[regalloc2] Lazily allocate intervals.

diff --git a/mono/mini/regalloc2.c b/mono/mini/regalloc2.c
index 098ff5d4b2224cace181f5ee13b093c5f57fa077..503a0662574df112a008d1e1f81a0775e21178ed 100644 (file)
--- a/mono/mini/regalloc2.c
+++ b/mono/mini/regalloc2.c
@@ -707,6 +707,17 @@ compute_live_in_out_sets (MonoCompile *cfg, MonoRegallocContext *ctx)
 #endif
 }
 
+static MonoLiveInterval*
+get_var_interval (MonoCompile *cfg, MonoRegallocContext *ctx, int idx)
+{
+       MonoLiveInterval *interval = ctx->varinfo [idx].interval;
+       if (interval)
+               return interval;
+       interval = mono_mempool_alloc0 (cfg->mempool, sizeof (MonoLiveInterval));
+       ctx->varinfo [idx].interval = interval;
+       return interval;
+}
+
 static inline void
 update_liveness (MonoCompile *cfg, MonoRegallocContext *ctx, MonoInst *ins, int inst_num, gint32 *last_use)
 {
@@ -730,9 +741,9 @@ update_liveness (MonoCompile *cfg, MonoRegallocContext *ctx, MonoInst *ins, int
                                         * Avoid a hole in the liveness range, since the allocation code
                                         * could think the register is free there.
                                         */
-                                       mono_linterval_add_range (ctx->cfg, ctx->varinfo [ins->dreg].interval, inst_num, last_use [ins->dreg]);
+                                       mono_linterval_add_range (ctx->cfg, get_var_interval (cfg, ctx, ins->dreg), inst_num, last_use [ins->dreg]);
                                } else {
-                                       mono_linterval_add_range (ctx->cfg, ctx->varinfo [ins->dreg].interval, inst_num + INS_POS_DEF, last_use [ins->dreg]);
+                                       mono_linterval_add_range (ctx->cfg, get_var_interval (cfg, ctx, ins->dreg), inst_num + INS_POS_DEF, last_use [ins->dreg]);
                                }
                                last_use [ins->dreg] = 0;
                        }
@@ -743,7 +754,7 @@ update_liveness (MonoCompile *cfg, MonoRegallocContext *ctx, MonoInst *ins, int
                                        spec = INS_INFO (ins->opcode);
                                } else {
                                        LIVENESS_DEBUG (printf ("\tdead def of R%d, add range to R%d: [%x, %x]\n", ins->dreg, ins->dreg, inst_num + INS_POS_DEF, inst_num + INS_POS_DEF));
-                                       mono_linterval_add_range (ctx->cfg, ctx->varinfo [ins->dreg].interval, inst_num + INS_POS_DEF, inst_num + INS_POS_DEF);
+                                       mono_linterval_add_range (ctx->cfg, get_var_interval (cfg, ctx, ins->dreg), inst_num + INS_POS_DEF, inst_num + INS_POS_DEF);
                                }
                        }
                }
@@ -830,15 +841,15 @@ update_liveness (MonoCompile *cfg, MonoRegallocContext *ctx, MonoInst *ins, int
                if (clob == 'c') {
                        /* A call clobbers some int/fp registers */
                        for (l = mono_arch_get_iregs_clobbered_by_call ((MonoCallInst*)ins); l; l = l->next)
-                               mono_linterval_add_range (ctx->cfg, ctx->varinfo [GPOINTER_TO_INT (l->data)].interval, inst_num + INS_POS_CLOB, inst_num + INS_POS_CLOB);
+                               mono_linterval_add_range (ctx->cfg, get_var_interval (cfg, ctx, GPOINTER_TO_INT (l->data)), inst_num + INS_POS_CLOB, inst_num + INS_POS_CLOB);
                        for (l = mono_arch_get_fregs_clobbered_by_call ((MonoCallInst*)ins); l; l = l->next)
-                               mono_linterval_add_range (ctx->cfg, ctx->varinfo [GPOINTER_TO_INT (l->data)].interval, inst_num + INS_POS_CLOB, inst_num + INS_POS_CLOB);
+                               mono_linterval_add_range (ctx->cfg, get_var_interval (cfg, ctx, GPOINTER_TO_INT (l->data)), inst_num + INS_POS_CLOB, inst_num + INS_POS_CLOB);
                }
                else {
                        int clob_reg = MONO_ARCH_INST_FIXED_REG (clob);
 
                        if (clob_reg != -1)
-                               mono_linterval_add_range (ctx->cfg, ctx->varinfo [clob_reg].interval, inst_num + INS_POS_CLOB, inst_num + INS_POS_CLOB);
+                               mono_linterval_add_range (ctx->cfg, get_var_interval (cfg, ctx, clob_reg), inst_num + INS_POS_CLOB, inst_num + INS_POS_CLOB);
                }
        }
 }
@@ -861,10 +872,6 @@ compute_intervals (MonoCompile *cfg, MonoRegallocContext *ctx)
        reverse_len = 1024;
        reverse = mono_mempool_alloc (cfg->mempool, sizeof (MonoInst*) * reverse_len);
 
-       for (idx = 0; idx < max_vars; ++idx) {
-               ctx->varinfo [idx].interval = mono_mempool_alloc0 (cfg->mempool, sizeof (MonoLiveInterval));
-       }
-
        /*
         * Process bblocks in reverse order, so the addition of new live ranges
         * to the intervals is faster.
@@ -931,7 +938,7 @@ compute_intervals (MonoCompile *cfg, MonoRegallocContext *ctx)
                        if (last_use [idx] != 0) {
                                /* Live at exit, not written -> live on enter */
                                LIVENESS_DEBUG (printf ("Var R%d live at enter, add range to R%d: [%x, %x)\n", idx, idx, block_from, last_use [idx]));
-                               mono_linterval_add_range (cfg, ctx->varinfo [idx].interval, block_from, last_use [idx]);
+                               mono_linterval_add_range (cfg, get_var_interval (cfg, ctx, idx), block_from, last_use [idx]);
                        }
                }
        }
@@ -946,14 +953,14 @@ compute_intervals (MonoCompile *cfg, MonoRegallocContext *ctx)
        for (i = 0; i < cfg->num_varinfo; i ++) {
                MonoMethodVar *vi = MONO_VARINFO (cfg, i);
                if ((cfg->varinfo [vi->idx]->opcode == OP_ARG) && (cfg->varinfo [vi->idx] != cfg->ret))
-                       mono_linterval_add_range (cfg, ctx->varinfo [cfg->varinfo [i]->dreg].interval, 0, 1);
+                       mono_linterval_add_range (cfg, get_var_interval (cfg, ctx, cfg->varinfo [i]->dreg), 0, 1);
        }
 #endif
 
 #if 0
                for (idx = 0; idx < max_vars; ++idx) {
                        printf ("LIVENESS R%d: ", idx);
-                       mono_linterval_print (ctx->varinfo [idx].interval);
+                       mono_linterval_print (get_var_interval (cfg, ctx, idx));
                        printf ("\n");
                }
        }
@@ -1204,7 +1211,7 @@ linear_scan (MonoCompile *cfg, MonoRegallocContext *ctx)
        /* Create list of allocatable variables */
        vars = NULL;
        for (i = MONO_FIRST_VREG; i < cfg->next_vreg; ++i) {
-               if (ctx->varinfo [i].interval->range)
+               if (get_var_interval (cfg, ctx, i)->range)
                        vars = g_list_prepend (vars, &ctx->varinfo [i]);
        }
 
@@ -1222,7 +1229,7 @@ linear_scan (MonoCompile *cfg, MonoRegallocContext *ctx)
        /* The hard registers are assigned to themselves */
        for (i = 0; i < MONO_MAX_IREGS + MONO_MAX_FREGS; ++i) {
                ctx->varinfo [i].hreg = i;
-               if (ctx->varinfo [i].interval->range)
+               if (get_var_interval (cfg, ctx, i)->range)
                        inactive = g_list_append (inactive, &ctx->varinfo [i]);         
        }