X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fopt%2Fjumpthreading.c;h=3f9e42e6d4ed7a6bb0a9ccef42660140ee7f7632;hb=01ddc5c06877693df7d5f286d43e433fedd87103;hp=1412eb8af2bebaa769224c34a86e6d652cc85eea;hpb=7213344d377bb242491dfb0c291b43157c3c81d6;p=libfirm

diff --git a/ir/opt/jumpthreading.c b/ir/opt/jumpthreading.c
index 1412eb8af..3f9e42e6d 100644
--- a/ir/opt/jumpthreading.c
+++ b/ir/opt/jumpthreading.c
@@ -44,6 +44,8 @@
 #include "tv.h"
 #include "opt_confirms.h"
 #include "iropt_dbg.h"
+#include "irpass.h"
+#include "vrp.h"
 
 #undef AVOID_PHIB
 
@@ -115,7 +117,7 @@ static ir_node *search_def_and_create_phis(ir_node *block, ir_mode *mode,
 
 	/* create a new Phi */
 	NEW_ARR_A(ir_node*, in, n_cfgpreds);
-	for(i = 0; i < n_cfgpreds; ++i)
+	for (i = 0; i < n_cfgpreds; ++i)
 		in[i] = new_Unknown(mode);
 
 	phi = new_r_Phi(block, n_cfgpreds, in, mode);
@@ -123,7 +125,7 @@ static ir_node *search_def_and_create_phis(ir_node *block, ir_mode *mode,
 	mark_irn_visited(block);
 
 	/* set Phi predecessors */
-	for(i = 0; i < n_cfgpreds; ++i) {
+	for (i = 0; i < n_cfgpreds; ++i) {
 		ir_node *pred_block = get_Block_cfgpred_block(block, i);
 		ir_node *pred_val   = search_def_and_create_phis(pred_block, mode, 0);
 
@@ -188,7 +190,8 @@ static void construct_ssa(ir_node *orig_block, ir_node *orig_val,
 	}
 }
 
-static void split_critical_edge(ir_node *block, int pos) {
+static void split_critical_edge(ir_node *block, int pos)
+{
 	ir_graph *irg = get_irn_irg(block);
 	ir_node *in[1];
 	ir_node *new_block;
@@ -234,7 +237,7 @@ static ir_node *copy_and_fix_node(const jumpthreading_env_t *env,
 		assert(get_irn_mode(copy) != mode_X);
 
 		arity = get_irn_arity(copy);
-		for(i = 0; i < arity; ++i) {
+		for (i = 0; i < arity; ++i) {
 			ir_node *pred     = get_irn_n(copy, i);
 			ir_node *new_pred;
 
@@ -370,6 +373,30 @@ static int eval_cmp_tv(pn_Cmp pnc, tarval *tv_left, tarval *tv_right)
 	return 1;
 }
 
+/**
+ * returns whether the cmp evaluates to true or false according to vrp
+ * information , or can't be evaluated!
+ * 1: true, 0: false, -1: can't evaluate
+ *
+ * @param pnc       the compare mode of the Compare
+ * @param left   the left node
+ * @param right  the right node
+ */
+static int eval_cmp_vrp(pn_Cmp pnc, ir_node *left, ir_node *right)
+{
+	pn_Cmp cmp_result = vrp_cmp(left, right);
+	/* does the compare evaluate to true? */
+	if (cmp_result == pn_Cmp_False) {
+		return -1;
+	}
+	if ((cmp_result & pnc) != cmp_result) {
+		if ((cmp_result & pnc) != 0) {
+			return -1;
+		}
+		return 0;
+	}
+	return 1;
+}
 /**
  * returns whether the cmp evaluates to true or false, or can't be evaluated!
  * 1: true, 0: false, -1: can't evaluate
@@ -454,7 +481,7 @@ static ir_node *find_const_or_confirm(jumpthreading_env_t *env, ir_node *jump,
 		}
 
 		arity = get_irn_arity(value);
-		for(i = 0; i < arity; ++i) {
+		for (i = 0; i < arity; ++i) {
 			ir_node *copy_block;
 			ir_node *phi_pred = get_Phi_pred(value, i);
 			ir_node *cfgpred  = get_Block_cfgpred(block, i);
@@ -518,7 +545,7 @@ static ir_node *find_candidate(jumpthreading_env_t *env, ir_node *jump,
 			return NULL;
 
 		arity = get_irn_arity(value);
-		for(i = 0; i < arity; ++i) {
+		for (i = 0; i < arity; ++i) {
 			ir_node *copy_block;
 			ir_node *phi_pred = get_Phi_pred(value, i);
 			ir_node *cfgpred  = get_Block_cfgpred(block, i);
@@ -640,8 +667,15 @@ static void thread_jumps(ir_node* block, void* data)
 				tarval *tv_right = get_Const_tarval(right);
 
 				selector_evaluated = eval_cmp_tv(pnc, tv_left, tv_right);
-				if (selector_evaluated < 0)
-					return;
+			}
+			if (selector_evaluated < 0) {
+				/* This is only the case if the predecessor nodes are not
+				 * constant or the comparison could not be evaluated.
+				 * Try with VRP information now.
+				 */
+				int pnc = get_Proj_proj(selector);
+
+				selector_evaluated = eval_cmp_vrp(pnc, left, right);
 			}
 		}
 	} else if (is_Const_or_Confirm(selector)) {
@@ -741,3 +775,9 @@ void opt_jumpthreading(ir_graph* irg)
 		optimize_cf(irg);
 	}
 }
+
+/* Creates an ir_graph pass for opt_jumpthreading. */
+ir_graph_pass_t *opt_jumpthreading_pass(const char *name)
+{
+	return def_graph_pass(name ? name : "jumpthreading", opt_jumpthreading);
+}  /* opt_jumpthreading_pass */