This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC project.

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]
Other format:	[Raw text]

patch: Re: rfc: auto-casted vector types

From: Aldy Hernandez <aldyh at redhat dot com>
To: Jim Wilson <wilson at redhat dot com>
Cc: GCC Mailinglist <gcc at gcc dot gnu dot org>, Nick Clifton <nickc at redhat dot com>, gcc-patches at gcc dot gnu dot org, Kumar Gala <kumar dot gala at motorola dot com>
Date: Mon, 17 Feb 2003 16:16:09 -0800
Subject: patch: Re: rfc: auto-casted vector types

Is there any publicly available documentation? My copy of the draft docs
say they are Motorola confidential. If there is documentation available,
it would be useful to point to it somewhere.

According to Kumar, no.

The patch looks pretty reasonable to me also. I agree with Zack's suggestions.

Done.

It might be useful to note in the comments in the rs6000 file that the
current implementation has a known flaw. It pretends that V2SI is the opaque
vector type. This means that it accidentally allows conversions to/from the
V2SI vector type without explicit casts. In order to fix this, we need to

I added a comment.

use a different otherwise unused vector type for the opaque vector type.
Nick started on a patch to do this, but didn't have enough time to finish it.

As I recall he used V8QI, but that had other problems. V1DI, as Kumar suggests,
is probably a better approach, but will require heavily massaging spe.h/spe.md. I'll try that later, since that will probably break other things I don't have time to fix right now ;-).

OK, I'm formally submitting the patch now. I've built an spe toolchain with this, and a generic powerpc-linux bootstrap/regtest is in progress.

OK to install when tests finish?

Aldy

2003-02-17 Nick Clifton <nickc@redhat.com>
Aldy Hernandez <aldyh@redhat.com>

* defaults.h (TARGET_VECTOR_TYPES_COMPATIBLE): Define.

* doc/tm.texi: Document TARGET_VECTOR_TYPES_COMPATIBLE.

* c-typeck.c (comptypes): Take into account
TARGET_VECTOR_TYPES_COMPATIBLE.
(convert_for_assignment): Same.
(really_start_incremental_init): Disallow initialization of
ev64_opaque types.

* config/rs6000/rs6000-protos.h
(rs6000_spe_vector_types_compatible): Prototype.

* config/rs6000/rs6000.c (is_ev64_opaque_type): New.
(rs6000_spe_vector_types_compatible): New.

* config/rs6000/rs6000.h (TARGET_VECTOR_TYPES_COMPATIBLE): Define.

Index: defaults.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/defaults.h,v
retrieving revision 1.101
diff -c -p -r1.101 defaults.h
*** defaults.h 24 Jan 2003 22:07:00 -0000 1.101
--- defaults.h 18 Feb 2003 00:09:35 -0000
*************** You Lose! You must define PREFERRED_DEB
*** 595,600 ****
--- 595,607 ----
#define VECTOR_MODE_SUPPORTED_P(MODE) 0
#endif

+ /* Define this macro to return nonzero if no cast is needed when
+ copying a vector value of type TYPE1 to a vector value of
+ type TYPE2. */
+ #ifndef TARGET_VECTOR_TYPES_COMPATIBLE
+ #define TARGET_VECTOR_TYPES_COMPATIBLE(TYPE1, TYPE2) 0
+ #endif
+
/* Determine whether __cxa_atexit, rather than atexit, is used to
register C++ destructors for local statics and global objects. */
#ifndef DEFAULT_USE_CXA_ATEXIT
Index: c-typeck.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/c-typeck.c,v
retrieving revision 1.218
diff -c -p -r1.218 c-typeck.c
*** c-typeck.c 1 Feb 2003 13:09:39 -0000 1.218
--- c-typeck.c 18 Feb 2003 00:09:41 -0000
*************** comptypes (type1, type2)
*** 574,579 ****
--- 574,584 ----
val = 1;
break;

+ case VECTOR_TYPE:
+ /* The target might allow certain vector types to be compatible. */
+ val = TARGET_VECTOR_TYPES_COMPATIBLE (t1, t2);
+ break;
+
default:
break;
}
*************** convert_for_assignment (type, rhs, errty
*** 4061,4066 ****
--- 4066,4075 ----
rhs = build1 (NOP_EXPR, type, rhs);
return rhs;
}
+ /* Some types can interconvert without explicit casts. */
+ else if (codel == VECTOR_TYPE && coder == VECTOR_TYPE
+ && TARGET_VECTOR_TYPES_COMPATIBLE (type, rhstype))
+ return convert (type, rhs);
/* Arithmetic types all interconvert, and enum is treated like int. */
else if ((codel == INTEGER_TYPE || codel == REAL_TYPE
|| codel == ENUMERAL_TYPE || codel == COMPLEX_TYPE
Index: doc/tm.texi
===================================================================
RCS file: /cvs/gcc/gcc/gcc/doc/tm.texi,v
retrieving revision 1.198
diff -c -p -r1.198 tm.texi
*** doc/tm.texi 31 Jan 2003 23:34:17 -0000 1.198
--- doc/tm.texi 18 Feb 2003 00:10:20 -0000
*************** Define this macro to be nonzero if the p
*** 1302,1307 ****
--- 1302,1313 ----
involving vector mode @var{mode}. At the very least, it must have move
patterns for this mode.

+ @findex TARGET_VECTOR_TYPES_COMPATIBLE
+ @item TARGET_VECTOR_TYPES_COMPATIBLE(@var{tree1}, @var{tree2})
+ Define this macro to return nonzero if no cast is needed when copying
+ a vector value of type @var{tree1} to a vector value of type
+ @var{tree2}.
+
@findex STACK_SAVEAREA_MODE
@item STACK_SAVEAREA_MODE (@var{save_level})
If defined, an expression of type @code{enum machine_mode} that
Index: config/rs6000/rs6000.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/rs6000/rs6000.c,v
retrieving revision 1.422
diff -c -p -r1.422 rs6000.c
*** config/rs6000/rs6000.c 10 Feb 2003 18:42:19 -0000 1.422
--- config/rs6000/rs6000.c 18 Feb 2003 00:10:29 -0000
*************** static void is_altivec_return_reg PARAMS
*** 265,270 ****
--- 265,271 ----
static rtx generate_set_vrsave PARAMS ((rtx, rs6000_stack_t *, int));
static void altivec_frame_fixup PARAMS ((rtx, rtx, HOST_WIDE_INT));
static int easy_vector_constant PARAMS ((rtx));
+ static int is_ev64_opaque_type PARAMS ((tree));

/* Hash table stuff for keeping track of TOC entries. */

*************** rs6000_memory_move_cost (mode, class, in
*** 13522,13527 ****
--- 13523,13558 ----
return 4 * HARD_REGNO_NREGS (FIRST_ALTIVEC_REGNO, mode);
else
return 4 + rs6000_register_move_cost (mode, class, GENERAL_REGS);
+ }
+
+ static int
+ is_ev64_opaque_type (type)
+ tree type;
+ {
+ return (TYPE_NAME (type)
+ && TREE_CODE (TYPE_NAME (type)) == TYPE_DECL
+ && DECL_NAME (TYPE_NAME (type))
+ && strcmp (IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (type))),
+ "__ev64_opaque__") == 0);
+ }
+
+ /* Return true iff vector type1 can be converted into vector type2. */
+
+ int
+ rs6000_spe_vector_types_compatible (t1, t2)
+ tree t1;
+ tree t2;
+ {
+ if (TREE_CODE (t1) != VECTOR_TYPE || TREE_CODE (t2) != VECTOR_TYPE)
+ return 0;
+
+ if (TYPE_NAME (t1) || TYPE_NAME (t2))
+ return is_ev64_opaque_type (t1) || is_ev64_opaque_type (t2);
+
+ /* FIXME: We assume V2SI is the opaque type, so we accidentally
+ allow inter conversion to and from V2SI modes. We could use
+ V1D1, and rewrite <spe.h> accordingly. */
+ return t1 == V2SI_type_node || t2 == V2SI_type_node;
}

#include "gt-rs6000.h"
Index: config/rs6000/rs6000.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/rs6000/rs6000.h,v
retrieving revision 1.251
diff -c -p -r1.251 rs6000.h
*** config/rs6000/rs6000.h 8 Feb 2003 03:59:40 -0000 1.251
--- config/rs6000/rs6000.h 18 Feb 2003 00:10:41 -0000
*************** extern int rs6000_default_long_calls;
*** 892,897 ****
--- 892,901 ----
|| (MODE) == V1DImode \
|| (MODE) == V2SImode)

+ /* Allow SPE vector types to be inter-converted. */
+ #define TARGET_VECTOR_TYPES_COMPATIBLE(t1,t2) \
+ (TARGET_SPE ? rs6000_spe_vector_types_compatible (t1, t2) : 0)
+
/* Define this macro to be nonzero if the port is prepared to handle
insns involving vector mode MODE. At the very least, it must have
move patterns for this mode. */

References:
- Re: rfc: auto-casted vector types
  - From: Jim Wilson

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]