diff mbox series

Another PR90316 improvement

Message ID alpine.LSU.2.20.1905071319420.10704@zhemvz.fhfr.qr
State New
Headers show
Series Another PR90316 improvement | expand

Commit Message

Richard Biener May 7, 2019, 11:20 a.m. UTC 
Well, not actually measurable but we can save get_continuation_for_phi
calls from translate_vuse_through_block if we do not end up using
the result.

Bootstrap / regtest running on x86_64-unknown-linux-gnu.

Richard.

2019-05-07  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/90316
	* tree-ssa-pre.c (translate_vuse_through_block): When
	same_valid is NULL do not bother to search for a virtual
	PHI continuation.
	(phi_translate_1): When operands changed we cannot keep
	the same value-number so do not bother to ask whether
	that's possible from translate_vuse_through_block.
diff mbox series

Patch

Index: gcc/tree-ssa-pre.c
===================================================================
--- gcc/tree-ssa-pre.c	(revision 270940)
+++ gcc/tree-ssa-pre.c	(working copy)
@@ -1146,7 +1146,8 @@  translate_vuse_through_block (vec<vn_ref
   edge e = NULL;
   bool use_oracle;
 
-  *same_valid = true;
+  if (same_valid)
+    *same_valid = true;
 
   if (gimple_bb (phi) != phiblock)
     return vuse;
@@ -1179,7 +1180,7 @@  translate_vuse_through_block (vec<vn_ref
 
   if (e)
     {
-      if (use_oracle)
+      if (use_oracle && same_valid)
 	{
 	  bitmap visited = NULL;
 	  /* Try to find a vuse that dominates this phi node by skipping
@@ -1191,13 +1192,9 @@  translate_vuse_through_block (vec<vn_ref
 	}
       else
 	vuse = NULL_TREE;
-      if (!vuse)
-	{
-	  /* If we didn't find any, the value ID can't stay the same,
-	     but return the translated vuse.  */
-	  *same_valid = false;
-	  vuse = PHI_ARG_DEF (phi, e->dest_idx);
-	}
+      /* If we didn't find any, the value ID can't stay the same.  */
+      if (!vuse && same_valid)
+	*same_valid = false;
       /* ??? We would like to return vuse here as this is the canonical
          upmost vdef that this reference is associated with.  But during
 	 insertion of the references into the hash tables we only ever
@@ -1535,7 +1532,8 @@  phi_translate_1 (bitmap_set_t dest,
 						    ? newoperands : operands,
 						    ref->set, ref->type,
 						    vuse, phiblock, pred,
-						    &same_valid);
+						    changed
+						    ? NULL : &same_valid);
 	    if (newvuse == NULL_TREE)
 	      {
 		newoperands.release ();