X-Git-Url: http://wien.tomnetworks.com/gitweb/?a=blobdiff_plain;f=mono%2Fmini%2Fdominators.c;h=208ae7597a00e73eefabd1719534c6aaef1b7088;hb=HEAD;hp=89466a6b8e806881f4297bf433e617d329744f25;hpb=5e7bbc29224d11a03b22d860fe0eff4ec7b1e65a;p=mono.git

diff --git a/mono/mini/dominators.c b/mono/mini/dominators.c
index 89466a6b8e8..208ae7597a0 100644
--- a/mono/mini/dominators.c
+++ b/mono/mini/dominators.c
@@ -1,11 +1,14 @@
-/*
- * dominators.c: Dominator computation on the control flow graph
+/**
+ * \file
+ * Dominator computation on the control flow graph
  *
  * Author:
  *   Dietmar Maurer (dietmar@ximian.com)
  *   Paolo Molaro (lupus@ximian.com)
  *
  * (C) 2003 Ximian, Inc.
+ * Copyright 2011 Xamarin, Inc (http://www.xamarin.com)
+ * Licensed under the MIT license. See LICENSE file in the project root for full license information.
  */
 #include <string.h>
 #include <mono/metadata/debug-helpers.h>
@@ -16,8 +19,6 @@
 
 #ifndef DISABLE_JIT
 
-//#define DEBUG_DOMINATORS
-
 /*
  * bb->dfn == 0 means either the bblock is ignored by the dfn calculation, or
  * it is the entry bblock.
@@ -34,7 +35,6 @@ static void
 compute_dominators (MonoCompile *cfg)
 {
 	int bindex, i, bitsize;
-	char* mem;
 	MonoBasicBlock *entry;
 	MonoBasicBlock **doms;
 	gboolean changed;
@@ -43,23 +43,22 @@ compute_dominators (MonoCompile *cfg)
 
 	bitsize = mono_bitset_alloc_size (cfg->num_bblocks, 0);
 
-	mem = mono_mempool_alloc0 (cfg->mempool, bitsize * cfg->num_bblocks);
-
 	entry = cfg->bblocks [0];
 
 	doms = g_new0 (MonoBasicBlock*, cfg->num_bblocks);
 	doms [entry->dfn] = entry;
 
-#ifdef DEBUG_DOMINATORS
-	for (i = 0; i < cfg->num_bblocks; ++i) {
-		MonoBasicBlock *bb = cfg->bblocks [i];
+	if (cfg->verbose_level > 1) {
+		for (i = 0; i < cfg->num_bblocks; ++i) {
+			int j;
+			MonoBasicBlock *bb = cfg->bblocks [i];
 
-		printf ("BB%d IN: ", bb->block_num);
-		for (j = 0; j < bb->in_count; ++j) 
-			printf ("%d ", bb->in_bb [j]->block_num);
-		printf ("\n");
+			printf ("BB%d IN: ", bb->block_num);
+			for (j = 0; j < bb->in_count; ++j)
+				printf ("%d ", bb->in_bb [j]->block_num);
+			printf ("\n");
+		}
 	}
-#endif
 
 	changed = TRUE;
 	while (changed) {
@@ -118,6 +117,9 @@ compute_dominators (MonoCompile *cfg)
 		MonoBasicBlock *bb = cfg->bblocks [i];
 		MonoBasicBlock *cbb;
 		MonoBitSet *dominators;
+		char *mem;
+
+		mem = (char *)mono_mempool_alloc0 (cfg->mempool, bitsize);
 
 		bb->dominators = dominators = mono_bitset_mem_new (mem, cfg->num_bblocks, 0);
 		mem += bitsize;
@@ -141,15 +143,15 @@ compute_dominators (MonoCompile *cfg)
 
 	cfg->comp_done |= MONO_COMP_DOM | MONO_COMP_IDOM;
 
-#ifdef DEBUG_DOMINATORS
-	printf ("DTREE %s %d\n", mono_method_full_name (cfg->method, TRUE), 
-		mono_method_get_header (cfg->method)->num_clauses);
-	for (i = 0; i < cfg->num_bblocks; ++i) {
-		MonoBasicBlock *bb = cfg->bblocks [i];
-		printf ("BB%d(dfn=%d) (IDOM=BB%d): ", bb->block_num, bb->dfn, bb->idom ? bb->idom->block_num : -1);
-		mono_blockset_print (cfg, bb->dominators, NULL, -1);
+	if (cfg->verbose_level > 1) {
+		printf ("DTREE %s %d\n", mono_method_full_name (cfg->method, TRUE),
+			cfg->header->num_clauses);
+		for (i = 0; i < cfg->num_bblocks; ++i) {
+			MonoBasicBlock *bb = cfg->bblocks [i];
+			printf ("BB%d(dfn=%d) (IDOM=BB%d): ", bb->block_num, bb->dfn, bb->idom ? bb->idom->block_num : -1);
+			mono_blockset_print (cfg, bb->dominators, NULL, -1);
+		}
 	}
-#endif
 }
 
 #if 0
@@ -199,7 +201,7 @@ compute_dominance_frontier (MonoCompile *cfg)
 		cfg->bblocks [i]->flags &= ~BB_VISITED;
 
 	bitsize = mono_bitset_alloc_size (cfg->num_bblocks, 0);
-	mem = mono_mempool_alloc0 (cfg->mempool, bitsize * cfg->num_bblocks);
+	mem = (char *)mono_mempool_alloc0 (cfg->mempool, bitsize * cfg->num_bblocks);
  
 	for (i = 0; i < cfg->num_bblocks; ++i) {
 		MonoBasicBlock *bb = cfg->bblocks [i];
@@ -295,8 +297,6 @@ mono_compile_dominator_info (MonoCompile *cfg, int dom_flags)
 		compute_dominance_frontier (cfg);
 }
 
-//#define DEBUG_NATURAL_LOOPS
-
 /*
  * code to detect loops and loop nesting level
  */
@@ -315,8 +315,13 @@ mono_compute_natural_loops (MonoCompile *cfg)
 
 		for (j = 0; j < n->out_count; j++) {
 			MonoBasicBlock *h = n->out_bb [j];
+			/* check for single block loops */
+			if (n == h) {
+				h->loop_blocks = g_list_prepend_mempool (cfg->mempool, h->loop_blocks, h);
+				h->nesting++;
+			}
 			/* check for back-edge from n to h */
-			if (n != h && mono_bitset_test_fast (n->dominators, h->dfn)) {
+			else if (n != h && mono_bitset_test_fast (n->dominators, h->dfn)) {
 				GSList *todo;
 
 				/* already in loop_blocks? */
@@ -329,7 +334,7 @@ mono_compute_natural_loops (MonoCompile *cfg)
 					GList *l;
 
 					for (l = h->loop_blocks; l; l = l->next) {
-						MonoBasicBlock *b = l->data;
+						MonoBasicBlock *b = (MonoBasicBlock *)l->data;
 						if (b->dfn)
 							mono_bitset_set_fast (in_loop_blocks, b->dfn);
 					}
@@ -343,7 +348,7 @@ mono_compute_natural_loops (MonoCompile *cfg)
 					if ((cb->dfn && mono_bitset_test_fast (in_loop_blocks, cb->dfn)) || (!cb->dfn && g_list_find (h->loop_blocks, cb)))
 						continue;
 
-					h->loop_blocks = g_list_prepend (h->loop_blocks, cb);
+					h->loop_blocks = g_list_prepend_mempool (cfg->mempool, h->loop_blocks, cb);
 					cb->nesting++;
 					if (cb->dfn)
 						mono_bitset_set_fast (in_loop_blocks, cb->dfn);
@@ -359,7 +364,7 @@ mono_compute_natural_loops (MonoCompile *cfg)
 
 				/* add the header if not already there */
 				if (!((h->dfn && mono_bitset_test_fast (in_loop_blocks, h->dfn)) || (!h->dfn && g_list_find (h->loop_blocks, h)))) {
-					h->loop_blocks = g_list_prepend (h->loop_blocks, h);
+					h->loop_blocks = g_list_prepend_mempool (cfg->mempool, h->loop_blocks, h);
 					h->nesting++;
 				}
 			}
@@ -399,20 +404,19 @@ mono_compute_natural_loops (MonoCompile *cfg)
 	}
 	g_free (bb_indexes);
 
-#ifdef DEBUG_NATURAL_LOOPS
-	for (i = 0; i < cfg->num_bblocks; ++i) {
-		if (cfg->bblocks [i]->loop_blocks) {
-			MonoBasicBlock *h = (MonoBasicBlock *)cfg->bblocks [i]->loop_blocks->data;
-			GList *l;
-			printf ("LOOP START %d\n", h->block_num);
-			for (l = h->loop_blocks; l; l = l->next) {
-				MonoBasicBlock *cb = (MonoBasicBlock *)l->data;
-				printf (" BB%d %d %p\n", cb->block_num, cb->nesting, cb->loop_blocks);
+	if (cfg->verbose_level > 1) {
+		for (i = 0; i < cfg->num_bblocks; ++i) {
+			if (cfg->bblocks [i]->loop_blocks) {
+				MonoBasicBlock *h = (MonoBasicBlock *)cfg->bblocks [i]->loop_blocks->data;
+				GList *l;
+				printf ("LOOP START %d\n", h->block_num);
+				for (l = h->loop_blocks; l; l = l->next) {
+					MonoBasicBlock *cb = (MonoBasicBlock *)l->data;
+					printf ("\tBB%d %d %p\n", cb->block_num, cb->nesting, cb->loop_blocks);
+				}
 			}
 		}
 	}
-#endif
-
 }
 
 static void
@@ -436,10 +440,7 @@ clear_loops (MonoCompile *cfg)
     
 	for (i = 0; i < cfg->num_bblocks; ++i) {
 		cfg->bblocks[i]->nesting = 0;
-		if (cfg->bblocks[i]->loop_blocks) {
-			g_list_free (cfg->bblocks[i]->loop_blocks);        
-			cfg->bblocks[i]->loop_blocks = NULL;
-		}
+		cfg->bblocks[i]->loop_blocks = NULL;
 	}
 
 	cfg->comp_done &= ~MONO_COMP_LOOPS;