From: Richard Biener <rguenther@suse.de>
Date: Thu, 4 May 2023 07:39:12 +0000 (+0200)
Subject: Revert "tree-optimization/106809 - compile time hog in VN"
X-Git-Tag: releases/gcc-10.5.0~101
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4ee3d035a9beddab30515d906dde5186e844d4a2;p=thirdparty%2Fgcc.git

Revert "tree-optimization/106809 - compile time hog in VN"

This reverts commit 051f78a5c1d6994c10ee7c35453ff0ccee94e5c6.
---

diff --git a/gcc/testsuite/gcc.dg/torture/pr106809.c b/gcc/testsuite/gcc.dg/torture/pr106809.c
deleted file mode 100644
index 11e158185cf4..000000000000
--- a/gcc/testsuite/gcc.dg/torture/pr106809.c
+++ /dev/null
@@ -1,28 +0,0 @@
-/* { dg-do compile } */
-/* { dg-additional-options "-Wuninitialized" } */
-
-int foo (int x, int *val)
-{
-  switch (x)
-    {
-#define C(n) \
-    case n + 0: return *val; \
-    case n + 1: return *val; \
-    case n + 2: return *val; \
-    case n + 3: return *val; \
-    case n + 4: return *val; \
-    case n + 5: return *val; \
-    case n + 6: return *val; \
-    case n + 7: return *val; \
-    case n + 8: return *val; \
-    case n + 9: return *val;
-#define C1(n) \
-    C(n+00) C(n+10) C(n+20) C(n+30) C(n+40) \
-    C(n+50) C(n+60) C(n+70) C(n+80) C(n+90)
-#define C10(n) \
-    C1(n+000) C1(n+100) C1(n+200) C1(n+300) C1(n+400) \
-    C1(n+500) C1(n+600) C1(n+700) C1(n+800) C1(n+900)
-    C10(1000)
-    }
-  return 0;
-}
diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c
index 666d7061aa88..2f6f5074b076 100644
--- a/gcc/tree-ssa-sccvn.c
+++ b/gcc/tree-ssa-sccvn.c
@@ -4509,44 +4509,41 @@ dominated_by_p_w_unex (basic_block bb1, basic_block bb2, bool allow_back)
     }
 
   /* Iterate to the single executable bb2 successor.  */
-  if (EDGE_COUNT (bb2->succs) > 1)
-    {
-      edge succe = NULL;
-      FOR_EACH_EDGE (e, ei, bb2->succs)
-	if ((e->flags & EDGE_EXECUTABLE)
-	    || (!allow_back && (e->flags & EDGE_DFS_BACK)))
+  edge succe = NULL;
+  FOR_EACH_EDGE (e, ei, bb2->succs)
+    if ((e->flags & EDGE_EXECUTABLE)
+	|| (!allow_back && (e->flags & EDGE_DFS_BACK)))
+      {
+	if (succe)
 	  {
-	    if (succe)
+	    succe = NULL;
+	    break;
+	  }
+	succe = e;
+      }
+  if (succe)
+    {
+      /* Verify the reached block is only reached through succe.
+	 If there is only one edge we can spare us the dominator
+	 check and iterate directly.  */
+      if (EDGE_COUNT (succe->dest->preds) > 1)
+	{
+	  FOR_EACH_EDGE (e, ei, succe->dest->preds)
+	    if (e != succe
+		&& ((e->flags & EDGE_EXECUTABLE)
+		    || (!allow_back && (e->flags & EDGE_DFS_BACK))))
 	      {
 		succe = NULL;
 		break;
 	      }
-	    succe = e;
-	  }
+	}
       if (succe)
 	{
-	  /* Verify the reached block is only reached through succe.
-	     If there is only one edge we can spare us the dominator
-	     check and iterate directly.  */
-	  if (EDGE_COUNT (succe->dest->preds) > 1)
-	    {
-	      FOR_EACH_EDGE (e, ei, succe->dest->preds)
-		if (e != succe
-		    && ((e->flags & EDGE_EXECUTABLE)
-			|| (!allow_back && (e->flags & EDGE_DFS_BACK))))
-		  {
-		    succe = NULL;
-		    break;
-		  }
-	    }
-	  if (succe)
-	    {
-	      bb2 = succe->dest;
+	  bb2 = succe->dest;
 
-	      /* Re-do the dominance check with changed bb2.  */
-	      if (dominated_by_p (CDI_DOMINATORS, bb1, bb2))
-		return true;
-	    }
+	  /* Re-do the dominance check with changed bb2.  */
+	  if (dominated_by_p (CDI_DOMINATORS, bb1, bb2))
+	    return true;
 	}
     }