[committed] Use valid_for_const_vector_p instead of CONSTANT_P

[Richard Sandiford]

This patch makes the VEC_SERIES code use valid_for_const_vector_p
instead of CONSTANT_P, to match what we already do for VEC_DUPLICATE.
This showed up as a failure in gcc.c-torture/execute/pr28982b.c for -m32
on x86_64-linux-gnu after later patches.

Tested on aarch64-linux-gnu, x86_64-linux-gnu and powerpc64-linux-gnu,
and with a before-and-after comparison of testsuite output for a range
of targets.  Applied as obvious.

Richard


2017-12-28  Richard Sandiford  <richard.sandiford@linaro.org>

gcc/
	* emit-rtl.c (gen_const_vec_series): Use valid_for_const_vector_p
	instead of CONSTANT_P.
	(gen_vec_series): Likewise.
	* simplify-rtx.c (simplify_binary_operation_1): Likewise.

Index: gcc/emit-rtl.c
===================================================================
--- gcc/emit-rtl.c	2017-12-23 09:29:19.465366872 +0000
+++ gcc/emit-rtl.c	2017-12-28 16:55:49.382742760 +0000
@@ -5949,7 +5949,8 @@ const_vec_series_p_1 (const_rtx x, rtx *
 rtx
 gen_const_vec_series (machine_mode mode, rtx base, rtx step)
 {
-  gcc_assert (CONSTANT_P (base) && CONSTANT_P (step));
+  gcc_assert (valid_for_const_vector_p (mode, base)
+	      && valid_for_const_vector_p (mode, step));
 
   int nunits = GET_MODE_NUNITS (mode);
   rtvec v = rtvec_alloc (nunits);
@@ -5970,7 +5971,8 @@ gen_vec_series (machine_mode mode, rtx b
 {
   if (step == const0_rtx)
     return gen_vec_duplicate (mode, base);
-  if (CONSTANT_P (base) && CONSTANT_P (step))
+  if (valid_for_const_vector_p (mode, base)
+      && valid_for_const_vector_p (mode, step))
     return gen_const_vec_series (mode, base, step);
   return gen_rtx_VEC_SERIES (mode, base, step);
 }
Index: gcc/simplify-rtx.c
===================================================================
--- gcc/simplify-rtx.c	2017-12-23 09:29:19.493365821 +0000
+++ gcc/simplify-rtx.c	2017-12-28 16:55:49.383742722 +0000
@@ -3590,7 +3590,8 @@ simplify_binary_operation_1 (enum rtx_co
     case VEC_SERIES:
       if (op1 == CONST0_RTX (GET_MODE_INNER (mode)))
 	return gen_vec_duplicate (mode, op0);
-      if (CONSTANT_P (op0) && CONSTANT_P (op1))
+      if (valid_for_const_vector_p (mode, op0)
+	  && valid_for_const_vector_p (mode, op1))
 	return gen_const_vec_series (mode, op0, op1);
       return 0;