diff options
Diffstat (limited to 'gcc/cse.c')
| -rw-r--r-- | gcc/cse.c | 128 |
1 files changed, 53 insertions, 75 deletions
@@ -22,6 +22,8 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA #include "config.h" /* stdio.h must precede rtl.h for FFS. */ #include "system.h" +#include "coretypes.h" +#include "tm.h" #include "rtl.h" #include "tm_p.h" @@ -266,11 +268,11 @@ static struct qty_table_elem *qty_table; static rtx prev_insn_cc0; static enum machine_mode prev_insn_cc0_mode; -#endif /* Previous actual insn. 0 if at first insn of basic block. */ static rtx prev_insn; +#endif /* Insn being scanned. */ @@ -591,55 +593,7 @@ struct cse_basic_block_data } path[PATHLENGTH]; }; -/* Nonzero if X has the form (PLUS frame-pointer integer). We check for - virtual regs here because the simplify_*_operation routines are called - by integrate.c, which is called before virtual register instantiation. - - ?!? FIXED_BASE_PLUS_P and NONZERO_BASE_PLUS_P need to move into - a header file so that their definitions can be shared with the - simplification routines in simplify-rtx.c. Until then, do not - change these macros without also changing the copy in simplify-rtx.c. */ - -#define FIXED_BASE_PLUS_P(X) \ - ((X) == frame_pointer_rtx || (X) == hard_frame_pointer_rtx \ - || ((X) == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM])\ - || (X) == virtual_stack_vars_rtx \ - || (X) == virtual_incoming_args_rtx \ - || (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 1)) == CONST_INT \ - && (XEXP (X, 0) == frame_pointer_rtx \ - || XEXP (X, 0) == hard_frame_pointer_rtx \ - || ((X) == arg_pointer_rtx \ - && fixed_regs[ARG_POINTER_REGNUM]) \ - || XEXP (X, 0) == virtual_stack_vars_rtx \ - || XEXP (X, 0) == virtual_incoming_args_rtx)) \ - || GET_CODE (X) == ADDRESSOF) - -/* Similar, but also allows reference to the stack pointer. - - This used to include FIXED_BASE_PLUS_P, however, we can't assume that - arg_pointer_rtx by itself is nonzero, because on at least one machine, - the i960, the arg pointer is zero when it is unused. */ - -#define NONZERO_BASE_PLUS_P(X) \ - ((X) == frame_pointer_rtx || (X) == hard_frame_pointer_rtx \ - || (X) == virtual_stack_vars_rtx \ - || (X) == virtual_incoming_args_rtx \ - || (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 1)) == CONST_INT \ - && (XEXP (X, 0) == frame_pointer_rtx \ - || XEXP (X, 0) == hard_frame_pointer_rtx \ - || ((X) == arg_pointer_rtx \ - && fixed_regs[ARG_POINTER_REGNUM]) \ - || XEXP (X, 0) == virtual_stack_vars_rtx \ - || XEXP (X, 0) == virtual_incoming_args_rtx)) \ - || (X) == stack_pointer_rtx \ - || (X) == virtual_stack_dynamic_rtx \ - || (X) == virtual_outgoing_args_rtx \ - || (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 1)) == CONST_INT \ - && (XEXP (X, 0) == stack_pointer_rtx \ - || XEXP (X, 0) == virtual_stack_dynamic_rtx \ - || XEXP (X, 0) == virtual_outgoing_args_rtx)) \ - || GET_CODE (X) == ADDRESSOF) - +static bool fixed_base_plus_p PARAMS ((rtx x)); static int notreg_cost PARAMS ((rtx, enum rtx_code)); static int approx_reg_cost_1 PARAMS ((rtx *, void *)); static int approx_reg_cost PARAMS ((rtx)); @@ -702,6 +656,39 @@ static bool insn_live_p PARAMS ((rtx, int *)); static bool set_live_p PARAMS ((rtx, rtx, int *)); static bool dead_libcall_p PARAMS ((rtx, int *)); +/* Nonzero if X has the form (PLUS frame-pointer integer). We check for + virtual regs here because the simplify_*_operation routines are called + by integrate.c, which is called before virtual register instantiation. */ + +static bool +fixed_base_plus_p (x) + rtx x; +{ + switch (GET_CODE (x)) + { + case REG: + if (x == frame_pointer_rtx || x == hard_frame_pointer_rtx) + return true; + if (x == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM]) + return true; + if (REGNO (x) >= FIRST_VIRTUAL_REGISTER + && REGNO (x) <= LAST_VIRTUAL_REGISTER) + return true; + return false; + + case PLUS: + if (GET_CODE (XEXP (x, 1)) != CONST_INT) + return false; + return fixed_base_plus_p (XEXP (x, 0)); + + case ADDRESSOF: + return true; + + default: + return false; + } +} + /* Dump the expressions in the equivalence class indicated by CLASSP. This function is used only for debugging. */ void @@ -1032,9 +1019,8 @@ new_basic_block () } } - prev_insn = 0; - #ifdef HAVE_cc0 + prev_insn = 0; prev_insn_cc0 = 0; #endif } @@ -1611,7 +1597,7 @@ insert (x, classp, hash, mode) || (GET_CODE (x) == REG && RTX_UNCHANGING_P (x) && REGNO (x) >= FIRST_PSEUDO_REGISTER) - || FIXED_BASE_PLUS_P (x)); + || fixed_base_plus_p (x)); if (table[hash]) table[hash]->prev_same_hash = elt; @@ -2378,10 +2364,9 @@ canon_hash (x, mode) do_not_record = 1; return 0; } - if (! RTX_UNCHANGING_P (x) || FIXED_BASE_PLUS_P (XEXP (x, 0))) - { - hash_arg_in_memory = 1; - } + if (! RTX_UNCHANGING_P (x) || fixed_base_plus_p (XEXP (x, 0))) + hash_arg_in_memory = 1; + /* Now that we have already found this special case, might as well speed it up as much as possible. */ hash += (unsigned) MEM; @@ -2399,7 +2384,7 @@ canon_hash (x, mode) hash += (unsigned) USE; x = XEXP (x, 0); - if (! RTX_UNCHANGING_P (x) || FIXED_BASE_PLUS_P (XEXP (x, 0))) + if (! RTX_UNCHANGING_P (x) || fixed_base_plus_p (XEXP (x, 0))) hash_arg_in_memory = 1; /* Now that we have already found this special case, @@ -3276,9 +3261,10 @@ find_comparison_args (code, parg1, parg2, pmode1, pmode2) break; } - /* If this is fp + constant, the equivalent is a better operand since - it may let us predict the value of the comparison. */ - else if (NONZERO_BASE_PLUS_P (p->exp)) + /* If this non-trapping address, e.g. fp + constant, the + equivalent is a better operand since it may let us predict + the value of the comparison. */ + else if (!rtx_addr_can_trap_p (p->exp)) { arg1 = p->exp; continue; @@ -3979,17 +3965,10 @@ fold_rtx (x, insn) comparison. */ if (const_arg0 == 0 || const_arg1 == 0) { - /* Is FOLDED_ARG0 frame-pointer plus a constant? Or - non-explicit constant? These aren't zero, but we - don't know their sign. */ + /* Some addresses are known to be nonzero. We don't know + their sign, but equality comparisons are known. */ if (const_arg1 == const0_rtx - && (NONZERO_BASE_PLUS_P (folded_arg0) -#if 0 /* Sad to say, on sysvr4, #pragma weak can make a symbol address - come out as 0. */ - || GET_CODE (folded_arg0) == SYMBOL_REF -#endif - || GET_CODE (folded_arg0) == LABEL_REF - || GET_CODE (folded_arg0) == CONST)) + && nonzero_address_p (folded_arg0)) { if (code == EQ) return false_rtx; @@ -6189,7 +6168,7 @@ cse_insn (insn, libcall_insn) elt->in_memory = (GET_CODE (sets[i].inner_dest) == MEM && (! RTX_UNCHANGING_P (sets[i].inner_dest) - || FIXED_BASE_PLUS_P (XEXP (sets[i].inner_dest, + || fixed_base_plus_p (XEXP (sets[i].inner_dest, 0)))); /* If we have (set (subreg:m1 (reg:m2 foo) 0) (bar:m1)), M1 is no @@ -6400,9 +6379,8 @@ cse_insn (insn, libcall_insn) prev_insn_cc0 = this_insn_cc0; prev_insn_cc0_mode = this_insn_cc0_mode; -#endif - prev_insn = insn; +#endif } /* Remove from the hash table all expressions that reference memory. */ @@ -7306,8 +7284,8 @@ cse_basic_block (from, to, next_branch, around_loop) Then follow this branch. */ #ifdef HAVE_cc0 prev_insn_cc0 = 0; -#endif prev_insn = insn; +#endif insn = JUMP_LABEL (insn); continue; } |