From: Michael Hayes <mhayes@cygnus.com>
Date: Tue, 26 Sep 2000 10:03:47 +0000 (+0000)
Subject: flow.c (flow_loop_pre_header_scan): Punt if loop enters from entry block.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=ef120fc0497b70180caf53e40eb1ea3eb00e0507;p=gcc.git

flow.c (flow_loop_pre_header_scan): Punt if loop enters from entry block.

	* flow.c (flow_loop_pre_header_scan): Punt if loop enters
	from entry block.

From-SVN: r36644
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index aeba67f9301..8c8b234a145 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2000-09-26  Michael Hayes  <mhayes@cygnus.com>
+
+	* flow.c (flow_loop_pre_header_scan): Punt if loop enters
+	from entry block.
+
 2000-09-25  Jim Wilson  <wilson@cygnus.com>
 
 	* config/ia64/ia64.h (INDEX_REG_CLASS): Define to GENERAL_REGS.
diff --git a/gcc/flow.c b/gcc/flow.c
index 9eef2442d80..b913c6ea8c7 100644
--- a/gcc/flow.c
+++ b/gcc/flow.c
@@ -7869,12 +7869,16 @@ flow_loop_pre_header_scan (loop)
   sbitmap_zero (loop->pre_header_trace);
   
   ebb = loop->entry_edges[0]->src;
-  SET_BIT (loop->pre_header_trace, ebb->index);
-  while (ebb->pred->src != ENTRY_BLOCK_PTR
-	 && ! ebb->pred->pred_next)
+
+  if (ebb != ENTRY_BLOCK_PTR)
     {
-      ebb = ebb->pred->src;
       SET_BIT (loop->pre_header_trace, ebb->index);
+      while (ebb->pred->src != ENTRY_BLOCK_PTR
+	     && ! ebb->pred->pred_next)
+	{
+	  ebb = ebb->pred->src;
+	  SET_BIT (loop->pre_header_trace, ebb->index);
+	}
     }
   
   loop->pre_header_root = ebb;