| /* Target-dependent code for PowerPC systems using the SVR4 ABI |
| for GDB, the GNU debugger. |
| |
| Copyright 2000, 2001, 2002 Free Software Foundation, Inc. |
| |
| This file is part of GDB. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, Inc., 59 Temple Place - Suite 330, |
| Boston, MA 02111-1307, USA. */ |
| |
| #include "defs.h" |
| #include "gdbcore.h" |
| #include "inferior.h" |
| #include "regcache.h" |
| #include "value.h" |
| #include "gdb_string.h" |
| |
| #include "ppc-tdep.h" |
| |
| /* round2 rounds x up to the nearest multiple of s assuming that s is a |
| power of 2 */ |
| |
| #undef round2 |
| #define round2(x,s) ((((long) (x) - 1) & ~(long)((s)-1)) + (s)) |
| |
| /* Pass the arguments in either registers, or in the stack. Using the |
| ppc sysv ABI, the first eight words of the argument list (that might |
| be less than eight parameters if some parameters occupy more than one |
| word) are passed in r3..r10 registers. float and double parameters are |
| passed in fpr's, in addition to that. Rest of the parameters if any |
| are passed in user stack. |
| |
| If the function is returning a structure, then the return address is passed |
| in r3, then the first 7 words of the parametes can be passed in registers, |
| starting from r4. */ |
| |
| CORE_ADDR |
| ppc_sysv_abi_push_arguments (int nargs, struct value **args, CORE_ADDR sp, |
| int struct_return, CORE_ADDR struct_addr) |
| { |
| int argno; |
| /* Next available general register for non-float, non-vector arguments. */ |
| int greg; |
| /* Next available floating point register for float arguments. */ |
| int freg; |
| /* Next available vector register for vector arguments. */ |
| int vreg; |
| int argstkspace; |
| int structstkspace; |
| int argoffset; |
| int structoffset; |
| struct type *type; |
| int len; |
| char old_sp_buf[4]; |
| CORE_ADDR saved_sp; |
| struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); |
| |
| greg = struct_return ? 4 : 3; |
| freg = 1; |
| vreg = 2; |
| argstkspace = 0; |
| structstkspace = 0; |
| |
| /* Figure out how much new stack space is required for arguments |
| which don't fit in registers. Unlike the PowerOpen ABI, the |
| SysV ABI doesn't reserve any extra space for parameters which |
| are put in registers. */ |
| for (argno = 0; argno < nargs; argno++) |
| { |
| struct value *arg = args[argno]; |
| type = check_typedef (VALUE_TYPE (arg)); |
| len = TYPE_LENGTH (type); |
| |
| if (TYPE_CODE (type) == TYPE_CODE_FLT |
| && ppc_floating_point_unit_p (current_gdbarch)) |
| { |
| if (freg <= 8) |
| freg++; |
| else |
| { |
| /* SysV ABI converts floats to doubles when placed in |
| memory and requires 8 byte alignment */ |
| if (argstkspace & 0x4) |
| argstkspace += 4; |
| argstkspace += 8; |
| } |
| } |
| else if (len == 8 |
| && (TYPE_CODE (type) == TYPE_CODE_INT /* long long */ |
| || (!ppc_floating_point_unit_p (current_gdbarch) |
| && TYPE_CODE (type) == TYPE_CODE_FLT))) /* double */ |
| { |
| if (greg > 9) |
| { |
| greg = 11; |
| if (argstkspace & 0x4) |
| argstkspace += 4; |
| argstkspace += 8; |
| } |
| else |
| { |
| if ((greg & 1) == 0) |
| greg++; |
| greg += 2; |
| } |
| } |
| else if (!TYPE_VECTOR (type)) |
| { |
| if (len > 4 |
| || TYPE_CODE (type) == TYPE_CODE_STRUCT |
| || TYPE_CODE (type) == TYPE_CODE_UNION) |
| { |
| /* Rounding to the nearest multiple of 8 may not be necessary, |
| but it is safe. Particularly since we don't know the |
| field types of the structure */ |
| structstkspace += round2 (len, 8); |
| } |
| if (greg <= 10) |
| greg++; |
| else |
| argstkspace += 4; |
| } |
| else |
| { |
| if (len == 16 |
| && TYPE_CODE (type) == TYPE_CODE_ARRAY |
| && TYPE_VECTOR (type)) |
| { |
| if (vreg <= 13) |
| vreg++; |
| else |
| { |
| /* Vector arguments must be aligned to 16 bytes on |
| the stack. */ |
| argstkspace += round2 (argstkspace, 16); |
| argstkspace += 16; |
| } |
| } |
| else if (len == 8 |
| && TYPE_CODE (type) == TYPE_CODE_ARRAY |
| && TYPE_VECTOR (type)) |
| { |
| if (greg <= 10) |
| greg++; |
| else |
| { |
| /* Vector arguments must be aligned to 8 bytes on |
| the stack. */ |
| argstkspace += round2 (argstkspace, 8); |
| argstkspace += 8; |
| } |
| } |
| } |
| } |
| |
| /* Get current SP location */ |
| saved_sp = read_sp (); |
| |
| sp -= argstkspace + structstkspace; |
| |
| /* Allocate space for backchain and callee's saved lr */ |
| sp -= 8; |
| |
| /* Make sure that we maintain 16 byte alignment */ |
| sp &= ~0x0f; |
| |
| /* Update %sp before proceeding any further */ |
| write_register (SP_REGNUM, sp); |
| |
| /* write the backchain */ |
| store_address (old_sp_buf, 4, saved_sp); |
| write_memory (sp, old_sp_buf, 4); |
| |
| argoffset = 8; |
| structoffset = argoffset + argstkspace; |
| freg = 1; |
| greg = 3; |
| vreg = 2; |
| |
| /* Fill in r3 with the return structure, if any */ |
| if (struct_return) |
| { |
| write_register (tdep->ppc_gp0_regnum + greg, struct_addr); |
| greg++; |
| } |
| |
| /* Now fill in the registers and stack... */ |
| for (argno = 0; argno < nargs; argno++) |
| { |
| struct value *arg = args[argno]; |
| char *val = VALUE_CONTENTS (arg); |
| type = check_typedef (VALUE_TYPE (arg)); |
| len = TYPE_LENGTH (type); |
| |
| if (TYPE_CODE (type) == TYPE_CODE_FLT |
| && ppc_floating_point_unit_p (current_gdbarch)) |
| { |
| if (freg <= 8) |
| { |
| ULONGEST regval; |
| if (len > 8) |
| printf_unfiltered ( |
| "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno); |
| regval = extract_unsigned_integer (val, len); |
| write_register (FP0_REGNUM + freg, regval); |
| freg++; |
| } |
| else |
| { |
| /* SysV ABI converts floats to doubles when placed in |
| memory and requires 8 byte alignment */ |
| /* FIXME: Convert floats to doubles */ |
| if (argoffset & 0x4) |
| argoffset += 4; |
| write_memory (sp + argoffset, val, len); |
| argoffset += 8; |
| } |
| } |
| else if (len == 8 |
| && (TYPE_CODE (type) == TYPE_CODE_INT /* long long */ |
| || (!ppc_floating_point_unit_p (current_gdbarch) |
| && TYPE_CODE (type) == TYPE_CODE_FLT))) /* double */ |
| { |
| if (greg > 9) |
| { |
| greg = 11; |
| if (argoffset & 0x4) |
| argoffset += 4; |
| write_memory (sp + argoffset, val, len); |
| argoffset += 8; |
| } |
| else |
| { |
| ULONGEST regval; |
| if ((greg & 1) == 0) |
| greg++; |
| regval = extract_unsigned_integer (val, 4); |
| write_register (tdep->ppc_gp0_regnum + greg, regval); |
| regval = extract_unsigned_integer (val + 4, 4); |
| write_register (tdep->ppc_gp0_regnum + greg + 1, regval); |
| greg += 2; |
| } |
| } |
| else if (!TYPE_VECTOR (type)) |
| { |
| char val_buf[4]; |
| if (len > 4 |
| || TYPE_CODE (type) == TYPE_CODE_STRUCT |
| || TYPE_CODE (type) == TYPE_CODE_UNION) |
| { |
| write_memory (sp + structoffset, val, len); |
| store_address (val_buf, 4, sp + structoffset); |
| structoffset += round2 (len, 8); |
| } |
| else |
| { |
| memset (val_buf, 0, 4); |
| memcpy (val_buf, val, len); |
| } |
| if (greg <= 10) |
| { |
| ULONGEST regval = extract_unsigned_integer (val_buf, 4); |
| write_register (tdep->ppc_gp0_regnum + greg, regval); |
| greg++; |
| } |
| else |
| { |
| write_memory (sp + argoffset, val_buf, 4); |
| argoffset += 4; |
| } |
| } |
| else |
| { |
| if (len == 16 |
| && TYPE_CODE (type) == TYPE_CODE_ARRAY |
| && TYPE_VECTOR (type)) |
| { |
| char *v_val_buf = alloca (16); |
| memset (v_val_buf, 0, 16); |
| memcpy (v_val_buf, val, len); |
| if (vreg <= 13) |
| { |
| regcache_cooked_write (current_regcache, |
| tdep->ppc_vr0_regnum + vreg, |
| v_val_buf); |
| vreg++; |
| } |
| else |
| { |
| write_memory (sp + argoffset, v_val_buf, 16); |
| argoffset += 16; |
| } |
| } |
| else if (len == 8 |
| && TYPE_CODE (type) == TYPE_CODE_ARRAY |
| && TYPE_VECTOR (type)) |
| { |
| char *v_val_buf = alloca (8); |
| memset (v_val_buf, 0, 8); |
| memcpy (v_val_buf, val, len); |
| if (greg <= 10) |
| { |
| regcache_cooked_write (current_regcache, |
| tdep->ppc_ev0_regnum + greg, |
| v_val_buf); |
| greg++; |
| } |
| else |
| { |
| write_memory (sp + argoffset, v_val_buf, 8); |
| argoffset += 8; |
| } |
| } |
| } |
| } |
| |
| target_store_registers (-1); |
| return sp; |
| } |
| |
| /* Until November 2001, gcc was not complying to the SYSV ABI for |
| returning structures less than or equal to 8 bytes in size. It was |
| returning everything in memory. When this was corrected, it wasn't |
| fixed for native platforms. */ |
| int |
| ppc_sysv_abi_broken_use_struct_convention (int gcc_p, struct type *value_type) |
| { |
| if ((TYPE_LENGTH (value_type) == 16 || TYPE_LENGTH (value_type) == 8) |
| && TYPE_VECTOR (value_type)) |
| return 0; |
| |
| return generic_use_struct_convention (gcc_p, value_type); |
| } |
| |
| /* Structures 8 bytes or less long are returned in the r3 & r4 |
| registers, according to the SYSV ABI. */ |
| int |
| ppc_sysv_abi_use_struct_convention (int gcc_p, struct type *value_type) |
| { |
| if ((TYPE_LENGTH (value_type) == 16 || TYPE_LENGTH (value_type) == 8) |
| && TYPE_VECTOR (value_type)) |
| return 0; |
| |
| return (TYPE_LENGTH (value_type) > 8); |
| } |
