diff options
Diffstat (limited to 'gcc/loop.h')
| -rw-r--r-- | gcc/loop.h | 102 |
1 files changed, 78 insertions, 24 deletions
diff --git a/gcc/loop.h b/gcc/loop.h index d0ae25f4d45..e164428d861 100644 --- a/gcc/loop.h +++ b/gcc/loop.h @@ -1,5 +1,5 @@ /* Loop optimization definitions for GNU C-Compiler - Copyright (C) 1991, 1995, 1998 Free Software Foundation, Inc. + Copyright (C) 1991, 1995, 1998, 1999 Free Software Foundation, Inc. This file is part of GNU CC. @@ -18,6 +18,8 @@ along with GNU CC; see the file COPYING. If not, write to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ +#include "varray.h" + /* Get the luid of an insn. Catch the error of trying to reference the LUID of an insn added during loop, since these don't have LUIDs. */ @@ -54,6 +56,8 @@ struct induction For a DEST_ADDR type giv, this is 0. */ rtx *location; /* Place in the insn where this giv occurs. If GIV_TYPE is DEST_REG, this is 0. */ + /* For a biv, this is the place where add_val + was found. */ enum machine_mode mode; /* The mode of this biv or giv */ enum machine_mode mem_mode; /* For DEST_ADDR, mode of the memory object. */ rtx mult_val; /* Multiplicative factor for src_reg. */ @@ -63,6 +67,9 @@ struct induction final value could be calculated, it is put here, and the giv is made replaceable. Set the giv to this value before the loop. */ + unsigned combined_with; /* The number of givs this giv has been + combined with. If nonzero, this giv + cannot combine with any other giv. */ unsigned replaceable : 1; /* 1 if we can substitute the strength-reduced variable for the original variable. 0 means they must be kept separate and the @@ -85,8 +92,6 @@ struct induction another giv. This occurs in many cases where a giv's lifetime spans an update to a biv. */ - unsigned combined_with : 1; /* 1 if this giv has been combined with. It - then cannot combine with any other giv. */ unsigned maybe_dead : 1; /* 1 if this giv might be dead. In that case, we won't use it to eliminate a biv, it would probably lose. */ @@ -97,7 +102,6 @@ struct induction unsigned shared : 1; unsigned no_const_addval : 1; /* 1 if add_val does not contain a const. */ int lifetime; /* Length of life of this giv */ - int times_used; /* # times this giv is used. */ rtx derive_adjustment; /* If nonzero, is an adjustment to be subtracted from add_val when this giv derives another. This occurs when the @@ -109,14 +113,20 @@ struct induction struct induction *same; /* If this giv has been combined with another giv, this points to the base giv. The base giv will have COMBINED_WITH non-zero. */ + struct induction *derived_from;/* For a giv, if we decided to derive this + giv from another one. */ HOST_WIDE_INT const_adjust; /* Used by loop unrolling, when an address giv is split, and a constant is eliminated from the address, the -constant is stored here for later use. */ + int ix; /* Used by recombine_givs, as n index into + the stats array. */ struct induction *same_insn; /* If there are multiple identical givs in the same insn, then all but one have this field set, and they all point to the giv that doesn't have this field set. */ + rtx last_use; /* For a giv made from a biv increment, this is + a substitute for the lifetime information. */ }; /* A `struct iv_class' is created for each biv. */ @@ -143,6 +153,45 @@ struct iv_class { biv controls. */ }; +/* Information required to calculate the number of loop iterations. + This is set by loop_iterations. */ + +struct loop_info +{ + /* Register or constant initial loop value. */ + rtx initial_value; + /* Register or constant value used for comparison test. */ + rtx comparison_value; + /* Register or constant approximate final value. */ + rtx final_value; + /* Register or constant initial loop value with term common to + final_value removed. */ + rtx initial_equiv_value; + /* Register or constant final loop value with term common to + initial_value removed. */ + rtx final_equiv_value; + /* Register corresponding to iteration variable. */ + rtx iteration_var; + /* Constant loop increment. */ + rtx increment; + enum rtx_code comparison_code; + /* Holds the number of loop iterations. It is zero if the number + could not be calculated. Must be unsigned since the number of + iterations can be as high as 2^wordsize - 1. For loops with a + wider iterator, this number will be zero if the number of loop + iterations is too large for an unsigned integer to hold. */ + unsigned HOST_WIDE_INT n_iterations; + /* The loop unrolling factor. + Potential values: + 0: unrolled + 1: not unrolled. + -1: completely unrolled + >0: holds the unroll exact factor. */ + unsigned int unroll_number; + /* Non-zero if the loop has a NOTE_INSN_LOOP_VTOP. */ + rtx vtop; +}; + /* Definitions used by the basic induction variable discovery code. */ enum iv_mode { UNKNOWN_INDUCT, BASIC_INDUCT, NOT_BASIC_INDUCT, GENERAL_INDUCT }; @@ -155,41 +204,46 @@ extern int *uid_loop_num; extern int *loop_outer_loop; extern rtx *loop_number_exit_labels; extern int *loop_number_exit_count; -extern unsigned HOST_WIDE_INT loop_n_iterations; extern int max_reg_before_loop; extern FILE *loop_dump_stream; -extern enum iv_mode *reg_iv_type; -extern struct induction **reg_iv_info; +extern varray_type reg_iv_type; +extern varray_type reg_iv_info; + +#define REG_IV_TYPE(n) \ + (*(enum iv_mode *) &VARRAY_INT(reg_iv_type, (n))) +#define REG_IV_INFO(n) \ + (*(struct induction **) &VARRAY_GENERIC_PTR(reg_iv_info, (n))) + extern struct iv_class **reg_biv_class; extern struct iv_class *loop_iv_list; +extern int first_increment_giv, last_increment_giv; + /* Forward declarations for non-static functions declared in loop.c and unroll.c. */ int invariant_p PROTO((rtx)); rtx get_condition_for_loop PROTO((rtx)); void emit_iv_add_mult PROTO((rtx, rtx, rtx, rtx, rtx)); +rtx express_from PROTO((struct induction *, struct induction *)); -/* Forward declarations for non-static functions declared in stmt.c. */ -void find_loop_tree_blocks PROTO((void)); -void unroll_block_trees PROTO((void)); - -void unroll_loop PROTO((rtx, int, rtx, rtx, int)); +void unroll_loop PROTO((rtx, int, rtx, rtx, struct loop_info *, int)); rtx biv_total_increment PROTO((struct iv_class *, rtx, rtx)); -unsigned HOST_WIDE_INT loop_iterations PROTO((rtx, rtx)); -rtx final_biv_value PROTO((struct iv_class *, rtx, rtx)); -rtx final_giv_value PROTO((struct induction *, rtx, rtx)); +unsigned HOST_WIDE_INT loop_iterations PROTO((rtx, rtx, struct loop_info *)); +int precondition_loop_p PROTO((rtx, struct loop_info *, + rtx *, rtx *, rtx *, + enum machine_mode *mode)); +rtx final_biv_value PROTO((struct iv_class *, rtx, rtx, + unsigned HOST_WIDE_INT)); +rtx final_giv_value PROTO((struct induction *, rtx, rtx, + unsigned HOST_WIDE_INT)); void emit_unrolled_add PROTO((rtx, rtx, rtx)); int back_branch_in_range_p PROTO((rtx, rtx, rtx)); +int loop_insn_first_p PROTO((rtx, rtx)); -extern int *loop_unroll_factor; - -#ifdef HAVE_decrement_and_branch_on_count -extern rtx loop_iteration_var; -extern rtx loop_initial_value; -extern rtx loop_increment; -extern rtx loop_final_value; -extern enum rtx_code loop_comparison_code; -#endif /* HAVE_decrement_and_branch_on_count */ +extern int *loop_unroll_number; +/* Forward declarations for non-static functions declared in stmt.c. */ +void find_loop_tree_blocks PROTO((void)); +void unroll_block_trees PROTO((void)); |