gfortran.h (gfc_expr): Remove from_H, add "representation" struct.

* gfortran.h (gfc_expr): Remove from_H, add "representation"
struct.
* primary.c (match_hollerith_constant): Store the representation
of the Hollerith in representation, not in value.character.
* arith.c: Add dependency on target-memory.h.
(eval_intrinsic): Remove check for from_H.
(hollerith2representation): New function.
(gfc_hollerith2int): Determine value of the new constant.
(gfc_hollerith2real): Likewise.
(gfc_hollerith2complex): Likewise.
(gfc_hollerith2logical): Likewise.
(gfc_hollerith2character): Point both representation.string and
value.character.string at the value string.
* data.c (create_character_initializer): For BT_HOLLERITH
rvalues, get the value from the representation rather than
value.character.
* expr.c (free_expr0): Update handling of BT_HOLLERITH values
and values with representation.string.
(gfc_copy_expr): Likewise.
* intrinsic.c (do_simplify): Remove special treatement of
variables resulting from Hollerith constants.
* dump-parse-trees.c (gfc_show_expr): Update handling of
Holleriths.
* trans-const.c (gfc_conv_constant_to_tree): Replace from_H
check with check for representation.string; get Hollerith
representation from representation.string, not value.character.
* trans-expr.c (is_zero_initializer_p): Replace from_H check
with check for representation.string.
* trans-stmt.c (gfc_trans_integer_select): Use
gfc_conv_mpz_to_tree for case values, so as to avoid picking up
the memory representation if the case is given by a transfer
expression.
* target-memory.c (gfc_target_encode_expr): Use the known memory
representation rather than the value, if it exists.
(gfc_target_interpret_expr): Store the memory representation of
the interpreted expression as well as its value.
(interpret_integer): Move to gfc_interpret_integer, make
non-static.
(interpret_float): Move to gfc_interpret_float, make non-static.
(interpret_complex): Move to gfc_interpret_complex, make
non-static.
(interpret_logical): Move to gfc_interpret_logical, make
non-static.
(interpret_character): Move to gfc_interpret_character, make
non-static.
(interpret_derived): Move to gfc_interpret_derived, make
non-static.
* target-memory.h: Add prototypes for newly-exported
gfc_interpret_* functions.

From-SVN: r125135

13 files changed, 287 insertions, 172 deletions

diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index 59278dc..e1265a6 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,55 @@
+2007-05-27  Brooks Moses  <brooks.moses@codesourcery.com>
+
+	* gfortran.h (gfc_expr): Remove from_H, add "representation"
+	struct.
+	* primary.c (match_hollerith_constant): Store the representation
+ 	of the Hollerith in representation, not in value.character.
+	* arith.c: Add dependency on target-memory.h.
+	(eval_intrinsic): Remove check for from_H.
+	(hollerith2representation): New function.
+	(gfc_hollerith2int): Determine value of the new constant.
+	(gfc_hollerith2real): Likewise.
+	(gfc_hollerith2complex): Likewise.
+	(gfc_hollerith2logical): Likewise.
+	(gfc_hollerith2character): Point both representation.string and
+	value.character.string at the value string.
+	* data.c (create_character_initializer): For BT_HOLLERITH
+	rvalues, get the value from the representation rather than
+	value.character.
+	* expr.c (free_expr0): Update handling of BT_HOLLERITH values
+	and values with representation.string.
+	(gfc_copy_expr): Likewise.
+	* intrinsic.c (do_simplify): Remove special treatement of
+	variables resulting from Hollerith constants.
+	* dump-parse-trees.c (gfc_show_expr): Update handling of
+	Holleriths.
+	* trans-const.c (gfc_conv_constant_to_tree): Replace from_H
+	check with check for representation.string; get Hollerith
+	representation from representation.string, not value.character.
+	* trans-expr.c (is_zero_initializer_p): Replace from_H check
+	with check for representation.string.
+	* trans-stmt.c (gfc_trans_integer_select): Use
+	gfc_conv_mpz_to_tree for case values, so as to avoid picking up
+	the memory representation if the case is given by a transfer
+	expression.
+	* target-memory.c (gfc_target_encode_expr): Use the known memory
+	representation rather than the value, if it exists.
+	(gfc_target_interpret_expr): Store the memory representation of
+	the interpreted expression as well as its value.
+	(interpret_integer): Move to gfc_interpret_integer, make
+	non-static.
+	(interpret_float): Move to gfc_interpret_float, make non-static.
+	(interpret_complex): Move to gfc_interpret_complex, make
+	non-static.
+	(interpret_logical): Move to gfc_interpret_logical, make
+	non-static.
+	(interpret_character): Move to gfc_interpret_character, make
+	non-static.
+	(interpret_derived): Move to gfc_interpret_derived, make
+	non-static.
+	* target-memory.h: Add prototypes for newly-exported
+	gfc_interpret_* functions.
+
 2007-05-27  Jerry DeLisle  <jvdelisle@gcc.gnu.org>
 
 	PR fortran/31812
diff --git a/gcc/fortran/arith.c b/gcc/fortran/arith.c
index 8c995ea..9d8428d 100644
--- a/gcc/fortran/arith.c
+++ b/gcc/fortran/arith.c
@@ -30,6 +30,7 @@ Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
 #include "flags.h"
 #include "gfortran.h"
 #include "arith.h"
+#include "target-memory.h"
 
 /* MPFR does not have a direct replacement for mpz_set_f() from GMP.
    It's easily implemented with a few calls though.  */
@@ -1613,17 +1614,15 @@ eval_intrinsic (gfc_intrinsic_op operator,
   if (operator == INTRINSIC_POWER && op2->ts.type != BT_INTEGER)
     goto runtime;
 
-  if (op1->from_H
-      || (op1->expr_type != EXPR_CONSTANT
-	  && (op1->expr_type != EXPR_ARRAY
-	      || !gfc_is_constant_expr (op1) || !gfc_expanded_ac (op1))))
+  if (op1->expr_type != EXPR_CONSTANT
+      && (op1->expr_type != EXPR_ARRAY
+	  || !gfc_is_constant_expr (op1) || !gfc_expanded_ac (op1)))
     goto runtime;
 
   if (op2 != NULL
-      && (op2->from_H
-	  || (op2->expr_type != EXPR_CONSTANT
-	      && (op2->expr_type != EXPR_ARRAY
-		  || !gfc_is_constant_expr (op2) || !gfc_expanded_ac (op2)))))
+      && op2->expr_type != EXPR_CONSTANT
+	 && (op2->expr_type != EXPR_ARRAY
+	     || !gfc_is_constant_expr (op2) || !gfc_expanded_ac (op2)))
     goto runtime;
 
   if (unary)
@@ -2307,37 +2306,52 @@ gfc_int2log (gfc_expr *src, int kind)
 }
 
 
+/* Helper function to set the representation in a Hollerith conversion.  
+   This assumes that the ts.type and ts.kind of the result have already
+   been set.  */
+
+static void
+hollerith2representation (gfc_expr *result, gfc_expr *src)
+{
+  int src_len, result_len;
+
+  src_len = src->representation.length;
+  result_len = gfc_target_expr_size (result);
+
+  if (src_len > result_len)
+    {
+      gfc_warning ("The Hollerith constant at %L is too long to convert to %s",
+		   &src->where, gfc_typename(&result->ts));
+    }
+
+  result->representation.string = gfc_getmem (result_len + 1);
+  memcpy (result->representation.string, src->representation.string,
+	MIN (result_len, src_len));
+
+  if (src_len < result_len)
+    memset (&result->representation.string[src_len], ' ', result_len - src_len);
+
+  result->representation.string[result_len] = '\0'; /* For debugger  */
+  result->representation.length = result_len;
+}
+
+
 /* Convert Hollerith to integer. The constant will be padded or truncated.  */
 
 gfc_expr *
 gfc_hollerith2int (gfc_expr *src, int kind)
 {
   gfc_expr *result;
-  int len;
-
-  len = src->value.character.length;
 
   result = gfc_get_expr ();
   result->expr_type = EXPR_CONSTANT;
   result->ts.type = BT_INTEGER;
   result->ts.kind = kind;
   result->where = src->where;
-  result->from_H = 1;
-
-  if (len > kind)
-    {
-      gfc_warning ("The Hollerith constant at %L is too long to convert to %s",
-		   &src->where, gfc_typename(&result->ts));
-    }
-  result->value.character.string = gfc_getmem (kind + 1);
-  memcpy (result->value.character.string, src->value.character.string,
-	MIN (kind, len));
-
-  if (len < kind)
-    memset (&result->value.character.string[len], ' ', kind - len);
 
-  result->value.character.string[kind] = '\0'; /* For debugger  */
-  result->value.character.length = kind;
+  hollerith2representation (result, src);
+  gfc_interpret_integer(kind, (unsigned char *) result->representation.string,
+			result->representation.length, result->value.integer);
 
   return result;
 }
@@ -2358,22 +2372,10 @@ gfc_hollerith2real (gfc_expr *src, int kind)
   result->ts.type = BT_REAL;
   result->ts.kind = kind;
   result->where = src->where;
-  result->from_H = 1;
 
-  if (len > kind)
-    {
-      gfc_warning ("The Hollerith constant at %L is too long to convert to %s",
-		   &src->where, gfc_typename(&result->ts));
-    }
-  result->value.character.string = gfc_getmem (kind + 1);
-  memcpy (result->value.character.string, src->value.character.string,
-	MIN (kind, len));
-
-  if (len < kind)
-    memset (&result->value.character.string[len], ' ', kind - len);
-
-  result->value.character.string[kind] = '\0'; /* For debugger.  */
-  result->value.character.length = kind;
+  hollerith2representation (result, src);
+  gfc_interpret_float(kind, (unsigned char *) result->representation.string,
+		      result->representation.length, result->value.real);
 
   return result;
 }
@@ -2394,24 +2396,11 @@ gfc_hollerith2complex (gfc_expr *src, int kind)
   result->ts.type = BT_COMPLEX;
   result->ts.kind = kind;
   result->where = src->where;
-  result->from_H = 1;
-
-  kind = kind * 2;
-
-  if (len > kind)
-    {
-      gfc_warning ("The Hollerith constant at %L is too long to convert to %s",
-		   &src->where, gfc_typename(&result->ts));
-    }
-  result->value.character.string = gfc_getmem (kind + 1);
-  memcpy (result->value.character.string, src->value.character.string,
-	  MIN (kind, len));
 
-  if (len < kind)
-    memset (&result->value.character.string[len], ' ', kind - len);
-
-  result->value.character.string[kind] = '\0'; /* For debugger  */
-  result->value.character.length = kind;
+  hollerith2representation (result, src);
+  gfc_interpret_complex(kind, (unsigned char *) result->representation.string,
+			result->representation.length, result->value.complex.r,
+			result->value.complex.i);
 
   return result;
 }
@@ -2427,7 +2416,9 @@ gfc_hollerith2character (gfc_expr *src, int kind)
   result = gfc_copy_expr (src);
   result->ts.type = BT_CHARACTER;
   result->ts.kind = kind;
-  result->from_H = 1;
+
+  result->value.character.string = result->representation.string;
+  result->value.character.length = result->representation.length;
 
   return result;
 }
@@ -2448,22 +2439,10 @@ gfc_hollerith2logical (gfc_expr *src, int kind)
   result->ts.type = BT_LOGICAL;
   result->ts.kind = kind;
   result->where = src->where;
-  result->from_H = 1;
-
-  if (len > kind)
-    {
-      gfc_warning ("The Hollerith constant at %L is too long to convert to %s",
-		   &src->where, gfc_typename(&result->ts));
-    }
-  result->value.character.string = gfc_getmem (kind + 1);
-  memcpy (result->value.character.string, src->value.character.string,
-	MIN (kind, len));
-
-  if (len < kind)
-    memset (&result->value.character.string[len], ' ', kind - len);
 
-  result->value.character.string[kind] = '\0'; /* For debugger  */
-  result->value.character.length = kind;
+  hollerith2representation (result, src);
+  gfc_interpret_logical(kind, (unsigned char *) result->representation.string,
+			result->representation.length, &result->value.logical);
 
   return result;
 }
diff --git a/gcc/fortran/data.c b/gcc/fortran/data.c
index 70a7151..75e4241 100644
--- a/gcc/fortran/data.c
+++ b/gcc/fortran/data.c
@@ -154,7 +154,7 @@ create_character_intializer (gfc_expr *init, gfc_typespec *ts,
   int len;
   int start;
   int end;
-  char *dest;
+  char *dest, *rvalue_string;
 	    
   gfc_extract_int (ts->cl->length, &len);
 
@@ -207,7 +207,17 @@ create_character_intializer (gfc_expr *init, gfc_typespec *ts,
     }
 
   /* Copy the initial value.  */
-  len = rvalue->value.character.length;
+  if (rvalue->ts.type == BT_HOLLERITH)
+    {
+      len = rvalue->representation.length;
+      rvalue_string = rvalue->representation.string;
+    }
+  else
+    {
+      len = rvalue->value.character.length;
+      rvalue_string = rvalue->value.character.string;
+    }
+
   if (len > end - start)
     {
       len = end - start;
@@ -215,14 +225,17 @@ create_character_intializer (gfc_expr *init, gfc_typespec *ts,
 		       "at %L", &rvalue->where);
     }
 
-  memcpy (&dest[start], rvalue->value.character.string, len);
+  memcpy (&dest[start], rvalue_string, len);
 
   /* Pad with spaces.  Substrings will already be blanked.  */
   if (len < end - start && ref == NULL)
     memset (&dest[start + len], ' ', end - (start + len));
 
   if (rvalue->ts.type == BT_HOLLERITH)
-    init->from_H = 1;
+    {
+      init->representation.length = init->value.character.length;
+      init->representation.string = init->value.character.string;
+    }
 
   return init;
 }
diff --git a/gcc/fortran/dump-parse-tree.c b/gcc/fortran/dump-parse-tree.c
index 6f2a6a7..51af1c4 100644
--- a/gcc/fortran/dump-parse-tree.c
+++ b/gcc/fortran/dump-parse-tree.c
@@ -340,16 +340,6 @@ gfc_show_expr (gfc_expr *p)
       break;
 
     case EXPR_CONSTANT:
-      if (p->from_H || p->ts.type == BT_HOLLERITH)
-	{
-	  gfc_status ("%dH", p->value.character.length);
-	  c = p->value.character.string;
-	  for (i = 0; i < p->value.character.length; i++, c++)
-	    {
-	      gfc_status_char (*c);
-	    }
-	  break;
-	}
       switch (p->ts.type)
 	{
 	case BT_INTEGER:
@@ -405,11 +395,33 @@ gfc_show_expr (gfc_expr *p)
 	  gfc_status (")");
 	  break;
 
+	case BT_HOLLERITH:
+	  gfc_status ("%dH", p->representation.length);
+	  c = p->representation.string;
+	  for (i = 0; i < p->representation.length; i++, c++)
+	    {
+	      gfc_status_char (*c);
+	    }
+	  break;
+
 	default:
 	  gfc_status ("???");
 	  break;
 	}
 
+      if (p->representation.string)
+	{
+	  gfc_status (" {");
+	  c = p->representation.string;
+	  for (i = 0; i < p->representation.length; i++, c++)
+	    {
+	      gfc_status ("%.2x", (unsigned int) *c);
+	      if (i < p->representation.length - 1)
+		gfc_status_char (',');
+	    }
+	  gfc_status_char ('}');
+	}
+
       break;
 
     case EXPR_VARIABLE:
diff --git a/gcc/fortran/expr.c b/gcc/fortran/expr.c
index 9957a46..849b406 100644
--- a/gcc/fortran/expr.c
+++ b/gcc/fortran/expr.c
@@ -140,12 +140,7 @@ free_expr0 (gfc_expr *e)
   switch (e->expr_type)
     {
     case EXPR_CONSTANT:
-      if (e->from_H)
-	{
-	  gfc_free (e->value.character.string);
-	  break;
-	}
-
+      /* Free any parts of the value that need freeing.  */
       switch (e->ts.type)
 	{
 	case BT_INTEGER:
@@ -157,7 +152,6 @@ free_expr0 (gfc_expr *e)
 	  break;
 
 	case BT_CHARACTER:
-	case BT_HOLLERITH:
 	  gfc_free (e->value.character.string);
 	  break;
 
@@ -170,6 +164,11 @@ free_expr0 (gfc_expr *e)
 	  break;
 	}
 
+      /* Free the representation, except in character constants where it
+	 is the same as value.character.string and thus already freed.  */
+      if (e->representation.string && e->ts.type != BT_CHARACTER)
+	gfc_free (e->representation.string);
+
       break;
 
     case EXPR_OP:
@@ -413,14 +412,16 @@ gfc_copy_expr (gfc_expr *p)
       break;
 
     case EXPR_CONSTANT:
-      if (p->from_H)
+      /* Copy target representation, if it exists.  */
+      if (p->representation.string)
 	{
-	  s = gfc_getmem (p->value.character.length + 1);
-	  q->value.character.string = s;
+	  s = gfc_getmem (p->representation.length + 1);
+	  q->representation.string = s;
 
-	  memcpy (s, p->value.character.string, p->value.character.length + 1);
-	  break;
+	  memcpy (s, p->representation.string, p->representation.length + 1);
 	}
+
+      /* Copy the values of any pointer components of p->value.  */
       switch (q->ts.type)
 	{
 	case BT_INTEGER:
@@ -442,13 +443,18 @@ gfc_copy_expr (gfc_expr *p)
 	  break;
 
 	case BT_CHARACTER:
-	case BT_HOLLERITH:
-	  s = gfc_getmem (p->value.character.length + 1);
-	  q->value.character.string = s;
+	  if (p->representation.string)
+	    q->value.character.string = q->representation.string;
+	  else
+	    {
+	      s = gfc_getmem (p->value.character.length + 1);
+	      q->value.character.string = s;
 
-	  memcpy (s, p->value.character.string, p->value.character.length + 1);
+	      memcpy (s, p->value.character.string, p->value.character.length + 1);
+	    }
 	  break;
 
+	case BT_HOLLERITH:
 	case BT_LOGICAL:
 	case BT_DERIVED:
 	  break;		/* Already done */
diff --git a/gcc/fortran/gfortran.h b/gcc/fortran/gfortran.h
index 38ef1a6..c7fa5f8 100644
--- a/gcc/fortran/gfortran.h
+++ b/gcc/fortran/gfortran.h
@@ -1290,17 +1290,28 @@ typedef struct gfc_expr
 
   locus where;
 
-  /* True if it is converted from Hollerith constant.  */
-  unsigned int from_H : 1;
   /* True if the expression is a call to a function that returns an array,
      and if we have decided not to allocate temporary data for that array.  */
   unsigned int inline_noncopying_intrinsic : 1;
-  /* Used to quickly find a given constructor by it's offset.  */
+
+  /* Used to quickly find a given constructor by its offset.  */
   splay_tree con_by_offset;
 
+  /* If an expression comes from a Hollerith constant or compile-time
+     evaluation of a transfer statement, it may have a prescribed target-
+     memory representation, and these cannot always be backformed from
+     the value.  */
+  struct
+  {
+    int length;
+    char *string;
+  }
+  representation;
+
   union
   {
     int logical;
+
     mpz_t integer;
 
     mpfr_t real;
diff --git a/gcc/fortran/intrinsic.c b/gcc/fortran/intrinsic.c
index d64f77f..d3392b0 100644
--- a/gcc/fortran/intrinsic.c
+++ b/gcc/fortran/intrinsic.c
@@ -3065,16 +3065,6 @@ do_simplify (gfc_intrinsic_sym *specific, gfc_expr *e)
   gfc_expr *result, *a1, *a2, *a3, *a4, *a5;
   gfc_actual_arglist *arg;
 
-  /* Check the arguments if there are Hollerith constants. We deal with
-     them at run-time.  */
-  for (arg = e->value.function.actual; arg != NULL; arg = arg->next)
-    {
-      if (arg->expr && arg->expr->from_H)
-	{
-	  result = NULL;
-	  goto finish;
-	}
-    }
   /* Max and min require special handling due to the variable number
      of args.  */
   if (specific->simplify.f1 == gfc_simplify_min)
diff --git a/gcc/fortran/primary.c b/gcc/fortran/primary.c
index 653df5d..ce81f44 100644
--- a/gcc/fortran/primary.c
+++ b/gcc/fortran/primary.c
@@ -236,7 +236,6 @@ match_hollerith_constant (gfc_expr **result)
   locus old_loc;
   gfc_expr *e = NULL;
   const char *msg;
-  char *buffer;
   int num;
   int i;  
 
@@ -270,18 +269,18 @@ match_hollerith_constant (gfc_expr **result)
 	}
       else
 	{
-	  buffer = (char *) gfc_getmem (sizeof(char) * num + 1);
-	  for (i = 0; i < num; i++)
-	    {
-	      buffer[i] = gfc_next_char_literal (1);
-	    }
 	  gfc_free_expr (e);
 	  e = gfc_constant_result (BT_HOLLERITH, gfc_default_character_kind,
 				   &gfc_current_locus);
-	  e->value.character.string = gfc_getmem (num + 1);
-	  memcpy (e->value.character.string, buffer, num);
-	  e->value.character.string[num] = '\0';
-	  e->value.character.length = num;
+
+	  e->representation.string = gfc_getmem (num + 1);
+	  for (i = 0; i < num; i++)
+	    {
+	      e->representation.string[i] = gfc_next_char_literal (1);
+	    }
+	  e->representation.string[num] = '\0';
+	  e->representation.length = num;
+
 	  *result = e;
 	  return MATCH_YES;
 	}
diff --git a/gcc/fortran/target-memory.c b/gcc/fortran/target-memory.c
index ba2363a..194bc0b 100644
--- a/gcc/fortran/target-memory.c
+++ b/gcc/fortran/target-memory.c
@@ -220,6 +220,15 @@ gfc_target_encode_expr (gfc_expr *source, unsigned char *buffer,
   gcc_assert (source->expr_type == EXPR_CONSTANT
 	      || source->expr_type == EXPR_STRUCTURE);
 
+  /* If we already have a target-memory representation, we use that rather 
+     than recreating one.  */
+  if (source->representation.string)
+    {
+      memcpy (buffer, source->representation.string,
+	      source->representation.length);
+      return source->representation.length;
+    }
+
   switch (source->ts.type)
     {
     case BT_INTEGER:
@@ -289,8 +298,8 @@ interpret_array (unsigned char *buffer, size_t buffer_size, gfc_expr *result)
 }
 
 
-static int
-interpret_integer (int kind, unsigned char *buffer, size_t buffer_size,
+int
+gfc_interpret_integer (int kind, unsigned char *buffer, size_t buffer_size,
 		   mpz_t integer)
 {
   mpz_init (integer);
@@ -301,8 +310,8 @@ interpret_integer (int kind, unsigned char *buffer, size_t buffer_size,
 }
 
 
-static int
-interpret_float (int kind, unsigned char *buffer, size_t buffer_size,
+int
+gfc_interpret_float (int kind, unsigned char *buffer, size_t buffer_size,
 		 mpfr_t real)
 {
   mpfr_init (real);
@@ -314,19 +323,19 @@ interpret_float (int kind, unsigned char *buffer, size_t buffer_size,
 }
 
 
-static int
-interpret_complex (int kind, unsigned char *buffer, size_t buffer_size,
+int
+gfc_interpret_complex (int kind, unsigned char *buffer, size_t buffer_size,
 		   mpfr_t real, mpfr_t imaginary)
 {
   int size;
-  size = interpret_float (kind, &buffer[0], buffer_size, real);
-  size += interpret_float (kind, &buffer[size], buffer_size - size, imaginary);
+  size = gfc_interpret_float (kind, &buffer[0], buffer_size, real);
+  size += gfc_interpret_float (kind, &buffer[size], buffer_size - size, imaginary);
   return size;
 }
 
 
-static int
-interpret_logical (int kind, unsigned char *buffer, size_t buffer_size,
+int
+gfc_interpret_logical (int kind, unsigned char *buffer, size_t buffer_size,
 		   int *logical)
 {
   tree t = native_interpret_expr (gfc_get_logical_type (kind), buffer,
@@ -337,8 +346,8 @@ interpret_logical (int kind, unsigned char *buffer, size_t buffer_size,
 }
 
 
-static int
-interpret_character (unsigned char *buffer, size_t buffer_size, gfc_expr *result)
+int
+gfc_interpret_character (unsigned char *buffer, size_t buffer_size, gfc_expr *result)
 {
   if (result->ts.cl && result->ts.cl->length)
     result->value.character.length =
@@ -355,8 +364,8 @@ interpret_character (unsigned char *buffer, size_t buffer_size, gfc_expr *result
 }
 
 
-static int
-interpret_derived (unsigned char *buffer, size_t buffer_size, gfc_expr *result)
+int
+gfc_interpret_derived (unsigned char *buffer, size_t buffer_size, gfc_expr *result)
 {
   gfc_component *cmp;
   gfc_constructor *head = NULL, *tail = NULL;
@@ -428,24 +437,55 @@ gfc_target_interpret_expr (unsigned char *buffer, size_t buffer_size,
   switch (result->ts.type)
     {
     case BT_INTEGER:
-      return interpret_integer (result->ts.kind, buffer, buffer_size,
-				result->value.integer);
+      result->representation.length = 
+        gfc_interpret_integer (result->ts.kind, buffer, buffer_size,
+			       result->value.integer);
+      break;
+
     case BT_REAL:
-      return interpret_float (result->ts.kind, buffer, buffer_size,
-			      result->value.real);
+      result->representation.length = 
+        gfc_interpret_float (result->ts.kind, buffer, buffer_size,
+    			     result->value.real);
+      break;
+
     case BT_COMPLEX:
-      return interpret_complex (result->ts.kind, buffer, buffer_size,
-				result->value.complex.r,
-				result->value.complex.i);
+      result->representation.length = 
+        gfc_interpret_complex (result->ts.kind, buffer, buffer_size,
+			       result->value.complex.r,
+			       result->value.complex.i);
+      break;
+
     case BT_LOGICAL:
-      return interpret_logical (result->ts.kind, buffer, buffer_size,
-				&result->value.logical);
+      result->representation.length = 
+        gfc_interpret_logical (result->ts.kind, buffer, buffer_size,
+			       &result->value.logical);
+      break;
+
     case BT_CHARACTER:
-      return interpret_character (buffer, buffer_size, result);
+      result->representation.length = 
+        gfc_interpret_character (buffer, buffer_size, result);
+      break;
+
     case BT_DERIVED:
-      return interpret_derived (buffer, buffer_size, result);
+      result->representation.length = 
+        gfc_interpret_derived (buffer, buffer_size, result);
+      break;
+
     default:
       gfc_internal_error ("Invalid expression in gfc_target_interpret_expr.");
+      break;
+    }
+
+  if (result->ts.type == BT_CHARACTER)
+    result->representation.string = result->value.character.string;
+  else
+    {
+      result->representation.string =
+        gfc_getmem (result->representation.length + 1);
+      memcpy (result->representation.string, buffer,
+	      result->representation.length);
+      result->representation.string[result->representation.length] = '\0';
     }
-  return 0;
+
+  return result->representation.length;
 }
diff --git a/gcc/fortran/target-memory.h b/gcc/fortran/target-memory.h
index 85ae552..8e35e69 100644
--- a/gcc/fortran/target-memory.h
+++ b/gcc/fortran/target-memory.h
@@ -32,6 +32,13 @@ size_t gfc_target_expr_size (gfc_expr *);
 int gfc_target_encode_expr (gfc_expr *, unsigned char *, size_t);
 
 /* Read a target buffer into a constant expression.  */
+
+int gfc_interpret_integer (int, unsigned char *, size_t, mpz_t);
+int gfc_interpret_float (int, unsigned char *, size_t, mpfr_t);
+int gfc_interpret_complex (int, unsigned char *, size_t, mpfr_t, mpfr_t);
+int gfc_interpret_logical (int, unsigned char *, size_t, int *);
+int gfc_interpret_character (unsigned char *, size_t, gfc_expr *);
+int gfc_interpret_derived (unsigned char *, size_t, gfc_expr *);
 int gfc_target_interpret_expr (unsigned char *, size_t, gfc_expr *);
 
 #endif /* GFC_TARGET_MEMORY_H  */
diff --git a/gcc/fortran/trans-const.c b/gcc/fortran/trans-const.c
index 435d5ec..24aa809 100644
--- a/gcc/fortran/trans-const.c
+++ b/gcc/fortran/trans-const.c
@@ -209,45 +209,45 @@ gfc_conv_constant_to_tree (gfc_expr * expr)
 {
   gcc_assert (expr->expr_type == EXPR_CONSTANT);
 
-  /* If it is converted from Hollerith constant, we build string constant
-     and VIEW_CONVERT to its type.  */
+  /* If it is has a prescribed memory representation, we build a string
+     constant and VIEW_CONVERT to its type.  */
  
   switch (expr->ts.type)
     {
     case BT_INTEGER:
-      if (expr->from_H)
+      if (expr->representation.string)
 	return build1 (VIEW_CONVERT_EXPR,
 			gfc_get_int_type (expr->ts.kind),
-			gfc_build_string_const (expr->value.character.length,
-				expr->value.character.string));
+			gfc_build_string_const (expr->representation.length,
+				expr->representation.string));
       else
 	return gfc_conv_mpz_to_tree (expr->value.integer, expr->ts.kind);
 
     case BT_REAL:
-      if (expr->from_H)
+      if (expr->representation.string)
 	return build1 (VIEW_CONVERT_EXPR,
 			gfc_get_real_type (expr->ts.kind),
-			gfc_build_string_const (expr->value.character.length,
-				expr->value.character.string));
+			gfc_build_string_const (expr->representation.length,
+				expr->representation.string));
       else
 	return gfc_conv_mpfr_to_tree (expr->value.real, expr->ts.kind);
 
     case BT_LOGICAL:
-      if (expr->from_H)
+      if (expr->representation.string)
 	return build1 (VIEW_CONVERT_EXPR,
 			gfc_get_logical_type (expr->ts.kind),
-			gfc_build_string_const (expr->value.character.length,
-				expr->value.character.string));
+			gfc_build_string_const (expr->representation.length,
+				expr->representation.string));
       else
 	return build_int_cst (gfc_get_logical_type (expr->ts.kind),
 			    expr->value.logical);
 
     case BT_COMPLEX:
-      if (expr->from_H)
+      if (expr->representation.string)
 	return build1 (VIEW_CONVERT_EXPR,
 			gfc_get_complex_type (expr->ts.kind),
-			gfc_build_string_const (expr->value.character.length,
-				expr->value.character.string));
+			gfc_build_string_const (expr->representation.length,
+				expr->representation.string));
       else
 	{
 	  tree real = gfc_conv_mpfr_to_tree (expr->value.complex.r,
@@ -260,10 +260,13 @@ gfc_conv_constant_to_tree (gfc_expr * expr)
 	}
 
     case BT_CHARACTER:
-    case BT_HOLLERITH:
       return gfc_build_string_const (expr->value.character.length,
 				     expr->value.character.string);
 
+    case BT_HOLLERITH:
+      return gfc_build_string_const (expr->representation.length,
+				     expr->representation.string);
+
     default:
       fatal_error ("gfc_conv_constant_to_tree(): invalid type: %s",
 		   gfc_typename (&expr->ts));
diff --git a/gcc/fortran/trans-expr.c b/gcc/fortran/trans-expr.c
index e621a6a..c8f8012 100644
--- a/gcc/fortran/trans-expr.c
+++ b/gcc/fortran/trans-expr.c
@@ -3567,8 +3567,9 @@ is_zero_initializer_p (gfc_expr * expr)
 {
   if (expr->expr_type != EXPR_CONSTANT)
     return false;
-  /* We ignore Hollerith constants for the time being.  */
-  if (expr->from_H)
+
+  /* We ignore constants with prescribed memory representations for now.  */
+  if (expr->representation.string)
     return false;
 
   switch (expr->ts.type)
diff --git a/gcc/fortran/trans-stmt.c b/gcc/fortran/trans-stmt.c
index ec7548e..b1cd029 100644
--- a/gcc/fortran/trans-stmt.c
+++ b/gcc/fortran/trans-stmt.c
@@ -1139,7 +1139,8 @@ gfc_trans_integer_select (gfc_code * code)
 
 	  if (cp->low)
 	    {
-	      low = gfc_conv_constant_to_tree (cp->low);
+	      low = gfc_conv_mpz_to_tree (cp->low->value.integer,
+					  cp->low->ts.kind);
 
 	      /* If there's only a lower bound, set the high bound to the
 		 maximum value of the case expression.  */
@@ -1169,7 +1170,8 @@ gfc_trans_integer_select (gfc_code * code)
 		  || (cp->low
 		      && mpz_cmp (cp->low->value.integer,
 				  cp->high->value.integer) != 0))
-		high = gfc_conv_constant_to_tree (cp->high);
+		high = gfc_conv_mpz_to_tree (cp->high->value.integer,
+					     cp->high->ts.kind);
 
 	      /* Unbounded case.  */
 	      if (!cp->low)