[RFC,v0,2/8] Propagate REG_NEXT_USE value through process of register allocation.

diff --git a/tcg/tcg.c b/tcg/tcg.c
index 821ffa7..c6e920e 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -1643,6 +1643,7 @@  static void tcg_reg_alloc_movi(TCGContext *s, const TCGArg *args)
 
 static void tcg_reg_alloc_mov(TCGContext *s, const TCGOpDef *def,
                               const TCGArg *args,
+                              const int *param_next_use,
                               unsigned int dead_iargs)
 {
     TCGTemp *ts, *ots;
@@ -1669,6 +1670,9 @@  static void tcg_reg_alloc_mov(TCGContext *s, const TCGOpDef *def,
                 reg = tcg_reg_alloc(s, arg_ct->u.regs, s->reserved_regs);
             }
             if (ts->reg != reg) {
+#ifdef USE_ADVANCED_REGALLOC
+                s->reg_next_use[ts->reg] = param_next_use[1];
+#endif
                 tcg_out_mov(s, ots->type, reg, ts->reg);
             }
         }
@@ -1694,6 +1698,9 @@  static void tcg_reg_alloc_mov(TCGContext *s, const TCGOpDef *def,
     } else {
         tcg_abort();
     }
+#ifdef USE_ADVANCED_REGALLOC
+    s->reg_next_use[reg] = param_next_use[0];
+#endif
     s->reg_to_temp[reg] = args[0];
     ots->reg = reg;
     ots->val_type = TEMP_VAL_REG;
@@ -1703,6 +1710,7 @@  static void tcg_reg_alloc_mov(TCGContext *s, const TCGOpDef *def,
 static void tcg_reg_alloc_op(TCGContext *s, 
                              const TCGOpDef *def, TCGOpcode opc,
                              const TCGArg *args,
+                             const int *param_next_use,
                              unsigned int dead_iargs)
 {
     TCGRegSet allocated_regs;
@@ -1776,6 +1784,9 @@  static void tcg_reg_alloc_op(TCGContext *s,
             reg = tcg_reg_alloc(s, arg_ct->u.regs, allocated_regs);
             tcg_out_mov(s, ts->type, reg, ts->reg);
         }
+#ifdef USE_ADVANCED_REGALLOC
+        s->reg_next_use[reg] = param_next_use[i];
+#endif
         new_args[i] = reg;
         const_args[i] = 0;
         tcg_regset_set_reg(allocated_regs, reg);
@@ -1845,6 +1856,9 @@  static void tcg_reg_alloc_op(TCGContext *s,
             }
         oarg_end:
             new_args[i] = reg;
+#ifdef USE_ADVANCED_REGALLOC
+            s->reg_next_use[reg] = param_next_use[i];
+#endif
         }
     }
 
@@ -1869,6 +1883,7 @@  static void tcg_reg_alloc_op(TCGContext *s,
 
 static int tcg_reg_alloc_call(TCGContext *s, const TCGOpDef *def,
                               TCGOpcode opc, const TCGArg *args,
+                              const int *param_next_use,
                               unsigned int dead_iargs)
 {
     int nb_iargs, nb_oargs, flags, nb_regs, i, reg, nb_params;
@@ -1953,6 +1968,9 @@  static int tcg_reg_alloc_call(TCGContext *s, const TCGOpDef *def,
                 tcg_abort();
             }
             tcg_regset_set_reg(allocated_regs, reg);
+#ifdef USE_ADVANCED_REGALLOC
+            s->reg_next_use[reg] = param_next_use[nb_oargs + i];
+#endif
         }
     }
     
@@ -2039,6 +2057,9 @@  static int tcg_reg_alloc_call(TCGContext *s, const TCGOpDef *def,
             ts->reg = reg;
             ts->mem_coherent = 0; 
             s->reg_to_temp[reg] = arg;
+#ifdef USE_ADVANCED_REGALLOC
+            s->reg_next_use[reg] = param_next_use[i];
+#endif
         }
     }
     
@@ -2068,6 +2089,8 @@  static inline int tcg_gen_code_common(TCGContext *s, uint8_t *gen_code_buf,
     TCGOpcode opc;
     int op_index;
     const TCGOpDef *def;
+    const int *param_next_use_ptr;
+    int nb_args;
     unsigned int dead_iargs;
     const TCGArg *args;
 
@@ -2095,6 +2118,8 @@  static inline int tcg_gen_code_common(TCGContext *s, uint8_t *gen_code_buf,
     }
 #endif
 
+    param_next_use_ptr = s->param_next_use;
+
     tcg_reg_alloc_start(s);
 
     s->code_buf = gen_code_buf;
@@ -2120,7 +2145,7 @@  static inline int tcg_gen_code_common(TCGContext *s, uint8_t *gen_code_buf,
         case INDEX_op_mov_i64:
 #endif
             dead_iargs = s->op_dead_iargs[op_index];
-            tcg_reg_alloc_mov(s, def, args, dead_iargs);
+            tcg_reg_alloc_mov(s, def, args, param_next_use_ptr, dead_iargs);
             break;
         case INDEX_op_movi_i32:
 #if TCG_TARGET_REG_BITS == 64
@@ -2137,6 +2162,7 @@  static inline int tcg_gen_code_common(TCGContext *s, uint8_t *gen_code_buf,
         case INDEX_op_nop3:
             break;
         case INDEX_op_nopn:
+            param_next_use_ptr += args[0];
             args += args[0];
             goto next;
         case INDEX_op_discard:
@@ -2157,7 +2183,10 @@  static inline int tcg_gen_code_common(TCGContext *s, uint8_t *gen_code_buf,
             break;
         case INDEX_op_call:
             dead_iargs = s->op_dead_iargs[op_index];
-            args += tcg_reg_alloc_call(s, def, opc, args, dead_iargs);
+            nb_args = tcg_reg_alloc_call(s, def, opc, args,
+                    param_next_use_ptr, dead_iargs);
+            args += nb_args;
+            param_next_use_ptr += nb_args;
             goto next;
         case INDEX_op_end:
             goto the_end;
@@ -2166,10 +2195,11 @@  static inline int tcg_gen_code_common(TCGContext *s, uint8_t *gen_code_buf,
                faster to have specialized register allocator functions for
                some common argument patterns */
             dead_iargs = s->op_dead_iargs[op_index];
-            tcg_reg_alloc_op(s, def, opc, args, dead_iargs);
+            tcg_reg_alloc_op(s, def, opc, args, param_next_use_ptr, dead_iargs);
             break;
         }
         args += def->nb_args;
+        param_next_use_ptr += def->nb_args;
     next:
         if (search_pc >= 0 && search_pc < s->code_ptr - gen_code_buf) {
             return op_index;