re PR rtl-optimization/16590 (Incorrect execution when compiling with -O2)

	PR rtl-optimization/16590
	* gcse.c (pre_delete): Do not create invalid REG_EQUAL notes.

	PR rtl-optimization/16590
	* g++.dg/opt/loop1.C: New test.

From-SVN: r86732

gcc/ChangeLog

+2004-08-29  Mark Mitchell  <mark@codesourcery.com>
+
+	PR rtl-optimization/16590
+	* gcse.c (pre_delete): Do not create invalid REG_EQUAL notes.
+
 2004-08-29  Diego Novillo  <dnovillo@redhat.com>
 
 	* tree-ssa-ccp.c (ccp_visit_stmt): Remove #if 0 guards.

gcc/gcse.c

@@ -4463,7 +4463,9 @@ pre_delete (void)
 		  expr->reaching_reg
 		    = gen_reg_rtx (GET_MODE (SET_DEST (set)));
 
-		gcse_emit_move_after (expr->reaching_reg, SET_DEST (set), insn);
+		emit_insn_after (gen_move_insn (SET_DEST (set), 
+						expr->reaching_reg), 
+				 insn);
 		delete_insn (insn);
 		occr->deleted_p = 1;
 		SET_BIT (pre_redundant_insns, INSN_CUID (insn));

gcc/testsuite/ChangeLog

+2004-08-29  Mark Mitchell  <mark@codesourcery.com>
+
+	PR rtl-optimization/16590
+	* g++.dg/opt/loop1.C: New test.
+
 2004-08-29  Tobias Schlueter  <tobias.schlueter@physik.uni-muenchen.de>
 
 	PR fortran/13910

gcc/testsuite/g++.dg/opt/loop1.C

+// PR rtl-optimization/16590
+// { dg-do run }
+// { dg-options "-O2" }
+
+extern "C" void abort(); 
+ 
+struct iterator { 
+  char * p; 
+  int *dummy; 
+}; 
+ 
+static iterator pend(char * start) { 
+  iterator p = {start, 0}; 
+  if (p.p == start) p.p = start+5; 
+  --p.p; 
+  return p; 
+} 
+ 
+int main() { 
+  char mem[4+1]; 
+ 
+  if(pend(mem).p != mem+4) 
+    abort (); 
+}