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Re: [ping] Re: [RFA] sh-tdep: multi-arch the push_dummy_call method.
- From: Elena Zannoni <ezannoni at redhat dot com>
- To: Michael Snyder <msnyder at redhat dot com>
- Cc: gdb-patches at sources dot redhat dot com, ezannoni at redhat dot com
- Date: Mon, 11 Aug 2003 21:11:15 -0400
- Subject: Re: [ping] Re: [RFA] sh-tdep: multi-arch the push_dummy_call method.
- References: <3F2AE7A7.4070604@redhat.com><3F3820A4.7060501@redhat.com>
Michael Snyder writes:
> Michael Snyder wrote:
>
> > Elena, this splits off two versions of push_dummy_call: one for sh2e,
> > sh3e, and sh4, and the other for all the others. There are two
> > differences:
> > how they pass floats, and how they pass large structs.
> >
> > This wins us 6 new passes in call-ar-st, one in call-rt-st, 13 in
> > callfuncs,
> > and one in varargs.
> >
For which versions do we get more passes? all versions < sh5?
I don't have an abi document, in front of me, you are not just making
the tests pass, i.e. complying with what gcc thinks the ABI is, right? ;-)
ok
elena
> >
> >
> >------------------------------------------------------------------------
> >
> >2003-07-30 Michael Snyder <msnyder@redhat.com>
> >
> > * sh-tdep.h (struct gdbarch_tdep): New member FLOAT_ARGLAST_REG.
> > * sh-tdep.c (sh_gdbarch_init): For sh2e, sh3e, and sh4, set
> > FLOAT_ARG0_REGNUM and FLOAT_ARGLAST_REGNUM, to be used for
> > argument passing.
> > (sh_push_dummy_call_fpu, sh_push_dummy_call_nofpu): New
> > functions, replace sh_push_dummy_call.
> > (sh_gdbarch_init): Set push_dummy_call to one of new methods.
> >
> >Index: sh-tdep.c
> >===================================================================
> >RCS file: /cvs/src/src/gdb/sh-tdep.c,v
> >retrieving revision 1.135
> >diff -p -r1.135 sh-tdep.c
> >*** sh-tdep.c 1 Aug 2003 19:52:49 -0000 1.135
> >--- sh-tdep.c 1 Aug 2003 22:00:40 -0000
> >*************** sh_frame_align (struct gdbarch *ignore,
> >*** 2034,2040 ****
> > return sp & ~3;
> > }
> >
> >! /* Function: push_arguments
> > Setup the function arguments for calling a function in the inferior.
> >
> > On the Hitachi SH architecture, there are four registers (R4 to R7)
> >--- 2034,2040 ----
> > return sp & ~3;
> > }
> >
> >! /* Function: sh_push_dummy_call (formerly push_arguments)
> > Setup the function arguments for calling a function in the inferior.
> >
> > On the Hitachi SH architecture, there are four registers (R4 to R7)
> >*************** sh_frame_align (struct gdbarch *ignore,
> >*** 2042,2047 ****
> >--- 2042,2051 ----
> > four arguments (depending on size) may go into these registers.
> > The rest go on the stack.
> >
> >+ MVS: Except on SH variants that have floating point registers.
> >+ In that case, float and double arguments are passed in the same
> >+ manner, but using FP registers instead of GP registers.
> >+
> > Arguments that are smaller than 4 bytes will still take up a whole
> > register or a whole 32-bit word on the stack, and will be
> > right-justified in the register or the stack word. This includes
> >*************** sh_frame_align (struct gdbarch *ignore,
> >*** 2055,2060 ****
> >--- 2059,2069 ----
> > that will be passed in this way; in other words, the convention of
> > passing a pointer to a large aggregate instead of a copy is not used.
> >
> >+ MVS: The above appears to be true for the SH variants that do not
> >+ have an FPU, however those that have an FPU appear to copy the
> >+ aggregate argument onto the stack (and not place it in registers)
> >+ if it is larger than 16 bytes (four GP registers).
> >+
> > An exceptional case exists for struct arguments (and possibly other
> > aggregates such as arrays) if the size is larger than 4 bytes but
> > not a multiple of 4 bytes. In this case the argument is never split
> >*************** sh_frame_align (struct gdbarch *ignore,
> >*** 2078,2088 ****
> > to R7. */
> >
> > static CORE_ADDR
> >! sh_push_dummy_call (struct gdbarch *gdbarch, CORE_ADDR func_addr,
> >! struct regcache *regcache, CORE_ADDR bp_addr, int nargs,
> >! struct value **args, CORE_ADDR sp, int struct_return,
> >! CORE_ADDR struct_addr)
> >
> > {
> > int stack_offset, stack_alloc;
> > int argreg;
> >--- 2087,2210 ----
> > to R7. */
> >
> > static CORE_ADDR
> >! sh_push_dummy_call_fpu (struct gdbarch *gdbarch,
> >! CORE_ADDR func_addr,
> >! struct regcache *regcache,
> >! CORE_ADDR bp_addr, int nargs,
> >! struct value **args,
> >! CORE_ADDR sp, int struct_return,
> >! CORE_ADDR struct_addr)
> >! {
> >! int stack_offset, stack_alloc;
> >! int argreg, flt_argreg;
> >! int argnum;
> >! struct type *type;
> >! CORE_ADDR regval;
> >! char *val;
> >! char valbuf[4];
> >! int len;
> >! int odd_sized_struct;
> >! struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
> >!
> >! /* first force sp to a 4-byte alignment */
> >! sp = sh_frame_align (gdbarch, sp);
> >!
> >! /* The "struct return pointer" pseudo-argument has its own dedicated
> >! register */
> >! if (struct_return)
> >! regcache_cooked_write_unsigned (regcache,
> >! STRUCT_RETURN_REGNUM,
> >! struct_addr);
> >!
> >! /* Now make sure there's space on the stack */
> >! for (argnum = 0, stack_alloc = 0; argnum < nargs; argnum++)
> >! stack_alloc += ((TYPE_LENGTH (VALUE_TYPE (args[argnum])) + 3) & ~3);
> >! sp -= stack_alloc; /* make room on stack for args */
> >!
> >! /* Now load as many as possible of the first arguments into
> >! registers, and push the rest onto the stack. There are 16 bytes
> >! in four registers available. Loop thru args from first to last. */
> >!
> >! argreg = tdep->ARG0_REGNUM;
> >! flt_argreg = tdep->FLOAT_ARG0_REGNUM;
> >! for (argnum = 0, stack_offset = 0; argnum < nargs; argnum++)
> >! {
> >! type = VALUE_TYPE (args[argnum]);
> >! len = TYPE_LENGTH (type);
> >! memset (valbuf, 0, sizeof (valbuf));
> >! if (len < 4)
> >! {
> >! /* value gets right-justified in the register or stack word */
> >! if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
> >! memcpy (valbuf + (4 - len),
> >! (char *) VALUE_CONTENTS (args[argnum]), len);
> >! else
> >! memcpy (valbuf, (char *) VALUE_CONTENTS (args[argnum]), len);
> >! val = valbuf;
> >! }
> >! else
> >! val = (char *) VALUE_CONTENTS (args[argnum]);
> >
> >+ if (len > 4 && (len & 3) != 0)
> >+ odd_sized_struct = 1; /* Such structs go entirely on stack. */
> >+ else if (len > 16)
> >+ odd_sized_struct = 1; /* So do aggregates bigger than 4 words. */
> >+ else
> >+ odd_sized_struct = 0;
> >+ while (len > 0)
> >+ {
> >+ if ((TYPE_CODE (type) == TYPE_CODE_FLT
> >+ && flt_argreg > tdep->FLOAT_ARGLAST_REGNUM)
> >+ || argreg > tdep->ARGLAST_REGNUM
> >+ || odd_sized_struct)
> >+ {
> >+ /* must go on the stack */
> >+ write_memory (sp + stack_offset, val, 4);
> >+ stack_offset += 4;
> >+ }
> >+ /* NOTE WELL!!!!! This is not an "else if" clause!!!
> >+ That's because some *&^%$ things get passed on the stack
> >+ AND in the registers! */
> >+ if (TYPE_CODE (type) == TYPE_CODE_FLT &&
> >+ flt_argreg > 0 && flt_argreg <= tdep->FLOAT_ARGLAST_REGNUM)
> >+ {
> >+ /* Argument goes in a single-precision fp reg. */
> >+ regval = extract_unsigned_integer (val, register_size (gdbarch,
> >+ argreg));
> >+ regcache_cooked_write_unsigned (regcache, flt_argreg++, regval);
> >+ }
> >+ else if (argreg <= tdep->ARGLAST_REGNUM)
> >+ {
> >+ /* there's room in a register */
> >+ regval = extract_unsigned_integer (val, register_size (gdbarch,
> >+ argreg));
> >+ regcache_cooked_write_unsigned (regcache, argreg++, regval);
> >+ }
> >+ /* Store the value 4 bytes at a time. This means that things
> >+ larger than 4 bytes may go partly in registers and partly
> >+ on the stack. */
> >+ len -= register_size (gdbarch, argreg);
> >+ val += register_size (gdbarch, argreg);
> >+ }
> >+ }
> >+
> >+ /* Store return address. */
> >+ regcache_cooked_write_unsigned (regcache, tdep->PR_REGNUM, bp_addr);
> >+
> >+ /* Update stack pointer. */
> >+ regcache_cooked_write_unsigned (regcache, SP_REGNUM, sp);
> >+
> >+ return sp;
> >+ }
> >+
> >+ static CORE_ADDR
> >+ sh_push_dummy_call_nofpu (struct gdbarch *gdbarch,
> >+ CORE_ADDR func_addr,
> >+ struct regcache *regcache,
> >+ CORE_ADDR bp_addr,
> >+ int nargs, struct value **args,
> >+ CORE_ADDR sp, int struct_return,
> >+ CORE_ADDR struct_addr)
> > {
> > int stack_offset, stack_alloc;
> > int argreg;
> >*************** sh_push_dummy_call (struct gdbarch *gdba
> >*** 2101,2107 ****
> > /* The "struct return pointer" pseudo-argument has its own dedicated
> > register */
> > if (struct_return)
> >! regcache_cooked_write_unsigned (regcache, STRUCT_RETURN_REGNUM, struct_addr);
> >
> > /* Now make sure there's space on the stack */
> > for (argnum = 0, stack_alloc = 0; argnum < nargs; argnum++)
> >--- 2223,2231 ----
> > /* The "struct return pointer" pseudo-argument has its own dedicated
> > register */
> > if (struct_return)
> >! regcache_cooked_write_unsigned (regcache,
> >! STRUCT_RETURN_REGNUM,
> >! struct_addr);
> >
> > /* Now make sure there's space on the stack */
> > for (argnum = 0, stack_alloc = 0; argnum < nargs; argnum++)
> >*************** sh_gdbarch_init (struct gdbarch_info inf
> >*** 4374,4380 ****
> > set_gdbarch_push_dummy_code (gdbarch, sh_push_dummy_code);
> > set_gdbarch_store_return_value (gdbarch, sh_default_store_return_value);
> > set_gdbarch_extract_return_value (gdbarch, sh_default_extract_return_value);
> >! set_gdbarch_push_dummy_call (gdbarch, sh_push_dummy_call);
> > set_gdbarch_extract_struct_value_address (gdbarch, sh_extract_struct_value_address);
> >
> > set_gdbarch_deprecated_frame_init_saved_regs (gdbarch, sh_nofp_frame_init_saved_regs);
> >--- 4498,4504 ----
> > set_gdbarch_push_dummy_code (gdbarch, sh_push_dummy_code);
> > set_gdbarch_store_return_value (gdbarch, sh_default_store_return_value);
> > set_gdbarch_extract_return_value (gdbarch, sh_default_extract_return_value);
> >! set_gdbarch_push_dummy_call (gdbarch, sh_push_dummy_call_nofpu);
> > set_gdbarch_extract_struct_value_address (gdbarch, sh_extract_struct_value_address);
> >
> > set_gdbarch_deprecated_frame_init_saved_regs (gdbarch, sh_nofp_frame_init_saved_regs);
> >*************** sh_gdbarch_init (struct gdbarch_info inf
> >*** 4387,4393 ****
> > set_gdbarch_push_dummy_code (gdbarch, sh_push_dummy_code);
> > set_gdbarch_store_return_value (gdbarch, sh_default_store_return_value);
> > set_gdbarch_extract_return_value (gdbarch, sh_default_extract_return_value);
> >! set_gdbarch_push_dummy_call (gdbarch, sh_push_dummy_call);
> > set_gdbarch_extract_struct_value_address (gdbarch, sh_extract_struct_value_address);
> >
> > set_gdbarch_deprecated_frame_init_saved_regs (gdbarch, sh_nofp_frame_init_saved_regs);
> >--- 4511,4517 ----
> > set_gdbarch_push_dummy_code (gdbarch, sh_push_dummy_code);
> > set_gdbarch_store_return_value (gdbarch, sh_default_store_return_value);
> > set_gdbarch_extract_return_value (gdbarch, sh_default_extract_return_value);
> >! set_gdbarch_push_dummy_call (gdbarch, sh_push_dummy_call_nofpu);
> > set_gdbarch_extract_struct_value_address (gdbarch, sh_extract_struct_value_address);
> >
> > set_gdbarch_deprecated_frame_init_saved_regs (gdbarch, sh_nofp_frame_init_saved_regs);
> >*************** sh_gdbarch_init (struct gdbarch_info inf
> >*** 4404,4416 ****
> > set_gdbarch_fp0_regnum (gdbarch, 25);
> > set_gdbarch_store_return_value (gdbarch, sh3e_sh4_store_return_value);
> > set_gdbarch_extract_return_value (gdbarch, sh3e_sh4_extract_return_value);
> >! set_gdbarch_push_dummy_call (gdbarch, sh_push_dummy_call);
> > set_gdbarch_extract_struct_value_address (gdbarch, sh_extract_struct_value_address);
> > tdep->FPUL_REGNUM = 23;
> > tdep->FPSCR_REGNUM = 24;
> > tdep->FP_LAST_REGNUM = 40;
> >
> >! set_gdbarch_deprecated_frame_init_saved_regs (gdbarch, sh_nofp_frame_init_saved_regs);
> > break;
> > case bfd_mach_sh_dsp:
> > set_gdbarch_register_name (gdbarch, sh_sh_dsp_register_name);
> >--- 4528,4543 ----
> > set_gdbarch_fp0_regnum (gdbarch, 25);
> > set_gdbarch_store_return_value (gdbarch, sh3e_sh4_store_return_value);
> > set_gdbarch_extract_return_value (gdbarch, sh3e_sh4_extract_return_value);
> >! set_gdbarch_push_dummy_call (gdbarch, sh_push_dummy_call_fpu);
> > set_gdbarch_extract_struct_value_address (gdbarch, sh_extract_struct_value_address);
> > tdep->FPUL_REGNUM = 23;
> > tdep->FPSCR_REGNUM = 24;
> > tdep->FP_LAST_REGNUM = 40;
> >+ tdep->FLOAT_ARG0_REGNUM = 29; /* FIXME use constants! */
> >+ tdep->FLOAT_ARGLAST_REGNUM = 36; /* FIXME use constants! */
> >
> >! set_gdbarch_deprecated_frame_init_saved_regs (gdbarch,
> >! sh_nofp_frame_init_saved_regs);
> > break;
> > case bfd_mach_sh_dsp:
> > set_gdbarch_register_name (gdbarch, sh_sh_dsp_register_name);
> >*************** sh_gdbarch_init (struct gdbarch_info inf
> >*** 4421,4427 ****
> > set_gdbarch_register_sim_regno (gdbarch, sh_dsp_register_sim_regno);
> > set_gdbarch_store_return_value (gdbarch, sh_default_store_return_value);
> > set_gdbarch_extract_return_value (gdbarch, sh_default_extract_return_value);
> >! set_gdbarch_push_dummy_call (gdbarch, sh_push_dummy_call);
> > set_gdbarch_extract_struct_value_address (gdbarch, sh_extract_struct_value_address);
> > tdep->DSR_REGNUM = 24;
> > tdep->A0G_REGNUM = 25;
> >--- 4548,4554 ----
> > set_gdbarch_register_sim_regno (gdbarch, sh_dsp_register_sim_regno);
> > set_gdbarch_store_return_value (gdbarch, sh_default_store_return_value);
> > set_gdbarch_extract_return_value (gdbarch, sh_default_extract_return_value);
> >! set_gdbarch_push_dummy_call (gdbarch, sh_push_dummy_call_nofpu);
> > set_gdbarch_extract_struct_value_address (gdbarch, sh_extract_struct_value_address);
> > tdep->DSR_REGNUM = 24;
> > tdep->A0G_REGNUM = 25;
> >*************** sh_gdbarch_init (struct gdbarch_info inf
> >*** 4448,4454 ****
> > set_gdbarch_push_dummy_code (gdbarch, sh_push_dummy_code);
> > set_gdbarch_store_return_value (gdbarch, sh_default_store_return_value);
> > set_gdbarch_extract_return_value (gdbarch, sh_default_extract_return_value);
> >! set_gdbarch_push_dummy_call (gdbarch, sh_push_dummy_call);
> > set_gdbarch_extract_struct_value_address (gdbarch, sh_extract_struct_value_address);
> > tdep->SSR_REGNUM = 41;
> > tdep->SPC_REGNUM = 42;
> >--- 4575,4581 ----
> > set_gdbarch_push_dummy_code (gdbarch, sh_push_dummy_code);
> > set_gdbarch_store_return_value (gdbarch, sh_default_store_return_value);
> > set_gdbarch_extract_return_value (gdbarch, sh_default_extract_return_value);
> >! set_gdbarch_push_dummy_call (gdbarch, sh_push_dummy_call_nofpu);
> > set_gdbarch_extract_struct_value_address (gdbarch, sh_extract_struct_value_address);
> > tdep->SSR_REGNUM = 41;
> > tdep->SPC_REGNUM = 42;
> >*************** sh_gdbarch_init (struct gdbarch_info inf
> >*** 4467,4477 ****
> > set_gdbarch_fp0_regnum (gdbarch, 25);
> > set_gdbarch_store_return_value (gdbarch, sh3e_sh4_store_return_value);
> > set_gdbarch_extract_return_value (gdbarch, sh3e_sh4_extract_return_value);
> >! set_gdbarch_push_dummy_call (gdbarch, sh_push_dummy_call);
> > set_gdbarch_extract_struct_value_address (gdbarch, sh_extract_struct_value_address);
> > tdep->FPUL_REGNUM = 23;
> > tdep->FPSCR_REGNUM = 24;
> > tdep->FP_LAST_REGNUM = 40;
> > tdep->SSR_REGNUM = 41;
> > tdep->SPC_REGNUM = 42;
> >
> >--- 4594,4606 ----
> > set_gdbarch_fp0_regnum (gdbarch, 25);
> > set_gdbarch_store_return_value (gdbarch, sh3e_sh4_store_return_value);
> > set_gdbarch_extract_return_value (gdbarch, sh3e_sh4_extract_return_value);
> >! set_gdbarch_push_dummy_call (gdbarch, sh_push_dummy_call_fpu);
> > set_gdbarch_extract_struct_value_address (gdbarch, sh_extract_struct_value_address);
> > tdep->FPUL_REGNUM = 23;
> > tdep->FPSCR_REGNUM = 24;
> > tdep->FP_LAST_REGNUM = 40;
> >+ tdep->FLOAT_ARG0_REGNUM = 29; /* FIXME use constants! */
> >+ tdep->FLOAT_ARGLAST_REGNUM = 36; /* FIXME use constants! */
> > tdep->SSR_REGNUM = 41;
> > tdep->SPC_REGNUM = 42;
> >
> >*************** sh_gdbarch_init (struct gdbarch_info inf
> >*** 4486,4492 ****
> > set_gdbarch_register_sim_regno (gdbarch, sh_dsp_register_sim_regno);
> > set_gdbarch_store_return_value (gdbarch, sh_default_store_return_value);
> > set_gdbarch_extract_return_value (gdbarch, sh_default_extract_return_value);
> >! set_gdbarch_push_dummy_call (gdbarch, sh_push_dummy_call);
> > set_gdbarch_extract_struct_value_address (gdbarch, sh_extract_struct_value_address);
> > tdep->DSR_REGNUM = 24;
> > tdep->A0G_REGNUM = 25;
> >--- 4615,4621 ----
> > set_gdbarch_register_sim_regno (gdbarch, sh_dsp_register_sim_regno);
> > set_gdbarch_store_return_value (gdbarch, sh_default_store_return_value);
> > set_gdbarch_extract_return_value (gdbarch, sh_default_extract_return_value);
> >! set_gdbarch_push_dummy_call (gdbarch, sh_push_dummy_call_nofpu);
> > set_gdbarch_extract_struct_value_address (gdbarch, sh_extract_struct_value_address);
> > tdep->DSR_REGNUM = 24;
> > tdep->A0G_REGNUM = 25;
> >*************** sh_gdbarch_init (struct gdbarch_info inf
> >*** 4519,4525 ****
> > set_gdbarch_pseudo_register_write (gdbarch, sh_pseudo_register_write);
> > set_gdbarch_store_return_value (gdbarch, sh3e_sh4_store_return_value);
> > set_gdbarch_extract_return_value (gdbarch, sh3e_sh4_extract_return_value);
> >! set_gdbarch_push_dummy_call (gdbarch, sh_push_dummy_call);
> > set_gdbarch_extract_struct_value_address (gdbarch, sh_extract_struct_value_address);
> > tdep->FPUL_REGNUM = 23;
> > tdep->FPSCR_REGNUM = 24;
> >--- 4648,4654 ----
> > set_gdbarch_pseudo_register_write (gdbarch, sh_pseudo_register_write);
> > set_gdbarch_store_return_value (gdbarch, sh3e_sh4_store_return_value);
> > set_gdbarch_extract_return_value (gdbarch, sh3e_sh4_extract_return_value);
> >! set_gdbarch_push_dummy_call (gdbarch, sh_push_dummy_call_fpu);
> > set_gdbarch_extract_struct_value_address (gdbarch, sh_extract_struct_value_address);
> > tdep->FPUL_REGNUM = 23;
> > tdep->FPSCR_REGNUM = 24;
> >*************** sh_gdbarch_init (struct gdbarch_info inf
> >*** 4530,4535 ****
> >--- 4659,4666 ----
> > tdep->DR_LAST_REGNUM = 66;
> > tdep->FV0_REGNUM = 67;
> > tdep->FV_LAST_REGNUM = 70;
> >+ tdep->FLOAT_ARG0_REGNUM = 29; /* FIXME use constants! */
> >+ tdep->FLOAT_ARGLAST_REGNUM = 36; /* FIXME use constants! */
> >
> > set_gdbarch_deprecated_frame_init_saved_regs (gdbarch, sh_fp_frame_init_saved_regs);
> > break;
> >Index: sh-tdep.h
> >===================================================================
> >RCS file: /cvs/src/src/gdb/sh-tdep.h,v
> >retrieving revision 1.3
> >diff -p -r1.3 sh-tdep.h
> >*** sh-tdep.h 4 Jan 2003 23:38:45 -0000 1.3
> >--- sh-tdep.h 1 Aug 2003 22:00:40 -0000
> >*************** struct gdbarch_tdep
> >*** 85,91 ****
> > int FV_LAST_C_REGNUM; /* sh5-compact*/
> > int ARG0_REGNUM;
> > int ARGLAST_REGNUM;
> >! int FLOAT_ARGLAST_REGNUM;
> > int RETURN_REGNUM;
> > enum sh_abi sh_abi;
> > };
> >--- 85,92 ----
> > int FV_LAST_C_REGNUM; /* sh5-compact*/
> > int ARG0_REGNUM;
> > int ARGLAST_REGNUM;
> >! int FLOAT_ARG0_REGNUM; /* sh4 */
> >! int FLOAT_ARGLAST_REGNUM; /* sh4, sh5 */
> > int RETURN_REGNUM;
> > enum sh_abi sh_abi;
> > };
> >
> >
>