From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <19990429194817.B20300@cygnus.com> Date: Thu, 29 Apr 1999 19:48:17 -0700 From: Richard Henderson To: Franz Sirl , egcs-patches@egcs.cygnus.com Cc: meissner@cygnus.com, David Edelsohn , linuxppc-dev@lists.linuxppc.org Subject: Re: PATCH: Fix 2 PPC/SYSV varargs problems References: <4.2.0.37.19990430013458.0489a950@mail.lauterbach.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <4.2.0.37.19990430013458.0489a950@mail.lauterbach.com>; from Franz Sirl on Fri, Apr 30, 1999 at 02:09:09AM +0200 Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: On Fri, Apr 30, 1999 at 02:09:09AM +0200, Franz Sirl wrote: > 1. the varargs save area calculation bug, this is a hack and Richard ;-) > probably won't like it, but maybe it's good enough for egcs-1.2 You're right -- I hate it. You'll have made it so I can't build a ppc cross compiler on my Alphas, and you'll have killed the compiler for a ppc64-linux. Here's an implementation of what I'd suggested before. It looks ok to the eye, but I don't have a ppc-linux box handy to try it out on. r~ * va-ppc.h (__va_start_common): Let __builtin_saveregs do the work. * rs6000.c (expand_builtin_saveregs): For SYSV, initialize a private va_list struct, and return a pointer to it. Index: ginclude/va-ppc.h =================================================================== RCS file: /egcs/carton/cvsfiles/egcs/gcc/ginclude/va-ppc.h,v retrieving revision 1.4 diff -c -p -d -r1.4 va-ppc.h *** va-ppc.h 1998/12/16 21:19:40 1.4 --- va-ppc.h 1999/04/30 02:45:30 *************** typedef struct { *** 59,92 **** ((TYPE *) (void *) (&(((__va_regsave_t *) \ (AP)->reg_save_area)->__gp_save[(int)(AP)->gpr]))) ! /* Common code for va_start for both varargs and stdarg. This depends ! on the format of rs6000_args in rs6000.h. The fields used are: ! ! #0 WORDS # words used for GP regs/stack values ! #1 FREGNO next available FP register ! #2 NARGS_PROTOTYPE # args left in the current prototype ! #3 ORIG_NARGS original value of NARGS_PROTOTYPE ! #4 VARARGS_OFFSET offset from frame pointer of varargs area */ ! ! #define __va_words __builtin_args_info (0) ! #define __va_fregno __builtin_args_info (1) ! #define __va_nargs __builtin_args_info (2) ! #define __va_orig_nargs __builtin_args_info (3) ! #define __va_varargs_offset __builtin_args_info (4) ! #define __va_start_common(AP, FAKE) \ ! __extension__ ({ \ ! register int __words = __va_words - FAKE; \ ! \ ! (AP)->gpr = (__words < 8) ? __words : 8; \ ! (AP)->fpr = __va_fregno - 33; \ ! (AP)->reg_save_area = (((char *) __builtin_frame_address (0)) \ ! + __va_varargs_offset); \ ! __va_overflow(AP) = ((char *)__builtin_saveregs () \ ! + (((__words >= 8) ? __words - 8 : 0) \ ! * sizeof (long))); \ ! (void)0; \ ! }) #ifdef _STDARG_H /* stdarg.h support */ --- 59,71 ---- ((TYPE *) (void *) (&(((__va_regsave_t *) \ (AP)->reg_save_area)->__gp_save[(int)(AP)->gpr]))) ! /* Common code for va_start for both varargs and stdarg. We allow all ! the work to be done by __builtin_saveregs. It returns a pointer to ! a va_list that was constructed on the stack; we must simply copy it ! to the user's variable. */ ! #define __va_start_common(AP, FAKE) \ ! __builtin_memcpy ((AP), __builtin_saveregs (), sizeof(__gnuc_va_list)) #ifdef _STDARG_H /* stdarg.h support */ Index: config/rs6000/rs6000.c =================================================================== RCS file: /egcs/carton/cvsfiles/egcs/gcc/config/rs6000/rs6000.c,v retrieving revision 1.66 diff -c -p -d -r1.66 rs6000.c *** rs6000.c 1999/04/27 12:39:58 1.66 --- rs6000.c 1999/04/30 02:45:30 *************** setup_incoming_varargs (cum, mode, type, *** 1704,1716 **** On the Power/PowerPC return the address of the area on the stack used to hold arguments. Under AIX, this includes the 8 word register ! save area. Under V.4 this does not. */ struct rtx_def * expand_builtin_saveregs (args) tree args ATTRIBUTE_UNUSED; { ! return virtual_incoming_args_rtx; } --- 1704,1786 ---- On the Power/PowerPC return the address of the area on the stack used to hold arguments. Under AIX, this includes the 8 word register ! save area. ! ! Under V.4, things are more complicated. We do not have access to ! all of the virtual registers required for va_start to do its job, ! so we construct the va_list in its entirity here, and reduce va_start ! to a block copy. This is similar to the way we do things on Alpha. */ struct rtx_def * expand_builtin_saveregs (args) tree args ATTRIBUTE_UNUSED; { ! rtx block, mem_gpr_fpr, mem_reg_save_area, mem_overflow, tmp; ! tree fntype; ! int stdarg_p; ! HOST_WIDE_INT words, gpr, fpr; ! ! if (DEFAULT_ABI != ABI_V4 && DEFAULT_ABI != ABI_SOLARIS) ! return virtual_incoming_args_rtx; ! ! fntype = TREE_TYPE (current_function_decl); ! stdarg_p = (TYPE_ARG_TYPES (fntype) != 0 ! && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype))) ! != void_type_node)); ! ! /* Allocate the va_list constructor. */ ! block = assign_stack_local (BLKmode, 3 * UNITS_PER_WORD, BITS_PER_WORD); ! RTX_UNCHANGING_P (block) = 1; ! RTX_UNCHANGING_P (XEXP (block, 0)) = 1; ! ! mem_gpr_fpr = change_address (block, word_mode, XEXP (block, 0)); ! mem_overflow = change_address (block, ptr_mode, ! plus_constant (XEXP (block, 0), ! UNITS_PER_WORD)); ! mem_reg_save_area = change_address (block, ptr_mode, ! plus_constant (XEXP (block, 0), ! 2 * UNITS_PER_WORD)); ! ! /* Construct the two characters of `gpr' and `fpr' as a unit. */ ! words = current_function_args_info.words - !stdarg_p; ! gpr = (words > 8 ? 8 : words); ! fpr = current_function_args_info.fregno - 33; ! ! if (BYTES_BIG_ENDIAN) ! { ! HOST_WIDE_INT bits = gpr << 8 | fpr; ! if (HOST_BITS_PER_WIDE_INT >= BITS_PER_WORD) ! tmp = GEN_INT (bits << (BITS_PER_WORD - 16)); ! else ! { ! bits <<= BITS_PER_WORD - HOST_BITS_PER_WIDE_INT - 16; ! tmp = immed_double_const (0, bits, word_mode); ! } ! } ! else ! tmp = GEN_INT (fpr << 8 | gpr); ! ! emit_move_insn (mem_gpr_fpr, tmp); ! ! /* Find the overflow area. */ ! if (words <= 8) ! tmp = virtual_incoming_args_rtx; ! else ! tmp = expand_binop (Pmode, add_optab, virtual_incoming_args_rtx, ! GEN_INT ((words - 8) * UNITS_PER_WORD), ! mem_overflow, 0, OPTAB_WIDEN); ! if (tmp != mem_overflow) ! emit_move_insn (mem_overflow, tmp); ! ! /* Find the register save area. */ ! tmp = expand_binop (Pmode, add_optab, virtual_stack_vars_rtx, ! GEN_INT (-RS6000_VARARGS_SIZE), ! mem_reg_save_area, 0, OPTAB_WIDEN); ! if (tmp != mem_reg_save_area) ! emit_move_insn (mem_reg_save_area, tmp); ! ! /* Return the address of the va_list constructor. */ ! return XEXP (block, 0); } [[ This message was sent via the linuxppc-dev mailing list. Replies are ]] [[ not forced back to the list, so be sure to Cc linuxppc-dev if your ]] [[ reply is of general interest. Please check http://lists.linuxppc.org/ ]] [[ and http://www.linuxppc.org/ for useful information before posting. ]]