X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fopt%2Fcfopt.c;h=6fa73c7bfa20c2ae983c0e85166d16ab5796ba13;hb=fe4dd08ecc09bf5c9e63cc2d2cb756295af7b423;hp=6485694091b52e11e5e211d32b5a532361106993;hpb=73c710d43962a445f4ecd84818b85d7403f9919d;p=libfirm

diff --git a/ir/opt/cfopt.c b/ir/opt/cfopt.c
index 648569409..6fa73c7bf 100644
--- a/ir/opt/cfopt.c
+++ b/ir/opt/cfopt.c
@@ -27,6 +27,8 @@
 # include "config.h"
 #endif
 
+#include "iroptimize.h"
+
 #include <assert.h>
 
 #include "plist.h"
@@ -51,7 +53,6 @@
 #include "irflag_t.h"
 #include "firmstat.h"
 
-#include "cfopt.h"
 #include "iropt_dbg.h"
 
 /*------------------------------------------------------------------*/
@@ -114,8 +115,9 @@ static void remove_senseless_conds(ir_node *bl, void *env) {
 
 /** An environment for merge_blocks and collect nodes. */
 typedef struct _merge_env {
-	int changed;
-	plist_t *list;
+	int changed;    /**< Set if the graph was changed. */
+	int phis_moved; /**< Set if Phi nodes were moved. */
+	plist_t *list;  /**< Helper list for all found Switch Conds. */
 } merge_env;
 
 /**
@@ -391,11 +393,11 @@ non_dispensable:
  * @@@ It is negotiable whether we should do this ... there might end up a copy
  * from the Phi in the loop when removing the Phis.
  */
-static void optimize_blocks(ir_node *b, void *env) {
+static void optimize_blocks(ir_node *b, void *ctx) {
 	int i, j, k, n, max_preds, n_preds, p_preds = -1;
 	ir_node *pred, *phi;
 	ir_node **in;
-	int *changed = env;
+	merge_env *env = ctx;
 
 	/* Count the number of predecessor if this block is merged with pred blocks
 	   that are empty. */
@@ -450,36 +452,37 @@ static void optimize_blocks(ir_node *b, void *env) {
 			exchange(phi, in[0]);
 		else
 			set_irn_in(phi, p_preds, in);
-		*changed = 1;
+		env->changed = 1;
 
 		phi = get_irn_link(phi);
 	}
 
 	/*- This happens only if merge between loop backedge and single loop entry.
-	    Moreover, it is only needed if pred is the direct dominator of b, else there can be no uses
-	    of the Phi's in pred ... -*/
+	    Moreover, it is only needed if predb is the direct dominator of b, else there can be no uses
+	    of the Phi's in predb ... -*/
 	for (k = 0, n = get_Block_n_cfgpreds(b); k < n; ++k) {
-		pred = get_nodes_block(get_Block_cfgpred(b, k));
+		ir_node *predb = get_nodes_block(get_Block_cfgpred(b, k));
 
-		if (get_Block_block_visited(pred) + 1 < get_irg_block_visited(current_ir_graph)) {
+		if (get_Block_block_visited(predb) + 1 < get_irg_block_visited(current_ir_graph)) {
 			ir_node *next_phi;
 
 			/* we found a predecessor block at position k that will be removed */
-			for (phi = get_irn_link(pred); phi; phi = next_phi) {
+			for (phi = get_irn_link(predb); phi; phi = next_phi) {
 				int q_preds = 0;
 				next_phi = get_irn_link(phi);
 
 				assert(is_Phi(phi));
 
-				if (get_Block_idom(b) != pred) {
-					/* pred is not the dominator. There can't be uses of pred's Phi nodes, kill them .*/
+				if (get_Block_idom(b) != predb) {
+					/* predb is not the dominator. There can't be uses of pred's Phi nodes, kill them .*/
 					exchange(phi, new_Bad());
 				} else {
-					/* pred is the direct dominator of b. There might be uses of the Phi nodes from
-					   pred in further block, so move this phi from the predecessor into the block b */
+					/* predb is the direct dominator of b. There might be uses of the Phi nodes from
+					   predb in further block, so move this phi from the predecessor into the block b */
 					set_nodes_block(phi, b);
 					set_irn_link(phi, get_irn_link(b));
 					set_irn_link(b, phi);
+					env->phis_moved = 1;
 
 					/* first, copy all 0..k-1 predecessors */
 					for (i = 0; i < k; i++) {
@@ -529,7 +532,7 @@ static void optimize_blocks(ir_node *b, void *env) {
 						exchange(phi, in[0]);
 					else
 						set_irn_in(phi, q_preds, in);
-					*changed = 1;
+					env->changed = 1;
 
 					assert(q_preds <= max_preds);
 					// assert(p_preds == q_preds && "Wrong Phi Fix");
@@ -568,7 +571,7 @@ static void optimize_blocks(ir_node *b, void *env) {
 	assert(n_preds <= max_preds);
 
 	set_irn_in(b, n_preds, in);
-	*changed = 1;
+	env->changed = 1;
 
 	assert(get_irn_link(b) == NULL || p_preds == -1 || (n_preds == p_preds && "Wrong Phi Fix"));
 	xfree(in);
@@ -578,13 +581,13 @@ static void optimize_blocks(ir_node *b, void *env) {
  * Block walker: optimize all blocks using the default optimizations.
  * This removes Blocks that with only a Jmp predecessor.
  */
-static void remove_simple_blocks(ir_node *block, void *env) {
+static void remove_simple_blocks(ir_node *block, void *ctx) {
 	ir_node *new_blk = equivalent_node(block);
-	int *changed = env;
+	merge_env *env = ctx;
 
 	if (new_blk != block) {
 		exchange(block, new_blk);
-		*changed = 1;
+		env->changed = 1;
 	}
 }
 
@@ -699,7 +702,9 @@ void optimize_cf(ir_graph *irg) {
 	/* FIXME: is this still needed? */
 	edges_deactivate(irg);
 
-	env.changed = 0;
+	env.changed    = 0;
+	env.phis_moved = 0;
+
 	if (get_opt_optimize() && get_opt_unreachable_code()) {
 		ir_node *end;
 
@@ -757,7 +762,7 @@ void optimize_cf(ir_graph *irg) {
 	/* Optimize the standard code. */
 	env.changed = 0;
 	assure_doms(irg);
-	irg_block_walk(get_irg_end_block(irg), optimize_blocks, remove_simple_blocks, &env.changed);
+	irg_block_walk(get_irg_end_block(irg), optimize_blocks, remove_simple_blocks, &env);
 
 	/* Walk all keep alives, optimize them if block, add to new in-array
 	   for end if useful. */
@@ -802,6 +807,45 @@ void optimize_cf(ir_graph *irg) {
 
 	clear_using_visited(irg);
 
+	if (env.phis_moved) {
+		/* Bad: when we moved Phi's, we might produce dead Phi nodes
+		   that are kept-alive.
+		   Some other phases cannot copy with this, so will them.
+		 */
+		n = get_End_n_keepalives(end);
+		if (n > 0) {
+			if (env.changed) {
+				/* Handle graph state if was changed. */
+				set_irg_outs_inconsistent(irg);
+			}
+			assure_irg_outs(irg);
+
+			for (i = j = 0; i < n; ++i) {
+				ir_node *ka = get_End_keepalive(end, i);
+
+				if (is_Phi(ka)) {
+					int k;
+
+					for (k = get_irn_n_outs(ka) - 1; k >= 0; --k) {
+						ir_node *user = get_irn_out(ka, k);
+
+						if (user != ka && user != end) {
+							/* Is it a real user or just a self loop ? */
+							break;
+						}
+					}
+					if (k >= 0)
+						in[j++] = ka;
+				} else
+					in[j++] = ka;
+			}
+			if (j != n) {
+				set_End_keepalives(end, j, in);
+				env.changed = 1;
+			}
+		}
+	}
+
 	if (env.changed) {
 		/* Handle graph state if was changed. */
 		set_irg_outs_inconsistent(irg);
@@ -810,6 +854,7 @@ void optimize_cf(ir_graph *irg) {
 		set_irg_loopinfo_inconsistent(irg);
 	}
 
+
 	/* the verifier doesn't work yet with floating nodes */
 	if (get_irg_pinned(irg) == op_pin_state_pinned) {
 		/* after optimize_cf(), only Bad data flow may remain. */