re PR target/77833 (ICE: in plus_constant, at explow.c:87 with -O -mavx512f)

2016-10-04  Richard Biener  <rguenther@suse.de>

	PR middle-end/77833
	* explow.c (plus_constant): Verify the mode of the constant
	pool offset before calling plus_constant.

	* gcc.target/i386/pr77833.c: New testcase.

From-SVN: r240743

gcc/ChangeLog

 2016-10-04  Richard Biener  <rguenther@suse.de>
 
+	PR middle-end/77833
+	* explow.c (plus_constant): Verify the mode of the constant
+	pool offset before calling plus_constant.
+
+2016-10-04  Richard Biener  <rguenther@suse.de>
+
 	PR middle-end/77407
 	* match.pd (X / abs (X) -> X < 0 ? -1 : 1): Drop vector
 	type support, mark with :C.

gcc/explow.c

@@ -114,12 +114,15 @@ plus_constant (machine_mode mode, rtx x, HOST_WIDE_INT c,
 	      cst = gen_lowpart (mode, cst);
 	      gcc_assert (cst);
 	    }
-	  tem = plus_constant (mode, cst, c);
-	  tem = force_const_mem (GET_MODE (x), tem);
-	  /* Targets may disallow some constants in the constant pool, thus
-	     force_const_mem may return NULL_RTX.  */
-	  if (tem && memory_address_p (GET_MODE (tem), XEXP (tem, 0)))
-	    return tem;
+	  if (GET_MODE (cst) == VOIDmode || GET_MODE (cst) == mode)
+	    {
+	      tem = plus_constant (mode, cst, c);
+	      tem = force_const_mem (GET_MODE (x), tem);
+	      /* Targets may disallow some constants in the constant pool, thus
+		 force_const_mem may return NULL_RTX.  */
+	      if (tem && memory_address_p (GET_MODE (tem), XEXP (tem, 0)))
+		return tem;
+	    }
 	}
       break;
 

gcc/testsuite/ChangeLog

+2016-10-04  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/77833
+	* gcc.target/i386/pr77833.c: New testcase.
+
 2016-09-26  Jeff Law  <law@redhat.com>
 
 	PR tree-optimization/71550

gcc/testsuite/gcc.target/i386/pr77833.c

+/* { dg-do compile } */
+/* { dg-options "-O -mavx512f" } */
+
+typedef unsigned long V __attribute__((vector_size(64)));
+typedef unsigned __int128 W __attribute__((vector_size(64)));
+
+V
+foo(int i, V v)
+{
+  i *= ((W)(V){0, 0, 0, 0, 0, 1, v[0]})[2];
+  v[i] = 0;
+  i--;
+  return v + i;
+}