[PATCH] Fix fortran/29951, transfer vs arrays to scalars

[Andrew Pinski <pinskia at gmail dot com>]

The problem here is that dereferencing an array for the
VIEW_CONVERT_EXPR causes us to just use the first element of the array.
This patch fixes the problem by using memcpy instead of let the
optimizers optimize it down to a VIEW_CONVERT_EXPR if they can, they do
with the testcase I was trying to fix before.

OK? Bootstrapped and tested on i686-linux-gnu with no regressions.

Thanks,
Andrew Pinski

ChangeLog:

	* trans-intrinsic.c (gfc_conv_intrinsic_transfer): Change to
	call memcpy instead of creating a VIEW_CONVERT_EXRP. 


	* gfortran.fortran-torture/execute/transfer2.f90: New test.

Index: testsuite/gfortran.fortran-torture/execute/transfer2.f90
===================================================================
--- testsuite/gfortran.fortran-torture/execute/transfer2.f90	(revision 0)
+++ testsuite/gfortran.fortran-torture/execute/transfer2.f90	(revision 0)
@@ -0,0 +1,19 @@
+program test_convert
+
+  implicit none
+  character(len=4)              :: byte_string
+  character(len=1),dimension(4) :: byte_array
+  integer*4 :: value,value1,n,i
+
+  byte_string(1:1) = char(157)
+  byte_string(2:2) = char(127)
+  byte_string(3:3) = char(100)
+  byte_string(4:4) = char(0)
+
+  byte_array(1:4) = (/char(157),char(127),char(100),char(0)/)
+
+  value = transfer(byte_string(1:4),value)
+  value1 = transfer(byte_array(1:4),value1)
+
+  if (value .ne. value1)  call abort()
+end program test_convert
Index: fortran/trans-intrinsic.c
===================================================================
--- fortran/trans-intrinsic.c	(revision 119148)
+++ fortran/trans-intrinsic.c	(working copy)
@@ -2989,7 +2989,7 @@ gfc_conv_intrinsic_array_transfer (gfc_s
 
 
 /* Scalar transfer statement.
-   TRANSFER (source, mold) = VIEW_CONVERT_EXPR<typeof<mold> >source.  */
+   TRANSFER (source, mold) = memcpy(&tmpdecl, &source, size), tmpdecl.  */
 
 static void
 gfc_conv_intrinsic_transfer (gfc_se * se, gfc_expr * expr)
@@ -2999,6 +2999,7 @@ gfc_conv_intrinsic_transfer (gfc_se * se
   tree type;
   tree ptr;
   gfc_ss *ss;
+  tree tmpdecl, tmp, args;
 
   /* Get a pointer to the source.  */
   arg = expr->value.function.actual;
@@ -3014,6 +3015,7 @@ gfc_conv_intrinsic_transfer (gfc_se * se
 
   arg = arg->next;
   type = gfc_typenode_for_spec (&expr->ts);
+
   if (expr->ts.type == BT_CHARACTER)
     {
       ptr = convert (build_pointer_type (type), ptr);
@@ -3026,8 +3028,22 @@ gfc_conv_intrinsic_transfer (gfc_se * se
     }
   else
     {
-      tree tmp = build_fold_indirect_ref (ptr);
-      se->expr = fold_build1 (VIEW_CONVERT_EXPR, type, tmp);
+      tree moldsize;
+      tmpdecl = gfc_create_var (type, "transfer");
+      moldsize = size_in_bytes (type);
+
+      /* Use memcpy to do the transfer.  */
+      tmp = build1 (ADDR_EXPR, build_pointer_type (type), tmpdecl);
+      tmp = fold_convert (pvoid_type_node, tmp);
+      args = gfc_chainon_list (NULL_TREE, tmp);
+      tmp = fold_convert (pvoid_type_node, ptr);
+      args = gfc_chainon_list (args, tmp);
+      args = gfc_chainon_list (args, moldsize);
+      tmp = built_in_decls[BUILT_IN_MEMCPY];
+      tmp = build_function_call_expr (tmp, args);
+      gfc_add_expr_to_block (&se->pre, tmp);
+
+      se->expr = tmpdecl;
     }
 }