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[RFA] sh-tdep: multi-arch the push_dummy_call method.


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.




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;
    };

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