re PR rtl-optimization/46649 (ICE: in move_bb_info, at sel-sched-ir.c:5080 with…

re PR rtl-optimization/46649 (ICE: in move_bb_info, at sel-sched-ir.c:5080 with -fschedule-insns -fselective-scheduling)

	PR rtl-optimization/46649
	* sel-sched-ir.c (purge_empty_blocks): Unconditionally skip the first
	basic block in the region.

testsuite:
	* g++.dg/opt/pr46649.C: New.

From-SVN: r167854

gcc/ChangeLog

+2010-12-15  Alexander Monakov  <amonakov@ispras.ru>
+
+	PR rtl-optimization/46649
+	* sel-sched-ir.c (purge_empty_blocks): Unconditionally skip the first
+	basic block in the region.
+
 2010-12-15  Joseph Myers  <joseph@codesourcery.com>
 
 	* config/stormy16/stormy16.h (LINK_SPEC, WCHAR_TYPE): Define.

gcc/sel-sched-ir.c

@@ -3766,10 +3766,10 @@ tidy_control_flow (basic_block xbb, bool full_tidying)
 void
 purge_empty_blocks (void)
 {
-  /* Do not attempt to delete preheader.  */
-  int i = sel_is_loop_preheader_p (BASIC_BLOCK (BB_TO_BLOCK (0))) ? 1 : 0;
+  int i;
 
-  while (i < current_nr_blocks)
+  /* Do not attempt to delete the first basic block in the region.  */
+  for (i = 1; i < current_nr_blocks; )
     {
       basic_block b = BASIC_BLOCK (BB_TO_BLOCK (i));
 

gcc/testsuite/ChangeLog

+2010-12-15  Alexander Monakov  <amonakov@ispras.ru>
+
+	PR rtl-optimization/46649
+	* g++.dg/opt/pr46649.C: New.
+
 2010-12-15  Dave Korn  <dave.korn.cygwin@gmail.com>
 
 	PR testsuite/46938

gcc/testsuite/g++.dg/opt/pr46649.C

+// { dg-do compile { target powerpc*-*-* ia64-*-* x86_64-*-* } }
+// { dg-options "-fschedule-insns -fselective-scheduling" }
+
+void foo ()
+{
+  for (;;)
+    for (;;({break;}))
+    ;
+}