This fixes a flaw in the mechanism implemented to register modes and types
declared in the back-end with the front-end. The mechanism was implicitly
making the assumption that it is possible to deduce the size of a FP mode
from its precision and alignment; that's wrong in the general case, although
exceptions to the rule are quite rare (typically for an IEEE extended mode).
This changes the registration interface to accept a new 'precision' parameter
in addition to the 'size' and align both notions in the back-end and in the
front-end (the back-end precision was previously passed as the front-end size
and the back-end size was second-guessed by the front-end).
No functional changes on already working platforms.
Tested on x86_64-suse-linux, applied on the mainline and, for a simplified
version, on the 4.8 and 4.7 branches.
2014-03-13 Eric Botcazou <ebotca...@adacore.com>
PR ada/51483
* cstand.adb (Register_Float_Type): Add 'precision' parameter and use
it to set the RM size. Use directly 'size' for the Esize.
(Create_Back_End_Float_Types): Adjust call to above.
* get_targ.ads (Register_Type_Proc): Add 'precision' parameter.
* set_targ.ads (FPT_Mode_Entry): Add 'precision' component.
(Write_Target_Dependent_Values): Adjust comment.
* set_targ.adb (Register_Float_Type): Add 'precision' parameter and
deal with it.
(Write_Target_Dependent_Values): Write the precision in lieu of size.
(Initialization): Read the precision in lieu of size and compute the
size from the precision and the alignment.
* gcc-interface/gigi.h (enumerate_modes): Add integer parameter.
* gcc-interface/misc.c (enumerate_modes): Likewise. Do not register
types for vector modes, pass the size in addition to the precision.
--
Eric BotcazouIndex: get_targ.ads
===================================================================
--- get_targ.ads (revision 208528)
+++ get_targ.ads (working copy)
@@ -6,7 +6,7 @@
-- --
-- S p e c --
-- --
--- Copyright (C) 1992-2013, Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2014, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
@@ -28,8 +28,8 @@
-- exp_dbug and the elaboration of ttypes, via the Set_Targs package.
-- It also contains the routine for registering floating-point types.
--- NOTE: Any changes in this package must be reflected in jgettarg.ads
--- and aa_getta.ads and any other versions of this package.
+-- NOTE: Any changes in this package must be reflected in aa_getta.adb
+-- and any other version in the various back ends.
-- Note that all these values return sizes of C types with corresponding
-- names. This allows GNAT to define the corresponding Ada types to have
@@ -134,6 +134,7 @@ package Get_Targ is
Complex : Boolean; -- True iff type has real and imaginary parts
Count : Natural; -- Number of elements in vector, 0 otherwise
Float_Rep : Float_Rep_Kind; -- Representation used for fpt type
+ Precision : Positive; -- Precision of representation in bits
Size : Positive; -- Size of representation in bits
Alignment : Natural); -- Required alignment in bits
pragma Convention (C, Register_Type_Proc);
Index: cstand.adb
===================================================================
--- cstand.adb (revision 208528)
+++ cstand.adb (working copy)
@@ -6,7 +6,7 @@
-- --
-- B o d y --
-- --
--- Copyright (C) 1992-2013, Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2014, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
@@ -158,6 +158,7 @@ package body CStand is
(Name : String;
Digs : Positive;
Float_Rep : Float_Rep_Kind;
+ Precision : Positive;
Size : Positive;
Alignment : Natural);
-- Registers a single back end floating-point type (from FPT_Mode_Table in
@@ -167,7 +168,8 @@ package body CStand is
-- as a normal format (non-null-terminated) string. Digs is the number of
-- digits, which is always non-zero, since non-floating-point types were
-- filtered out earlier. Float_Rep indicates the kind of floating-point
- -- type, and Size and Alignment are the size and alignment in bits.
+ -- type, and Precision, Size and Alignment are the precision, size and
+ -- alignment in bits.
procedure Set_Integer_Bounds
(Id : Entity_Id;
@@ -480,7 +482,8 @@ package body CStand is
E : FPT_Mode_Entry renames FPT_Mode_Table (J);
begin
Register_Float_Type
- (E.NAME.all, E.DIGS, E.FLOAT_REP, E.SIZE, E.ALIGNMENT);
+ (E.NAME.all, E.DIGS, E.FLOAT_REP, E.PRECISION, E.SIZE,
+ E.ALIGNMENT);
end;
end loop;
end Create_Back_End_Float_Types;
@@ -2083,19 +2086,18 @@ package body CStand is
(Name : String;
Digs : Positive;
Float_Rep : Float_Rep_Kind;
+ Precision : Positive;
Size : Positive;
Alignment : Natural)
is
- Ent : constant Entity_Id := New_Standard_Entity;
- Esize : constant Pos :=
- Pos ((Size + Alignment - 1) / Alignment * Alignment);
+ Ent : constant Entity_Id := New_Standard_Entity;
begin
Set_Defining_Identifier (New_Node (N_Full_Type_Declaration, Stloc), Ent);
Make_Name (Ent, Name);
Set_Scope (Ent, Standard_Standard);
- Build_Float_Type (Ent, Esize, Float_Rep, Pos (Digs));
- Set_RM_Size (Ent, UI_From_Int (Int (Size)));
+ Build_Float_Type (Ent, Int (Size), Float_Rep, Pos (Digs));
+ Set_RM_Size (Ent, UI_From_Int (Int (Precision)));
Set_Alignment (Ent, UI_From_Int (Int (Alignment / 8)));
if No (Back_End_Float_Types) then
Index: set_targ.adb
===================================================================
--- set_targ.adb (revision 208528)
+++ set_targ.adb (working copy)
@@ -6,7 +6,7 @@
-- --
-- B o d y --
-- --
--- Copyright (C) 2013, Free Software Foundation, Inc. --
+-- Copyright (C) 2013-2014, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
@@ -140,6 +140,7 @@ package body Set_Targ is
Complex : Boolean;
Count : Natural;
Float_Rep : Float_Rep_Kind;
+ Precision : Positive;
Size : Positive;
Alignment : Natural);
pragma Convention (C, Register_Float_Type);
@@ -151,7 +152,8 @@ package body Set_Targ is
-- non-zero if the type has real and imaginary parts (also ignored during
-- registration). Count is the number of elements in a vector type (zero =
-- not a vector, registration ignores vectors). Float_Rep shows the kind of
- -- floating-point type, and Size/Alignment are the size/alignment in bits.
+ -- floating-point type, and Precision, Size and Alignment are the precision
+ -- size and alignment in bits.
--
-- So to summarize, the only types that are actually registered have Digs
-- non-zero, Complex zero (false), and Count zero (not a vector).
@@ -179,6 +181,7 @@ package body Set_Targ is
Complex : Boolean;
Count : Natural;
Float_Rep : Float_Rep_Kind;
+ Precision : Positive;
Size : Positive;
Alignment : Natural)
is
@@ -244,13 +247,24 @@ package body Set_Targ is
else
Write_Str ("mod 2**");
- Write_Int (Int (Size / Positive'Max (1, Count)));
+ Write_Int (Int (Precision / Positive'Max (1, Count)));
Write_Line (";");
end if;
- Write_Str ("for " & T (1 .. Last) & "'Size use ");
- Write_Int (Int (Size));
- Write_Line (";");
+ if Precision = Size then
+ Write_Str ("for " & T (1 .. Last) & "'Size use ");
+ Write_Int (Int (Size));
+ Write_Line (";");
+
+ else
+ Write_Str ("for " & T (1 .. Last) & "'Value_Size use ");
+ Write_Int (Int (Precision));
+ Write_Line (";");
+
+ Write_Str ("for " & T (1 .. Last) & "'Object_Size use ");
+ Write_Int (Int (Size));
+ Write_Line (";");
+ end if;
Write_Str ("for " & T (1 .. Last) & "'Alignment use ");
Write_Int (Int (Alignment / 8));
@@ -286,6 +300,7 @@ package body Set_Targ is
(NAME => new String'(T (1 .. Last)),
DIGS => Digs,
FLOAT_REP => Float_Rep,
+ PRECISION => Precision,
SIZE => Size,
ALIGNMENT => Alignment);
end if;
@@ -448,7 +463,7 @@ package body Set_Targ is
AddC (' ');
- AddN (E.SIZE);
+ AddN (E.PRECISION);
AddC (' ');
AddN (E.ALIGNMENT);
@@ -826,7 +841,7 @@ begin
N := N + 1;
Check_Spaces;
- E.SIZE := Get_Nat;
+ E.PRECISION := Get_Nat;
Check_Spaces;
E.ALIGNMENT := Get_Nat;
@@ -835,6 +850,11 @@ begin
FailN ("junk at end of line for");
end if;
+ -- ??? We do not read E.SIZE, see Write_Target_Dependent_Values
+
+ E.SIZE :=
+ (E.PRECISION + E.ALIGNMENT - 1) / E.ALIGNMENT * E.ALIGNMENT;
+
N := N + 1;
end;
end loop;
Index: set_targ.ads
===================================================================
--- set_targ.ads (revision 208528)
+++ set_targ.ads (working copy)
@@ -6,7 +6,7 @@
-- --
-- S p e c --
-- --
--- Copyright (C) 2013, Free Software Foundation, Inc. --
+-- Copyright (C) 2013-2014, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
@@ -94,6 +94,7 @@ package Set_Targ is
NAME : String_Ptr; -- Name of mode (no null character at end)
DIGS : Natural; -- Digits for floating-point type
FLOAT_REP : Float_Rep_Kind; -- Float representation
+ PRECISION : Natural; -- Precision in bits
SIZE : Natural; -- Size in bits
ALIGNMENT : Natural; -- Alignment in bits
end record;
@@ -130,7 +131,7 @@ package Set_Targ is
--
-- One line per registered mode
--
- -- name digs float_rep size alignment
+ -- name digs float_rep precision alignment
--
-- where name is the string name of the type (which can have single
-- spaces embedded in the name (e.g. long double). The name is followed
@@ -138,5 +139,12 @@ package Set_Targ is
-- for a Mode_Entry (where float_rep is I/V/A for IEEE-754-Binary,
-- Vax_Native, AAMP), fields are separated by at least one blank, and
-- a LF character immediately follows the alignment field.
+ --
+ -- ??? We do not write the size for backward compatibility reasons,
+ -- which means that target.atp will not be a complete description for
+ -- the very peculiar cases where the size cannot be computed from the
+ -- precision and the alignment by the formula:
+ --
+ -- size := (precision + alignment - 1) / alignment * alignment
end Set_Targ;
Index: gcc-interface/gigi.h
===================================================================
--- gcc-interface/gigi.h (revision 208528)
+++ gcc-interface/gigi.h (working copy)
@@ -6,7 +6,7 @@
* *
* C Header File *
* *
- * Copyright (C) 1992-2013, Free Software Foundation, Inc. *
+ * Copyright (C) 1992-2014, Free Software Foundation, Inc. *
* *
* GNAT is free software; you can redistribute it and/or modify it under *
* terms of the GNU General Public License as published by the Free Soft- *
@@ -1044,7 +1044,7 @@ extern Nat get_target_double_scalar_alig
/* This function is called by the front-end to enumerate all the supported
modes for the machine, as well as some predefined C types. */
extern void enumerate_modes (void (*f) (const char *, int, int, int, int, int,
- int));
+ int, int));
#ifdef __cplusplus
}
Index: gcc-interface/misc.c
===================================================================
--- gcc-interface/misc.c (revision 208528)
+++ gcc-interface/misc.c (working copy)
@@ -6,7 +6,7 @@
* *
* C Implementation File *
* *
- * Copyright (C) 1992-2013, Free Software Foundation, Inc. *
+ * Copyright (C) 1992-2014, Free Software Foundation, Inc. *
* *
* GNAT is free software; you can redistribute it and/or modify it under *
* terms of the GNU General Public License as published by the Free Soft- *
@@ -683,7 +683,7 @@ must_pass_by_ref (tree gnu_type)
/* This function is called by the front-end to enumerate all the supported
modes for the machine, as well as some predefined C types. F is a function
which is called back with the parameters as listed below, first a string,
- then six ints. The name is any arbitrary null-terminated string and has
+ then seven ints. The name is any arbitrary null-terminated string and has
no particular significance, except for the case of predefined C types, where
it should be the name of the C type. For integer types, only signed types
should be listed, unsigned versions are assumed. The order of types should
@@ -699,11 +699,12 @@ must_pass_by_ref (tree gnu_type)
COMPLEX_P nonzero is this represents a complex mode
COUNT count of number of items, nonzero for vector mode
FLOAT_REP Float_Rep_Kind for FP, otherwise undefined
- SIZE number of bits used to store data
+ PRECISION number of bits used to store data
+ SIZE number of bits occupied by the mode
ALIGN number of bits to which mode is aligned. */
void
-enumerate_modes (void (*f) (const char *, int, int, int, int, int, int))
+enumerate_modes (void (*f) (const char *, int, int, int, int, int, int, int))
{
const tree c_types[]
= { float_type_node, double_type_node, long_double_type_node };
@@ -777,28 +778,26 @@ enumerate_modes (void (*f) (const char *
/* First register any C types for this mode that the front end
may need to know about, unless the mode should be skipped. */
-
- if (!skip_p)
+ if (!skip_p && !vector_p)
for (nameloop = 0; nameloop < ARRAY_SIZE (c_types); nameloop++)
{
- tree typ = c_types[nameloop];
- const char *nam = c_names[nameloop];
+ tree type = c_types[nameloop];
+ const char *name = c_names[nameloop];
- if (TYPE_MODE (typ) == i)
+ if (TYPE_MODE (type) == i)
{
- f (nam, digs, complex_p,
- vector_p ? GET_MODE_NUNITS (i) : 0, float_rep,
- TYPE_PRECISION (typ), TYPE_ALIGN (typ));
+ f (name, digs, complex_p, 0, float_rep, TYPE_PRECISION (type),
+ TREE_INT_CST_LOW (TYPE_SIZE (type)), TYPE_ALIGN (type));
skip_p = true;
}
}
/* If no predefined C types were found, register the mode itself. */
-
if (!skip_p)
f (GET_MODE_NAME (i), digs, complex_p,
vector_p ? GET_MODE_NUNITS (i) : 0, float_rep,
- GET_MODE_PRECISION (i), GET_MODE_ALIGNMENT (i));
+ GET_MODE_PRECISION (i), GET_MODE_BITSIZE (i),
+ GET_MODE_ALIGNMENT (i));
}
}
