Add a vect_masked_store target selector

This patch adds a target selector that says whether the target
supports IFN_MASK_STORE.

2017-11-09  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* doc/sourcebuild.texi (vect_masked_store): Document.

gcc/testsuite/
	* lib/target-supports.exp (check_effective_target_vect_masked_store):
	New proc.
	* gcc.dg/vect/vect-cselim-1.c (foo): Mention that the second loop
	is vectorizable with masked stores.  Update scan-tree-dump-times
	accordingly.

Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>

From-SVN: r254597

gcc/ChangeLog

@@ -2,6 +2,12 @@
 	    Alan Hayward  <alan.hayward@arm.com>
 	    David Sherwood  <david.sherwood@arm.com>
 
+	* doc/sourcebuild.texi (vect_masked_store): Document.
+
+2017-11-09  Richard Sandiford  <richard.sandiford@linaro.org>
+	    Alan Hayward  <alan.hayward@arm.com>
+	    David Sherwood  <david.sherwood@arm.com>
+
 	* doc/sourcebuild.texi (vect_align_stack_vars): Document.
 
 2017-11-09  Richard Sandiford  <richard.sandiford@linaro.org>

gcc/doc/sourcebuild.texi

@@ -1403,6 +1403,9 @@ Target supports hardware vectors of @code{long}.
 @item vect_long_long
 Target supports hardware vectors of @code{long long}.
 
+@item vect_masked_store
+Target supports vector masked stores.
+
 @item vect_aligned_arrays
 Target aligns arrays to vector alignment boundary.
 

gcc/testsuite/ChangeLog

@@ -2,6 +2,16 @@
 	    Alan Hayward  <alan.hayward@arm.com>
 	    David Sherwood  <david.sherwood@arm.com>
 
+	* lib/target-supports.exp (check_effective_target_vect_masked_store):
+	New proc.
+	* gcc.dg/vect/vect-cselim-1.c (foo): Mention that the second loop
+	is vectorizable with masked stores.  Update scan-tree-dump-times
+	accordingly.
+
+2017-11-09  Richard Sandiford  <richard.sandiford@linaro.org>
+	    Alan Hayward  <alan.hayward@arm.com>
+	    David Sherwood  <david.sherwood@arm.com>
+
 	* lib/target-supports.exp
 	(check_effective_target_vect_align_stack_vars): New proc.
 	* gcc.dg/vect/vect-23.c: Only expect the array to be aligned if

gcc/testsuite/gcc.dg/vect/vect-cselim-1.c

@@ -38,7 +38,7 @@ foo ()
         }
     }
 
-  /* Not vectorizable.  */
+  /* Only vectorizable with masked stores.  */
   for (i = 0; i < N; i++)
     {
       c = in1[i].b;
@@ -82,4 +82,5 @@ main (void)
   return 0;
 }
 
-/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect"  { xfail { { vect_no_align && { ! vect_hw_misalign } } || { ! vect_strided2 } } } } } */
+/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" { target { ! vect_masked_store } xfail { { vect_no_align && { ! vect_hw_misalign } } || { ! vect_strided2 } } } } } */
+/* { dg-final { scan-tree-dump-times "vectorized 2 loops" 1 "vect" { target { vect_masked_store } } } } */

gcc/testsuite/lib/target-supports.exp

@@ -6433,6 +6433,12 @@ proc check_effective_target_vect_load_lanes { } {
     return $et_vect_load_lanes
 }
 
+# Return 1 if the target supports vector masked stores.
+
+proc check_effective_target_vect_masked_store { } {
+    return 0
+}
+
 # Return 1 if the target supports vector conditional operations, 0 otherwise.
 
 proc check_effective_target_vect_condition { } {