/* Analyze RTL for C-Compiler Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc. This file is part of GCC. GCC 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. GCC 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 GCC; see the file COPYING. If not, write to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include "config.h" #include "system.h" #include "toplev.h" #include "rtl.h" #include "hard-reg-set.h" #include "insn-config.h" #include "recog.h" #include "tm_p.h" #include "flags.h" #include "basic-block.h" #include "real.h" /* Forward declarations */ static int global_reg_mentioned_p_1 PARAMS ((rtx *, void *)); static void set_of_1 PARAMS ((rtx, rtx, void *)); static void insn_dependent_p_1 PARAMS ((rtx, rtx, void *)); static int computed_jump_p_1 PARAMS ((rtx)); static void parms_set PARAMS ((rtx, rtx, void *)); static bool hoist_test_store PARAMS ((rtx, rtx, regset)); static void hoist_update_store PARAMS ((rtx, rtx *, rtx, rtx)); /* Bit flags that specify the machine subtype we are compiling for. Bits are tested using macros TARGET_... defined in the tm.h file and set by `-m...' switches. Must be defined in rtlanal.c. */ int target_flags; /* Return 1 if the value of X is unstable (would be different at a different point in the program). The frame pointer, arg pointer, etc. are considered stable (within one function) and so is anything marked `unchanging'. */ int rtx_unstable_p (x) rtx x; { RTX_CODE code = GET_CODE (x); int i; const char *fmt; switch (code) { case MEM: return ! RTX_UNCHANGING_P (x) || rtx_unstable_p (XEXP (x, 0)); case QUEUED: return 1; case ADDRESSOF: case CONST: case CONST_INT: case CONST_DOUBLE: case CONST_VECTOR: case SYMBOL_REF: case LABEL_REF: return 0; case REG: /* As in rtx_varies_p, we have to use the actual rtx, not reg number. */ if (x == frame_pointer_rtx || x == hard_frame_pointer_rtx /* The arg pointer varies if it is not a fixed register. */ || (x == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM]) || RTX_UNCHANGING_P (x)) return 0; #ifndef PIC_OFFSET_TABLE_REG_CALL_CLOBBERED /* ??? When call-clobbered, the value is stable modulo the restore that must happen after a call. This currently screws up local-alloc into believing that the restore is not needed. */ if (x == pic_offset_table_rtx) return 0; #endif return 1; case ASM_OPERANDS: if (MEM_VOLATILE_P (x)) return 1; /* FALLTHROUGH */ default: break; } fmt = GET_RTX_FORMAT (code); for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) if (fmt[i] == 'e') { if (rtx_unstable_p (XEXP (x, i))) return 1; } else if (fmt[i] == 'E') { int j; for (j = 0; j < XVECLEN (x, i); j++) if (rtx_unstable_p (XVECEXP (x, i, j))) return 1; } return 0; } /* Return 1 if X has a value that can vary even between two executions of the program. 0 means X can be compared reliably against certain constants or near-constants. FOR_ALIAS is nonzero if we are called from alias analysis; if it is zero, we are slightly more conservative. The frame pointer and the arg pointer are considered constant. */ int rtx_varies_p (x, for_alias) rtx x; int for_alias; { RTX_CODE code = GET_CODE (x); int i; const char *fmt; switch (code) { case MEM: return ! RTX_UNCHANGING_P (x) || rtx_varies_p (XEXP (x, 0), for_alias); case QUEUED: return 1; case CONST: case CONST_INT: case CONST_DOUBLE: case CONST_VECTOR: case SYMBOL_REF: case LABEL_REF: return 0; case REG: /* Note that we have to test for the actual rtx used for the frame and arg pointers and not just the register number in case we have eliminated the frame and/or arg pointer and are using it for pseudos. */ if (x == frame_pointer_rtx || x == hard_frame_pointer_rtx /* The arg pointer varies if it is not a fixed register. */ || (x == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM])) return 0; if (x == pic_offset_table_rtx #ifdef PIC_OFFSET_TABLE_REG_CALL_CLOBBERED /* ??? When call-clobbered, the value is stable modulo the restore that must happen after a call. This currently screws up local-alloc into believing that the restore is not needed, so we must return 0 only if we are called from alias analysis. */ && for_alias #endif ) return 0; return 1; case LO_SUM: /* The operand 0 of a LO_SUM is considered constant (in fact it is related specifically to operand 1) during alias analysis. */ return (! for_alias && rtx_varies_p (XEXP (x, 0), for_alias)) || rtx_varies_p (XEXP (x, 1), for_alias); case ASM_OPERANDS: if (MEM_VOLATILE_P (x)) return 1; /* FALLTHROUGH */ default: break; } fmt = GET_RTX_FORMAT (code); for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) if (fmt[i] == 'e') { if (rtx_varies_p (XEXP (x, i), for_alias)) return 1; } else if (fmt[i] == 'E') { int j; for (j = 0; j < XVECLEN (x, i); j++) if (rtx_varies_p (XVECEXP (x, i, j), for_alias)) return 1; } return 0; } /* Return 0 if the use of X as an address in a MEM can cause a trap. */ int rtx_addr_can_trap_p (x) rtx x; { enum rtx_code code = GET_CODE (x); switch (code) { case SYMBOL_REF: return SYMBOL_REF_WEAK (x); case LABEL_REF: return 0; case REG: /* As in rtx_varies_p, we have to use the actual rtx, not reg number. */ if (x == frame_pointer_rtx || x == hard_frame_pointer_rtx || x == stack_pointer_rtx /* The arg pointer varies if it is not a fixed register. */ || (x == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM])) return 0; /* All of the virtual frame registers are stack references. */ if (REGNO (x) >= FIRST_VIRTUAL_REGISTER && REGNO (x) <= LAST_VIRTUAL_REGISTER) return 0; return 1; case CONST: return rtx_addr_can_trap_p (XEXP (x, 0)); case PLUS: /* An address is assumed not to trap if it is an address that can't trap plus a constant integer or it is the pic register plus a constant. */ return ! ((! rtx_addr_can_trap_p (XEXP (x, 0)) && GET_CODE (XEXP (x, 1)) == CONST_INT) || (XEXP (x, 0) == pic_offset_table_rtx && CONSTANT_P (XEXP (x, 1)))); case LO_SUM: case PRE_MODIFY: return rtx_addr_can_trap_p (XEXP (x, 1)); case PRE_DEC: case PRE_INC: case POST_DEC: case POST_INC: case POST_MODIFY: return rtx_addr_can_trap_p (XEXP (x, 0)); default: break; } /* If it isn't one of the case above, it can cause a trap. */ return 1; } /* Return 1 if X refers to a memory location whose address cannot be compared reliably with constant addresses, or if X refers to a BLKmode memory object. FOR_ALIAS is nonzero if we are called from alias analysis; if it is zero, we are slightly more conservative. */ int rtx_addr_varies_p (x, for_alias) rtx x; int for_alias; { enum rtx_code code; int i; const char *fmt; if (x == 0) return 0; code = GET_CODE (x); if (code == MEM) return GET_MODE (x) == BLKmode || rtx_varies_p (XEXP (x, 0), for_alias); fmt = GET_RTX_FORMAT (code); for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) if (fmt[i] == 'e') { if (rtx_addr_varies_p (XEXP (x, i), for_alias)) return 1; } else if (fmt[i] == 'E') { int j; for (j = 0; j < XVECLEN (x, i); j++) if (rtx_addr_varies_p (XVECEXP (x, i, j), for_alias)) return 1; } return 0; } /* Return the value of the integer term in X, if one is apparent; otherwise return 0. Only obvious integer terms are detected. This is used in cse.c with the `related_value' field. */ HOST_WIDE_INT get_integer_term (x) rtx x; { if (GET_CODE (x) == CONST) x = XEXP (x, 0); if (GET_CODE (x) == MINUS && GET_CODE (XEXP (x, 1)) == CONST_INT) return - INTVAL (XEXP (x, 1)); if (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 1)) == CONST_INT) return INTVAL (XEXP (x, 1)); return 0; } /* If X is a constant, return the value sans apparent integer term; otherwise return 0. Only obvious integer terms are detected. */ rtx get_related_value (x) rtx x; { if (GET_CODE (x) != CONST) return 0; x = XEXP (x, 0); if (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 1)) == CONST_INT) return XEXP (x, 0); else if (GET_CODE (x) == MINUS && GET_CODE (XEXP (x, 1)) == CONST_INT) return XEXP (x, 0); return 0; } /* Given a tablejump insn INSN, return the RTL expression for the offset into the jump table. If the offset cannot be determined, then return NULL_RTX. If EARLIEST is non-zero, it is a pointer to a place where the earliest insn used in locating the offset was found. */ rtx get_jump_table_offset (insn, earliest) rtx insn; rtx *earliest; { rtx label; rtx table; rtx set; rtx old_insn; rtx x; rtx old_x; rtx y; rtx old_y; int i; if (GET_CODE (insn) != JUMP_INSN || ! (label = JUMP_LABEL (insn)) || ! (table = NEXT_INSN (label)) || GET_CODE (table) != JUMP_INSN || (GET_CODE (PATTERN (table)) != ADDR_VEC && GET_CODE (PATTERN (table)) != ADDR_DIFF_VEC) || ! (set = single_set (insn))) return NULL_RTX; x = SET_SRC (set); /* Some targets (eg, ARM) emit a tablejump that also contains the out-of-range target. */ if (GET_CODE (x) == IF_THEN_ELSE && GET_CODE (XEXP (x, 2)) == LABEL_REF) x = XEXP (x, 1); /* Search backwards and locate the expression stored in X. */ for (old_x = NULL_RTX; GET_CODE (x) == REG && x != old_x; old_x = x, x = find_last_value (x, &insn, NULL_RTX, 0)) ; /* If X is an expression using a relative address then strip off the addition / subtraction of PC, PIC_OFFSET_TABLE_REGNUM, or the jump table label. */ if (GET_CODE (PATTERN (table)) == ADDR_DIFF_VEC && (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS)) { for (i = 0; i < 2; i++) { old_insn = insn; y = XEXP (x, i); if (y == pc_rtx || y == pic_offset_table_rtx) break; for (old_y = NULL_RTX; GET_CODE (y) == REG && y != old_y; old_y = y, y = find_last_value (y, &old_insn, NULL_RTX, 0)) ; if ((GET_CODE (y) == LABEL_REF && XEXP (y, 0) == label)) break; } if (i >= 2) return NULL_RTX; x = XEXP (x, 1 - i); for (old_x = NULL_RTX; GET_CODE (x) == REG && x != old_x; old_x = x, x = find_last_value (x, &insn, NULL_RTX, 0)) ; } /* Strip off any sign or zero extension. */ if (GET_CODE (x) == SIGN_EXTEND || GET_CODE (x) == ZERO_EXTEND) { x = XEXP (x, 0); for (old_x = NULL_RTX; GET_CODE (x) == REG && x != old_x; old_x = x, x = find_last_value (x, &insn, NULL_RTX, 0)) ; } /* If X isn't a MEM then this isn't a tablejump we understand. */ if (GET_CODE (x) != MEM) return NULL_RTX; /* Strip off the MEM. */ x = XEXP (x, 0); for (old_x = NULL_RTX; GET_CODE (x) == REG && x != old_x; old_x = x, x = find_last_value (x, &insn, NULL_RTX, 0)) ; /* If X isn't a PLUS than this isn't a tablejump we understand. */ if (GET_CODE (x) != PLUS) return NULL_RTX; /* At this point we should have an expression representing the jump table plus an offset. Examine each operand in order to determine which one represents the jump table. Knowing that tells us that the other operand must represent the offset. */ for (i = 0; i < 2; i++) { old_insn = insn; y = XEXP (x, i); for (old_y = NULL_RTX; GET_CODE (y) == REG && y != old_y; old_y = y, y = find_last_value (y, &old_insn, NULL_RTX, 0)) ; if ((GET_CODE (y) == CONST || GET_CODE (y) == LABEL_REF) && reg_mentioned_p (label, y)) break; } if (i >= 2) return NULL_RTX; x = XEXP (x, 1 - i); /* Strip off the addition / subtraction of PIC_OFFSET_TABLE_REGNUM. */ if (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS) for (i = 0; i < 2; i++) if (XEXP (x, i) == pic_offset_table_rtx) { x = XEXP (x, 1 - i); break; } if (earliest) *earliest = insn; /* Return the RTL expression representing the offset. */ return x; } /* A subroutine of global_reg_mentioned_p, returns 1 if *LOC mentions a global register. */ static int global_reg_mentioned_p_1 (loc, data) rtx *loc; void *data ATTRIBUTE_UNUSED; { int regno; rtx x = *loc; if (! x) return 0; switch (GET_CODE (x)) { case SUBREG: if (GET_CODE (SUBREG_REG (x)) == REG) { if (REGNO (SUBREG_REG (x)) < FIRST_PSEUDO_REGISTER && global_regs[subreg_regno (x)]) return 1; return 0; } break; case REG: regno = REGNO (x); if (regno < FIRST_PSEUDO_REGISTER && global_regs[regno]) return 1; return 0; case SCRATCH: case PC: case CC0: case CONST_INT: case CONST_DOUBLE: case CONST: case LABEL_REF: return 0; case CALL: /* A non-constant call might use a global register. */ return 1; default: break; } return 0; } /* Returns non-zero if X mentions a global register. */ int global_reg_mentioned_p (x) rtx x; { if (INSN_P (x)) { if (GET_CODE (x) == CALL_INSN) { if (! CONST_OR_PURE_CALL_P (x)) return 1; x = CALL_INSN_FUNCTION_USAGE (x); if (x == 0) return 0; } else x = PATTERN (x); } return for_each_rtx (&x, global_reg_mentioned_p_1, NULL); } /* Return the number of places FIND appears within X. If COUNT_DEST is zero, we do not count occurrences inside the destination of a SET. */ int count_occurrences (x, find, count_dest) rtx x, find; int count_dest; { int i, j; enum rtx_code code; const char *format_ptr; int count; if (x == find) return 1; code = GET_CODE (x); switch (code) { case REG: case CONST_INT: case CONST_DOUBLE: case CONST_VECTOR: case SYMBOL_REF: case CODE_LABEL: case PC: case CC0: return 0; case MEM: if (GET_CODE (find) == MEM && rtx_equal_p (x, find)) return 1; break; case SET: if (SET_DEST (x) == find && ! count_dest) return count_occurrences (SET_SRC (x), find, count_dest); break; default: break; } format_ptr = GET_RTX_FORMAT (code); count = 0; for (i = 0; i < GET_RTX_LENGTH (code); i++) { switch (*format_ptr++) { case 'e': count += count_occurrences (XEXP (x, i), find, count_dest); break; case 'E': for (j = 0; j < XVECLEN (x, i); j++) count += count_occurrences (XVECEXP (x, i, j), find, count_dest); break; } } return count; } /* Nonzero if register REG appears somewhere within IN. Also works if REG is not a register; in this case it checks for a subexpression of IN that is Lisp "equal" to REG. */ int reg_mentioned_p (reg, in) rtx reg, in; { const char *fmt; int i; enum rtx_code code; if (in == 0) return 0; if (reg == in) return 1; if (GET_CODE (in) == LABEL_REF) return reg == XEXP (in, 0); code = GET_CODE (in); switch (code) { /* Compare registers by number. */ case REG: return GET_CODE (reg) == REG && REGNO (in) == REGNO (reg); /* These codes have no constituent expressions and are unique. */ case SCRATCH: case CC0: case PC: return 0; case CONST_INT: return GET_CODE (reg) == CONST_INT && INTVAL (in) == INTVAL (reg); case CONST_VECTOR: case CONST_DOUBLE: /* These are kept unique for a given value. */ return 0; default: break; } if (GET_CODE (reg) == code && rtx_equal_p (reg, in)) return 1; fmt = GET_RTX_FORMAT (code); for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) { if (fmt[i] == 'E') { int j; for (j = XVECLEN (in, i) - 1; j >= 0; j--) if (reg_mentioned_p (reg, XVECEXP (in, i, j))) return 1; } else if (fmt[i] == 'e' && reg_mentioned_p (reg, XEXP (in, i))) return 1; } return 0; } /* Return 1 if in between BEG and END, exclusive of BEG and END, there is no CODE_LABEL insn. */ int no_labels_between_p (beg, end) rtx beg, end; { rtx p; if (beg == end) return 0; for (p = NEXT_INSN (beg); p != end; p = NEXT_INSN (p)) if (GET_CODE (p) == CODE_LABEL) return 0; return 1; } /* Return 1 if in between BEG and END, exclusive of BEG and END, there is no JUMP_INSN insn. */ int no_jumps_between_p (beg, end) rtx beg, end; { rtx p; for (p = NEXT_INSN (beg); p != end; p = NEXT_INSN (p)) if (GET_CODE (p) == JUMP_INSN) return 0; return 1; } /* Nonzero if register REG is used in an insn between FROM_INSN and TO_INSN (exclusive of those two). */ int reg_used_between_p (reg, from_insn, to_insn) rtx reg, from_insn, to_insn; { rtx insn; if (from_insn == to_insn) return 0; for (insn = NEXT_INSN (from_insn); insn != to_insn; insn = NEXT_INSN (insn)) if (INSN_P (insn) && (reg_overlap_mentioned_p (reg, PATTERN (insn)) || (GET_CODE (insn) == CALL_INSN && (find_reg_fusage (insn, USE, reg) || find_reg_fusage (insn, CLOBBER, reg))))) return 1; return 0; } /* Nonzero if the old value of X, a register, is referenced in BODY. If X is entirely replaced by a new value and the only use is as a SET_DEST, we do not consider it a reference. */ int reg_referenced_p (x, body) rtx x; rtx body; { int i; switch (GET_CODE (body)) { case SET: if (reg_overlap_mentioned_p (x, SET_SRC (body))) return 1; /* If the destination is anything other than CC0, PC, a REG or a SUBREG of a REG that occupies all of the REG, the insn references X if it is mentioned in the destination. */ if (GET_CODE (SET_DEST (body)) != CC0 && GET_CODE (SET_DEST (body)) != PC && GET_CODE (SET_DEST (body)) != REG && ! (GET_CODE (SET_DEST (body)) == SUBREG && GET_CODE (SUBREG_REG (SET_DEST (body))) == REG && (((GET_MODE_SIZE (GET_MODE (SUBREG_REG (SET_DEST (body)))) + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD) == ((GET_MODE_SIZE (GET_MODE (SET_DEST (body))) + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD))) && reg_overlap_mentioned_p (x, SET_DEST (body))) return 1; return 0; case ASM_OPERANDS: for (i = ASM_OPERANDS_INPUT_LENGTH (body) - 1; i >= 0; i--) if (reg_overlap_mentioned_p (x, ASM_OPERANDS_INPUT (body, i))) return 1; return 0; case CALL: case USE: case IF_THEN_ELSE: return reg_overlap_mentioned_p (x, body); case TRAP_IF: return reg_overlap_mentioned_p (x, TRAP_CONDITION (body)); case PREFETCH: return reg_overlap_mentioned_p (x, XEXP (body, 0)); case UNSPEC: case UNSPEC_VOLATILE: for (i = XVECLEN (body, 0) - 1; i >= 0; i--) if (reg_overlap_mentioned_p (x, XVECEXP (body, 0, i))) return 1; return 0; case PARALLEL: for (i = XVECLEN (body, 0) - 1; i >= 0; i--) if (reg_referenced_p (x, XVECEXP (body, 0, i))) return 1; return 0; case CLOBBER: if (GET_CODE (XEXP (body, 0)) == MEM) if (reg_overlap_mentioned_p (x, XEXP (XEXP (body, 0), 0))) return 1; return 0; case COND_EXEC: if (reg_overlap_mentioned_p (x, COND_EXEC_TEST (body))) return 1; return reg_referenced_p (x, COND_EXEC_CODE (body)); default: return 0; } } /* Nonzero if register REG is referenced in an insn between FROM_INSN and TO_INSN (exclusive of those two). Sets of REG do not count. */ int reg_referenced_between_p (reg, from_insn, to_insn) rtx reg, from_insn, to_insn; { rtx insn; if (from_insn == to_insn) return 0; for (insn = NEXT_INSN (from_insn); insn != to_insn; insn = NEXT_INSN (insn)) if (INSN_P (insn) && (reg_referenced_p (reg, PATTERN (insn)) || (GET_CODE (insn) == CALL_INSN && find_reg_fusage (insn, USE, reg)))) return 1; return 0; } /* Nonzero if register REG is set or clobbered in an insn between FROM_INSN and TO_INSN (exclusive of those two). */ int reg_set_between_p (reg, from_insn, to_insn) rtx reg, from_insn, to_insn; { rtx insn; if (from_insn == to_insn) return 0; for (insn = NEXT_INSN (from_insn); insn != to_insn; insn = NEXT_INSN (insn)) if (INSN_P (insn) && reg_set_p (reg, insn)) return 1; return 0; } /* Internals of reg_set_between_p. */ int reg_set_p (reg, insn) rtx reg, insn; { rtx body = insn; /* We can be passed an insn or part of one. If we are passed an insn, check if a side-effect of the insn clobbers REG. */ if (INSN_P (insn)) { if (FIND_REG_INC_NOTE (insn, reg) || (GET_CODE (insn) == CALL_INSN /* We'd like to test call_used_regs here, but rtlanal.c can't reference that variable due to its use in genattrtab. So we'll just be more conservative. ??? Unless we could ensure that the CALL_INSN_FUNCTION_USAGE information holds all clobbered registers. */ && ((GET_CODE (reg) == REG && REGNO (reg) < FIRST_PSEUDO_REGISTER) || GET_CODE (reg) == MEM || find_reg_fusage (insn, CLOBBER, reg)))) return 1; body = PATTERN (insn); } return set_of (reg, insn) != NULL_RTX; } /* Similar to reg_set_between_p, but check all registers in X. Return 0 only if none of them are modified between START and END. Do not consider non-registers one way or the other. */ int regs_set_between_p (x, start, end) rtx x; rtx start, end; { enum rtx_code code = GET_CODE (x); const char *fmt; int i, j; switch (code) { case CONST_INT: case CONST_DOUBLE: case CONST_VECTOR: case CONST: case SYMBOL_REF: case LABEL_REF: case PC: case CC0: return 0; case REG: return reg_set_between_p (x, start, end); default: break; } fmt = GET_RTX_FORMAT (code); for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) { if (fmt[i] == 'e' && regs_set_between_p (XEXP (x, i), start, end)) return 1; else if (fmt[i] == 'E') for (j = XVECLEN (x, i) - 1; j >= 0; j--) if (regs_set_between_p (XVECEXP (x, i, j), start, end)) return 1; } return 0; } /* Similar to reg_set_between_p, but check all registers in X. Return 0 only if none of them are modified between START and END. Return 1 if X contains a MEM; this routine does not perform any memory aliasing. */ int modified_between_p (x, start, end) rtx x; rtx start, end; { enum rtx_code code = GET_CODE (x); const char *fmt; int i, j; switch (code) { case CONST_INT: case CONST_DOUBLE: case CONST_VECTOR: case CONST: case SYMBOL_REF: case LABEL_REF: return 0; case PC: case CC0: return 1; case MEM: /* If the memory is not constant, assume it is modified. If it is constant, we still have to check the address. */ if (! RTX_UNCHANGING_P (x)) return 1; break; case REG: return reg_set_between_p (x, start, end); default: break; } fmt = GET_RTX_FORMAT (code); for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) { if (fmt[i] == 'e' && modified_between_p (XEXP (x, i), start, end)) return 1; else if (fmt[i] == 'E') for (j = XVECLEN (x, i) - 1; j >= 0; j--) if (modified_between_p (XVECEXP (x, i, j), start, end)) return 1; } return 0; } /* Similar to reg_set_p, but check all registers in X. Return 0 only if none of them are modified in INSN. Return 1 if X contains a MEM; this routine does not perform any memory aliasing. */ int modified_in_p (x, insn) rtx x; rtx insn; { enum rtx_code code = GET_CODE (x); const char *fmt; int i, j; switch (code) { case CONST_INT: case CONST_DOUBLE: case CONST_VECTOR: case CONST: case SYMBOL_REF: case LABEL_REF: return 0; case PC: case CC0: return 1; case MEM: /* If the memory is not constant, assume it is modified. If it is constant, we still have to check the address. */ if (! RTX_UNCHANGING_P (x)) return 1; break; case REG: return reg_set_p (x, insn); default: break; } fmt = GET_RTX_FORMAT (code); for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) { if (fmt[i] == 'e' && modified_in_p (XEXP (x, i), insn)) return 1; else if (fmt[i] == 'E') for (j = XVECLEN (x, i) - 1; j >= 0; j--) if (modified_in_p (XVECEXP (x, i, j), insn)) return 1; } return 0; } /* Return true if anything in insn X is (anti,output,true) dependent on anything in insn Y. */ int insn_dependent_p (x, y) rtx x, y; { rtx tmp; if (! INSN_P (x) || ! INSN_P (y)) abort (); tmp = PATTERN (y); note_stores (PATTERN (x), insn_dependent_p_1, &tmp); if (tmp == NULL_RTX) return 1; tmp = PATTERN (x); note_stores (PATTERN (y), insn_dependent_p_1, &tmp); if (tmp == NULL_RTX) return 1; return 0; } /* A helper routine for insn_dependent_p called through note_stores. */ static void insn_dependent_p_1 (x, pat, data) rtx x; rtx pat ATTRIBUTE_UNUSED; void *data; { rtx * pinsn = (rtx *) data; if (*pinsn && reg_mentioned_p (x, *pinsn)) *pinsn = NULL_RTX; } /* Helper function for set_of. */ struct set_of_data { rtx found; rtx pat; }; static void set_of_1 (x, pat, data1) rtx x; rtx pat; void *data1; { struct set_of_data *data = (struct set_of_data *) (data1); if (rtx_equal_p (x, data->pat) || (GET_CODE (x) != MEM && reg_overlap_mentioned_p (data->pat, x))) data->found = pat; } /* Give an INSN, return a SET or CLOBBER expression that does modify PAT (either directly or via STRICT_LOW_PART and similar modifiers). */ rtx set_of (pat, insn) rtx pat, insn; { struct set_of_data data; data.found = NULL_RTX; data.pat = pat; note_stores (INSN_P (insn) ? PATTERN (insn) : insn, set_of_1, &data); return data.found; } /* Given an INSN, return a SET expression if this insn has only a single SET. It may also have CLOBBERs, USEs, or SET whose output will not be used, which we ignore. */ rtx single_set_2 (insn, pat) rtx insn, pat; { rtx set = NULL; int set_verified = 1; int i; if (GET_CODE (pat) == PARALLEL) { for (i = 0; i < XVECLEN (pat, 0); i++) { rtx sub = XVECEXP (pat, 0, i); switch (GET_CODE (sub)) { case USE: case CLOBBER: break; case SET: /* We can consider insns having multiple sets, where all but one are dead as single set insns. In common case only single set is present in the pattern so we want to avoid checking for REG_UNUSED notes unless necessary. When we reach set first time, we just expect this is the single set we are looking for and only when more sets are found in the insn, we check them. */ if (!set_verified) { if (find_reg_note (insn, REG_UNUSED, SET_DEST (set)) && !side_effects_p (set)) set = NULL; else set_verified = 1; } if (!set) set = sub, set_verified = 0; else if (!find_reg_note (insn, REG_UNUSED, SET_DEST (sub)) || side_effects_p (sub)) return NULL_RTX; break; default: return NULL_RTX; } } } return set; } /* Given an INSN, return nonzero if it has more than one SET, else return zero. */ int multiple_sets (insn) rtx insn; { int found; int i; /* INSN must be an insn. */ if (! INSN_P (insn)) return 0; /* Only a PARALLEL can have multiple SETs. */ if (GET_CODE (PATTERN (insn)) == PARALLEL) { for (i = 0, found = 0; i < XVECLEN (PATTERN (insn), 0); i++) if (GET_CODE (XVECEXP (PATTERN (insn), 0, i)) == SET) { /* If we have already found a SET, then return now. */ if (found) return 1; else found = 1; } } /* Either zero or one SET. */ return 0; } /* Return nonzero if the destination of SET equals the source and there are no side effects. */ int set_noop_p (set) rtx set; { rtx src = SET_SRC (set); rtx dst = SET_DEST (set); if (side_effects_p (src) || side_effects_p (dst)) return 0; if (GET_CODE (dst) == MEM && GET_CODE (src) == MEM) return rtx_equal_p (dst, src); if (dst == pc_rtx && src == pc_rtx) return 1; if (GET_CODE (dst) == SIGN_EXTRACT || GET_CODE (dst) == ZERO_EXTRACT) return rtx_equal_p (XEXP (dst, 0), src) && ! BYTES_BIG_ENDIAN && XEXP (dst, 2) == const0_rtx; if (GET_CODE (dst) == STRICT_LOW_PART) dst = XEXP (dst, 0); if (GET_CODE (src) == SUBREG && GET_CODE (dst) == SUBREG) { if (SUBREG_BYTE (src) != SUBREG_BYTE (dst)) return 0; src = SUBREG_REG (src); dst = SUBREG_REG (dst); } return (GET_CODE (src) == REG && GET_CODE (dst) == REG && REGNO (src) == REGNO (dst)); } /* Return nonzero if an insn consists only of SETs, each of which only sets a value to itself. */ int noop_move_p (insn) rtx insn; { rtx pat = PATTERN (insn); if (INSN_CODE (insn) == NOOP_MOVE_INSN_CODE) return 1; /* Insns carrying these notes are useful later on. */ if (find_reg_note (insn, REG_EQUAL, NULL_RTX)) return 0; /* For now treat an insn with a REG_RETVAL note as a a special insn which should not be considered a no-op. */ if (find_reg_note (insn, REG_RETVAL, NULL_RTX)) return 0; if (GET_CODE (pat) == SET && set_noop_p (pat)) return 1; if (GET_CODE (pat) == PARALLEL) { int i; /* If nothing but SETs of registers to themselves, this insn can also be deleted. */ for (i = 0; i < XVECLEN (pat, 0); i++) { rtx tem = XVECEXP (pat, 0, i); if (GET_CODE (tem) == USE || GET_CODE (tem) == CLOBBER) continue; if (GET_CODE (tem) != SET || ! set_noop_p (tem)) return 0; } return 1; } return 0; } /* Return the last thing that X was assigned from before *PINSN. If VALID_TO is not NULL_RTX then verify that the object is not modified up to VALID_TO. If the object was modified, if we hit a partial assignment to X, or hit a CODE_LABEL first, return X. If we found an assignment, update *PINSN to point to it. ALLOW_HWREG is set to 1 if hardware registers are allowed to be the src. */ rtx find_last_value (x, pinsn, valid_to, allow_hwreg) rtx x; rtx *pinsn; rtx valid_to; int allow_hwreg; { rtx p; for (p = PREV_INSN (*pinsn); p && GET_CODE (p) != CODE_LABEL; p = PREV_INSN (p)) if (INSN_P (p)) { rtx set = single_set (p); rtx note = find_reg_note (p, REG_EQUAL, NULL_RTX); if (set && rtx_equal_p (x, SET_DEST (set))) { rtx src = SET_SRC (set); if (note && GET_CODE (XEXP (note, 0)) != EXPR_LIST) src = XEXP (note, 0); if ((valid_to == NULL_RTX || ! modified_between_p (src, PREV_INSN (p), valid_to)) /* Reject hard registers because we don't usually want to use them; we'd rather use a pseudo. */ && (! (GET_CODE (src) == REG && REGNO (src) < FIRST_PSEUDO_REGISTER) || allow_hwreg)) { *pinsn = p; return src; } } /* If set in non-simple way, we don't have a value. */ if (reg_set_p (x, p)) break; } return x; } /* Return nonzero if register in range [REGNO, ENDREGNO) appears either explicitly or implicitly in X other than being stored into. References contained within the substructure at LOC do not count. LOC may be zero, meaning don't ignore anything. */ int refers_to_regno_p (regno, endregno, x, loc) unsigned int regno, endregno; rtx x; rtx *loc; { int i; unsigned int x_regno; RTX_CODE code; const char *fmt; repeat: /* The contents of a REG_NONNEG note is always zero, so we must come here upon repeat in case the last REG_NOTE is a REG_NONNEG note. */ if (x == 0) return 0; code = GET_CODE (x); switch (code) { case REG: x_regno = REGNO (x); /* If we modifying the stack, frame, or argument pointer, it will clobber a virtual register. In fact, we could be more precise, but it isn't worth it. */ if ((x_regno == STACK_POINTER_REGNUM #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM || x_regno == ARG_POINTER_REGNUM #endif || x_regno == FRAME_POINTER_REGNUM) && regno >= FIRST_VIRTUAL_REGISTER && regno <= LAST_VIRTUAL_REGISTER) return 1; return (endregno > x_regno && regno < x_regno + (x_regno < FIRST_PSEUDO_REGISTER ? HARD_REGNO_NREGS (x_regno, GET_MODE (x)) : 1)); case SUBREG: /* If this is a SUBREG of a hard reg, we can see exactly which registers are being modified. Otherwise, handle normally. */ if (GET_CODE (SUBREG_REG (x)) == REG && REGNO (SUBREG_REG (x)) < FIRST_PSEUDO_REGISTER) { unsigned int inner_regno = subreg_regno (x); unsigned int inner_endregno = inner_regno + (inner_regno < FIRST_PSEUDO_REGISTER ? HARD_REGNO_NREGS (regno, GET_MODE (x)) : 1); return endregno > inner_regno && regno < inner_endregno; } break; case CLOBBER: case SET: if (&SET_DEST (x) != loc /* Note setting a SUBREG counts as referring to the REG it is in for a pseudo but not for hard registers since we can treat each word individually. */ && ((GET_CODE (SET_DEST (x)) == SUBREG && loc != &SUBREG_REG (SET_DEST (x)) && GET_CODE (SUBREG_REG (SET_DEST (x))) == REG && REGNO (SUBREG_REG (SET_DEST (x))) >= FIRST_PSEUDO_REGISTER && refers_to_regno_p (regno, endregno, SUBREG_REG (SET_DEST (x)), loc)) || (GET_CODE (SET_DEST (x)) != REG && refers_to_regno_p (regno, endregno, SET_DEST (x), loc)))) return 1; if (code == CLOBBER || loc == &SET_SRC (x)) return 0; x = SET_SRC (x); goto repeat; default: break; } /* X does not match, so try its subexpressions. */ fmt = GET_RTX_FORMAT (code); for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) { if (fmt[i] == 'e' && loc != &XEXP (x, i)) { if (i == 0) { x = XEXP (x, 0); goto repeat; } else if (refers_to_regno_p (regno, endregno, XEXP (x, i), loc)) return 1; } else if (fmt[i] == 'E') { int j; for (j = XVECLEN (x, i) - 1; j >=0; j--) if (loc != &XVECEXP (x, i, j) && refers_to_regno_p (regno, endregno, XVECEXP (x, i, j), loc)) return 1; } } return 0; } /* Nonzero if modifying X will affect IN. If X is a register or a SUBREG, we check if any register number in X conflicts with the relevant register numbers. If X is a constant, return 0. If X is a MEM, return 1 iff IN contains a MEM (we don't bother checking for memory addresses that can't conflict because we expect this to be a rare case. */ int reg_overlap_mentioned_p (x, in) rtx x, in; { unsigned int regno, endregno; /* Overly conservative. */ if (GET_CODE (x) == STRICT_LOW_PART) x = XEXP (x, 0); /* If either argument is a constant, then modifying X can not affect IN. */ if (CONSTANT_P (x) || CONSTANT_P (in)) return 0; switch (GET_CODE (x)) { case SUBREG: regno = REGNO (SUBREG_REG (x)); if (regno < FIRST_PSEUDO_REGISTER) regno = subreg_regno (x); goto do_reg; case REG: regno = REGNO (x); do_reg: endregno = regno + (regno < FIRST_PSEUDO_REGISTER ? HARD_REGNO_NREGS (regno, GET_MODE (x)) : 1); return refers_to_regno_p (regno, endregno, in, (rtx*) 0); case MEM: { const char *fmt; int i; if (GET_CODE (in) == MEM) return 1; fmt = GET_RTX_FORMAT (GET_CODE (in)); for (i = GET_RTX_LENGTH (GET_CODE (in)) - 1; i >= 0; i--) if (fmt[i] == 'e' && reg_overlap_mentioned_p (x, XEXP (in, i))) return 1; return 0; } case SCRATCH: case PC: case CC0: return reg_mentioned_p (x, in); case PARALLEL: { int i; /* If any register in here refers to it we return true. */ for (i = XVECLEN (x, 0) - 1; i >= 0; i--) if (XEXP (XVECEXP (x, 0, i), 0) != 0 && reg_overlap_mentioned_p (XEXP (XVECEXP (x, 0, i), 0), in)) return 1; return 0; } default: break; } abort (); } /* Return the last value to which REG was set prior to INSN. If we can't find it easily, return 0. We only return a REG, SUBREG, or constant because it is too hard to check if a MEM remains unchanged. */ rtx reg_set_last (x, insn) rtx x; rtx insn; { rtx orig_insn = insn; /* Scan backwards until reg_set_last_1 changed one of the above flags. Stop when we reach a label or X is a hard reg and we reach a CALL_INSN (if reg_set_last_last_regno is a hard reg). If we find a set of X, ensure that its SET_SRC remains unchanged. */ /* We compare with <= here, because reg_set_last_last_regno is actually the number of the first reg *not* in X. */ for (; insn && GET_CODE (insn) != CODE_LABEL && ! (GET_CODE (insn) == CALL_INSN && REGNO (x) <= FIRST_PSEUDO_REGISTER); insn = PREV_INSN (insn)) if (INSN_P (insn)) { rtx set = set_of (x, insn); /* OK, this function modify our register. See if we understand it. */ if (set) { rtx last_value; if (GET_CODE (set) != SET || SET_DEST (set) != x) return 0; last_value = SET_SRC (x); if (CONSTANT_P (last_value) || ((GET_CODE (last_value) == REG || GET_CODE (last_value) == SUBREG) && ! reg_set_between_p (last_value, insn, orig_insn))) return last_value; else return 0; } } return 0; } /* Call FUN on each register or MEM that is stored into or clobbered by X. (X would be the pattern of an insn). FUN receives two arguments: the REG, MEM, CC0 or PC being stored in or clobbered, the SET or CLOBBER rtx that does the store. If the item being stored in or clobbered is a SUBREG of a hard register, the SUBREG will be passed. */ void note_stores (x, fun, data) rtx x; void (*fun) PARAMS ((rtx, rtx, void *)); void *data; { int i; if (GET_CODE (x) == COND_EXEC) x = COND_EXEC_CODE (x); if (GET_CODE (x) == SET || GET_CODE (x) == CLOBBER) { rtx dest = SET_DEST (x); while ((GET_CODE (dest) == SUBREG && (GET_CODE (SUBREG_REG (dest)) != REG || REGNO (SUBREG_REG (dest)) >= FIRST_PSEUDO_REGISTER)) || GET_CODE (dest) == ZERO_EXTRACT || GET_CODE (dest) == SIGN_EXTRACT || GET_CODE (dest) == STRICT_LOW_PART) dest = XEXP (dest, 0); /* If we have a PARALLEL, SET_DEST is a list of EXPR_LIST expressions, each of whose first operand is a register. */ if (GET_CODE (dest) == PARALLEL) { for (i = XVECLEN (dest, 0) - 1; i >= 0; i--) if (XEXP (XVECEXP (dest, 0, i), 0) != 0) (*fun) (XEXP (XVECEXP (dest, 0, i), 0), x, data); } else (*fun) (dest, x, data); } else if (GET_CODE (x) == PARALLEL) for (i = XVECLEN (x, 0) - 1; i >= 0; i--) note_stores (XVECEXP (x, 0, i), fun, data); } /* Like notes_stores, but call FUN for each expression that is being referenced in PBODY, a pointer to the PATTERN of an insn. We only call FUN for each expression, not any interior subexpressions. FUN receives a pointer to the expression and the DATA passed to this function. Note that this is not quite the same test as that done in reg_referenced_p since that considers something as being referenced if it is being partially set, while we do not. */ void note_uses (pbody, fun, data) rtx *pbody; void (*fun) PARAMS ((rtx *, void *)); void *data; { rtx body = *pbody; int i; switch (GET_CODE (body)) { case COND_EXEC: (*fun) (&COND_EXEC_TEST (body), data); note_uses (&COND_EXEC_CODE (body), fun, data); return; case PARALLEL: for (i = XVECLEN (body, 0) - 1; i >= 0; i--) note_uses (&XVECEXP (body, 0, i), fun, data); return; case USE: (*fun) (&XEXP (body, 0), data); return; case ASM_OPERANDS: for (i = ASM_OPERANDS_INPUT_LENGTH (body) - 1; i >= 0; i--) (*fun) (&ASM_OPERANDS_INPUT (body, i), data); return; case TRAP_IF: (*fun) (&TRAP_CONDITION (body), data); return; case PREFETCH: (*fun) (&XEXP (body, 0), data); return; case UNSPEC: case UNSPEC_VOLATILE: for (i = XVECLEN (body, 0) - 1; i >= 0; i--) (*fun) (&XVECEXP (body, 0, i), data); return; case CLOBBER: if (GET_CODE (XEXP (body, 0)) == MEM) (*fun) (&XEXP (XEXP (body, 0), 0), data); return; case SET: { rtx dest = SET_DEST (body); /* For sets we replace everything in source plus registers in memory expression in store and operands of a ZERO_EXTRACT. */ (*fun) (&SET_SRC (body), data); if (GET_CODE (dest) == ZERO_EXTRACT) { (*fun) (&XEXP (dest, 1), data); (*fun) (&XEXP (dest, 2), data); } while (GET_CODE (dest) == SUBREG || GET_CODE (dest) == STRICT_LOW_PART) dest = XEXP (dest, 0); if (GET_CODE (dest) == MEM) (*fun) (&XEXP (dest, 0), data); } return; default: /* All the other possibilities never store. */ (*fun) (pbody, data); return; } } /* Return nonzero if X's old contents don't survive after INSN. This will be true if X is (cc0) or if X is a register and X dies in INSN or because INSN entirely sets X. "Entirely set" means set directly and not through a SUBREG, ZERO_EXTRACT or SIGN_EXTRACT, so no trace of the old contents remains. Likewise, REG_INC does not count. REG may be a hard or pseudo reg. Renumbering is not taken into account, but for this use that makes no difference, since regs don't overlap during their lifetimes. Therefore, this function may be used at any time after deaths have been computed (in flow.c). If REG is a hard reg that occupies multiple machine registers, this function will only return 1 if each of those registers will be replaced by INSN. */ int dead_or_set_p (insn, x) rtx insn; rtx x; { unsigned int regno, last_regno; unsigned int i; /* Can't use cc0_rtx below since this file is used by genattrtab.c. */ if (GET_CODE (x) == CC0) return 1; if (GET_CODE (x) != REG) abort (); regno = REGNO (x); last_regno = (regno >= FIRST_PSEUDO_REGISTER ? regno : regno + HARD_REGNO_NREGS (regno, GET_MODE (x)) - 1); for (i = regno; i <= last_regno; i++) if (! dead_or_set_regno_p (insn, i)) return 0; return 1; } /* Utility function for dead_or_set_p to check an individual register. Also called from flow.c. */ int dead_or_set_regno_p (insn, test_regno) rtx insn; unsigned int test_regno; { unsigned int regno, endregno; rtx pattern; /* See if there is a death note for something that includes TEST_REGNO. */ if (find_regno_note (insn, REG_DEAD, test_regno)) return 1; if (GET_CODE (insn) == CALL_INSN && find_regno_fusage (insn, CLOBBER, test_regno)) return 1; pattern = PATTERN (insn); if (GET_CODE (pattern) == COND_EXEC) pattern = COND_EXEC_CODE (pattern); if (GET_CODE (pattern) == SET) { rtx dest = SET_DEST (pattern); /* A value is totally replaced if it is the destination or the destination is a SUBREG of REGNO that does not change the number of words in it. */ if (GET_CODE (dest) == SUBREG && (((GET_MODE_SIZE (GET_MODE (dest)) + UNITS_PER_WORD - 1) / UNITS_PER_WORD) == ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest))) + UNITS_PER_WORD - 1) / UNITS_PER_WORD))) dest = SUBREG_REG (dest); if (GET_CODE (dest) != REG) return 0; regno = REGNO (dest); endregno = (regno >= FIRST_PSEUDO_REGISTER ? regno + 1 : regno + HARD_REGNO_NREGS (regno, GET_MODE (dest))); return (test_regno >= regno && test_regno < endregno); } else if (GET_CODE (pattern) == PARALLEL) { int i; for (i = XVECLEN (pattern, 0) - 1; i >= 0; i--) { rtx body = XVECEXP (pattern, 0, i); if (GET_CODE (body) == COND_EXEC) body = COND_EXEC_CODE (body); if (GET_CODE (body) == SET || GET_CODE (body) == CLOBBER) { rtx dest = SET_DEST (body); if (GET_CODE (dest) == SUBREG && (((GET_MODE_SIZE (GET_MODE (dest)) + UNITS_PER_WORD - 1) / UNITS_PER_WORD) == ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest))) + UNITS_PER_WORD - 1) / UNITS_PER_WORD))) dest = SUBREG_REG (dest); if (GET_CODE (dest) != REG) continue; regno = REGNO (dest); endregno = (regno >= FIRST_PSEUDO_REGISTER ? regno + 1 : regno + HARD_REGNO_NREGS (regno, GET_MODE (dest))); if (test_regno >= regno && test_regno < endregno) return 1; } } } return 0; } /* Return the reg-note of kind KIND in insn INSN, if there is one. If DATUM is nonzero, look for one whose datum is DATUM. */ rtx find_reg_note (insn, kind, datum) rtx insn; enum reg_note kind; rtx datum; { rtx link; /* Ignore anything that is not an INSN, JUMP_INSN or CALL_INSN. */ if (! INSN_P (insn)) return 0; for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) if (REG_NOTE_KIND (link) == kind && (datum == 0 || datum == XEXP (link, 0))) return link; return 0; } /* Return the reg-note of kind KIND in insn INSN which applies to register number REGNO, if any. Return 0 if there is no such reg-note. Note that the REGNO of this NOTE need not be REGNO if REGNO is a hard register; it might be the case that the note overlaps REGNO. */ rtx find_regno_note (insn, kind, regno) rtx insn; enum reg_note kind; unsigned int regno; { rtx link; /* Ignore anything that is not an INSN, JUMP_INSN or CALL_INSN. */ if (! INSN_P (insn)) return 0; for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) if (REG_NOTE_KIND (link) == kind /* Verify that it is a register, so that scratch and MEM won't cause a problem here. */ && GET_CODE (XEXP (link, 0)) == REG && REGNO (XEXP (link, 0)) <= regno && ((REGNO (XEXP (link, 0)) + (REGNO (XEXP (link, 0)) >= FIRST_PSEUDO_REGISTER ? 1 : HARD_REGNO_NREGS (REGNO (XEXP (link, 0)), GET_MODE (XEXP (link, 0))))) > regno)) return link; return 0; } /* Return a REG_EQUIV or REG_EQUAL note if insn has only a single set and has such a note. */ rtx find_reg_equal_equiv_note (insn) rtx insn; { rtx note; if (single_set (insn) == 0) return 0; else if ((note = find_reg_note (insn, REG_EQUIV, NULL_RTX)) != 0) return note; else return find_reg_note (insn, REG_EQUAL, NULL_RTX); } /* Return true if DATUM, or any overlap of DATUM, of kind CODE is found in the CALL_INSN_FUNCTION_USAGE information of INSN. */ int find_reg_fusage (insn, code, datum) rtx insn; enum rtx_code code; rtx datum; { /* If it's not a CALL_INSN, it can't possibly have a CALL_INSN_FUNCTION_USAGE field, so don't bother checking. */ if (GET_CODE (insn) != CALL_INSN) return 0; if (! datum) abort (); if (GET_CODE (datum) != REG) { rtx link; for (link = CALL_INSN_FUNCTION_USAGE (insn); link; link = XEXP (link, 1)) if (GET_CODE (XEXP (link, 0)) == code && rtx_equal_p (datum, XEXP (XEXP (link, 0), 0))) return 1; } else { unsigned int regno = REGNO (datum); /* CALL_INSN_FUNCTION_USAGE information cannot contain references to pseudo registers, so don't bother checking. */ if (regno < FIRST_PSEUDO_REGISTER) { unsigned int end_regno = regno + HARD_REGNO_NREGS (regno, GET_MODE (datum)); unsigned int i; for (i = regno; i < end_regno; i++) if (find_regno_fusage (insn, code, i)) return 1; } } return 0; } /* Return true if REGNO, or any overlap of REGNO, of kind CODE is found in the CALL_INSN_FUNCTION_USAGE information of INSN. */ int find_regno_fusage (insn, code, regno) rtx insn; enum rtx_code code; unsigned int regno; { rtx link; /* CALL_INSN_FUNCTION_USAGE information cannot contain references to pseudo registers, so don't bother checking. */ if (regno >= FIRST_PSEUDO_REGISTER || GET_CODE (insn) != CALL_INSN ) return 0; for (link = CALL_INSN_FUNCTION_USAGE (insn); link; link = XEXP (link, 1)) { unsigned int regnote; rtx op, reg; if (GET_CODE (op = XEXP (link, 0)) == code && GET_CODE (reg = XEXP (op, 0)) == REG && (regnote = REGNO (reg)) <= regno && regnote + HARD_REGNO_NREGS (regnote, GET_MODE (reg)) > regno) return 1; } return 0; } /* Return true if INSN is a call to a pure function. */ int pure_call_p (insn) rtx insn; { rtx link; if (GET_CODE (insn) != CALL_INSN || ! CONST_OR_PURE_CALL_P (insn)) return 0; /* Look for the note that differentiates const and pure functions. */ for (link = CALL_INSN_FUNCTION_USAGE (insn); link; link = XEXP (link, 1)) { rtx u, m; if (GET_CODE (u = XEXP (link, 0)) == USE && GET_CODE (m = XEXP (u, 0)) == MEM && GET_MODE (m) == BLKmode && GET_CODE (XEXP (m, 0)) == SCRATCH) return 1; } return 0; } /* Remove register note NOTE from the REG_NOTES of INSN. */ void remove_note (insn, note) rtx insn; rtx note; { rtx link; if (note == NULL_RTX) return; if (REG_NOTES (insn) == note) { REG_NOTES (insn) = XEXP (note, 1); return; } for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) if (XEXP (link, 1) == note) { XEXP (link, 1) = XEXP (note, 1); return; } abort (); } /* Search LISTP (an EXPR_LIST) for an entry whose first operand is NODE and return 1 if it is found. A simple equality test is used to determine if NODE matches. */ int in_expr_list_p (listp, node) rtx listp; rtx node; { rtx x; for (x = listp; x; x = XEXP (x, 1)) if (node == XEXP (x, 0)) return 1; return 0; } /* Search LISTP (an EXPR_LIST) for an entry whose first operand is NODE and remove that entry from the list if it is found. A simple equality test is used to determine if NODE matches. */ void remove_node_from_expr_list (node, listp) rtx node; rtx *listp; { rtx temp = *listp; rtx prev = NULL_RTX; while (temp) { if (node == XEXP (temp, 0)) { /* Splice the node out of the list. */ if (prev) XEXP (prev, 1) = XEXP (temp, 1); else *listp = XEXP (temp, 1); return; } prev = temp; temp = XEXP (temp, 1); } } /* Nonzero if X contains any volatile instructions. These are instructions which may cause unpredictable machine state instructions, and thus no instructions should be moved or combined across them. This includes only volatile asms and UNSPEC_VOLATILE instructions. */ int volatile_insn_p (x) rtx x; { RTX_CODE code; code = GET_CODE (x); switch (code) { case LABEL_REF: case SYMBOL_REF: case CONST_INT: case CONST: case CONST_DOUBLE: case CONST_VECTOR: case CC0: case PC: case REG: case SCRATCH: case CLOBBER: case ASM_INPUT: case ADDR_VEC: case ADDR_DIFF_VEC: case CALL: case MEM: return 0; case UNSPEC_VOLATILE: /* case TRAP_IF: This isn't clear yet. */ return 1; case ASM_OPERANDS: if (MEM_VOLATILE_P (x)) return 1; default: break; } /* Recursively scan the operands of this expression. */ { const char *fmt = GET_RTX_FORMAT (code); int i; for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) { if (fmt[i] == 'e') { if (volatile_insn_p (XEXP (x, i))) return 1; } else if (fmt[i] == 'E') { int j; for (j = 0; j < XVECLEN (x, i); j++) if (volatile_insn_p (XVECEXP (x, i, j))) return 1; } } } return 0; } /* Nonzero if X contains any volatile memory references UNSPEC_VOLATILE operations or volatile ASM_OPERANDS expressions. */ int volatile_refs_p (x) rtx x; { RTX_CODE code; code = GET_CODE (x); switch (code) { case LABEL_REF: case SYMBOL_REF: case CONST_INT: case CONST: case CONST_DOUBLE: case CONST_VECTOR: case CC0: case PC: case REG: case SCRATCH: case CLOBBER: case ASM_INPUT: case ADDR_VEC: case ADDR_DIFF_VEC: return 0; case UNSPEC_VOLATILE: return 1; case MEM: case ASM_OPERANDS: if (MEM_VOLATILE_P (x)) return 1; default: break; } /* Recursively scan the operands of this expression. */ { const char *fmt = GET_RTX_FORMAT (code); int i; for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) { if (fmt[i] == 'e') { if (volatile_refs_p (XEXP (x, i))) return 1; } else if (fmt[i] == 'E') { int j; for (j = 0; j < XVECLEN (x, i); j++) if (volatile_refs_p (XVECEXP (x, i, j))) return 1; } } } return 0; } /* Similar to above, except that it also rejects register pre- and post- incrementing. */ int side_effects_p (x) rtx x; { RTX_CODE code; code = GET_CODE (x); switch (code) { case LABEL_REF: case SYMBOL_REF: case CONST_INT: case CONST: case CONST_DOUBLE: case CONST_VECTOR: case CC0: case PC: case REG: case SCRATCH: case ASM_INPUT: case ADDR_VEC: case ADDR_DIFF_VEC: return 0; case CLOBBER: /* Reject CLOBBER with a non-VOID mode. These are made by combine.c when some combination can't be done. If we see one, don't think that we can simplify the expression. */ return (GET_MODE (x) != VOIDmode); case PRE_INC: case PRE_DEC: case POST_INC: case POST_DEC: case PRE_MODIFY: case POST_MODIFY: case CALL: case UNSPEC_VOLATILE: /* case TRAP_IF: This isn't clear yet. */ return 1; case MEM: case ASM_OPERANDS: if (MEM_VOLATILE_P (x)) return 1; default: break; } /* Recursively scan the operands of this expression. */ { const char *fmt = GET_RTX_FORMAT (code); int i; for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) { if (fmt[i] == 'e') { if (side_effects_p (XEXP (x, i))) return 1; } else if (fmt[i] == 'E') { int j; for (j = 0; j < XVECLEN (x, i); j++) if (side_effects_p (XVECEXP (x, i, j))) return 1; } } } return 0; } /* Return nonzero if evaluating rtx X might cause a trap. */ int may_trap_p (x) rtx x; { int i; enum rtx_code code; const char *fmt; if (x == 0) return 0; code = GET_CODE (x); switch (code) { /* Handle these cases quickly. */ case CONST_INT: case CONST_DOUBLE: case CONST_VECTOR: case SYMBOL_REF: case LABEL_REF: case CONST: case PC: case CC0: case REG: case SCRATCH: return 0; case ASM_INPUT: case UNSPEC_VOLATILE: case TRAP_IF: return 1; case ASM_OPERANDS: return MEM_VOLATILE_P (x); /* Memory ref can trap unless it's a static var or a stack slot. */ case MEM: return rtx_addr_can_trap_p (XEXP (x, 0)); /* Division by a non-constant might trap. */ case DIV: case MOD: case UDIV: case UMOD: if (HONOR_SNANS (GET_MODE (x))) return 1; if (! CONSTANT_P (XEXP (x, 1)) || (GET_MODE_CLASS (GET_MODE (x)) == MODE_FLOAT && flag_trapping_math)) return 1; /* This was const0_rtx, but by not using that, we can link this file into other programs. */ if (GET_CODE (XEXP (x, 1)) == CONST_INT && INTVAL (XEXP (x, 1)) == 0) return 1; break; case EXPR_LIST: /* An EXPR_LIST is used to represent a function call. This certainly may trap. */ return 1; case GE: case GT: case LE: case LT: case COMPARE: /* Some floating point comparisons may trap. */ if (!flag_trapping_math) break; /* ??? There is no machine independent way to check for tests that trap when COMPARE is used, though many targets do make this distinction. For instance, sparc uses CCFPE for compares which generate exceptions and CCFP for compares which do not generate exceptions. */ if (HONOR_NANS (GET_MODE (x))) return 1; /* But often the compare has some CC mode, so check operand modes as well. */ if (HONOR_NANS (GET_MODE (XEXP (x, 0))) || HONOR_NANS (GET_MODE (XEXP (x, 1)))) return 1; break; case EQ: case NE: if (HONOR_SNANS (GET_MODE (x))) return 1; /* Often comparison is CC mode, so check operand modes. */ if (HONOR_SNANS (GET_MODE (XEXP (x, 0))) || HONOR_SNANS (GET_MODE (XEXP (x, 1)))) return 1; break; case NEG: case ABS: /* These operations don't trap even with floating point. */ break; default: /* Any floating arithmetic may trap. */ if (GET_MODE_CLASS (GET_MODE (x)) == MODE_FLOAT && flag_trapping_math) return 1; } fmt = GET_RTX_FORMAT (code); for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) { if (fmt[i] == 'e') { if (may_trap_p (XEXP (x, i))) return 1; } else if (fmt[i] == 'E') { int j; for (j = 0; j < XVECLEN (x, i); j++) if (may_trap_p (XVECEXP (x, i, j))) return 1; } } return 0; } /* Return nonzero if X contains a comparison that is not either EQ or NE, i.e., an inequality. */ int inequality_comparisons_p (x) rtx x; { const char *fmt; int len, i; enum rtx_code code = GET_CODE (x); switch (code) { case REG: case SCRATCH: case PC: case CC0: case CONST_INT: case CONST_DOUBLE: case CONST_VECTOR: case CONST: case LABEL_REF: case SYMBOL_REF: return 0; case LT: case LTU: case GT: case GTU: case LE: case LEU: case GE: case GEU: return 1; default: break; } len = GET_RTX_LENGTH (code); fmt = GET_RTX_FORMAT (code); for (i = 0; i < len; i++) { if (fmt[i] == 'e') { if (inequality_comparisons_p (XEXP (x, i))) return 1; } else if (fmt[i] == 'E') { int j; for (j = XVECLEN (x, i) - 1; j >= 0; j--) if (inequality_comparisons_p (XVECEXP (x, i, j))) return 1; } } return 0; } /* Replace any occurrence of FROM in X with TO. The function does not enter into CONST_DOUBLE for the replace. Note that copying is not done so X must not be shared unless all copies are to be modified. */ rtx replace_rtx (x, from, to) rtx x, from, to; { int i, j; const char *fmt; /* The following prevents loops occurrence when we change MEM in CONST_DOUBLE onto the same CONST_DOUBLE. */ if (x != 0 && GET_CODE (x) == CONST_DOUBLE) return x; if (x == from) return to; /* Allow this function to make replacements in EXPR_LISTs. */ if (x == 0) return 0; if (GET_CODE (x) == SUBREG) { rtx new = replace_rtx (SUBREG_REG (x), from, to); if (GET_CODE (new) == CONST_INT) { x = simplify_subreg (GET_MODE (x), new, GET_MODE (SUBREG_REG (x)), SUBREG_BYTE (x)); if (! x) abort (); } else SUBREG_REG (x) = new; return x; } else if (GET_CODE (x) == ZERO_EXTEND) { rtx new = replace_rtx (XEXP (x, 0), from, to); if (GET_CODE (new) == CONST_INT) { x = simplify_unary_operation (ZERO_EXTEND, GET_MODE (x), new, GET_MODE (XEXP (x, 0))); if (! x) abort (); } else XEXP (x, 0) = new; return x; } fmt = GET_RTX_FORMAT (GET_CODE (x)); for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--) { if (fmt[i] == 'e') XEXP (x, i) = replace_rtx (XEXP (x, i), from, to); else if (fmt[i] == 'E') for (j = XVECLEN (x, i) - 1; j >= 0; j--) XVECEXP (x, i, j) = replace_rtx (XVECEXP (x, i, j), from, to); } return x; } /* Throughout the rtx X, replace many registers according to REG_MAP. Return the replacement for X (which may be X with altered contents). REG_MAP[R] is the replacement for register R, or 0 for don't replace. NREGS is the length of REG_MAP; regs >= NREGS are not mapped. We only support REG_MAP entries of REG or SUBREG. Also, hard registers should not be mapped to pseudos or vice versa since validate_change is not called. If REPLACE_DEST is 1, replacements are also done in destinations; otherwise, only sources are replaced. */ rtx replace_regs (x, reg_map, nregs, replace_dest) rtx x; rtx *reg_map; unsigned int nregs; int replace_dest; { enum rtx_code code; int i; const char *fmt; if (x == 0) return x; code = GET_CODE (x); switch (code) { case SCRATCH: case PC: case CC0: case CONST_INT: case CONST_DOUBLE: case CONST_VECTOR: case CONST: case SYMBOL_REF: case LABEL_REF: return x; case REG: /* Verify that the register has an entry before trying to access it. */ if (REGNO (x) < nregs && reg_map[REGNO (x)] != 0) { /* SUBREGs can't be shared. Always return a copy to ensure that if this replacement occurs more than once then each instance will get distinct rtx. */ if (GET_CODE (reg_map[REGNO (x)]) == SUBREG) return copy_rtx (reg_map[REGNO (x)]); return reg_map[REGNO (x)]; } return x; case SUBREG: /* Prevent making nested SUBREGs. */ if (GET_CODE (SUBREG_REG (x)) == REG && REGNO (SUBREG_REG (x)) < nregs && reg_map[REGNO (SUBREG_REG (x))] != 0 && GET_CODE (reg_map[REGNO (SUBREG_REG (x))]) == SUBREG) { rtx map_val = reg_map[REGNO (SUBREG_REG (x))]; return simplify_gen_subreg (GET_MODE (x), map_val, GET_MODE (SUBREG_REG (x)), SUBREG_BYTE (x)); } break; case SET: if (replace_dest) SET_DEST (x) = replace_regs (SET_DEST (x), reg_map, nregs, 0); else if (GET_CODE (SET_DEST (x)) == MEM || GET_CODE (SET_DEST (x)) == STRICT_LOW_PART) /* Even if we are not to replace destinations, replace register if it is CONTAINED in destination (destination is memory or STRICT_LOW_PART). */ XEXP (SET_DEST (x), 0) = replace_regs (XEXP (SET_DEST (x), 0), reg_map, nregs, 0); else if (GET_CODE (SET_DEST (x)) == ZERO_EXTRACT) /* Similarly, for ZERO_EXTRACT we replace all operands. */ break; SET_SRC (x) = replace_regs (SET_SRC (x), reg_map, nregs, 0); return x; default: break; } fmt = GET_RTX_FORMAT (code); for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) { if (fmt[i] == 'e') XEXP (x, i) = replace_regs (XEXP (x, i), reg_map, nregs, replace_dest); else if (fmt[i] == 'E') { int j; for (j = 0; j < XVECLEN (x, i); j++) XVECEXP (x, i, j) = replace_regs (XVECEXP (x, i, j), reg_map, nregs, replace_dest); } } return x; } /* A subroutine of computed_jump_p, return 1 if X contains a REG or MEM or constant that is not in the constant pool and not in the condition of an IF_THEN_ELSE. */ static int computed_jump_p_1 (x) rtx x; { enum rtx_code code = GET_CODE (x); int i, j; const char *fmt; switch (code) { case LABEL_REF: case PC: return 0; case CONST: case CONST_INT: case CONST_DOUBLE: case CONST_VECTOR: case SYMBOL_REF: case REG: return 1; case MEM: return ! (GET_CODE (XEXP (x, 0)) == SYMBOL_REF && CONSTANT_POOL_ADDRESS_P (XEXP (x, 0))); case IF_THEN_ELSE: return (computed_jump_p_1 (XEXP (x, 1)) || computed_jump_p_1 (XEXP (x, 2))); default: break; } fmt = GET_RTX_FORMAT (code); for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) { if (fmt[i] == 'e' && computed_jump_p_1 (XEXP (x, i))) return 1; else if (fmt[i] == 'E') for (j = 0; j < XVECLEN (x, i); j++) if (computed_jump_p_1 (XVECEXP (x, i, j))) return 1; } return 0; } /* Return nonzero if INSN is an indirect jump (aka computed jump). Tablejumps and casesi insns are not considered indirect jumps; we can recognize them by a (use (label_ref)). */ int computed_jump_p (insn) rtx insn; { int i; if (GET_CODE (insn) == JUMP_INSN) { rtx pat = PATTERN (insn); if (find_reg_note (insn, REG_LABEL, NULL_RTX)) return 0; else if (GET_CODE (pat) == PARALLEL) { int len = XVECLEN (pat, 0); int has_use_labelref = 0; for (i = len - 1; i >= 0; i--) if (GET_CODE (XVECEXP (pat, 0, i)) == USE && (GET_CODE (XEXP (XVECEXP (pat, 0, i), 0)) == LABEL_REF)) has_use_labelref = 1; if (! has_use_labelref) for (i = len - 1; i >= 0; i--) if (GET_CODE (XVECEXP (pat, 0, i)) == SET && SET_DEST (XVECEXP (pat, 0, i)) == pc_rtx && computed_jump_p_1 (SET_SRC (XVECEXP (pat, 0, i)))) return 1; } else if (GET_CODE (pat) == SET && SET_DEST (pat) == pc_rtx && computed_jump_p_1 (SET_SRC (pat))) return 1; } return 0; } /* Traverse X via depth-first search, calling F for each sub-expression (including X itself). F is also passed the DATA. If F returns -1, do not traverse sub-expressions, but continue traversing the rest of the tree. If F ever returns any other non-zero value, stop the traversal, and return the value returned by F. Otherwise, return 0. This function does not traverse inside tree structure that contains RTX_EXPRs, or into sub-expressions whose format code is `0' since it is not known whether or not those codes are actually RTL. This routine is very general, and could (should?) be used to implement many of the other routines in this file. */ int for_each_rtx (x, f, data) rtx *x; rtx_function f; void *data; { int result; int length; const char *format; int i; /* Call F on X. */ result = (*f) (x, data); if (result == -1) /* Do not traverse sub-expressions. */ return 0; else if (result != 0) /* Stop the traversal. */ return result; if (*x == NULL_RTX) /* There are no sub-expressions. */ return 0; length = GET_RTX_LENGTH (GET_CODE (*x)); format = GET_RTX_FORMAT (GET_CODE (*x)); for (i = 0; i < length; ++i) { switch (format[i]) { case 'e': result = for_each_rtx (&XEXP (*x, i), f, data); if (result != 0) return result; break; case 'V': case 'E': if (XVEC (*x, i) != 0) { int j; for (j = 0; j < XVECLEN (*x, i); ++j) { result = for_each_rtx (&XVECEXP (*x, i, j), f, data); if (result != 0) return result; } } break; default: /* Nothing to do. */ break; } } return 0; } /* Searches X for any reference to REGNO, returning the rtx of the reference found if any. Otherwise, returns NULL_RTX. */ rtx regno_use_in (regno, x) unsigned int regno; rtx x; { const char *fmt; int i, j; rtx tem; if (GET_CODE (x) == REG && REGNO (x) == regno) return x; fmt = GET_RTX_FORMAT (GET_CODE (x)); for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--) { if (fmt[i] == 'e') { if ((tem = regno_use_in (regno, XEXP (x, i)))) return tem; } else if (fmt[i] == 'E') for (j = XVECLEN (x, i) - 1; j >= 0; j--) if ((tem = regno_use_in (regno , XVECEXP (x, i, j)))) return tem; } return NULL_RTX; } /* Return a value indicating whether OP, an operand of a commutative operation, is preferred as the first or second operand. The higher the value, the stronger the preference for being the first operand. We use negative values to indicate a preference for the first operand and positive values for the second operand. */ int commutative_operand_precedence (op) rtx op; { /* Constants always come the second operand. Prefer "nice" constants. */ if (GET_CODE (op) == CONST_INT) return -5; if (GET_CODE (op) == CONST_DOUBLE) return -4; if (CONSTANT_P (op)) return -3; /* SUBREGs of objects should come second. */ if (GET_CODE (op) == SUBREG && GET_RTX_CLASS (GET_CODE (SUBREG_REG (op))) == 'o') return -2; /* If only one operand is a `neg', `not', `mult', `plus', or `minus' expression, it will be the first operand. */ if (GET_CODE (op) == NEG || GET_CODE (op) == NOT || GET_CODE (op) == MULT || GET_CODE (op) == PLUS || GET_CODE (op) == MINUS) return 2; /* Complex expressions should be the first, so decrease priority of objects. */ if (GET_RTX_CLASS (GET_CODE (op)) == 'o') return -1; return 0; } /* Return 1 iff it is necessary to swap operands of commutative operation in order to canonicalize expression. */ int swap_commutative_operands_p (x, y) rtx x, y; { return (commutative_operand_precedence (x) < commutative_operand_precedence (y)); } /* Return 1 if X is an autoincrement side effect and the register is not the stack pointer. */ int auto_inc_p (x) rtx x; { switch (GET_CODE (x)) { case PRE_INC: case POST_INC: case PRE_DEC: case POST_DEC: case PRE_MODIFY: case POST_MODIFY: /* There are no REG_INC notes for SP. */ if (XEXP (x, 0) != stack_pointer_rtx) return 1; default: break; } return 0; } /* Return 1 if the sequence of instructions beginning with FROM and up to and including TO is safe to move. If NEW_TO is non-NULL, and the sequence is not already safe to move, but can be easily extended to a sequence which is safe, then NEW_TO will point to the end of the extended sequence. For now, this function only checks that the region contains whole exception regions, but it could be extended to check additional conditions as well. */ int insns_safe_to_move_p (from, to, new_to) rtx from; rtx to; rtx *new_to; { int eh_region_count = 0; int past_to_p = 0; rtx r = from; /* By default, assume the end of the region will be what was suggested. */ if (new_to) *new_to = to; while (r) { if (GET_CODE (r) == NOTE) { switch (NOTE_LINE_NUMBER (r)) { case NOTE_INSN_EH_REGION_BEG: ++eh_region_count; break; case NOTE_INSN_EH_REGION_END: if (eh_region_count == 0) /* This sequence of instructions contains the end of an exception region, but not he beginning. Moving it will cause chaos. */ return 0; --eh_region_count; break; default: break; } } else if (past_to_p) /* If we've passed TO, and we see a non-note instruction, we can't extend the sequence to a movable sequence. */ return 0; if (r == to) { if (!new_to) /* It's OK to move the sequence if there were matched sets of exception region notes. */ return eh_region_count == 0; past_to_p = 1; } /* It's OK to move the sequence if there were matched sets of exception region notes. */ if (past_to_p && eh_region_count == 0) { *new_to = r; return 1; } /* Go to the next instruction. */ r = NEXT_INSN (r); } return 0; } /* Return non-zero if IN contains a piece of rtl that has the address LOC */ int loc_mentioned_in_p (loc, in) rtx *loc, in; { enum rtx_code code = GET_CODE (in); const char *fmt = GET_RTX_FORMAT (code); int i, j; for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) { if (loc == &in->fld[i].rtx) return 1; if (fmt[i] == 'e') { if (loc_mentioned_in_p (loc, XEXP (in, i))) return 1; } else if (fmt[i] == 'E') for (j = XVECLEN (in, i) - 1; j >= 0; j--) if (loc_mentioned_in_p (loc, XVECEXP (in, i, j))) return 1; } return 0; } /* Given a subreg X, return the bit offset where the subreg begins (counting from the least significant bit of the reg). */ unsigned int subreg_lsb (x) rtx x; { enum machine_mode inner_mode = GET_MODE (SUBREG_REG (x)); enum machine_mode mode = GET_MODE (x); unsigned int bitpos; unsigned int byte; unsigned int word; /* A paradoxical subreg begins at bit position 0. */ if (GET_MODE_BITSIZE (mode) > GET_MODE_BITSIZE (inner_mode)) return 0; if (WORDS_BIG_ENDIAN != BYTES_BIG_ENDIAN) /* If the subreg crosses a word boundary ensure that it also begins and ends on a word boundary. */ if ((SUBREG_BYTE (x) % UNITS_PER_WORD + GET_MODE_SIZE (mode)) > UNITS_PER_WORD && (SUBREG_BYTE (x) % UNITS_PER_WORD || GET_MODE_SIZE (mode) % UNITS_PER_WORD)) abort (); if (WORDS_BIG_ENDIAN) word = (GET_MODE_SIZE (inner_mode) - (SUBREG_BYTE (x) + GET_MODE_SIZE (mode))) / UNITS_PER_WORD; else word = SUBREG_BYTE (x) / UNITS_PER_WORD; bitpos = word * BITS_PER_WORD; if (BYTES_BIG_ENDIAN) byte = (GET_MODE_SIZE (inner_mode) - (SUBREG_BYTE (x) + GET_MODE_SIZE (mode))) % UNITS_PER_WORD; else byte = SUBREG_BYTE (x) % UNITS_PER_WORD; bitpos += byte * BITS_PER_UNIT; return bitpos; } /* This function returns the regno offset of a subreg expression. xregno - A regno of an inner hard subreg_reg (or what will become one). xmode - The mode of xregno. offset - The byte offset. ymode - The mode of a top level SUBREG (or what may become one). RETURN - The regno offset which would be used. */ unsigned int subreg_regno_offset (xregno, xmode, offset, ymode) unsigned int xregno; enum machine_mode xmode; unsigned int offset; enum machine_mode ymode; { int nregs_xmode, nregs_ymode; int mode_multiple, nregs_multiple; int y_offset; if (xregno >= FIRST_PSEUDO_REGISTER) abort (); nregs_xmode = HARD_REGNO_NREGS (xregno, xmode); nregs_ymode = HARD_REGNO_NREGS (xregno, ymode); /* If this is a big endian paradoxical subreg, which uses more actual hard registers than the original register, we must return a negative offset so that we find the proper highpart of the register. */ if (offset == 0 && nregs_ymode > nregs_xmode && (GET_MODE_SIZE (ymode) > UNITS_PER_WORD ? WORDS_BIG_ENDIAN : BYTES_BIG_ENDIAN)) return nregs_xmode - nregs_ymode; if (offset == 0 || nregs_xmode == nregs_ymode) return 0; /* size of ymode must not be greater than the size of xmode. */ mode_multiple = GET_MODE_SIZE (xmode) / GET_MODE_SIZE (ymode); if (mode_multiple == 0) abort (); y_offset = offset / GET_MODE_SIZE (ymode); nregs_multiple = nregs_xmode / nregs_ymode; return (y_offset / (mode_multiple / nregs_multiple)) * nregs_ymode; } /* Return the final regno that a subreg expression refers to. */ unsigned int subreg_regno (x) rtx x; { unsigned int ret; rtx subreg = SUBREG_REG (x); int regno = REGNO (subreg); ret = regno + subreg_regno_offset (regno, GET_MODE (subreg), SUBREG_BYTE (x), GET_MODE (x)); return ret; } struct parms_set_data { int nregs; HARD_REG_SET regs; }; /* Helper function for noticing stores to parameter registers. */ static void parms_set (x, pat, data) rtx x, pat ATTRIBUTE_UNUSED; void *data; { struct parms_set_data *d = data; if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER && TEST_HARD_REG_BIT (d->regs, REGNO (x))) { CLEAR_HARD_REG_BIT (d->regs, REGNO (x)); d->nregs--; } } /* Look backward for first parameter to be loaded. Do not skip BOUNDARY. */ rtx find_first_parameter_load (call_insn, boundary) rtx call_insn, boundary; { struct parms_set_data parm; rtx p, before; /* Since different machines initialize their parameter registers in different orders, assume nothing. Collect the set of all parameter registers. */ CLEAR_HARD_REG_SET (parm.regs); parm.nregs = 0; for (p = CALL_INSN_FUNCTION_USAGE (call_insn); p; p = XEXP (p, 1)) if (GET_CODE (XEXP (p, 0)) == USE && GET_CODE (XEXP (XEXP (p, 0), 0)) == REG) { if (REGNO (XEXP (XEXP (p, 0), 0)) >= FIRST_PSEUDO_REGISTER) abort (); /* We only care about registers which can hold function arguments. */ if (!FUNCTION_ARG_REGNO_P (REGNO (XEXP (XEXP (p, 0), 0)))) continue; SET_HARD_REG_BIT (parm.regs, REGNO (XEXP (XEXP (p, 0), 0))); parm.nregs++; } before = call_insn; /* Search backward for the first set of a register in this set. */ while (parm.nregs && before != boundary) { before = PREV_INSN (before); /* It is possible that some loads got CSEed from one call to another. Stop in that case. */ if (GET_CODE (before) == CALL_INSN) break; /* Our caller needs either ensure that we will find all sets (in case code has not been optimized yet), or take care for possible labels in a way by setting boundary to preceding CODE_LABEL. */ if (GET_CODE (before) == CODE_LABEL) { if (before != boundary) abort (); break; } if (INSN_P (before)) note_stores (PATTERN (before), parms_set, &parm); } return before; } /* Return true if we should avoid inserting code between INSN and preceeding call instruction. */ bool keep_with_call_p (insn) rtx insn; { rtx set; if (INSN_P (insn) && (set = single_set (insn)) != NULL) { if (GET_CODE (SET_DEST (set)) == REG && REGNO (SET_DEST (set)) < FIRST_PSEUDO_REGISTER && fixed_regs[REGNO (SET_DEST (set))] && general_operand (SET_SRC (set), VOIDmode)) return true; if (GET_CODE (SET_SRC (set)) == REG && FUNCTION_VALUE_REGNO_P (REGNO (SET_SRC (set))) && GET_CODE (SET_DEST (set)) == REG && REGNO (SET_DEST (set)) >= FIRST_PSEUDO_REGISTER) return true; /* There may be a stack pop just after the call and before the store of the return register. Search for the actual store when deciding if we can break or not. */ if (SET_DEST (set) == stack_pointer_rtx) { rtx i2 = next_nonnote_insn (insn); if (i2 && keep_with_call_p (i2)) return true; } } return false; } /* Return true when store to register X can be hoisted to the place with LIVE registers (can be NULL). Value VAL contains destination whose value will be used. */ static bool hoist_test_store (x, val, live) rtx x, val; regset live; { if (GET_CODE (x) == SCRATCH) return true; if (rtx_equal_p (x, val)) return true; /* Allow subreg of X in case it is not writting just part of multireg pseudo. Then we would need to update all users to care hoisting the store too. Caller may represent that by specifying whole subreg as val. */ if (GET_CODE (x) == SUBREG && rtx_equal_p (SUBREG_REG (x), val)) { if (GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))) > UNITS_PER_WORD && GET_MODE_BITSIZE (GET_MODE (x)) < GET_MODE_BITSIZE (GET_MODE (SUBREG_REG (x)))) return false; return true; } if (GET_CODE (x) == SUBREG) x = SUBREG_REG (x); /* Anything except register store is not hoistable. This includes the partial stores to registers. */ if (!REG_P (x)) return false; /* Pseudo registers can be allways replaced by another pseudo to avoid the side effect, for hard register we must ensure that they are dead. Eventually we may want to add code to try turn pseudos to hards, but it is unlikely usefull. */ if (REGNO (x) < FIRST_PSEUDO_REGISTER) { int regno = REGNO (x); int n = HARD_REGNO_NREGS (regno, GET_MODE (x)); if (!live) return false; if (REGNO_REG_SET_P (live, regno)) return false; while (--n > 0) if (REGNO_REG_SET_P (live, regno + n)) return false; } return true; } /* Return true if INSN can be hoisted to place with LIVE hard registers (LIVE can be NULL when unknown). VAL is expected to be stored by the insn and used by the hoisting pass. */ bool can_hoist_insn_p (insn, val, live) rtx insn, val; regset live; { rtx pat = PATTERN (insn); int i; /* It probably does not worth the complexity to handle multiple set stores. */ if (!single_set (insn)) return false; /* We can move CALL_INSN, but we need to check that all caller clobbered regs are dead. */ if (GET_CODE (insn) == CALL_INSN) return false; /* In future we will handle hoisting of libcall sequences, but give up for now. */ if (find_reg_note (insn, REG_RETVAL, NULL_RTX)) return false; switch (GET_CODE (pat)) { case SET: if (!hoist_test_store (SET_DEST (pat), val, live)) return false; break; case USE: /* USES do have sick semantics, so do not move them. */ return false; break; case CLOBBER: if (!hoist_test_store (XEXP (pat, 0), val, live)) return false; break; case PARALLEL: for (i = 0; i < XVECLEN (pat, 0); i++) { rtx x = XVECEXP (pat, 0, i); switch (GET_CODE (x)) { case SET: if (!hoist_test_store (SET_DEST (x), val, live)) return false; break; case USE: /* We need to fix callers to really ensure availability of all values inisn uses, but for now it is safe to prohibit hoisting of any insn having such a hiden uses. */ return false; break; case CLOBBER: if (!hoist_test_store (SET_DEST (x), val, live)) return false; break; default: break; } } break; default: abort (); } return true; } /* Update store after hoisting - replace all stores to pseudo registers by new ones to avoid clobbering of values except for store to VAL that will be updated to NEW. */ static void hoist_update_store (insn, xp, val, new) rtx insn, *xp, val, new; { rtx x = *xp; if (GET_CODE (x) == SCRATCH) return; if (GET_CODE (x) == SUBREG && SUBREG_REG (x) == val) validate_change (insn, xp, simplify_gen_subreg (GET_MODE (x), new, GET_MODE (new), SUBREG_BYTE (x)), 1); if (rtx_equal_p (x, val)) { validate_change (insn, xp, new, 1); return; } if (GET_CODE (x) == SUBREG) { xp = &SUBREG_REG (x); x = *xp; } if (!REG_P (x)) abort (); /* We've verified that hard registers are dead, so we may keep the side effect. Otherwise replace it by new pseudo. */ if (REGNO (x) >= FIRST_PSEUDO_REGISTER) validate_change (insn, xp, gen_reg_rtx (GET_MODE (x)), 1); REG_NOTES (insn) = alloc_EXPR_LIST (REG_UNUSED, *xp, REG_NOTES (insn)); } /* Create a copy of INSN after AFTER replacing store of VAL to NEW and each other side effect to pseudo register by new pseudo register. */ rtx hoist_insn_after (insn, after, val, new) rtx insn, after, val, new; { rtx pat; int i; rtx note; insn = emit_copy_of_insn_after (insn, after); pat = PATTERN (insn); /* Remove REG_UNUSED notes as we will re-emit them. */ while ((note = find_reg_note (insn, REG_UNUSED, NULL_RTX))) remove_note (insn, note); /* To get this working callers must ensure to move everything referenced by REG_EQUAL/REG_EQUIV notes too. Lets remove them, it is probably easier. */ while ((note = find_reg_note (insn, REG_EQUAL, NULL_RTX))) remove_note (insn, note); while ((note = find_reg_note (insn, REG_EQUIV, NULL_RTX))) remove_note (insn, note); /* Remove REG_DEAD notes as they might not be valid anymore in case we create redundancy. */ while ((note = find_reg_note (insn, REG_DEAD, NULL_RTX))) remove_note (insn, note); switch (GET_CODE (pat)) { case SET: hoist_update_store (insn, &SET_DEST (pat), val, new); break; case USE: break; case CLOBBER: hoist_update_store (insn, &XEXP (pat, 0), val, new); break; case PARALLEL: for (i = 0; i < XVECLEN (pat, 0); i++) { rtx x = XVECEXP (pat, 0, i); switch (GET_CODE (x)) { case SET: hoist_update_store (insn, &SET_DEST (x), val, new); break; case USE: break; case CLOBBER: hoist_update_store (insn, &SET_DEST (x), val, new); break; default: break; } } break; default: abort (); } if (!apply_change_group ()) abort (); return insn; } rtx hoist_insn_to_edge (insn, e, val, new) rtx insn, val, new; edge e; { rtx new_insn; /* We cannot insert instructions on an abnormal critical edge. It will be easier to find the culprit if we die now. */ if ((e->flags & EDGE_ABNORMAL) && EDGE_CRITICAL_P (e)) abort (); /* Do not use emit_insn_on_edge as we want to preserve notes and similar stuff. We also emit CALL_INSNS and firends. */ if (e->insns == NULL_RTX) { start_sequence (); emit_note (NULL, NOTE_INSN_DELETED); } else push_to_sequence (e->insns); new_insn = hoist_insn_after (insn, get_last_insn (), val, new); e->insns = get_insns (); end_sequence (); return new_insn; }