X-Git-Url: http://wien.tomnetworks.com/gitweb/?a=blobdiff_plain;f=mono%2Fmini%2Fabcremoval.c;h=8a9349d293d1467718f93e1796c44f2b8c005307;hb=7f23a0c1f3b357cea793f429b52a918f45157855;hp=0e84305fa7b2a973dacef3119d3676ebb18456e4;hpb=9e1f34dd2d7be45b2a3a6b1c133a4a1de8c3d864;p=mono.git

diff --git a/mono/mini/abcremoval.c b/mono/mini/abcremoval.c
index 0e84305fa7b..8a9349d293d 100644
--- a/mono/mini/abcremoval.c
+++ b/mono/mini/abcremoval.c
@@ -14,6 +14,8 @@
 #include <mono/metadata/opcodes.h>
 #include <mono/metadata/mempool-internals.h>
 
+#include <config.h>
+
 #ifndef DISABLE_JIT
 
 #include "abcremoval.h"
@@ -314,6 +316,13 @@ get_relation_from_ins (MonoVariableRelationsEvaluationArea *area, MonoInst *ins,
 		value->type = MONO_VARIABLE_SUMMARIZED_VALUE;
 		value->value.variable.variable = ins->sreg1;
 		value->value.variable.delta = 0;
+		area->defs [ins->dreg] = ins;
+		break;
+	case OP_LDADDR:
+		/* The result is non-null */
+		result->relation = MONO_GT_RELATION;
+		value->type = MONO_CONSTANT_SUMMARIZED_VALUE;
+		value->value.constant.value = 0;
 		break;
 
 		/* FIXME: Add more opcodes */
@@ -997,6 +1006,34 @@ remove_abc_from_inst (MonoInst *ins, MonoVariableRelationsEvaluationArea *area)
 	}
 }
 
+static gboolean
+eval_non_null (MonoVariableRelationsEvaluationArea *area, int reg)
+{
+	MonoRelationsEvaluationContext *context = &(area->contexts [reg]);
+
+	clean_contexts (area->contexts, area->cfg->next_vreg);
+	evaluate_relation_with_target_variable (area, reg, reg, NULL);
+				
+	return context->ranges.zero.lower > 0;
+}
+
+static void
+add_non_null (MonoVariableRelationsEvaluationArea *area, MonoCompile *cfg, int reg,
+			  GSList **check_relations)
+{
+	MonoAdditionalVariableRelation *rel;
+
+	rel = mono_mempool_alloc0 (cfg->mempool, sizeof (MonoAdditionalVariableRelation));
+	rel->variable = reg;
+	rel->relation.relation = MONO_GT_RELATION;
+	rel->relation.related_value.type = MONO_CONSTANT_SUMMARIZED_VALUE;
+	rel->relation.related_value.value.constant.value = 0;
+
+	apply_change_to_evaluation_area (area, rel);
+
+	*check_relations = g_slist_append_mempool (cfg->mempool, *check_relations, rel);
+}
+
 /*
  * Process a BB removing bounds checks from array accesses.
  * It does the following (in sequence):
@@ -1087,28 +1124,57 @@ process_block (MonoCompile *cfg, MonoBasicBlock *bb, MonoVariableRelationsEvalua
 		}
 
 		if (ins->opcode == OP_CHECK_THIS) {
-			MonoRelationsEvaluationContext *context = &(area->contexts [ins->sreg1]);
-
-			clean_contexts (area->contexts, area->cfg->next_vreg);
-			evaluate_relation_with_target_variable (area, ins->sreg1, ins->sreg1, NULL);
-				
-			if (context->ranges.zero.lower > 0) {
+			if (eval_non_null (area, ins->sreg1)) {
 				if (REPORT_ABC_REMOVAL)
 					printf ("ARRAY-ACCESS: removed check_this instruction.\n");
 				NULLIFY_INS (ins);
 			}
 		}
 
-		if (ins->opcode == OP_NOT_NULL) {
-			rel = mono_mempool_alloc0 (cfg->mempool, sizeof (MonoAdditionalVariableRelation));
-			rel->variable = ins->sreg1;
-			rel->relation.relation = MONO_GT_RELATION;
-			rel->relation.related_value.type = MONO_CONSTANT_SUMMARIZED_VALUE;
-			rel->relation.related_value.value.constant.value = 0;
+		if (ins->opcode == OP_NOT_NULL)
+			add_non_null (area, cfg, ins->sreg1, &check_relations);
 
-			apply_change_to_evaluation_area (area, rel);
-
-			check_relations = g_slist_append_mempool (cfg->mempool, check_relations, rel);
+		/* 
+		 * FIXME: abcrem equates an array with its length,
+		 * so a = new int [100] implies a != null, but a = new int [0] doesn't.
+		 */
+		/*
+		 * Eliminate MONO_INST_FAULT flags if possible.
+		 */
+		if (COMPILE_LLVM (cfg) && (ins->opcode == OP_LDLEN ||
+								   ins->opcode == OP_BOUNDS_CHECK ||
+								   ins->opcode == OP_STRLEN ||
+								   (MONO_IS_LOAD_MEMBASE (ins) && (ins->flags & MONO_INST_FAULT)) ||
+								   (MONO_IS_STORE_MEMBASE (ins) && (ins->flags & MONO_INST_FAULT)))) {
+			int reg;
+
+			if (MONO_IS_STORE_MEMBASE (ins))
+				reg = ins->inst_destbasereg;
+			else if (MONO_IS_LOAD_MEMBASE (ins))
+				reg = ins->inst_basereg;
+			else
+				reg = ins->sreg1;
+
+			/*
+			 * This doesn't work because LLVM can move the non-faulting loads before the faulting
+			 * ones (test_0_llvm_moving_faulting_loads ()).
+			 * So only do it if we know the load cannot be moved before the instruction which ensures it is not
+			 * null (i.e. the def of its sreg).
+			 */
+			if (area->defs [reg] && area->defs [reg]->opcode == OP_NEWARR) {
+				if (REPORT_ABC_REMOVAL)
+					printf ("ARRAY-ACCESS: removed MONO_INST_FAULT flag.\n");
+				ins->flags &= ~MONO_INST_FAULT;
+			}
+			/*
+			if (eval_non_null (area, reg)) {
+				if (REPORT_ABC_REMOVAL)
+					printf ("ARRAY-ACCESS: removed MONO_INST_FAULT flag.\n");
+				ins->flags &= ~MONO_INST_FAULT;
+			} else {
+				add_non_null (area, cfg, reg, &check_relations);
+			}
+			*/
 		}
 	}	
 	
@@ -1203,12 +1269,14 @@ mono_perform_abc_removal (MonoCompile *cfg)
 		mono_mempool_alloc (cfg->mempool, sizeof (MonoRelationsEvaluationContext) * (cfg->next_vreg));
 	area.variable_value_kind = (MonoIntegerValueKind *)
 		mono_mempool_alloc (cfg->mempool, sizeof (MonoIntegerValueKind) * (cfg->next_vreg));
+	area.defs = mono_mempool_alloc (cfg->mempool, sizeof (MonoInst*) * cfg->next_vreg);
 	for (i = 0; i < cfg->next_vreg; i++) {
 		area.variable_value_kind [i] = MONO_UNKNOWN_INTEGER_VALUE;
 		area.relations [i].relation = MONO_EQ_RELATION;
 		area.relations [i].relation_is_static_definition = TRUE;
 		MAKE_VALUE_ANY (area.relations [i].related_value);
 		area.relations [i].next = NULL;
+		area.defs [i] = NULL;
 	}
 
 	for (bb = cfg->bb_entry; bb; bb = bb->next_bb) {