README.C4X: New file with information about the c4x ports.

        * README.C4X: New file with information about the c4x ports.
        * ginclude/va-c4x.h: New file for c4x varargs support.
        * config/c4x: New directory with c4x port files.

From-SVN: r22475

gcc/ChangeLog

+Sat Sep 19 01:00:32 1998  Michael Hayes  (mph@elec.canterbury.ac.nz)
+
+	* README.C4X: New file with information about the c4x ports.
+	* ginclude/va-c4x.h: New file for c4x varargs support.
+	* config/c4x: New directory with c4x port files.
+
 Fri Sep 18 22:52:05 1998  Jeffrey A Law  (law@cygnus.com)
 
 	* reload.c (find_reloads): Do not replace a pseudo with 

gcc/README.C4X

+This file describes the implementation notes of the GNU C Compiler for
+the Texas Instruments Floating Point Digital Signal Processor
+families, TMS320C3x and TMS320C4x (including the C30, C31, C32, C40,
+and C44 chips).
+
+
+Currently, only two code variants are generated---those for the C3x
+and C4x architectures.  Note that the new operand combinations for
+parallel instructions, included in newer silicon revisions, are not
+yet supported.  These should be trivial to add for someone with the
+newer chips and the inclination.
+
+
+While the generated assembly code is fairly similar to that recognised
+by the TI assembler, there are a few differences (currently the machine
+option -mti, designed to enfore compatibility, is not fully
+implemented).  The major difference is the use of the ^ operator to
+load the 16 MSBs of an address or constant for the C4x.
+
+
+The generated assembly code requires the GNU assembler (GAS).  This is
+not currently included as part of the binutils package, due to the
+many hacks required to be compatible with TI's kludged COFF
+implementation, and the binutils not being designed for 32-bit bytes.
+Patches against binutils-2.7.2 can be obtained from
+ftp://ongaonga.chch.cri.nz/pub/c4x.  This site also has patches for
+the GNU debugger (GDB), incoporating a cycle accurate simulator that
+can display profiles and histories of code execution, detailing
+pipeline conflicts etc.
+
+
+GCC can be configured as a cross compiler for both the C3x and C4x
+architectures on the same system.  Use `configure --target=c4x' to
+configure GCC for both the C3x and C4x.  Then use the -m30 option to
+generate code for the C30 or -m40 (the default) for the C40.
+
+
+Further installation notes and other optimization patches for GCC can
+also be obtained from ftp://ongaonga.chch.cri.nz/pub/c4x.
+
+
+A Majordomo mailing list, gcc_c40@atlantek.com.au, exists to discuss
+related issues and suggestions for further optimizations.  To
+subscribe send a message with `subscribe gcc_c40' in the body to
+majordomo@atlantek.com.au.
+
+
+Michael Hayes,  16 Sep 98

gcc/config/c4x/t-c4x

+CROSS_LIBGCC1 = libgcc1-asm.a
+LIB1ASMSRC = c4x/libgcc.S
+LIB1ASMFUNCS = _divqf3 _divqi3 _udivqi3 _umodqi3 _modqi3 _mulqi3 \
+	_mulhf3 _divhf3 _unsfltconst _unsfltcompare \
+	_mulhi3 _umulhi3_high _smulhi3_high _divhi3 _modhi3 _umodhi3 _udivhi3 \
+	_fix_truncqfhi2 _ufix_truncqfhi2 _floathiqf2 _ufloathiqf2 \
+	_floathihf2 _ufloathihf2 _fix_trunchfhi2 _ufix_trunchfhi2 _ffs
+
+# We do not have DF or DI types (or SF and SI for that matter),
+# so fake out the libgcc2 compilation.
+LIBGCC2_CFLAGS = -O2 -Dexit=unused_exit $(GCC_CFLAGS) $(LIBGCC2_INCLUDES) -DDF=HF -DDI=HI -DSF=QF -DSI=QI
+
+MULTILIB_OPTIONS = m30 msmall mmemparm
+MULTILIB_DIRNAMES = c3x small mem
+MULTILIB_MATCHES = m30=mcpu?30 m30=mcpu?31 m30=mcpu?32 m30=m31 m30=m32
+MULTILIB_EXCEPTIONS =
+MULTILIB_EXTRA_OPTS =
+LIBGCC = stmp-multilib
+INSTALL_LIBGCC = install-multilib
+
+# Don't make libgcc1-test since require crt0.o
+LIBGCC1_TEST =
+
+# Don't make objective C because we can't compile the libraries.
+LANGUAGES = c proto  c++
+
+# C[34]x has its own float and limits.h
+TARGET_FLOAT_H=config/c4x/c4x-float.h
+TARGET_LIMITS_H=config/c4x/c4x-limits.h

gcc/config/c4x/xm-c4x.h

+/* #defines that need visibility everywhere.  */
+#define FALSE 0
+#define TRUE 1
+
+/* This describes the machine the compiler is hosted on.  */
+#define HOST_BITS_PER_CHAR 32
+#define HOST_BITS_PER_SHORT 32
+#define HOST_BITS_PER_INT 32
+#define HOST_BITS_PER_LONG 32
+#define HOST_BITS_PER_LONGLONG 64
+
+#define HOST_WORDS_BIG_ENDIAN
+
+/* target machine dependencies.
+   tm.h is a symbolic link to the actual target specific file.   */
+#include "tm.h"
+
+/* Arguments to use with `exit'.  */
+#define SUCCESS_EXIT_CODE 0
+#define FATAL_EXIT_CODE 33
+

gcc/ginclude/va-c4x.h

+/* GNU C varargs support for the TMS320C[34]x  */
+
+/* C[34]x arguments grow in weird ways (downwards) that the standard
+   varargs stuff can't handle. */
+
+#ifndef __GNUC_VA_LIST
+#define __GNUC_VA_LIST
+
+typedef void *__gnuc_va_list;
+
+#endif /* not __GNUC_VA_LIST */
+
+/* If this is for internal libc use, don't define anything but
+   __gnuc_va_list.  */
+#if defined (_STDARG_H) || defined (_VARARGS_H)
+
+#ifdef _STDARG_H /* stdarg.h support */
+
+#define va_start(AP,LASTARG) AP=(__gnuc_va_list) __builtin_next_arg (LASTARG)
+
+#else /* varargs.h support */
+
+#define	__va_ellipsis	...
+#define	va_alist	__builtin_va_alist
+#define	va_dcl		int __builtin_va_alist; __va_ellipsis
+#define va_start(AP)	AP=(__gnuc_va_list) ((int *)&__builtin_va_alist +  1)
+
+#endif /* _STDARG_H */
+
+#define va_end(AP)	((void) 0)
+#define va_arg(AP,TYPE)	(AP = (__gnuc_va_list) ((char *) (AP) - sizeof(TYPE)), \
+			 *((TYPE *) ((char *) (AP))))
+
+#endif /* defined (_STDARG_H) || defined (_VARARGS_H) */