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- /* Output routines for GCC for ARM/RISCiX.
- Copyright (C) 1991, 1993 Free Software Foundation, Inc.
- Contributed by Pieter `Tiggr' Schoenmakers (rcpieter@win.tue.nl)
- and Martin Simmons (@harleqn.co.uk).
- More major hacks by Richard Earnshaw (rwe11@cl.cam.ac.uk)
-
- This file is part of GNU CC.
-
- GNU CC 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, or (at your option)
- any later version.
-
- GNU CC 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 GNU CC; see the file COPYING. If not, write to
- the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
-
- #include <stdio.h>
- #include "assert.h"
- #include "config.h"
- #include "rtl.h"
- #include "regs.h"
- #include "hard-reg-set.h"
- #include "real.h"
- #include "insn-config.h"
- #include "conditions.h"
- #include "insn-flags.h"
- #include "output.h"
- #include "insn-attr.h"
- #include "flags.h"
- #include "reload.h"
-
- /* The maximum number of insns skipped which will be conditionalised if
- possible. */
- #define MAX_INSNS_SKIPPED 5
-
- /* Some function declarations. */
- extern FILE *asm_out_file;
- extern char *output_multi_immediate ();
- extern char *arm_output_asm_insn ();
- extern void arm_increase_location ();
-
- /* Define the information needed to generate branch insns. This is
- stored from the compare operation. */
-
- rtx arm_compare_op0, arm_compare_op1;
- int arm_compare_fp;
-
- /* What type of cpu are we compiling for? */
-
- enum processor_type arm_cpu;
-
- /* In case of a PRE_INC, POST_INC, PRE_DEC, POST_DEC memory reference, we
- must report the mode of the memory reference from PRINT_OPERAND to
- PRINT_OPERAND_ADDRESS. */
- int output_memory_reference_mode;
-
- /* Nonzero if the prologue must setup `fp'. */
- int current_function_anonymous_args;
-
- /* Location counter of .text segment. */
- int arm_text_location = 0;
-
- /* Set to one if we think that lr is only saved because of subroutine calls,
- but all of these can be `put after' return insns */
- int lr_save_eliminated;
-
- /* A hash table is used to store text segment labels and their associated
- offset from the start of the text segment. */
- struct label_offset
- {
- char *name;
- int offset;
- struct label_offset *cdr;
- };
-
- #define LABEL_HASH_SIZE 257
-
- static struct label_offset *offset_table[LABEL_HASH_SIZE];
-
- /* Set to 1 when a return insn is output, this means that the epilogue
- is not needed. */
-
- static int return_used_this_function;
-
- /* For an explanation of these variables, see final_prescan_insn below. */
- int arm_ccfsm_state;
- int arm_current_cc;
- rtx arm_target_insn;
- int arm_target_label;
-
- /* Return 1 if it is possible to return using a single instruction */
-
- int
- use_return_insn ()
- {
- int regno;
-
- if (!reload_completed ||current_function_pretend_args_size
- || current_function_anonymous_args
- || (get_frame_size () && !(TARGET_APCS || frame_pointer_needed)))
- return 0;
-
- /* Can't be done if any of the FPU regs are pushed, since this also
- requires an insn */
- for (regno = 20; regno < 24; regno++)
- if (regs_ever_live[regno])
- return 0;
-
- return 1;
- }
-
- /* Return the number of mov instructions needed to get the constant VALUE into
- a register. */
-
- int
- arm_const_nmoves (value)
- register int value;
- {
- register int i;
-
- if (value == 0)
- return (1);
- for (i = 0; value; i++, value &= ~0xff)
- while ((value & 3) == 0)
- value = (value >> 2) | ((value & 3) << 30);
- return (i);
- } /* arm_const_nmoves */
-
-
- /* Return TRUE if int I is a valid immediate ARM constant. */
-
- int
- const_ok_for_arm (i)
- HOST_WIDE_INT i;
- {
- unsigned HOST_WIDE_INT mask = ~0xFF;
-
- do
- {
- if ((i & mask & (unsigned HOST_WIDE_INT) 0xffffffff) == 0)
- return(TRUE);
- mask =
- (mask << 2) | ((mask & (unsigned HOST_WIDE_INT) 0xffffffff)
- >> (32 - 2)) | ~((unsigned HOST_WIDE_INT) 0xffffffff);
- } while (mask != ~0xFF);
-
- return (FALSE);
- } /* const_ok_for_arm */
-
- /* This code has been fixed for cross compilation. */
-
- static int fpa_consts_inited = 0;
-
- char *strings_fpa[8] = {
- "0.0",
- "1.0",
- "2.0",
- "3.0",
- "4.0",
- "5.0",
- "0.5",
- "10.0"
- };
-
- static REAL_VALUE_TYPE values_fpa[8];
-
- static void
- init_fpa_table ()
- {
- int i;
- REAL_VALUE_TYPE r;
-
- for (i = 0; i < 8; i++)
- {
- r = REAL_VALUE_ATOF (strings_fpa[i], DFmode);
- values_fpa[i] = r;
- }
- fpa_consts_inited = 1;
- }
-
- /* Return TRUE if rtx X is a valid immediate FPU constant. */
-
- int
- const_double_rtx_ok_for_fpu (x)
- rtx x;
- {
- REAL_VALUE_TYPE r;
- int i;
-
- if (!fpa_consts_inited)
- init_fpa_table ();
-
- REAL_VALUE_FROM_CONST_DOUBLE (r, x);
- if (REAL_VALUE_MINUS_ZERO (r))
- return 0;
- for (i = 0; i < 8; i++)
- if (REAL_VALUES_EQUAL (r, values_fpa[i]))
- return 1;
- return 0;
- } /* const_double_rtx_ok_for_fpu */
-
- /* Return TRUE if rtx X is a valid immediate FPU constant. */
-
- int
- neg_const_double_rtx_ok_for_fpu (x)
- rtx x;
- {
- REAL_VALUE_TYPE r;
- int i;
-
- if (!fpa_consts_inited)
- init_fpa_table ();
-
- REAL_VALUE_FROM_CONST_DOUBLE (r, x);
- r = REAL_VALUE_NEGATE (r);
- if (REAL_VALUE_MINUS_ZERO (r))
- return 0;
- for (i = 0; i < 8; i++)
- if (REAL_VALUES_EQUAL (r, values_fpa[i]))
- return 1;
- return 0;
- } /* neg_const_double_rtx_ok_for_fpu */
-
- /* Predicates for `match_operand' and `match_operator'. */
-
- /* s_register_operand is the same as register_operand, but it doesn't accept
- (SUBREG (MEM)...). */
-
- int
- s_register_operand (op, mode)
- register rtx op;
- enum machine_mode mode;
- {
- if (GET_MODE (op) != mode && mode != VOIDmode)
- return 0;
-
- if (GET_CODE (op) == SUBREG)
- {
- op = SUBREG_REG (op);
- }
-
- /* We don't consider registers whose class is NO_REGS
- to be a register operand. */
- return (GET_CODE (op) == REG
- && (REGNO (op) >= FIRST_PSEUDO_REGISTER
- || REGNO_REG_CLASS (REGNO (op)) != NO_REGS));
- }
-
- /* Return 1 if OP is an item in memory, given that we are in reload. */
-
- int
- reload_memory_operand (op, mode)
- rtx op;
- enum machine_mode mode;
- {
- int regno = true_regnum (op);
-
- return (! CONSTANT_P (op)
- && (regno == -1
- || (GET_CODE (op) == REG
- && REGNO (op) >= FIRST_PSEUDO_REGISTER)));
- }
-
- /* Return TRUE for valid operands for the rhs of an ARM instruction. */
-
- int
- arm_rhs_operand (op, mode)
- rtx op;
- enum machine_mode mode;
- {
- return (s_register_operand (op, mode)
- || (GET_CODE (op) == CONST_INT && const_ok_for_arm (INTVAL (op))));
- } /* arm_rhs_operand */
-
- /* Return TRUE for valid operands for the rhs of an ARM instruction, or a load.
- */
-
- int
- arm_rhsm_operand (op, mode)
- rtx op;
- enum machine_mode mode;
- {
- return (s_register_operand (op, mode)
- || (GET_CODE (op) == CONST_INT && const_ok_for_arm (INTVAL (op)))
- || memory_operand (op, mode));
- } /* arm_rhs_operand */
-
- /* Return TRUE for valid operands for the rhs of an ARM instruction, or if a
- constant that is valid when negated. */
-
- int
- arm_add_operand (op, mode)
- rtx op;
- enum machine_mode mode;
- {
- return (s_register_operand (op, mode)
- || (GET_CODE (op) == CONST_INT
- && (const_ok_for_arm (INTVAL (op))
- || const_ok_for_arm (-INTVAL (op)))));
- } /* arm_rhs_operand */
-
- int
- arm_not_operand (op, mode)
- rtx op;
- enum machine_mode mode;
- {
- return (s_register_operand (op, mode)
- || (GET_CODE (op) == CONST_INT
- && (const_ok_for_arm (INTVAL (op))
- || const_ok_for_arm (~INTVAL (op)))));
- } /* arm_rhs_operand */
-
- /* Return TRUE for valid operands for the rhs of an FPU instruction. */
-
- int
- fpu_rhs_operand (op, mode)
- rtx op;
- enum machine_mode mode;
- {
- if (s_register_operand (op, mode))
- return(TRUE);
- else if (GET_CODE (op) == CONST_DOUBLE)
- return (const_double_rtx_ok_for_fpu (op));
- else return (FALSE);
- } /* fpu_rhs_operand */
-
- int
- fpu_add_operand (op, mode)
- rtx op;
- enum machine_mode mode;
- {
- if (s_register_operand (op, mode))
- return(TRUE);
- else if (GET_CODE (op) == CONST_DOUBLE)
- return const_double_rtx_ok_for_fpu (op)
- || neg_const_double_rtx_ok_for_fpu (op);
- return (FALSE);
- }
-
- /* Return nonzero if OP is a constant power of two. */
-
- int
- power_of_two_operand (op, mode)
- rtx op;
- enum machine_mode mode;
- {
- if (GET_CODE (op) == CONST_INT)
- {
- int value = INTVAL(op);
- return (value != 0 && (value & (value-1)) == 0);
- }
- return (FALSE);
- } /* power_of_two_operand */
-
- /* Return TRUE for a valid operand of a DImode operation.
- Either: REG, CONST_DOUBLE or MEM(DImode_address).
- Note that this disallows MEM(REG+REG), but allows
- MEM(PRE/POST_INC/DEC(REG)). */
-
- int
- di_operand (op, mode)
- rtx op;
- enum machine_mode mode;
- {
- if (s_register_operand (op, mode))
- return (TRUE);
-
- switch (GET_CODE (op))
- {
- case CONST_DOUBLE:
- case CONST_INT:
- return (TRUE);
- case MEM:
- return (memory_address_p (DImode, XEXP (op, 0)));
- default:
- return (FALSE);
- }
- } /* di_operand */
-
- /* Return TRUE for valid index operands. */
-
- int
- index_operand (op, mode)
- rtx op;
- enum machine_mode mode;
- {
- return (s_register_operand(op, mode)
- || (immediate_operand (op, mode)
- && INTVAL (op) < 4096 && INTVAL (op) > -4096));
- } /* index_operand */
-
- /* Return TRUE for valid shifts by a constant. This also accepts any
- power of two on the (somewhat overly relaxed) assumption that the
- shift operator in this case was a mult. */
-
- int
- const_shift_operand (op, mode)
- rtx op;
- enum machine_mode mode;
- {
- return (power_of_two_operand (op, mode)
- || (immediate_operand (op, mode)
- && (INTVAL (op) < 32 && INTVAL (op) > 0)));
- } /* const_shift_operand */
-
- /* Return TRUE for arithmetic operators which can be combined with a multiply
- (shift). */
-
- int
- shiftable_operator (x, mode)
- rtx x;
- enum machine_mode mode;
- {
- if (GET_MODE (x) != mode)
- return FALSE;
- else
- {
- enum rtx_code code = GET_CODE (x);
-
- return (code == PLUS || code == MINUS
- || code == IOR || code == XOR || code == AND);
- }
- } /* shiftable_operator */
-
- /* Return TRUE for shift operators. */
-
- int
- shift_operator (x, mode)
- rtx x;
- enum machine_mode mode;
- {
- if (GET_MODE (x) != mode)
- return FALSE;
- else
- {
- enum rtx_code code = GET_CODE (x);
-
- if (code == MULT)
- return power_of_two_operand (XEXP (x, 1));
- return (code == ASHIFT || code == LSHIFT
- || code == ASHIFTRT || code == LSHIFTRT);
- }
- } /* shift_operator */
-
- int equality_operator (x, mode)
- rtx x;
- enum machine_mode mode;
- {
- return (GET_CODE (x) == EQ || GET_CODE (x) == NE);
- }
-
- /* Return TRUE for SMIN SMAX UMIN UMAX operators. */
-
- int
- minmax_operator (x, mode)
- rtx x;
- enum machine_mode mode;
- {
- enum rtx_code code = GET_CODE (x);
-
- if (GET_MODE (x) != mode)
- return FALSE;
- return code == SMIN || code == SMAX || code == UMIN || code == UMAX;
- } /* minmax_operator */
-
- /* return TRUE if x is EQ or NE */
-
- /* Return TRUE if this is the condition code register, if we aren't given
- a mode, accept any class CCmode register */
-
- int
- cc_register (x, mode)
- rtx x;
- enum machine_mode mode;
- {
- if (mode == VOIDmode)
- {
- mode = GET_MODE (x);
- if (GET_MODE_CLASS (mode) != MODE_CC)
- return FALSE;
- }
- if (mode == GET_MODE (x) && GET_CODE (x) == REG && REGNO (x) == 24)
- return TRUE;
- return FALSE;
- }
-
- enum rtx_code
- minmax_code (x)
- rtx x;
- {
- enum rtx_code code = GET_CODE (x);
-
- if (code == SMAX)
- return GE;
- if (code == SMIN)
- return LE;
- if (code == UMIN)
- return LEU;
- if (code == UMAX)
- return GEU;
- abort ();
- }
-
- /* Return 1 if memory locations are adjacent */
-
- adjacent_mem_locations (a, b)
- rtx a, b;
- {
- int val0 = 0, val1 = 0;
- int reg0, reg1;
-
- if ((GET_CODE (XEXP (a, 0)) == REG
- || (GET_CODE (XEXP (a, 0)) == PLUS
- && GET_CODE (XEXP (XEXP (a, 0), 1)) == CONST_INT))
- && (GET_CODE (XEXP (b, 0)) == REG
- || (GET_CODE (XEXP (b, 0)) == PLUS
- && GET_CODE (XEXP (XEXP (b, 0), 1)) == CONST_INT)))
- {
- if (GET_CODE (XEXP (a, 0)) == PLUS)
- {
- reg0 = REGNO (XEXP (XEXP (a, 0), 0));
- val0 = INTVAL (XEXP (XEXP (a, 0), 1));
- }
- else
- reg0 = REGNO (XEXP (a, 0));
- if (GET_CODE (XEXP (b, 0)) == PLUS)
- {
- reg1 = REGNO (XEXP (XEXP (b, 0), 0));
- val1 = INTVAL (XEXP (XEXP (b, 0), 1));
- }
- else
- reg1 = REGNO (XEXP (b, 0));
- return (reg0 == reg1) && ((val1 - val0) == 4 || (val0 - val1) == 4);
- }
- return 0;
- }
-
- /* Return 1 if OP is a load multiple operation. It is known to be
- parallel and the first section will be tested. */
-
- load_multiple_operation (op, mode)
- rtx op;
- enum machine_mode mode;
- {
- int count = XVECLEN (op, 0);
- int dest_regno;
- rtx src_addr;
- int i = 1, base = 0;
- rtx elt;
-
- if (count <= 1
- || GET_CODE (XVECEXP (op, 0, 0)) != SET)
- return 0;
-
- /* Check to see if this might be a write-back */
- if (GET_CODE (SET_SRC (elt = XVECEXP (op, 0, 0))) == PLUS)
- {
- i++;
- base = 1;
-
- /* Now check it more carefully */
- if (GET_CODE (SET_DEST (elt)) != REG
- || GET_CODE (XEXP (SET_SRC (elt), 0)) != REG
- || REGNO (XEXP (SET_SRC (elt), 0)) != REGNO (SET_DEST (elt))
- || GET_CODE (XEXP (SET_SRC (elt), 1)) != CONST_INT
- || INTVAL (XEXP (SET_SRC (elt), 1)) != (count - 2) * 4
- || GET_CODE (XVECEXP (op, 0, count - 1)) != CLOBBER
- || GET_CODE (XEXP (XVECEXP (op, 0, count - 1), 0)) != REG
- || REGNO (XEXP (XVECEXP (op, 0, count - 1), 0))
- != REGNO (SET_DEST (elt)))
- return 0;
- count--;
- }
-
- /* Perform a quick check so we don't blow up below. */
- if (count <= i
- || GET_CODE (XVECEXP (op, 0, i - 1)) != SET
- || GET_CODE (SET_DEST (XVECEXP (op, 0, i - 1))) != REG
- || GET_CODE (SET_SRC (XVECEXP (op, 0, i - 1))) != MEM)
- return 0;
-
- dest_regno = REGNO (SET_DEST (XVECEXP (op, 0, i - 1)));
- src_addr = XEXP (SET_SRC (XVECEXP (op, 0, i - 1)), 0);
-
- for (; i < count; i++)
- {
- rtx elt = XVECEXP (op, 0, i);
-
- if (GET_CODE (elt) != SET
- || GET_CODE (SET_DEST (elt)) != REG
- || GET_MODE (SET_DEST (elt)) != SImode
- || REGNO (SET_DEST (elt)) != dest_regno + i - base
- || GET_CODE (SET_SRC (elt)) != MEM
- || GET_MODE (SET_SRC (elt)) != SImode
- || GET_CODE (XEXP (SET_SRC (elt), 0)) != PLUS
- || ! rtx_equal_p (XEXP (XEXP (SET_SRC (elt), 0), 0), src_addr)
- || GET_CODE (XEXP (XEXP (SET_SRC (elt), 0), 1)) != CONST_INT
- || INTVAL (XEXP (XEXP (SET_SRC (elt), 0), 1)) != (i - base) * 4)
- return 0;
- }
-
- return 1;
- }
-
- /* Return 1 if OP is a store multiple operation. It is known to be
- parallel and the first section will be tested. */
-
- store_multiple_operation (op, mode)
- rtx op;
- enum machine_mode mode;
- {
- int count = XVECLEN (op, 0);
- int src_regno;
- rtx dest_addr;
- int i = 1, base = 0;
- rtx elt;
-
- if (count <= 1
- || GET_CODE (XVECEXP (op, 0, 0)) != SET)
- return 0;
-
- /* Check to see if this might be a write-back */
- if (GET_CODE (SET_SRC (elt = XVECEXP (op, 0, 0))) == PLUS)
- {
- i++;
- base = 1;
-
- /* Now check it more carefully */
- if (GET_CODE (SET_DEST (elt)) != REG
- || GET_CODE (XEXP (SET_SRC (elt), 0)) != REG
- || REGNO (XEXP (SET_SRC (elt), 0)) != REGNO (SET_DEST (elt))
- || GET_CODE (XEXP (SET_SRC (elt), 1)) != CONST_INT
- || INTVAL (XEXP (SET_SRC (elt), 1)) != (count - 2) * 4
- || GET_CODE (XVECEXP (op, 0, count - 1)) != CLOBBER
- || GET_CODE (XEXP (XVECEXP (op, 0, count - 1), 0)) != REG
- || REGNO (XEXP (XVECEXP (op, 0, count - 1), 0))
- != REGNO (SET_DEST (elt)))
- return 0;
- count--;
- }
-
- /* Perform a quick check so we don't blow up below. */
- if (count <= i
- || GET_CODE (XVECEXP (op, 0, i - 1)) != SET
- || GET_CODE (SET_DEST (XVECEXP (op, 0, i - 1))) != MEM
- || GET_CODE (SET_SRC (XVECEXP (op, 0, i - 1))) != REG)
- return 0;
-
- src_regno = REGNO (SET_SRC (XVECEXP (op, 0, i - 1)));
- dest_addr = XEXP (SET_DEST (XVECEXP (op, 0, i - 1)), 0);
-
- for (; i < count; i++)
- {
- elt = XVECEXP (op, 0, i);
-
- if (GET_CODE (elt) != SET
- || GET_CODE (SET_SRC (elt)) != REG
- || GET_MODE (SET_SRC (elt)) != SImode
- || REGNO (SET_SRC (elt)) != src_regno + i - base
- || GET_CODE (SET_DEST (elt)) != MEM
- || GET_MODE (SET_DEST (elt)) != SImode
- || GET_CODE (XEXP (SET_DEST (elt), 0)) != PLUS
- || ! rtx_equal_p (XEXP (XEXP (SET_DEST (elt), 0), 0), dest_addr)
- || GET_CODE (XEXP (XEXP (SET_DEST (elt), 0), 1)) != CONST_INT
- || INTVAL (XEXP (XEXP (SET_DEST (elt), 0), 1)) != (i - base) * 4)
- return 0;
- }
-
- return 1;
- }
-
- /* Routines for use in generating RTL */
-
- rtx arm_gen_load_multiple (base_regno, count, from, up, write_back)
- int base_regno;
- int count;
- rtx from;
- int up;
- int write_back;
- {
- int i = 0, j;
- rtx result;
- int sign = up ? 1 : -1;
-
- result = gen_rtx (PARALLEL, VOIDmode,
- rtvec_alloc (count + (write_back ? 2 : 0)));
- if (write_back)
- {
- XVECEXP (result, 0, 0)
- = gen_rtx (SET, GET_MODE (from), from,
- plus_constant (from, count * 4 * sign));
- i = 1;
- count++;
- }
- for (j = 0; i < count; i++, j++)
- {
- XVECEXP (result, 0, i)
- = gen_rtx (SET, VOIDmode, gen_rtx (REG, SImode, base_regno + j),
- gen_rtx (MEM, SImode,
- plus_constant (from, j * 4 * sign)));
- }
- if (write_back)
- XVECEXP (result, 0, i) = gen_rtx (CLOBBER, SImode, from);
-
- return result;
- }
-
- rtx arm_gen_store_multiple (base_regno, count, to, up, write_back)
- int base_regno;
- int count;
- rtx to;
- int up;
- int write_back;
- {
- int i = 0, j;
- rtx result;
- int sign = up ? 1 : -1;
-
- result = gen_rtx (PARALLEL, VOIDmode,
- rtvec_alloc (count + (write_back ? 2 : 0)));
- if (write_back)
- {
- XVECEXP (result, 0, 0)
- = gen_rtx (SET, GET_MODE (to), to,
- plus_constant (to, count * 4 * sign));
- i = 1;
- count++;
- }
- for (j = 0; i < count; i++, j++)
- {
- XVECEXP (result, 0, i)
- = gen_rtx (SET, VOIDmode,
- gen_rtx (MEM, SImode, plus_constant (to, j * 4 * sign)),
- gen_rtx (REG, SImode, base_regno + j));
- }
- if (write_back)
- XVECEXP (result, 0, i) = gen_rtx (CLOBBER, SImode, to);
-
- return result;
- }
-
- /* X and Y are two things to compare using CODE. Emit the compare insn and
- return the rtx for register 0 in the proper mode. FP means this is a
- floating point compare: I don't think that it is needed on the arm. */
-
- rtx
- gen_compare_reg (code, x, y, fp)
- enum rtx_code code;
- rtx x, y;
- {
- enum machine_mode mode = SELECT_CC_MODE (code, x, y);
- rtx cc_reg = gen_rtx (REG, mode, 24);
-
- emit_insn (gen_rtx (SET, VOIDmode, cc_reg,
- gen_rtx (COMPARE, mode, x, y)));
-
- return cc_reg;
- }
-
- arm_reload_out_hi (operands)
- rtx operands[];
- {
- rtx base = find_replacement (&XEXP (operands[0], 0));
-
- emit_insn (gen_rtx (SET, VOIDmode,
- gen_rtx (MEM, QImode, base),
- gen_rtx (SUBREG, QImode, operands[1], 0)));
- emit_insn (gen_rtx (SET, VOIDmode, operands[2],
- gen_rtx (LSHIFTRT, SImode,
- gen_rtx (SUBREG, SImode, operands[1], 0),
- GEN_INT (8))));
- emit_insn (gen_rtx (SET, VOIDmode,
- gen_rtx (MEM, QImode,
- plus_constant (base, 1)),
- gen_rtx (SUBREG, QImode, operands[2], 0)));
- }
-
- /* Check to see if a branch is forwards or backwards. Return TRUE if it
- is backwards. */
-
- int
- arm_backwards_branch (from, to)
- int from, to;
- {
- return (insn_addresses[to] <= insn_addresses[from]);
- }
-
- /* Check to see if a branch is within the distance that can be done using
- an arithmetic expression. */
- int
- short_branch (from, to)
- int from, to;
- {
- int delta = insn_addresses[from] + 2 - insn_addresses[to];
-
- return abs (delta) < 245; /* A small margin for safety */
- }
-
- /* Check to see that the insn isn't the target of the conditionalizing
- code */
- int
- arm_insn_not_targeted (insn)
- rtx insn;
- {
- return insn != arm_target_insn;
- }
-
-
- /* Routines to output assembly language. */
-
- /* fp_immediate_constant
- if the rtx is the correct value then return the string of the number.
- In this way we can ensure that valid double constants are generated even
- when cross compiling. */
- char *
- fp_immediate_constant (x)
- rtx (x);
- {
- REAL_VALUE_TYPE r;
- int i;
-
- if (!fpa_consts_inited)
- init_fpa_table ();
-
- REAL_VALUE_FROM_CONST_DOUBLE (r, x);
- for (i = 0; i < 8; i++)
- if (REAL_VALUES_EQUAL (r, values_fpa[i]))
- return strings_fpa[i];
- abort ();
- }
-
-
- /* Output the operands of a LDM/STM instruction to STREAM.
- MASK is the ARM register set mask of which only bits 0-15 are important.
- INSTR is the possibly suffixed base register. HAT unequals zero if a hat
- must follow the register list. */
-
- void
- print_multi_reg (stream, instr, mask, hat)
- FILE *stream;
- char *instr;
- int mask, hat;
- {
- int i;
- int not_first = FALSE;
-
- fprintf (stream, "\t%s, {", instr);
- for (i = 0; i < 16; i++)
- if (mask & (1 << i))
- {
- if (not_first)
- fprintf (stream, ", ");
- fprintf (stream, "%s", reg_names[i]);
- not_first = TRUE;
- }
- fprintf (stream, "}%s\n", hat ? "^" : "");
- } /* print_multi_reg */
-
- /* Output a 'call' insn. */
-
- char *
- output_call (operands)
- rtx operands[];
- {
- /* Handle calls to lr using ip (which may be clobbered in subr anyway). */
-
- if (REGNO (operands[0]) == 14)
- {
- operands[0] = gen_rtx (REG, SImode, 12);
- arm_output_asm_insn ("mov\t%0, lr", operands);
- }
- arm_output_asm_insn ("mov\tlr, pc", operands);
- arm_output_asm_insn ("mov\tpc, %0", operands);
- return ("");
- } /* output_call */
-
- static int
- eliminate_lr2ip (x)
- rtx *x;
- {
- int something_changed = 0;
- rtx x0 = *x;
- int code = GET_CODE (x0);
- register int i, j;
- register char *fmt;
-
- switch (code)
- {
- case REG:
- if (REGNO (x0) == 14)
- {
- *x = gen_rtx (REG, SImode, 12);
- return 1;
- }
- return 0;
- default:
- /* Scan through the sub-elements and change any references there */
- fmt = GET_RTX_FORMAT (code);
- for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
- if (fmt[i] == 'e')
- something_changed |= eliminate_lr2ip (&XEXP (x0, i));
- else if (fmt[i] == 'E')
- for (j = 0; j < XVECLEN (x0, i); j++)
- something_changed |= eliminate_lr2ip (&XVECEXP (x0, i, j));
- return something_changed;
- }
- }
-
- /* Output a 'call' insn that is a reference in memory. */
-
- char *
- output_call_mem (operands)
- rtx operands[];
- {
- operands[0] = copy_rtx (operands[0]); /* Be ultra careful */
- /* Handle calls using lr by using ip (which may be clobbered in subr anyway).
- */
- if (eliminate_lr2ip (&operands[0]))
- arm_output_asm_insn ("mov\tip, lr", operands);
- arm_output_asm_insn ("mov\tlr, pc", operands);
- arm_output_asm_insn ("ldr\tpc, %0", operands);
- return ("");
- } /* output_call */
-
-
- /* Output a move from arm registers to an fpu registers.
- OPERANDS[0] is an fpu register.
- OPERANDS[1] is the first registers of an arm register pair. */
-
- char *
- output_mov_long_double_fpu_from_arm (operands)
- rtx operands[];
- {
- int arm_reg0 = REGNO (operands[1]);
- rtx ops[3];
-
- if (arm_reg0 == 12)
- abort();
- ops[0] = gen_rtx (REG, SImode, arm_reg0);
- ops[1] = gen_rtx (REG, SImode, 1 + arm_reg0);
- ops[2] = gen_rtx (REG, SImode, 2 + arm_reg0);
-
- arm_output_asm_insn ("stmfd\tsp!, {%0, %1, %2}", ops);
- arm_output_asm_insn ("ldfe\t%0, [sp], #12", operands);
- return ("");
- } /* output_mov_long_double_fpu_from_arm */
-
- /* Output a move from an fpu register to arm registers.
- OPERANDS[0] is the first registers of an arm register pair.
- OPERANDS[1] is an fpu register. */
-
- char *
- output_mov_long_double_arm_from_fpu (operands)
- rtx operands[];
- {
- int arm_reg0 = REGNO (operands[0]);
- rtx ops[3];
-
- if (arm_reg0 == 12)
- abort();
- ops[0] = gen_rtx (REG, SImode, arm_reg0);
- ops[1] = gen_rtx (REG, SImode, 1 + arm_reg0);
- ops[2] = gen_rtx (REG, SImode, 2 + arm_reg0);
-
- arm_output_asm_insn ("stfe\t%1, [sp, #-12]!", operands);
- arm_output_asm_insn ("ldmfd\tsp!, {%0, %1, %2}", ops);
- return("");
- } /* output_mov_long_double_arm_from_fpu */
-
- /* Output a move from arm registers to arm registers of a long double
- OPERANDS[0] is the destination.
- OPERANDS[1] is the source. */
- char *
- output_mov_long_double_arm_from_arm (operands)
- rtx operands[];
- {
- /* We have to be careful here because the two might overlap */
- int dest_start = REGNO (operands[0]);
- int src_start = REGNO (operands[1]);
- rtx ops[2];
- int i;
-
- if (dest_start < src_start)
- {
- for (i = 0; i < 3; i++)
- {
- ops[0] = gen_rtx (REG, SImode, dest_start + i);
- ops[1] = gen_rtx (REG, SImode, src_start + i);
- arm_output_asm_insn ("mov\t%0, %1", ops);
- }
- }
- else
- {
- for (i = 2; i >= 0; i--)
- {
- ops[0] = gen_rtx (REG, SImode, dest_start + i);
- ops[1] = gen_rtx (REG, SImode, src_start + i);
- arm_output_asm_insn ("mov\t%0, %1", ops);
- }
- }
- return "";
- }
-
-
- /* Output a move from arm registers to an fpu registers.
- OPERANDS[0] is an fpu register.
- OPERANDS[1] is the first registers of an arm register pair. */
-
- char *
- output_mov_double_fpu_from_arm (operands)
- rtx operands[];
- {
- int arm_reg0 = REGNO (operands[1]);
- rtx ops[2];
-
- if (arm_reg0 == 12)
- abort();
- ops[0] = gen_rtx (REG, SImode, arm_reg0);
- ops[1] = gen_rtx (REG, SImode, 1 + arm_reg0);
- arm_output_asm_insn ("stmfd\tsp!, {%0, %1}", ops);
- arm_output_asm_insn ("ldfd\t%0, [sp], #8", operands);
- return ("");
- } /* output_mov_double_fpu_from_arm */
-
- /* Output a move from an fpu register to arm registers.
- OPERANDS[0] is the first registers of an arm register pair.
- OPERANDS[1] is an fpu register. */
-
- char *
- output_mov_double_arm_from_fpu (operands)
- rtx operands[];
- {
- int arm_reg0 = REGNO (operands[0]);
- rtx ops[2];
-
- if (arm_reg0 == 12)
- abort();
- ops[0] = gen_rtx (REG, SImode, arm_reg0);
- ops[1] = gen_rtx (REG, SImode, 1 + arm_reg0);
- arm_output_asm_insn ("stfd\t%1, [sp, #-8]!", operands);
- arm_output_asm_insn ("ldmfd\tsp!, {%0, %1}", ops);
- return("");
- } /* output_mov_double_arm_from_fpu */
-
- /* Output a move between double words.
- It must be REG<-REG, REG<-CONST_DOUBLE, REG<-CONST_INT, REG<-MEM
- or MEM<-REG and all MEMs must be offsettable addresses. */
-
- char *
- output_move_double (operands)
- rtx operands[];
- {
- enum rtx_code code0 = GET_CODE (operands[0]);
- enum rtx_code code1 = GET_CODE (operands[1]);
- rtx otherops[2];
-
- if (code0 == REG)
- {
- int reg0 = REGNO (operands[0]);
-
- otherops[0] = gen_rtx (REG, SImode, 1 + reg0);
- if (code1 == REG)
- {
- int reg1 = REGNO (operands[1]);
- if (reg1 == 12)
- abort();
- otherops[1] = gen_rtx (REG, SImode, 1 + reg1);
-
- /* Ensure the second source is not overwritten */
- if (reg0 == 1 + reg1)
- {
- arm_output_asm_insn("mov\t%0, %1", otherops);
- arm_output_asm_insn("mov\t%0, %1", operands);
- }
- else
- {
- arm_output_asm_insn("mov\t%0, %1", operands);
- arm_output_asm_insn("mov\t%0, %1", otherops);
- }
- }
- else if (code1 == CONST_DOUBLE)
- {
- otherops[1] = gen_rtx (CONST_INT, VOIDmode,
- CONST_DOUBLE_HIGH (operands[1]));
- operands[1] = gen_rtx (CONST_INT, VOIDmode,
- CONST_DOUBLE_LOW (operands[1]));
- output_mov_immediate (operands, FALSE, "");
- output_mov_immediate (otherops, FALSE, "");
- }
- else if (code1 == CONST_INT)
- {
- otherops[1] = const0_rtx;
- /* sign extend the intval into the high-order word */
- /* Note: output_mov_immediate may clobber operands[1], so we
- put this out first */
- if (INTVAL (operands[1]) < 0)
- arm_output_asm_insn ("mvn\t%0, %1", otherops);
- else
- arm_output_asm_insn ("mov\t%0, %1", otherops);
- output_mov_immediate (operands, FALSE, "");
- }
- else if (code1 == MEM)
- {
- switch (GET_CODE (XEXP (operands[1], 0)))
- {
- case REG:
- /* Handle the simple case where address is [r, #0] more
- efficient. */
- operands[1] = XEXP (operands[1], 0);
- arm_output_asm_insn ("ldmia\t%1, %M0", operands);
- break;
- case PRE_INC:
- operands[1] = XEXP (XEXP (operands[1], 0), 0);
- arm_output_asm_insn ("add\t%1, %1, #8", operands);
- arm_output_asm_insn ("ldmia\t%1, %M0", operands);
- break;
- case PRE_DEC:
- operands[1] = XEXP (XEXP (operands[1], 0), 0);
- arm_output_asm_insn ("sub\t%1, %1, #8", operands);
- arm_output_asm_insn ("ldmia\t%1, %M0", operands);
- break;
- case POST_INC:
- operands[1] = XEXP (XEXP (operands[1], 0), 0);
- arm_output_asm_insn ("ldmia\t%1!, %M0", operands);
- break;
- case POST_DEC:
- operands[1] = XEXP (XEXP (operands[1], 0), 0);
- arm_output_asm_insn ("ldmia\t%1, %M0", operands);
- arm_output_asm_insn ("sub\t%1, %1, #8", operands);
- break;
- default:
- otherops[1] = adj_offsettable_operand (operands[1], 4);
- /* Take care of overlapping base/data reg. */
- if (reg_mentioned_p (operands[0], operands[1]))
- {
- arm_output_asm_insn ("ldr\t%0, %1", otherops);
- arm_output_asm_insn ("ldr\t%0, %1", operands);
- }
- else
- {
- arm_output_asm_insn ("ldr\t%0, %1", operands);
- arm_output_asm_insn ("ldr\t%0, %1", otherops);
- }
- }
- }
- else abort(); /* Constraints should prevent this */
- }
- else if (code0 == MEM && code1 == REG)
- {
- if (REGNO (operands[1]) == 12)
- abort();
- switch (GET_CODE (XEXP (operands[0], 0)))
- {
- case REG:
- operands[0] = XEXP (operands[0], 0);
- arm_output_asm_insn ("stmia\t%0, %M1", operands);
- break;
- case PRE_INC:
- operands[0] = XEXP (XEXP (operands[0], 0), 0);
- arm_output_asm_insn ("add\t%0, %0, #8", operands);
- arm_output_asm_insn ("stmia\t%0, %M1", operands);
- break;
- case PRE_DEC:
- operands[0] = XEXP (XEXP (operands[0], 0), 0);
- arm_output_asm_insn ("sub\t%0, %0, #8", operands);
- arm_output_asm_insn ("stmia\t%0, %M1", operands);
- break;
- case POST_INC:
- operands[0] = XEXP (XEXP (operands[0], 0), 0);
- arm_output_asm_insn ("stmia\t%0!, %M1", operands);
- break;
- case POST_DEC:
- operands[0] = XEXP (XEXP (operands[0], 0), 0);
- arm_output_asm_insn ("stmia\t%0, %M1", operands);
- arm_output_asm_insn ("sub\t%0, %0, #8", operands);
- break;
- default:
- otherops[0] = adj_offsettable_operand (operands[0], 4);
- otherops[1] = gen_rtx (REG, SImode, 1 + REGNO (operands[1]));
- arm_output_asm_insn ("str\t%1, %0", operands);
- arm_output_asm_insn ("str\t%1, %0", otherops);
- }
- }
- else abort(); /* Constraints should prevent this */
-
- return("");
- } /* output_move_double */
-
-
- /* Output an arbitrary MOV reg, #n.
- OPERANDS[0] is a register. OPERANDS[1] is a const_int. */
-
- char *
- output_mov_immediate (operands)
- rtx operands[2];
- {
- int n = INTVAL (operands[1]);
- int n_ones = 0;
- int i;
-
- /* Try to use one MOV */
-
- if (const_ok_for_arm (n))
- return (arm_output_asm_insn ("mov\t%0, %1", operands));
-
- /* Try to use one MVN */
-
- if (const_ok_for_arm(~n))
- {
- operands[1] = gen_rtx (CONST_INT, VOIDmode, ~n);
- return (arm_output_asm_insn ("mvn\t%0, %1", operands));
- }
-
- /* If all else fails, make it out of ORRs or BICs as appropriate. */
-
- for (i=0; i < 32; i++)
- if (n & 1 << i)
- n_ones++;
-
- if (n_ones > 16) /* Shorter to use MVN with BIC in this case. */
- output_multi_immediate(operands, "mvn\t%0, %1", "bic\t%0, %0, %1", 1, ~n);
- else
- output_multi_immediate(operands, "mov\t%0, %1", "orr\t%0, %0, %1", 1, n);
- return("");
- } /* output_mov_immediate */
-
-
- /* Output an ADD r, s, #n where n may be too big for one instruction. If
- adding zero to one register, output nothing. */
-
- char *
- output_add_immediate (operands)
- rtx operands[3];
- {
- int n = INTVAL (operands[2]);
-
- if (n != 0 || REGNO (operands[0]) != REGNO (operands[1]))
- {
- if (n < 0)
- output_multi_immediate (operands,
- "sub\t%0, %1, %2", "sub\t%0, %0, %2", 2, -n);
- else
- output_multi_immediate (operands,
- "add\t%0, %1, %2", "add\t%0, %0, %2", 2, n);
- }
- return("");
- } /* output_add_immediate */
-
-
- /* Output a multiple immediate operation.
- OPERANDS is the vector of operands referred to in the output patterns.
- INSTR1 is the output pattern to use for the first constant.
- INSTR2 is the output pattern to use for subsequent constants.
- IMMED_OP is the index of the constant slot in OPERANDS.
- N is the constant value. */
-
- char *
- output_multi_immediate (operands, instr1, instr2, immed_op, n)
- rtx operands[];
- char *instr1, *instr2;
- int immed_op, n;
- {
- if (n == 0)
- {
- operands[immed_op] = const0_rtx;
- arm_output_asm_insn (instr1, operands); /* Quick and easy output */
- }
- else
- {
- int i;
- char *instr = instr1;
-
- /* Note that n is never zero here (which would give no output) */
-
- for (i = 0; i < 32; i += 2)
- {
- if (n & (3 << i))
- {
- operands[immed_op] = gen_rtx (CONST_INT, VOIDmode,
- n & (255 << i));
- arm_output_asm_insn (instr, operands);
- instr = instr2;
- i += 6;
- }
- }
- }
- return ("");
- } /* output_multi_immediate */
-
-
- /* Return the appropriate ARM instruction for the operation code.
- The returned result should not be overwritten. OP is the rtx of the
- operation. SHIFT_FIRST_ARG is TRUE if the first argument of the operator
- was shifted. */
-
- char *
- arithmetic_instr (op, shift_first_arg)
- rtx op;
- {
- switch (GET_CODE(op))
- {
- case PLUS:
- return ("add");
- case MINUS:
- if (shift_first_arg)
- return ("rsb");
- else
- return ("sub");
- case IOR:
- return ("orr");
- case XOR:
- return ("eor");
- case AND:
- return ("and");
- default:
- abort();
- }
- return (""); /* stupid cc */
- } /* arithmetic_instr */
-
-
- /* Ensure valid constant shifts and return the appropriate shift mnemonic
- for the operation code. The returned result should not be overwritten.
- OP is the rtx code of the shift.
- SHIFT_PTR points to the shift size operand. */
-
- char *
- shift_instr (op, shift_ptr)
- enum rtx_code op;
- rtx *shift_ptr;
- {
- int min_shift = 0;
- int max_shift = 31;
- char *mnem;
-
- switch (op)
- {
- case ASHIFT:
- mnem = "asl";
- break;
- case LSHIFT:
- mnem = "lsl";
- break;
- case ASHIFTRT:
- mnem = "asr";
- max_shift = 32;
- break;
- case LSHIFTRT:
- mnem = "lsr";
- max_shift = 32;
- break;
- case MULT:
- *shift_ptr = gen_rtx (CONST_INT, VOIDmode,
- int_log2 (INTVAL (*shift_ptr)));
- return ("asl");
- default:
- abort();
- }
-
- if (GET_CODE (*shift_ptr) == CONST_INT)
- {
- int shift = INTVAL (*shift_ptr);
-
- if (shift < min_shift)
- *shift_ptr = gen_rtx (CONST_INT, VOIDmode, 0);
- else if (shift > max_shift)
- *shift_ptr = gen_rtx (CONST_INT, VOIDmode, max_shift);
- }
- return (mnem);
- } /* shift_instr */
-
-
- /* Obtain the shift from the POWER of two. */
-
- int
- int_log2 (power)
- unsigned int power;
- {
- int shift = 0;
-
- while (((1 << shift) & power) == 0)
- {
- if (shift > 31)
- abort();
- shift++;
- }
- return (shift);
- } /* int_log2 */
-
-
- /* Output an arithmetic instruction which may set the condition code.
- OPERANDS[0] is the destination register.
- OPERANDS[1] is the arithmetic operator expression.
- OPERANDS[2] is the left hand argument.
- OPERANDS[3] is the right hand argument.
- CONST_FIRST_ARG is TRUE if the first argument of the operator was constant.
- SET_COND is TRUE when the condition code should be set. */
-
- char *
- output_arithmetic (operands, const_first_arg, set_cond)
- rtx operands[4];
- int const_first_arg;
- int set_cond;
- {
- char mnemonic[80];
- char *instr = arithmetic_instr (operands[1], const_first_arg);
-
- sprintf (mnemonic, "%s%s\t%%0, %%2, %%3", instr, set_cond ? "s" : "");
- return (arm_output_asm_insn (mnemonic, operands));
- } /* output_arithmetic */
-
-
- /* Output an arithmetic instruction with a shift.
- OPERANDS[0] is the destination register.
- OPERANDS[1] is the arithmetic operator expression.
- OPERANDS[2] is the unshifted register.
- OPERANDS[3] is the shift operator expression.
- OPERANDS[4] is the shifted register.
- OPERANDS[5] is the shift constant or register.
- SHIFT_FIRST_ARG is TRUE if the first argument of the operator was shifted.
- SET_COND is TRUE when the condition code should be set. */
-
- char *
- output_arithmetic_with_shift (operands, shift_first_arg, set_cond)
- rtx operands[6];
- int shift_first_arg;
- int set_cond;
- {
- char mnemonic[80];
- char *instr = arithmetic_instr (operands[1], shift_first_arg);
- char *condbit = set_cond ? "s" : "";
- char *shift = shift_instr (GET_CODE (operands[3]), &operands[5]);
-
- sprintf (mnemonic, "%s%s\t%%0, %%2, %%4, %s %%5", instr, condbit, shift);
- return (arm_output_asm_insn (mnemonic, operands));
- } /* output_arithmetic_with_shift */
-
-
- /* Output an arithmetic instruction with a power of two multiplication.
- OPERANDS[0] is the destination register.
- OPERANDS[1] is the arithmetic operator expression.
- OPERANDS[2] is the unmultiplied register.
- OPERANDS[3] is the multiplied register.
- OPERANDS[4] is the constant multiple (power of two).
- SHIFT_FIRST_ARG is TRUE if the first arg of the operator was multiplied. */
-
- char *
- output_arithmetic_with_immediate_multiply (operands, shift_first_arg)
- rtx operands[5];
- int shift_first_arg;
- {
- char mnemonic[80];
- char *instr = arithmetic_instr (operands[1], shift_first_arg);
- int shift = int_log2 (INTVAL (operands[4]));
-
- sprintf (mnemonic, "%s\t%%0, %%2, %%3, asl#%d", instr, shift);
- return (arm_output_asm_insn (mnemonic, operands));
- } /* output_arithmetic_with_immediate_multiply */
-
-
- /* Output a move with a shift.
- OP is the shift rtx code.
- OPERANDS[0] = destination register.
- OPERANDS[1] = source register.
- OPERANDS[2] = shift constant or register. */
-
- char *
- output_shifted_move (op, operands)
- enum rtx_code op;
- rtx operands[2];
- {
- char mnemonic[80];
-
- if (GET_CODE (operands[2]) == CONST_INT && INTVAL (operands[2]) == 0)
- sprintf (mnemonic, "mov\t%%0, %%1");
- else
- sprintf (mnemonic, "mov\t%%0, %%1, %s %%2",
- shift_instr (op, &operands[2]));
- return (arm_output_asm_insn (mnemonic, operands));
- } /* output_shifted_move */
-
- char *
- output_shift_compare (operands, neg)
- rtx *operands;
- int neg;
- {
- char buf[80];
-
- if (neg)
- sprintf (buf, "cmn\t%%1, %%3, %s %%4", shift_instr (GET_CODE (operands[2]),
- &operands[4]));
- else
- sprintf (buf, "cmp\t%%1, %%3, %s %%4", shift_instr (GET_CODE (operands[2]),
- &operands[4]));
- return arm_output_asm_insn (buf, operands);
- } /* output_shift_compare */
-
- /* Output a .ascii pseudo-op, keeping track of lengths. This is because
- /bin/as is horribly restrictive. */
-
- void
- output_ascii_pseudo_op (stream, p, len)
- FILE *stream;
- unsigned char *p;
- int len;
- {
- int i;
- int len_so_far = 1000;
- int chars_so_far = 0;
-
- for (i = 0; i < len; i++)
- {
- register int c = p[i];
-
- if (len_so_far > 50)
- {
- if (chars_so_far)
- fputs ("\"\n", stream);
- fputs ("\t.ascii\t\"", stream);
- len_so_far = 0;
- arm_increase_location (chars_so_far);
- chars_so_far = 0;
- }
-
- if (c == '\"' || c == '\\')
- {
- putc('\\', stream);
- len_so_far++;
- }
- if (c >= ' ' && c < 0177)
- {
- putc (c, stream);
- len_so_far++;
- }
- else
- {
- fprintf (stream, "\\%03o", c);
- len_so_far +=4;
- }
- chars_so_far++;
- }
- fputs ("\"\n", stream);
- arm_increase_location (chars_so_far);
- } /* output_ascii_pseudo_op */
-
-
- /* Try to determine whether a pattern really clobbers the link register.
- This information is useful when peepholing, so that lr need not be pushed
- if we combine a call followed by a return.
- NOTE: This code does not check for side-effect expressions in a SET_SRC:
- such a check should not be needed because these only update an existing
- value within a register; the register must still be set elsewhere within
- the function. */
-
- static int
- pattern_really_clobbers_lr (x)
- rtx x;
- {
- int i;
-
- switch (GET_CODE (x))
- {
- case SET:
- switch (GET_CODE (SET_DEST (x)))
- {
- case REG:
- return REGNO (SET_DEST (x)) == 14;
- case SUBREG:
- if (GET_CODE (XEXP (SET_DEST (x), 0)) == REG)
- return REGNO (XEXP (SET_DEST (x), 0)) == 14;
- if (GET_CODE (XEXP (SET_DEST (x), 0)) == MEM)
- return 0;
- abort ();
- default:
- return 0;
- }
- case PARALLEL:
- for (i = 0; i < XVECLEN (x, 0); i++)
- if (pattern_really_clobbers_lr (XVECEXP (x, 0, i)))
- return 1;
- return 0;
- case CLOBBER:
- switch (GET_CODE (XEXP (x, 0)))
- {
- case REG:
- return REGNO (XEXP (x, 0)) == 14;
- case SUBREG:
- if (GET_CODE (XEXP (XEXP (x, 0), 0)) == REG)
- return REGNO (XEXP (XEXP (x, 0), 0)) == 14;
- abort ();
- default:
- return 0;
- }
- case UNSPEC:
- return 1;
- default:
- return 0;
- }
- }
-
- static int
- function_really_clobbers_lr (first)
- rtx first;
- {
- rtx insn, next;
-
- for (insn = first; insn; insn = next_nonnote_insn (insn))
- {
- switch (GET_CODE (insn))
- {
- case BARRIER:
- case NOTE:
- case CODE_LABEL:
- case JUMP_INSN: /* Jump insns only change the PC (and conds) */
- case INLINE_HEADER:
- break;
- case INSN:
- if (pattern_really_clobbers_lr (PATTERN (insn)))
- return 1;
- break;
- case CALL_INSN:
- /* Don't yet know how to handle those calls that are not to a
- SYMBOL_REF */
- if (GET_CODE (PATTERN (insn)) != PARALLEL)
- abort ();
- switch (GET_CODE (XVECEXP (PATTERN (insn), 0, 0)))
- {
- case CALL:
- if (GET_CODE (XEXP (XEXP (XVECEXP (PATTERN (insn), 0, 0), 0), 0))
- != SYMBOL_REF)
- return 1;
- break;
- case SET:
- if (GET_CODE (XEXP (XEXP (SET_SRC (XVECEXP (PATTERN (insn),
- 0, 0)), 0), 0))
- != SYMBOL_REF)
- return 1;
- break;
- default: /* Don't recognize it, be safe */
- return 1;
- }
- /* A call can be made (by peepholing) not to clobber lr iff it is
- followed by a return. There may, however, be a use insn iff
- we are returning the result of the call.
- If we run off the end of the insn chain, then that means the
- call was at the end of the function. Unfortunately we don't
- have a return insn for the peephole to recognize, so we
- must reject this. (Can this be fixed by adding our own insn?) */
- if ((next = next_nonnote_insn (insn)) == NULL)
- return 1;
- if (GET_CODE (next) == INSN && GET_CODE (PATTERN (next)) == USE
- && (GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) == SET)
- && (REGNO (SET_DEST (XVECEXP (PATTERN (insn), 0, 0)))
- == REGNO (XEXP (PATTERN (next), 0))))
- if ((next = next_nonnote_insn (next)) == NULL)
- return 1;
- if (GET_CODE (next) == JUMP_INSN
- && GET_CODE (PATTERN (next)) == RETURN)
- break;
- return 1;
- default:
- abort ();
- }
- }
- /* We have reached the end of the chain so lr was _not_ clobbered */
- return 0;
- }
-
- char *
- output_return_instruction (operand, really_return)
- rtx operand;
- int really_return;
- {
- char instr[100];
- int reg, live_regs = 0;
-
- if (current_function_calls_alloca && !really_return)
- abort();
-
- for (reg = 4; reg < 10; reg++)
- if (regs_ever_live[reg])
- live_regs++;
-
- if (live_regs || (regs_ever_live[14] && !lr_save_eliminated))
- live_regs++;
-
- if (frame_pointer_needed)
- live_regs += 4;
-
- if (live_regs)
- {
- if (lr_save_eliminated || !regs_ever_live[14])
- live_regs++;
- if (frame_pointer_needed)
- strcpy (instr, "ldm%d0ea\tfp, {");
- else
- strcpy (instr, "ldm%d0fd\tsp!, {");
- for (reg = 4; reg < 10; reg++)
- if (regs_ever_live[reg])
- {
- strcat (instr, reg_names[reg]);
- if (--live_regs)
- strcat (instr, ", ");
- }
- if (frame_pointer_needed)
- {
- strcat (instr, reg_names[11]);
- strcat (instr, ", ");
- strcat (instr, reg_names[13]);
- strcat (instr, ", ");
- strcat (instr, really_return ? reg_names[15] : reg_names[14]);
- }
- else
- strcat (instr, really_return ? reg_names[15] : reg_names[14]);
- strcat (instr, (TARGET_6 || !really_return) ? "}" : "}^");
- arm_output_asm_insn (instr, &operand);
- }
- else if (really_return)
- {
- strcpy (instr, TARGET_6 ? "mov%d0\tpc, lr" : "mov%d0s\tpc, lr");
- arm_output_asm_insn (instr, &operand);
- }
- return_used_this_function = 1;
- return "";
- }
-
- /* The amount of stack adjustment that happens here, in output_return and in
- output_epilogue must be exactly the same as was calculated during reload,
- or things will point to the wrong place. The only time we can safely
- ignore this constraint is when a function has no arguments on the stack,
- no stack frame requirement and no live registers execpt for `lr'. If we
- can guarantee that by making all function calls into tail calls and that
- lr is not clobbered in any other way, then there is no need to push lr
- onto the stack. */
-
- void
- output_prologue (f, frame_size)
- FILE *f;
- int frame_size;
- {
- int reg, live_regs_mask = 0, code_size = 0;
- rtx operands[3];
-
- /* Nonzero if we must stuff some register arguments onto the stack as if
- they were passed there. */
- int store_arg_regs = 0;
-
- if (arm_ccfsm_state || arm_target_insn)
- abort (); /* Sanity check */
-
- return_used_this_function = 0;
- lr_save_eliminated = 0;
-
- fprintf (f, "\t@ args = %d, pretend = %d, frame = %d\n",
- current_function_args_size, current_function_pretend_args_size,
- frame_size);
- fprintf (f, "\t@ frame_needed = %d, current_function_anonymous_args = %d\n",
- frame_pointer_needed, current_function_anonymous_args);
-
- if (current_function_anonymous_args && current_function_pretend_args_size)
- store_arg_regs = 1;
-
- for (reg = 4; reg < 10; reg++)
- if (regs_ever_live[reg])
- live_regs_mask |= (1 << reg);
-
- if (frame_pointer_needed)
- {
- live_regs_mask |= 0xD800;
- fputs ("\tmov\tip, sp\n", f);
- code_size += 4;
- }
- else if (regs_ever_live[14])
- {
- if (! current_function_args_size
- && !function_really_clobbers_lr (get_insns ()))
- {
- fprintf (f,"\t@ I don't think this function clobbers lr\n");
- lr_save_eliminated = 1;
- }
- else
- live_regs_mask |= 0x4000;
- }
-
- /* If CURRENT_FUNCTION_PRETEND_ARGS_SIZE, adjust the stack pointer to make
- room. If also STORE_ARG_REGS store the argument registers involved in
- the created slot (this is for stdarg and varargs). */
- if (current_function_pretend_args_size)
- {
- if (store_arg_regs)
- {
- int arg_size, mask = 0;
-
- assert (current_function_pretend_args_size <= 16);
- for (reg = 3, arg_size = current_function_pretend_args_size;
- arg_size > 0; reg--, arg_size -= 4)
- mask |= (1 << reg);
- print_multi_reg (f, "stmfd\tsp!", mask, FALSE);
- code_size += 4;
- }
- else
- {
- operands[0] = operands[1] = stack_pointer_rtx;
- operands[2] = gen_rtx (CONST_INT, VOIDmode,
- -current_function_pretend_args_size);
- output_add_immediate (operands);
- }
- }
-
- if (live_regs_mask)
- {
- /* if a di mode load/store multiple is used, and the base register
- is r3, then r4 can become an ever live register without lr
- doing so, in this case we need to push lr as well, or we
- will fail to get a proper return. */
-
- live_regs_mask |= 0x4000;
- lr_save_eliminated = 0;
- print_multi_reg (f, "stmfd\tsp!", live_regs_mask, FALSE);
- code_size += 4;
- }
-
- for (reg = 23; reg > 19; reg--)
- if (regs_ever_live[reg])
- {
- fprintf (f, "\tstfe\t%s, [sp, #-12]!\n", reg_names[reg]);
- code_size += 4;
- }
-
- if (frame_pointer_needed)
- {
- /* Make `fp' point to saved value of `pc'. */
-
- operands[0] = gen_rtx (REG, SImode, HARD_FRAME_POINTER_REGNUM);
- operands[1] = gen_rtx (REG, SImode, 12);
- operands[2] = gen_rtx (CONST_INT, VOIDmode,
- - (4 + current_function_pretend_args_size));
- output_add_immediate (operands);
- }
-
- if (frame_size)
- {
- operands[0] = operands[1] = stack_pointer_rtx;
- operands[2] = gen_rtx (CONST_INT, VOIDmode, -frame_size);
- output_add_immediate (operands);
- }
-
- arm_increase_location (code_size);
- } /* output_prologue */
-
-
- void
- output_epilogue (f, frame_size)
- FILE *f;
- int frame_size;
- {
- int reg, live_regs_mask = 0, code_size = 0;
- /* If we need this then it will always be at lesat this much */
- int floats_offset = 24;
- rtx operands[3];
-
- if (use_return_insn() && return_used_this_function)
- {
- if (frame_size && !(frame_pointer_needed || TARGET_APCS))
- {
- abort ();
- }
- return;
- }
-
- for (reg = 4; reg <= 10; reg++)
- if (regs_ever_live[reg])
- {
- live_regs_mask |= (1 << reg);
- floats_offset += 4;
- }
-
-
- if (frame_pointer_needed)
- {
- for (reg = 23; reg >= 20; reg--)
- if (regs_ever_live[reg])
- {
- fprintf (f, "\tldfe\t%s, [fp, #-%d]\n", reg_names[reg],
- floats_offset);
- floats_offset += 12;
- code_size += 4;
- }
-
- live_regs_mask |= 0xA800;
- print_multi_reg (f, "ldmea\tfp", live_regs_mask,
- TARGET_6 ? FALSE : TRUE);
- code_size += 4;
- }
- else
- {
- /* Restore stack pointer if necessary. */
- if (frame_size)
- {
- operands[0] = operands[1] = stack_pointer_rtx;
- operands[2] = gen_rtx (CONST_INT, VOIDmode, frame_size);
- output_add_immediate (operands);
- }
-
- for (reg = 20; reg < 24; reg++)
- if (regs_ever_live[reg])
- {
- fprintf (f, "\tldfe\t%s, [sp], #12\n", reg_names[reg]);
- code_size += 4;
- }
- if (current_function_pretend_args_size == 0 && regs_ever_live[14])
- {
- print_multi_reg (f, "ldmfd\tsp!", live_regs_mask | 0x8000,
- TARGET_6 ? FALSE : TRUE);
- code_size += 4;
- }
- else
- {
- if (live_regs_mask || regs_ever_live[14])
- {
- live_regs_mask |= 0x4000;
- print_multi_reg (f, "ldmfd\tsp!", live_regs_mask, FALSE);
- code_size += 4;
- }
- if (current_function_pretend_args_size)
- {
- operands[0] = operands[1] = stack_pointer_rtx;
- operands[2] = gen_rtx (CONST_INT, VOIDmode,
- current_function_pretend_args_size);
- output_add_immediate (operands);
- }
- fputs (TARGET_6 ? "\tmov\tpc, lr\n" : "\tmovs\tpc, lr\n", f);
- code_size += 4;
- }
- }
- arm_increase_location (code_size);
- current_function_anonymous_args = 0;
- } /* output_epilogue */
-
- /* Increase the `arm_text_location' by AMOUNT if we're in the text
- segment. */
-
- void
- arm_increase_location (amount)
- int amount;
- {
- if (in_text_section ())
- arm_text_location += amount;
- } /* arm_increase_location */
-
-
- /* Like output_asm_insn (), but also increases the arm_text_location (if in
- the .text segment, of course, even though this will always be true).
- Returns the empty string. */
-
- char *
- arm_output_asm_insn (template, operands)
- char *template;
- rtx *operands;
- {
- extern FILE *asm_out_file;
-
- output_asm_insn (template, operands);
- if (in_text_section ())
- arm_text_location += 4;
- fflush (asm_out_file);
- return ("");
- } /* arm_output_asm_insn */
-
-
- /* Output a label definition. If this label is within the .text segment, it
- is stored in OFFSET_TABLE, to be used when building `llc' instructions.
- Maybe GCC remembers names not starting with a `*' for a long time, but this
- is a minority anyway, so we just make a copy. Do not store the leading `*'
- if the name starts with one. */
-
- void
- arm_asm_output_label (stream, name)
- FILE *stream;
- char *name;
- {
- char *real_name, *s;
- struct label_offset *cur;
- int hash = 0;
-
- assemble_name (stream, name);
- fputs (":\n", stream);
- if (! in_text_section ())
- return;
-
- if (name[0] == '*')
- {
- real_name = xmalloc (1 + strlen (&name[1]));
- strcpy (real_name, &name[1]);
- }
- else
- {
- real_name = xmalloc (2 + strlen (name));
- strcpy (real_name, "_");
- strcat (real_name, name);
- }
- for (s = real_name; *s; s++)
- hash += *s;
- hash = hash % LABEL_HASH_SIZE;
- cur = (struct label_offset *) xmalloc (sizeof (struct label_offset));
- cur->name = real_name;
- cur->offset = arm_text_location;
- cur->cdr = offset_table[hash];
- offset_table[hash] = cur;
- } /* arm_asm_output_label */
-
-
- /* Output the instructions needed to perform what Martin's /bin/as called
- llc: load an SImode thing from the function's constant pool.
-
- XXX This could be enhanced in that we do not really need a pointer in the
- constant pool pointing to the real thing. If we can address this pointer,
- we can also address what it is pointing at, in fact, anything in the text
- segment which has been defined already within this .s file. */
-
- char *
- arm_output_llc (operands)
- rtx *operands;
- {
- char *s, *name = XSTR (XEXP (operands[1], 0), 0);
- struct label_offset *he;
- int hash = 0, conditional = (arm_ccfsm_state == 3 || arm_ccfsm_state == 4);
-
- if (*name != '*')
- abort ();
-
- for (s = &name[1]; *s; s++)
- hash += *s;
- hash = hash % LABEL_HASH_SIZE;
- he = offset_table[hash];
- while (he && strcmp (he->name, &name[1]))
- he = he->cdr;
-
- if (!he)
- abort ();
-
- if (arm_text_location + 8 - he->offset < 4095)
- {
- fprintf (asm_out_file, "\tldr%s\t%s, [pc, #%s - . - 8]\n",
- conditional ? arm_condition_codes[arm_current_cc] : "",
- reg_names[REGNO (operands[0])], &name[1]);
- arm_increase_location (4);
- return ("");
- }
- else
- {
- int offset = - (arm_text_location + 8 - he->offset);
- char *reg_name = reg_names[REGNO (operands[0])];
-
- /* ??? This is a hack, assuming the constant pool never is more than
- (1 + 255) * 4096 == 1Meg away from the PC. */
-
- if (offset > 1000000)
- abort ();
-
- fprintf (asm_out_file, "\tsub%s\t%s, pc, #(8 + . - %s) & ~4095\n",
- conditional ? arm_condition_codes[arm_current_cc] : "",
- reg_name, &name[1]);
- fprintf (asm_out_file, "\tldr%s\t%s, [%s, #- ((4 + . - %s) & 4095)]\n",
- conditional ? arm_condition_codes[arm_current_cc] : "",
- reg_name, reg_name, &name[1]);
- arm_increase_location (8);
- }
- return ("");
- } /* arm_output_llc */
-
- /* output_load_symbol ()
- load a symbol that is known to be in the text segment into a register */
-
- char *
- output_load_symbol (operands)
- rtx *operands;
- {
- char *s, *name = XSTR (operands[1], 0);
- struct label_offset *he;
- int hash = 0;
- int offset;
-
- if (*name != '*')
- abort ();
-
- for (s = &name[1]; *s; s++)
- hash += *s;
- hash = hash % LABEL_HASH_SIZE;
- he = offset_table[hash];
- while (he && strcmp (he->name, &name[1]))
- he = he->cdr;
-
- if (!he)
- abort ();
-
- offset = (arm_text_location + 8 - he->offset);
- if (offset < 0)
- abort ();
-
- /* If the symbol is word aligned then we might be able to reduce the
- number of loads */
- if ((offset & 3) == 0)
- {
- arm_output_asm_insn ("sub\t%0, pc, #(8 + . -%a1) & 1023", operands);
- if (offset > 0x3ff)
- {
- arm_output_asm_insn ("sub\t%0, %0, #(4 + . -%a1) & 261120",
- operands);
- if (offset > 0x3ffff)
- {
- arm_output_asm_insn ("sub\t%0, %0, #(. -%a1) & 66846720",
- operands);
- if (offset > 0x3ffffff)
- arm_output_asm_insn ("sub\t%0, %0, #(. - 4 -%a1) & -67108864",
- operands);
- }
- }
- }
- else
- {
- arm_output_asm_insn ("sub\t%0, pc, #(8 + . -%a1) & 255", operands);
- if (offset > 0x0ff)
- {
- arm_output_asm_insn ("sub\t%0, %0, #(4 + . -%a1) & 65280", operands);
- if (offset > 0x0ffff)
- {
- arm_output_asm_insn ("sub\t%0, %0, #(. -%a1) & 16711680",
- operands);
- if (offset > 0x0ffffff)
- arm_output_asm_insn ("sub\t%0, %0, #(. - 4 -%a1) & -16777216",
- operands);
- }
- }
- }
- return "";
- }
-
- /* Output code resembling an .lcomm directive. /bin/as doesn't have this
- directive hence this hack, which works by reserving some `.space' in the
- bss segment directly.
-
- XXX This is a severe hack, which is guaranteed NOT to work since it doesn't
- define STATIC COMMON space but merely STATIC BSS space. */
-
- void
- output_lcomm_directive (stream, name, size, rounded)
- FILE *stream;
- char *name;
- int size, rounded;
- {
- fputs ("\n\t.bss\t@ .lcomm\n", stream);
- assemble_name (stream, name);
- fprintf (stream, ":\t.space\t%d\n", rounded);
- if (in_text_section ())
- fputs ("\n\t.text\n", stream);
- else
- fputs ("\n\t.data\n", stream);
- } /* output_lcomm_directive */
-
- /* A finite state machine takes care of noticing whether or not instructions
- can be conditionally executed, and thus decrease execution time and code
- size by deleting branch instructions. The fsm is controlled by
- final_prescan_insn, and controls the actions of ASM_OUTPUT_OPCODE. */
-
- /* The state of the fsm controlling condition codes are:
- 0: normal, do nothing special
- 1: make ASM_OUTPUT_OPCODE not output this instruction
- 2: make ASM_OUTPUT_OPCODE not output this instruction
- 3: make instructions conditional
- 4: make instructions conditional
-
- State transitions (state->state by whom under condition):
- 0 -> 1 final_prescan_insn if the `target' is a label
- 0 -> 2 final_prescan_insn if the `target' is an unconditional branch
- 1 -> 3 ASM_OUTPUT_OPCODE after not having output the conditional branch
- 2 -> 4 ASM_OUTPUT_OPCODE after not having output the conditional branch
- 3 -> 0 ASM_OUTPUT_INTERNAL_LABEL if the `target' label is reached
- (the target label has CODE_LABEL_NUMBER equal to arm_target_label).
- 4 -> 0 final_prescan_insn if the `target' unconditional branch is reached
- (the target insn is arm_target_insn).
-
- If the jump clobbers the conditions then we use states 2 and 4.
-
- A similar thing can be done with conditional return insns.
-
- XXX In case the `target' is an unconditional branch, this conditionalising
- of the instructions always reduces code size, but not always execution
- time. But then, I want to reduce the code size to somewhere near what
- /bin/cc produces. */
-
- /* The condition codes of the ARM, and the inverse function. */
- char *arm_condition_codes[] =
- {
- "eq", "ne", "cs", "cc", "mi", "pl", "vs", "vc",
- "hi", "ls", "ge", "lt", "gt", "le", "al", "nv"
- };
-
- #define ARM_INVERSE_CONDITION_CODE(X) ((X) ^ 1)
-
- /* Returns the index of the ARM condition code string in
- `arm_condition_codes'. COMPARISON should be an rtx like
- `(eq (...) (...))'. */
-
- int
- get_arm_condition_code (comparison)
- rtx comparison;
- {
- switch (GET_CODE (comparison))
- {
- case NE: return (1);
- case EQ: return (0);
- case GE: return (10);
- case GT: return (12);
- case LE: return (13);
- case LT: return (11);
- case GEU: return (2);
- case GTU: return (8);
- case LEU: return (9);
- case LTU: return (3);
- default: abort ();
- }
- /*NOTREACHED*/
- return (42);
- } /* get_arm_condition_code */
-
-
- void
- final_prescan_insn (insn, opvec, noperands)
- rtx insn;
- rtx *opvec;
- int noperands;
- {
- /* BODY will hold the body of INSN. */
- register rtx body = PATTERN (insn);
-
- /* This will be 1 if trying to repeat the trick, and things need to be
- reversed if it appears to fail. */
- int reverse = 0;
-
- /* JUMP_CLOBBERS will be one implies that the conditions if a branch is
- taken are clobbered, even if the rtl suggests otherwise. It also
- means that we have to grub around within the jump expression to find
- out what the conditions are when the jump isn't taken. */
- int jump_clobbers = 0;
-
- /* If we start with a return insn, we only succeed if we find another one. */
- int seeking_return = 0;
-
- /* START_INSN will hold the insn from where we start looking. This is the
- first insn after the following code_label if REVERSE is true. */
- rtx start_insn = insn;
-
- /* If in state 4, check if the target branch is reached, in order to
- change back to state 0. */
- if (arm_ccfsm_state == 4)
- {
- if (insn == arm_target_insn)
- {
- arm_target_insn = NULL;
- arm_ccfsm_state = 0;
- }
- return;
- }
-
- /* If in state 3, it is possible to repeat the trick, if this insn is an
- unconditional branch to a label, and immediately following this branch
- is the previous target label which is only used once, and the label this
- branch jumps to is not too far off. */
- if (arm_ccfsm_state == 3)
- {
- if (simplejump_p (insn))
- {
- start_insn = next_nonnote_insn (start_insn);
- if (GET_CODE (start_insn) == BARRIER)
- {
- /* XXX Isn't this always a barrier? */
- start_insn = next_nonnote_insn (start_insn);
- }
- if (GET_CODE (start_insn) == CODE_LABEL
- && CODE_LABEL_NUMBER (start_insn) == arm_target_label
- && LABEL_NUSES (start_insn) == 1)
- reverse = TRUE;
- else
- return;
- }
- else if (GET_CODE (body) == RETURN)
- {
- start_insn = next_nonnote_insn (start_insn);
- if (GET_CODE (start_insn) == BARRIER)
- start_insn = next_nonnote_insn (start_insn);
- if (GET_CODE (start_insn) == CODE_LABEL
- && CODE_LABEL_NUMBER (start_insn) == arm_target_label
- && LABEL_NUSES (start_insn) == 1)
- {
- reverse = TRUE;
- seeking_return = 1;
- }
- else
- return;
- }
- else
- return;
- }
-
- if (arm_ccfsm_state != 0 && !reverse)
- abort ();
- if (GET_CODE (insn) != JUMP_INSN)
- return;
-
- /* This jump might be paralled with a clobber of the condition codes
- the jump should always come first */
- if (GET_CODE (body) == PARALLEL && XVECLEN (body, 0) > 0)
- body = XVECEXP (body, 0, 0);
-
- #if 0
- /* If this is a conditional return then we don't want to know */
- if (GET_CODE (body) == SET && GET_CODE (SET_DEST (body)) == PC
- && GET_CODE (SET_SRC (body)) == IF_THEN_ELSE
- && (GET_CODE (XEXP (SET_SRC (body), 1)) == RETURN
- || GET_CODE (XEXP (SET_SRC (body), 2)) == RETURN))
- return;
- #endif
-
- if (reverse
- || (GET_CODE (body) == SET && GET_CODE (SET_DEST (body)) == PC
- && GET_CODE (SET_SRC (body)) == IF_THEN_ELSE))
- {
- int insns_skipped = 0, fail = FALSE, succeed = FALSE;
- /* Flag which part of the IF_THEN_ELSE is the LABEL_REF. */
- int then_not_else = TRUE;
- rtx this_insn = start_insn, label = 0;
-
- if (get_attr_conds (insn) == CONDS_JUMP_CLOB)
- jump_clobbers = 1;
-
- /* Register the insn jumped to. */
- if (reverse)
- {
- if (!seeking_return)
- label = XEXP (SET_SRC (body), 0);
- }
- else if (GET_CODE (XEXP (SET_SRC (body), 1)) == LABEL_REF)
- label = XEXP (XEXP (SET_SRC (body), 1), 0);
- else if (GET_CODE (XEXP (SET_SRC (body), 2)) == LABEL_REF)
- {
- label = XEXP (XEXP (SET_SRC (body), 2), 0);
- then_not_else = FALSE;
- }
- else if (GET_CODE (XEXP (SET_SRC (body), 1)) == RETURN)
- seeking_return = 1;
- else if (GET_CODE (XEXP (SET_SRC (body), 2)) == RETURN)
- {
- seeking_return = 1;
- then_not_else = FALSE;
- }
- else
- abort ();
-
- /* See how many insns this branch skips, and what kind of insns. If all
- insns are okay, and the label or unconditional branch to the same
- label is not too far away, succeed. */
- for (insns_skipped = 0;
- !fail && !succeed && insns_skipped < MAX_INSNS_SKIPPED;
- insns_skipped++)
- {
- rtx scanbody;
-
- this_insn = next_nonnote_insn (this_insn);
- if (!this_insn)
- break;
-
- scanbody = PATTERN (this_insn);
-
- switch (GET_CODE (this_insn))
- {
- case CODE_LABEL:
- /* Succeed if it is the target label, otherwise fail since
- control falls in from somewhere else. */
- if (this_insn == label)
- {
- if (jump_clobbers)
- {
- arm_ccfsm_state = 2;
- this_insn = next_nonnote_insn (this_insn);
- }
- else
- arm_ccfsm_state = 1;
- succeed = TRUE;
- }
- else
- fail = TRUE;
- break;
-
- case BARRIER:
- /* Succeed if the following insn is the target label.
- Otherwise fail.
- If return insns are used then the last insn in a function
- will be a barrier. */
- this_insn = next_nonnote_insn (this_insn);
- if (this_insn && this_insn == label)
- {
- if (jump_clobbers)
- {
- arm_ccfsm_state = 2;
- this_insn = next_nonnote_insn (this_insn);
- }
- else
- arm_ccfsm_state = 1;
- succeed = TRUE;
- }
- else
- fail = TRUE;
- break;
-
- case CALL_INSN:
- /* The arm 6xx uses full 32 bit addresses so the cc is not
- preserved over calls */
- if (TARGET_6)
- fail = TRUE;
- break;
- case JUMP_INSN:
- /* If this is an unconditional branch to the same label, succeed.
- If it is to another label, do nothing. If it is conditional,
- fail. */
- /* XXX Probably, the test for the SET and the PC are unnecessary. */
-
- if (GET_CODE (scanbody) == SET
- && GET_CODE (SET_DEST (scanbody)) == PC)
- {
- if (GET_CODE (SET_SRC (scanbody)) == LABEL_REF
- && XEXP (SET_SRC (scanbody), 0) == label && !reverse)
- {
- arm_ccfsm_state = 2;
- succeed = TRUE;
- }
- else if (GET_CODE (SET_SRC (scanbody)) == IF_THEN_ELSE)
- fail = TRUE;
- }
- else if (GET_CODE (scanbody) == RETURN
- && seeking_return)
- {
- arm_ccfsm_state = 2;
- succeed = TRUE;
- }
- else if (GET_CODE (scanbody) == PARALLEL)
- {
- switch (get_attr_conds (this_insn))
- {
- case CONDS_NOCOND:
- break;
- default:
- fail = TRUE;
- break;
- }
- }
- break;
-
- case INSN:
- /* Instructions using or affecting the condition codes make it
- fail. */
- if ((GET_CODE (scanbody) == SET
- || GET_CODE (scanbody) == PARALLEL)
- && get_attr_conds (this_insn) != CONDS_NOCOND)
- fail = TRUE;
- break;
-
- default:
- break;
- }
- }
- if (succeed)
- {
- if ((!seeking_return) && (arm_ccfsm_state == 1 || reverse))
- arm_target_label = CODE_LABEL_NUMBER (label);
- else if (seeking_return || arm_ccfsm_state == 2)
- {
- while (this_insn && GET_CODE (PATTERN (this_insn)) == USE)
- {
- this_insn = next_nonnote_insn (this_insn);
- if (this_insn && (GET_CODE (this_insn) == BARRIER
- || GET_CODE (this_insn) == CODE_LABEL))
- abort ();
- }
- if (!this_insn)
- {
- /* Oh, dear! we ran off the end.. give up */
- recog (PATTERN (insn), insn, NULL_PTR);
- arm_ccfsm_state = 0;
- arm_target_insn = NULL;
- return;
- }
- arm_target_insn = this_insn;
- }
- else
- abort ();
- if (jump_clobbers)
- {
- if (reverse)
- abort ();
- arm_current_cc =
- get_arm_condition_code (XEXP (XEXP (XEXP (SET_SRC (body),
- 0), 0), 1));
- if (GET_CODE (XEXP (XEXP (SET_SRC (body), 0), 0)) == AND)
- arm_current_cc = ARM_INVERSE_CONDITION_CODE (arm_current_cc);
- if (GET_CODE (XEXP (SET_SRC (body), 0)) == NE)
- arm_current_cc = ARM_INVERSE_CONDITION_CODE (arm_current_cc);
- }
- else
- {
- /* If REVERSE is true, ARM_CURRENT_CC needs to be inverted from
- what it was. */
- if (!reverse)
- arm_current_cc = get_arm_condition_code (XEXP (SET_SRC (body),
- 0));
- }
-
- if (reverse || then_not_else)
- arm_current_cc = ARM_INVERSE_CONDITION_CODE (arm_current_cc);
- }
- /* restore recog_operand (getting the attributes of other insns can
- destroy this array, but final.c assumes that it remains intact
- accross this call; since the insn has been recognized already we
- call recog direct). */
- recog (PATTERN (insn), insn, NULL_PTR);
- }
- } /* final_prescan_insn */
-
- /* EOF */
-