From: Christoph Mallon <christoph.mallon@gmx.de>
Date: Wed, 4 Jul 2007 21:43:20 +0000 (+0000)
Subject: Split looking for Cmp-Phi-Constant into a separate function.
X-Git-Url: http://nsz.repo.hu/git/?a=commitdiff_plain;h=538c4575073ccf7f933f545301b706f610ff7fa0;p=libfirm

Split looking for Cmp-Phi-Constant into a separate function.

[r14944]
---

diff --git a/ir/opt/condeval.c b/ir/opt/condeval.c
index c7c66833b..65c4d80f0 100644
--- a/ir/opt/condeval.c
+++ b/ir/opt/condeval.c
@@ -362,61 +362,23 @@ static ir_node *find_phi_with_const(ir_node *jump, ir_node *value, condeval_env_
 }
 
 
-/**
- * Block-walker: searches for the following construct
- *
- *  Const or Phi with constants
- *           |
- *          Cmp
- *           |
- *         Cond
- *          /
- *       ProjX
- *        /
- *     Block
- */
-static void cond_eval(ir_node* block, void* data)
+static int cond_eval_cmp(ir_node* proj_b, ir_node* block, ir_node* projx, ir_node* cond)
 {
-	condeval_env_t env;
-	int *changed = data;
 	ir_graph *irg = current_ir_graph;
-	ir_node *copy_block;
-	ir_node *pred;
-	ir_node *projx;
-	ir_node *cond;
-	ir_node *cmp;
-	ir_node *left;
-	ir_node *right;
-	ir_node *cond_block;
-	pn_Cmp pnc;
-
-	if(get_Block_n_cfgpreds(block) != 1)
-		return;
+	ir_node  *cmp = get_Proj_pred(proj_b);
+	ir_node  *left;
+	ir_node  *right;
+	ir_node  *cond_block;
+	ir_node  *copy_block;
+	pn_Cmp    pnc;
 
-	projx = get_Block_cfgpred(block, 0);
-	if (!is_Proj(projx))
-		return;
-	assert(get_irn_mode(projx) == mode_X);
-
-	cond = get_Proj_pred(projx);
-	if (!is_Cond(cond))
-		return;
-
-	pred = get_Cond_selector(cond);
-	// TODO handle switches
-	if (get_irn_mode(pred) != mode_b)
-		return;
-	if (!is_Proj(pred))
-		return;
-	pnc = get_Proj_proj(pred);
-
-	cmp = get_Proj_pred(pred);
 	assert(is_Cmp(cmp));
 
 	left  = get_Cmp_left(cmp);
 	right = get_Cmp_right(cmp);
 	assert(get_irn_mode(left) == get_irn_mode(right));
 
+	pnc = get_Proj_proj(proj_b);
 	/* we assume that the cond_block is the true case */
 	if (get_Proj_proj(projx) == pn_Cond_false) {
 		pnc = get_negated_pnc(pnc, get_irn_mode(left));
@@ -433,7 +395,7 @@ static void cond_eval(ir_node* block, void* data)
 	}
 
 	if(!is_Const(right))
-		return;
+		return 0;
 
 	cond_block = get_nodes_block(cond);
 
@@ -448,13 +410,11 @@ static void cond_eval(ir_node* block, void* data)
 			pred = new_Bad();
 		}
 		set_Block_cfgpred(block, 0, pred);
-		*changed = 1;
-		set_irg_doms_inconsistent(irg);
-		set_irg_extblk_inconsistent(irg);
-		set_irg_loopinfo_inconsistent(irg);
 	} else {
+		condeval_env_t env;
+
 		if(get_nodes_block(left) != cond_block)
-			return;
+			return 0;
 
 		// (recursively) look if a pred of a phi is a constant
 		env.true_block = block;
@@ -465,28 +425,72 @@ static void cond_eval(ir_node* block, void* data)
 
 		copy_block = find_phi_with_const(projx, left, &env);
 
-		if(copy_block != NULL) {
-			/* we have to remove the edge towards the pred as the pred now
-			 * jumps into the true_block. We also have to shorten phis
-			 * in our block because of this */
-			const ir_edge_t *edge, *next;
-			ir_node* bad = new_Bad();
-			size_t cnst_pos = env.cnst_pos;
+		if (copy_block == NULL)
+			return 0;
 
-			/* shorten phis */
-			foreach_out_edge_safe(env.cnst_pred, edge, next) {
-				ir_node *node = get_edge_src_irn(edge);
+		/* we have to remove the edge towards the pred as the pred now
+		 * jumps into the true_block. We also have to shorten phis
+		 * in our block because of this */
+		const ir_edge_t *edge, *next;
+		ir_node* bad = new_Bad();
+		size_t cnst_pos = env.cnst_pos;
 
-				if(is_Phi(node))
-					set_Phi_pred(node, cnst_pos, bad);
-			}
+		/* shorten phis */
+		foreach_out_edge_safe(env.cnst_pred, edge, next) {
+			ir_node *node = get_edge_src_irn(edge);
 
-			set_Block_cfgpred(env.cnst_pred, cnst_pos, bad);
-
-			/* the graph is changed now */
-			*changed = 1;
+			if(is_Phi(node))
+				set_Phi_pred(node, cnst_pos, bad);
 		}
+
+		set_Block_cfgpred(env.cnst_pred, cnst_pos, bad);
 	}
+	/* the graph is changed now */
+	return 1;
+}
+
+
+/**
+ * Block-walker: searches for the following construct
+ *
+ *  Const or Phi with constants
+ *           |
+ *          Cmp
+ *           |
+ *         Cond
+ *          /
+ *       ProjX
+ *        /
+ *     Block
+ */
+static void cond_eval(ir_node* block, void* data)
+{
+	int *changed = data;
+	ir_node *pred;
+	ir_node *projx;
+	ir_node *cond;
+
+	if(get_Block_n_cfgpreds(block) != 1)
+		return;
+
+	projx = get_Block_cfgpred(block, 0);
+	if (!is_Proj(projx))
+		return;
+	assert(get_irn_mode(projx) == mode_X);
+
+	cond = get_Proj_pred(projx);
+	if (!is_Cond(cond))
+		return;
+
+	pred = get_Cond_selector(cond);
+	// TODO handle switches
+	if (get_irn_mode(pred) != mode_b)
+		return;
+	if (!is_Proj(pred))
+		return;
+
+	if (cond_eval_cmp(pred, block, projx, cond))
+		*changed = 1;
 }
 
 void opt_cond_eval(ir_graph* irg)