Add missing check for BUILT_IN_MD (PR 91444)

In this PR we were passing an ordinary non-built-in function to
targetm.vectorize.builtin_md_vectorized_function, which is only
supposed to handle BUILT_IN_MD.

2019-08-15  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	PR middle-end/91444
	* tree-vect-stmts.c (vectorizable_call): Check that the function
	is a BUILT_IN_MD function before passing it to
	targetm.vectorize.builtin_md_vectorized_function.

From-SVN: r274524

gcc/ChangeLog

 2019-08-15  Richard Sandiford  <richard.sandiford@arm.com>
 
+	PR middle-end/91444
+	* tree-vect-stmts.c (vectorizable_call): Check that the function
+	is a BUILT_IN_MD function before passing it to
+	targetm.vectorize.builtin_md_vectorized_function.
+
+2019-08-15  Richard Sandiford  <richard.sandiford@arm.com>
+
 	* config/aarch64/aarch64-protos.h (aarch64_sve_mode_p): Declare.
 	* config/aarch64/aarch64.c (aarch64_sve_mode_p): New function.
 	(aarch64_select_early_remat_modes): Use it.

gcc/tree-vect-stmts.c

@@ -3376,7 +3376,7 @@ vectorizable_call (stmt_vec_info stmt_info, gimple_stmt_iterator *gsi,
       if (cfn != CFN_LAST)
 	fndecl = targetm.vectorize.builtin_vectorized_function
 	  (cfn, vectype_out, vectype_in);
-      else if (callee)
+      else if (callee && fndecl_built_in_p (callee, BUILT_IN_MD))
 	fndecl = targetm.vectorize.builtin_md_vectorized_function
 	  (callee, vectype_out, vectype_in);
     }