re PR rtl-optimization/69891 (wrong code with -mstringop-strategy=libcall @ i686)

	PR rtl-optimization/69891
	* dse.c (scan_insn): If we can't figure out memset arguments
	or they are non-constant, call clear_rhs_from_active_local_stores.

	* gcc.target/i386/pr69891.c: New test.

Co-Authored-By: Eric Botcazou <ebotcazou@adacore.com>

From-SVN: r233743

gcc/ChangeLog

+2016-02-26  Jakub Jelinek  <jakub@redhat.com>
+	    Eric Botcazou  <ebotcazou@adacore.com>
+
+	PR rtl-optimization/69891
+	* dse.c (scan_insn): If we can't figure out memset arguments
+	or they are non-constant, call clear_rhs_from_active_local_stores.
+
 2016-02-26  Martin Liska  <mliska@suse.cz>
 
 	* doc/extend.texi: Mention clog10, clog10f an clog10l

gcc/dse.c

@@ -2556,6 +2556,8 @@ scan_insn (bb_info_t bb_info, rtx_insn *insn)
 		      active_local_stores = insn_info;
 		    }
 		}
+	      else
+		clear_rhs_from_active_local_stores ();
 	    }
 	}
       else if (SIBLING_CALL_P (insn) && reload_completed)

gcc/testsuite/ChangeLog

+2016-02-26  Jakub Jelinek  <jakub@redhat.com>
+
+	PR rtl-optimization/69891
+	* gcc.target/i386/pr69891.c: New test.
+
 2016-02-26  Michael Meissner  <meissner@linux.vnet.ibm.com>
 	    Bill Schmidt  <wschmidt@linux.vnet.ibm.com>
 

gcc/testsuite/gcc.target/i386/pr69891.c

+/* PR rtl-optimization/69891 */
+/* { dg-do run } */
+/* { dg-options "-O -fno-tree-fre -mstringop-strategy=libcall -Wno-psabi" } */
+/* { dg-additional-options "-mno-sse" { target ia32 } } */
+
+typedef unsigned short A;
+typedef unsigned short B __attribute__ ((vector_size (32)));
+typedef unsigned int C;
+typedef unsigned int D __attribute__ ((vector_size (32)));
+typedef unsigned long long E;
+typedef unsigned long long F __attribute__ ((vector_size (32)));
+
+__attribute__((noinline, noclone)) unsigned
+foo(D a, B b, D c, F d)
+{
+  b /= (B) {1, -c[0]} | 1;
+  c[0] |= 7;
+  a %= c | 1;
+  c ^= c;
+  return a[0] + b[15] + c[0] + d[3];
+}
+
+int
+main ()
+{
+  unsigned x = foo ((D) {}, (B) {}, (D) {}, (F) {});
+  if (x != 0)
+    __builtin_abort ();
+  return 0;
+}