[runtime] Use ins->prev in mono_analyze_liveness. (#4296)

* [runtime] Add the missing MONO_BB_FOR_EACH_INS_REVERSE macro.

* [runtime] Use ins->prev instead of building reverse ins array in mono_analyze_liveness.

diff --git a/mono/mini/liveness.c b/mono/mini/liveness.c
index 7cc05634123e8b4a78b0d5f3c007578e563b3c1c..cdd1c42ef491a6b772f6155f11bfd424dee7ffcd 100644 (file)
--- a/mono/mini/liveness.c
+++ b/mono/mini/liveness.c
@@ -852,10 +852,9 @@ update_liveness2 (MonoCompile *cfg, MonoInst *ins, gboolean set_volatile, int in
 static void
 mono_analyze_liveness2 (MonoCompile *cfg)
 {
-       int bnum, idx, i, j, nins, max, max_vars, block_from, block_to, pos, reverse_len;
+       int bnum, idx, i, j, nins, max, max_vars, block_from, block_to, pos;
        gint32 *last_use;
        static guint32 disabled = -1;
-       MonoInst **reverse;
 
        if (disabled == -1)
                disabled = g_getenv ("DISABLED") != NULL;
@@ -890,9 +889,6 @@ mono_analyze_liveness2 (MonoCompile *cfg)
        max_vars = cfg->num_varinfo;
        last_use = g_new0 (gint32, max_vars);
 
-       reverse_len = 1024;
-       reverse = (MonoInst **)mono_mempool_alloc (cfg->mempool, sizeof (MonoInst*) * reverse_len);
-
        for (idx = 0; idx < max_vars; ++idx) {
                MonoMethodVar *vi = MONO_VARINFO (cfg, idx);
 
@@ -940,25 +936,13 @@ mono_analyze_liveness2 (MonoCompile *cfg)
                if (cfg->ret)
                        last_use [cfg->ret->inst_c0] = block_to;
 
-               for (nins = 0, pos = block_from, ins = bb->code; ins; ins = ins->next, ++nins, ++pos) {
-                       if (nins >= reverse_len) {
-                               int new_reverse_len = reverse_len * 2;
-                               MonoInst **new_reverse = (MonoInst **)mono_mempool_alloc (cfg->mempool, sizeof (MonoInst*) * new_reverse_len);
-                               memcpy (new_reverse, reverse, sizeof (MonoInst*) * reverse_len);
-                               reverse = new_reverse;
-                               reverse_len = new_reverse_len;
-                       }
-
-                       reverse [nins] = ins;
-               }
+               pos = block_from + 1;
+               MONO_BB_FOR_EACH_INS (bb, ins) pos++;
 
                /* Process instructions backwards */
-               for (i = nins - 1; i >= 0; --i) {
-                       MonoInst *ins = (MonoInst*)reverse [i];
-
-                       update_liveness2 (cfg, ins, FALSE, pos, last_use);
-
-                       pos --;
+               MONO_BB_FOR_EACH_INS_REVERSE (bb, ins) {
+                       update_liveness2 (cfg, ins, FALSE, pos, last_use);
+                       pos--;
                }
 
                for (idx = 0; idx < max_vars; ++idx) {

diff --git a/mono/mini/mini.h b/mono/mini/mini.h
index b183be756b49615af2825b1edcc2e5096f744c72..415290c17bd6f57de65ff347c937a0153273f063 100644 (file)
--- a/mono/mini/mini.h
+++ b/mono/mini/mini.h
@@ -590,6 +590,8 @@ extern const gint8 ins_sreg_counts [];
 
 #define MONO_BB_FOR_EACH_INS_SAFE(bb, n, ins) for ((ins) = (bb)->code, n = (ins) ? (ins)->next : NULL; (ins); (ins) = (n), (n) = (ins) ? (ins)->next : NULL)
 
+#define MONO_BB_FOR_EACH_INS_REVERSE(bb, ins) for ((ins) = (bb)->last_ins; (ins); (ins) = (ins)->prev)
+
 #define MONO_BB_FOR_EACH_INS_REVERSE_SAFE(bb, p, ins) for ((ins) = (bb)->last_ins, p = (ins) ? (ins)->prev : NULL; (ins); (ins) = (p), (p) = (ins) ? (ins)->prev : NULL)
 
 #define mono_bb_first_ins(bb) (bb)->code