X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fbe%2Fbelower.c;h=ab2559f5fddee99422dcdd02101284aa67125fb2;hb=04906225f6fe1bc22f73b5d6a98eb9c0992a9b54;hp=2c18953bff3e5f341df24bc72c9ee304f4bafa4b;hpb=cc8920adef35bcde828590f537e0147f784555b7;p=libfirm

diff --git a/ir/be/belower.c b/ir/be/belower.c
index 2c18953bf..ab2559f5f 100644
--- a/ir/be/belower.c
+++ b/ir/be/belower.c
@@ -30,7 +30,6 @@
 
 #include "ircons.h"
 #include "debug.h"
-#include "irhooks.h"
 #include "xmalloc.h"
 #include "irnodeset.h"
 #include "irnodemap.h"
@@ -98,15 +97,17 @@ typedef struct _perm_cycle_t {
 } perm_cycle_t;
 
 /** returns the number register pairs marked as checked. */
-static int get_n_checked_pairs(reg_pair_t *pairs, int n) {
-	int i, n_checked = 0;
+static int get_n_unchecked_pairs(reg_pair_t const *const pairs, int const n)
+{
+	int n_unchecked = 0;
+	int i;
 
 	for (i = 0; i < n; i++) {
-		if (pairs[i].checked)
-			n_checked++;
+		if (!pairs[i].checked)
+			n_unchecked++;
 	}
 
-	return n_checked;
+	return n_unchecked;
 }
 
 /**
@@ -213,7 +214,7 @@ static void get_perm_cycle(perm_cycle_t *const cycle,
 {
 	int         head         = pairs[start].in_reg->index;
 	int         cur_idx      = pairs[start].out_reg->index;
-	int   const n_pairs_done = get_n_checked_pairs(pairs, n);
+	int   const n_pairs_todo = get_n_unchecked_pairs(pairs, n);
 	perm_type_t cycle_tp     = PERM_CYCLE;
 	int         idx;
 
@@ -232,7 +233,7 @@ static void get_perm_cycle(perm_cycle_t *const cycle,
 	}
 
 	/* assume worst case: all remaining pairs build a cycle or chain */
-	cycle->elems    = XMALLOCNZ(const arch_register_t*, (n - n_pairs_done) * 2);
+	cycle->elems    = XMALLOCNZ(const arch_register_t*, n_pairs_todo * 2);
 	cycle->n_elems  = 2;  /* initial number of elements is 2 */
 	cycle->elems[0] = pairs[start].in_reg;
 	cycle->elems[1] = pairs[start].out_reg;
@@ -289,8 +290,8 @@ static void lower_perm_node(ir_node *irn, lower_env_t *env)
 	const arch_register_class_t *const reg_class   = arch_get_irn_register(get_irn_n(irn, 0))->reg_class;
 	ir_graph                    *const irg         = get_irn_irg(irn);
 	ir_node                     *const block       = get_nodes_block(irn);
-	int                          const n           = get_irn_arity(irn);
-	reg_pair_t                  *const pairs       = alloca(n * sizeof(pairs[0]));
+	int                          const arity       = get_irn_arity(irn);
+	reg_pair_t                  *const pairs       = alloca(arity * sizeof(pairs[0]));
 	int                                keep_perm   = 0;
 	int                                do_copy     = env->do_copy;
 	/* Get the schedule predecessor node to the perm.
@@ -298,21 +299,33 @@ static void lower_perm_node(ir_node *irn, lower_env_t *env)
 	 * nodes after this node, everything should be ok. */
 	ir_node                     *      sched_point = sched_prev(irn);
 	const ir_edge_t             *      edge;
+	const ir_edge_t             *      next;
+	int                                n;
 	int                                i;
 
 	DBG((dbg, LEVEL_1, "perm: %+F, sched point is %+F\n", irn, sched_point));
 	assert(sched_point && "Perm is not scheduled or has no predecessor");
 
-	assert(n == get_irn_n_edges(irn) && "perm's in and out numbers different");
+	assert(arity == get_irn_n_edges(irn) && "perm's in and out numbers different");
 
 	/* build the list of register pairs (in, out) */
-	i = 0;
-	foreach_out_edge(irn, edge) {
-		reg_pair_t *const pair = &pairs[i++];
-		ir_node    *const out  = get_edge_src_irn(edge);
-		long        const pn   = get_Proj_proj(out);
-		ir_node    *const in   = get_irn_n(irn, pn);
+	n = 0;
+	foreach_out_edge_safe(irn, edge, next) {
+		ir_node               *const out     = get_edge_src_irn(edge);
+		long                   const pn      = get_Proj_proj(out);
+		ir_node               *const in      = get_irn_n(irn, pn);
+		arch_register_t const *const in_reg  = arch_get_irn_register(in);
+		arch_register_t const *const out_reg = arch_get_irn_register(out);
+		reg_pair_t            *      pair;
+
+		if (in_reg == out_reg) {
+			DBG((dbg, LEVEL_1, "%+F removing equal perm register pair (%+F, %+F, %s)\n",
+						irn, in, out, out_reg->name));
+			exchange(out, in);
+			continue;
+		}
 
+		pair           = &pairs[n++];
 		pair->in_node  = in;
 		pair->in_reg   = arch_get_irn_register(in);
 		pair->out_node = out;
@@ -320,22 +333,7 @@ static void lower_perm_node(ir_node *irn, lower_env_t *env)
 		pair->checked  = 0;
 	}
 
-	/* Mark all equal pairs as checked, and exchange the OUT proj with the IN
-	 * node. */
-	for (i = 0; i < n; i++) {
-		reg_pair_t *const pair = &pairs[i];
-
-		if (pair->in_reg->index != pair->out_reg->index)
-			continue;
-
-		DBG((dbg, LEVEL_1, "%+F removing equal perm register pair (%+F, %+F, %s)\n",
-					irn, pair->in_node, pair->out_node, pair->out_reg->name));
-
-		/* reroute the edges from the proj to the argument */
-		exchange(pair->out_node, pair->in_node);
-
-		pair->checked = 1;
-	}
+	DBG((dbg, LEVEL_1, "%+F has %d unresolved constraints\n", irn, n));
 
 	/* Set do_copy to 0 if it's on but we have no free register */
 	/* TODO check for free register */
@@ -344,7 +342,7 @@ static void lower_perm_node(ir_node *irn, lower_env_t *env)
 	}
 
 	/* check for cycles and chains */
-	while (get_n_checked_pairs(pairs, n) < n) {
+	while (get_n_unchecked_pairs(pairs, n) > 0) {
 		perm_cycle_t cycle;
 		int          j;
 
@@ -358,7 +356,7 @@ static void lower_perm_node(ir_node *irn, lower_env_t *env)
 		}
 		DB((dbg, LEVEL_1, "\n"));
 
-		if (n == 2 && cycle.type == PERM_CYCLE) {
+		if (cycle.type == PERM_CYCLE && arity == 2) {
 			/* We don't need to do anything if we have a Perm with two elements
 			 * which represents a cycle, because those nodes already represent
 			 * exchange nodes */