)
+        if (n > s->op_count_max) {
             s->op_count_max = n;
+        }
 
-        s->temp_count += s->nb_temps;
-        if (s->nb_temps > s->temp_count_max)
-            s->temp_count_max = s->nb_temps;
+        n = s->nb_temps;
+        s->temp_count += n;
+        if (n > s->temp_count_max) {
+            s->temp_count_max = n;
+        }
     }
 #endif
 
diff --git a/tcg/tcg.h b/tcg/tcg.h
index 95f1aad7dc..596e30a4b6 100644
--- a/tcg/tcg.h
+++ b/tcg/tcg.h
@@ -448,10 +448,28 @@ typedef struct TCGTempSet {
     unsigned long l[BITS_TO_LONGS(TCG_MAX_TEMPS)];
 } TCGTempSet;
 
+typedef struct TCGOp {
+    TCGOpcode opc   : 8;
+
+    /* The number of out and in parameter for a call.  */
+    unsigned callo  : 2;
+    unsigned calli  : 6;
+
+    /* Index of the arguments for this op, or -1 for zero-operand ops.  */
+    signed args     : 16;
+
+    /* Index of the prex/next op, or -1 for the end of the list.  */
+    signed prev     : 16;
+    signed next     : 16;
+} TCGOp;
+
+QEMU_BUILD_BUG_ON(NB_OPS > 0xff);
+QEMU_BUILD_BUG_ON(OPC_BUF_SIZE >= 0x7fff);
+QEMU_BUILD_BUG_ON(OPPARAM_BUF_SIZE >= 0x7fff);
+
 struct TCGContext {
     uint8_t *pool_cur, *pool_end;
     TCGPool *pool_first, *pool_current, *pool_first_large;
-    TCGLabel *labels;
     int nb_labels;
     int nb_globals;
     int nb_temps;
@@ -469,9 +487,6 @@ struct TCGContext {
                                corresponding output argument needs to be
                                sync to memory. */
     
-    /* tells in which temporary a given register is. It does not take
-       into account fixed registers */
-    int reg_to_temp[TCG_TARGET_NB_REGS];
     TCGRegSet reserved_regs;
     intptr_t current_frame_offset;
     intptr_t frame_start;
@@ -479,8 +494,6 @@ struct TCGContext {
     int frame_reg;
 
     tcg_insn_unit *code_ptr;
-    TCGTemp temps[TCG_MAX_TEMPS]; /* globals first, temps after */
-    TCGTempSet free_temps[TCG_TYPE_COUNT * 2];
 
     GHashTable *helpers;
 
@@ -508,14 +521,10 @@ struct TCGContext {
     int goto_tb_issue_mask;
 #endif
 
-    uint16_t gen_opc_buf[OPC_BUF_SIZE];
-    TCGArg gen_opparam_buf[OPPARAM_BUF_SIZE];
-
-    uint16_t *gen_opc_ptr;
-    TCGArg *gen_opparam_ptr;
-    target_ulong gen_opc_pc[OPC_BUF_SIZE];
-    uint16_t gen_opc_icount[OPC_BUF_SIZE];
-    uint8_t gen_opc_instr_start[OPC_BUF_SIZE];
+    int gen_first_op_idx;
+    int gen_last_op_idx;
+    int gen_next_op_idx;
+    int gen_next_parm_idx;
 
     /* Code generation.  Note that we specifically do not use tcg_insn_unit
        here, because there's too much arithmetic throughout that relies
@@ -533,6 +542,22 @@ struct TCGContext {
 
     /* The TCGBackendData structure is private to tcg-target.c.  */
     struct TCGBackendData *be;
+
+    TCGTempSet free_temps[TCG_TYPE_COUNT * 2];
+    TCGTemp temps[TCG_MAX_TEMPS]; /* globals first, temps after */
+
+    /* tells in which temporary a given register is. It does not take
+       into account fixed registers */
+    int reg_to_temp[TCG_TARGET_NB_REGS];
+
+    TCGOp gen_op_buf[OPC_BUF_SIZE];
+    TCGArg gen_opparam_buf[OPPARAM_BUF_SIZE];
+
+    target_ulong gen_opc_pc[OPC_BUF_SIZE];
+    uint16_t gen_opc_icount[OPC_BUF_SIZE];
+    uint8_t gen_opc_instr_start[OPC_BUF_SIZE];
+
+    TCGLabel labels[TCG_MAX_LABELS];
 };
 
 extern TCGContext tcg_ctx;
@@ -540,7 +565,7 @@ extern TCGContext tcg_ctx;
 /* The number of opcodes emitted so far.  */
 static inline int tcg_op_buf_count(void)
 {
-    return tcg_ctx.gen_opc_ptr - tcg_ctx.gen_opc_buf;
+    return tcg_ctx.gen_next_op_idx;
 }
 
 /* Test for whether to terminate the TB for using too many opcodes.  */
@@ -718,8 +743,7 @@ void tcg_add_target_add_op_defs(const TCGTargetOpDef *tdefs);
 void tcg_gen_callN(TCGContext *s, void *func,
                    TCGArg ret, int nargs, TCGArg *args);
 
-TCGArg *tcg_optimize(TCGContext *s, uint16_t *tcg_opc_ptr, TCGArg *args,
-                     TCGOpDef *tcg_op_def);
+void tcg_optimize(TCGContext *s);
 
 /* only used for debugging purposes */
 void tcg_dump_ops(TCGContext *s);