--- /dev/null
+/* Compute register class preferences for pseudo-registers.
+ Copyright (C) 1987-1991 Free Software Foundation, Inc.
+
+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. */
+
+
+/* This file contains two passes of the compiler: reg_scan and reg_class.
+ It also defines some tables of information about the hardware registers
+ and a function init_reg_sets to initialize the tables. */
+
+#include "config.h"
+#include "rtl.h"
+#include "hard-reg-set.h"
+#include "flags.h"
+#include "basic-block.h"
+#include "regs.h"
+#include "insn-config.h"
+#include "recog.h"
+
+#ifndef REGISTER_MOVE_COST
+#define REGISTER_MOVE_COST(x, y) 2
+#endif
+
+#ifndef MEMORY_MOVE_COST
+#define MEMORY_MOVE_COST(x) 2
+#endif
+\f
+/* Register tables used by many passes. */
+
+/* Indexed by hard register number, contains 1 for registers
+ that are fixed use (stack pointer, pc, frame pointer, etc.).
+ These are the registers that cannot be used to allocate
+ a pseudo reg whose life does not cross calls. */
+
+char fixed_regs[FIRST_PSEUDO_REGISTER];
+
+/* Same info as a HARD_REG_SET. */
+
+HARD_REG_SET fixed_reg_set;
+
+/* Data for initializing the above. */
+
+static char initial_fixed_regs[] = FIXED_REGISTERS;
+
+/* Indexed by hard register number, contains 1 for registers
+ that are fixed use or are clobbered by function calls.
+ These are the registers that cannot be used to allocate
+ a pseudo reg whose life crosses calls. */
+
+char call_used_regs[FIRST_PSEUDO_REGISTER];
+
+/* Same info as a HARD_REG_SET. */
+
+HARD_REG_SET call_used_reg_set;
+
+/* Data for initializing the above. */
+
+static char initial_call_used_regs[] = CALL_USED_REGISTERS;
+
+/* Indexed by hard register number, contains 1 for registers that are
+ fixed use -- i.e. in fixed_regs -- or a function value return register
+ or STRUCT_VALUE_REGNUM or STATIC_CHAIN_REGNUM. These are the
+ registers that cannot hold quantities across calls even if we are
+ willing to save and restore them. */
+
+char call_fixed_regs[FIRST_PSEUDO_REGISTER];
+
+/* The same info as a HARD_REG_SET. */
+
+HARD_REG_SET call_fixed_reg_set;
+
+/* Number of non-fixed registers. */
+
+int n_non_fixed_regs;
+
+/* Indexed by hard register number, contains 1 for registers
+ that are being used for global register decls.
+ These must be exempt from ordinary flow analysis
+ and are also considered fixed. */
+
+char global_regs[FIRST_PSEUDO_REGISTER];
+
+/* Table of register numbers in the order in which to try to use them. */
+#ifdef REG_ALLOC_ORDER
+int reg_alloc_order[FIRST_PSEUDO_REGISTER] = REG_ALLOC_ORDER;
+#endif
+
+/* For each reg class, a HARD_REG_SET saying which registers are in it. */
+
+HARD_REG_SET reg_class_contents[] = REG_CLASS_CONTENTS;
+
+/* For each reg class, number of regs it contains. */
+
+int reg_class_size[N_REG_CLASSES];
+
+/* For each reg class, table listing all the containing classes. */
+
+enum reg_class reg_class_superclasses[N_REG_CLASSES][N_REG_CLASSES];
+
+/* For each reg class, table listing all the classes contained in it. */
+
+enum reg_class reg_class_subclasses[N_REG_CLASSES][N_REG_CLASSES];
+
+/* For each pair of reg classes,
+ a largest reg class contained in their union. */
+
+enum reg_class reg_class_subunion[N_REG_CLASSES][N_REG_CLASSES];
+
+/* For each pair of reg classes,
+ the smallest reg class containing their union. */
+
+enum reg_class reg_class_superunion[N_REG_CLASSES][N_REG_CLASSES];
+
+/* Array containing all of the register names */
+
+char *reg_names[] = REGISTER_NAMES;
+
+
+/* Indexed by n, gives number of times (REG n) is set or clobbered.
+ This information remains valid for the rest of the compilation
+ of the current function; it is used to control register allocation.
+
+ This information applies to both hard registers and pseudo registers,
+ unlike much of the information above. */
+
+short *reg_n_sets;
+
+/* Function called only once to initialize the above data on reg usage.
+ Once this is done, various switches may override. */
+
+void
+init_reg_sets ()
+{
+ register int i, j;
+
+ bcopy (initial_fixed_regs, fixed_regs, sizeof fixed_regs);
+ bcopy (initial_call_used_regs, call_used_regs, sizeof call_used_regs);
+ bzero (global_regs, sizeof global_regs);
+
+ /* Compute number of hard regs in each class. */
+
+ bzero (reg_class_size, sizeof reg_class_size);
+ for (i = 0; i < N_REG_CLASSES; i++)
+ for (j = 0; j < FIRST_PSEUDO_REGISTER; j++)
+ if (TEST_HARD_REG_BIT (reg_class_contents[i], j))
+ reg_class_size[i]++;
+
+ /* Initialize the table of subunions.
+ reg_class_subunion[I][J] gets the largest-numbered reg-class
+ that is contained in the union of classes I and J. */
+
+ for (i = 0; i < N_REG_CLASSES; i++)
+ {
+ for (j = 0; j < N_REG_CLASSES; j++)
+ {
+#ifdef HARD_REG_SET
+ register /* Declare it register if it's a scalar. */
+#endif
+ HARD_REG_SET c;
+ register int k;
+
+ COPY_HARD_REG_SET (c, reg_class_contents[i]);
+ IOR_HARD_REG_SET (c, reg_class_contents[j]);
+ for (k = 0; k < N_REG_CLASSES; k++)
+ {
+ GO_IF_HARD_REG_SUBSET (reg_class_contents[k], c,
+ subclass1);
+ continue;
+
+ subclass1:
+ /* keep the largest subclass */ /* SPEE 900308 */
+ GO_IF_HARD_REG_SUBSET (reg_class_contents[k],
+ reg_class_contents[(int) reg_class_subunion[i][j]],
+ subclass2);
+ reg_class_subunion[i][j] = (enum reg_class) k;
+ subclass2:
+ ;
+ }
+ }
+ }
+
+ /* Initialize the table of superunions.
+ reg_class_superunion[I][J] gets the smallest-numbered reg-class
+ containing the union of classes I and J. */
+
+ for (i = 0; i < N_REG_CLASSES; i++)
+ {
+ for (j = 0; j < N_REG_CLASSES; j++)
+ {
+#ifdef HARD_REG_SET
+ register /* Declare it register if it's a scalar. */
+#endif
+ HARD_REG_SET c;
+ register int k;
+
+ COPY_HARD_REG_SET (c, reg_class_contents[i]);
+ IOR_HARD_REG_SET (c, reg_class_contents[j]);
+ for (k = 0; k < N_REG_CLASSES; k++)
+ GO_IF_HARD_REG_SUBSET (c, reg_class_contents[k], superclass);
+
+ superclass:
+ reg_class_superunion[i][j] = (enum reg_class) k;
+ }
+ }
+
+ /* Initialize the tables of subclasses and superclasses of each reg class.
+ First clear the whole table, then add the elements as they are found. */
+
+ for (i = 0; i < N_REG_CLASSES; i++)
+ {
+ for (j = 0; j < N_REG_CLASSES; j++)
+ {
+ reg_class_superclasses[i][j] = LIM_REG_CLASSES;
+ reg_class_subclasses[i][j] = LIM_REG_CLASSES;
+ }
+ }
+
+ for (i = 0; i < N_REG_CLASSES; i++)
+ {
+ if (i == (int) NO_REGS)
+ continue;
+
+ for (j = i + 1; j < N_REG_CLASSES; j++)
+ {
+ enum reg_class *p;
+
+ GO_IF_HARD_REG_SUBSET (reg_class_contents[i], reg_class_contents[j],
+ subclass);
+ continue;
+ subclass:
+ /* Reg class I is a subclass of J.
+ Add J to the table of superclasses of I. */
+ p = ®_class_superclasses[i][0];
+ while (*p != LIM_REG_CLASSES) p++;
+ *p = (enum reg_class) j;
+ /* Add I to the table of superclasses of J. */
+ p = ®_class_subclasses[j][0];
+ while (*p != LIM_REG_CLASSES) p++;
+ *p = (enum reg_class) i;
+ }
+ }
+}
+
+/* After switches have been processed, which perhaps alter
+ `fixed_regs' and `call_used_regs', convert them to HARD_REG_SETs. */
+
+void
+init_reg_sets_1 ()
+{
+ register int i;
+
+ /* This macro allows the fixed or call-used registers
+ to depend on target flags. */
+
+#ifdef CONDITIONAL_REGISTER_USAGE
+ CONDITIONAL_REGISTER_USAGE;
+#endif
+
+ for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
+ if (global_regs[i])
+ {
+ if (call_used_regs[i] && ! fixed_regs[i])
+ warning ("call-clobbered register used for global register variable");
+ fixed_regs[i] = 1;
+ /* Prevent saving/restoring of this reg. */
+ call_used_regs[i] = 1;
+ }
+
+ /* Initialize "constant" tables. */
+
+ CLEAR_HARD_REG_SET (fixed_reg_set);
+ CLEAR_HARD_REG_SET (call_used_reg_set);
+ CLEAR_HARD_REG_SET (call_fixed_reg_set);
+
+ bcopy (fixed_regs, call_fixed_regs, sizeof call_fixed_regs);
+#ifdef STRUCT_VALUE_REGNUM
+ call_fixed_regs[STRUCT_VALUE_REGNUM] = 1;
+#endif
+#ifdef STATIC_CHAIN_REGNUM
+ call_fixed_regs[STATIC_CHAIN_REGNUM] = 1;
+#endif
+
+ n_non_fixed_regs = 0;
+
+ for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
+ {
+ if (FUNCTION_VALUE_REGNO_P (i))
+ call_fixed_regs[i] = 1;
+ if (fixed_regs[i])
+ SET_HARD_REG_BIT (fixed_reg_set, i);
+ else
+ n_non_fixed_regs++;
+
+ if (call_used_regs[i])
+ SET_HARD_REG_BIT (call_used_reg_set, i);
+ if (call_fixed_regs[i])
+ SET_HARD_REG_BIT (call_fixed_reg_set, i);
+ }
+}
+
+/* Specify the usage characteristics of the register named NAME.
+ It should be a fixed register if FIXED and a
+ call-used register if CALL_USED. */
+
+void
+fix_register (name, fixed, call_used)
+ char *name;
+ int fixed, call_used;
+{
+ int i;
+
+ /* Decode the name and update the primary form of
+ the register info. */
+
+ for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
+ if (!strcmp (reg_names[i], name))
+ {
+ fixed_regs[i] = fixed;
+ call_used_regs[i] = call_used;
+ break;
+ }
+
+ if (i == FIRST_PSEUDO_REGISTER)
+ {
+ warning ("unknown register name: %s", name);
+ return;
+ }
+}
+\f
+/* Now the data and code for the `regclass' pass, which happens
+ just before local-alloc. */
+
+/* savings[R].savings[CL] is twice the amount saved by putting register R
+ in class CL. This data is used within `regclass' and freed
+ when it is finished. */
+
+struct savings
+{
+ short savings[N_REG_CLASSES];
+ short memcost;
+ short nrefs;
+};
+
+static struct savings *savings;
+
+/* (enum reg_class) prefclass[R] is the preferred class for pseudo number R.
+ This is available after `regclass' is run. */
+
+static char *prefclass;
+
+/* preferred_or_nothing[R] is nonzero if we should put pseudo number R
+ in memory if we can't get its perferred class.
+ This is available after `regclass' is run. */
+
+static char *preferred_or_nothing;
+
+/* Record the depth of loops that we are in, 1 for no loops. */
+
+static int loop_depth;
+
+void reg_class_record ();
+void record_address_regs ();
+
+
+/* Return the reg_class in which pseudo reg number REGNO is best allocated.
+ This function is sometimes called before the info has been computed.
+ When that happens, just return GENERAL_REGS, which is innocuous. */
+
+enum reg_class
+reg_preferred_class (regno)
+ int regno;
+{
+ if (prefclass == 0)
+ return GENERAL_REGS;
+ return (enum reg_class) prefclass[regno];
+}
+
+int
+reg_preferred_or_nothing (regno)
+{
+ if (prefclass == 0)
+ return 0;
+ return preferred_or_nothing[regno];
+}
+
+/* This prevents dump_flow_info from losing if called
+ before regclass is run. */
+
+void
+regclass_init ()
+{
+ prefclass = 0;
+}
+\f
+/* This is a pass of the compiler that scans all instructions
+ and calculates the preferred class for each pseudo-register.
+ This information can be accessed later by calling `reg_preferred_class'.
+ This pass comes just before local register allocation. */
+
+void
+regclass (f, nregs)
+ rtx f;
+ int nregs;
+{
+#ifdef REGISTER_CONSTRAINTS
+ register rtx insn;
+ register int i;
+
+ init_recog ();
+
+ /* Zero out our accumulation of the cost of each class for each reg. */
+
+ savings = (struct savings *) alloca (nregs * sizeof (struct savings));
+ bzero (savings, nregs * sizeof (struct savings));
+
+ loop_depth = 1;
+
+ /* Scan the instructions and record each time it would
+ save code to put a certain register in a certain class. */
+
+ for (insn = f; insn; insn = NEXT_INSN (insn))
+ {
+ if (GET_CODE (insn) == NOTE
+ && NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
+ loop_depth++;
+ else if (GET_CODE (insn) == NOTE
+ && NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END)
+ loop_depth--;
+ else if ((GET_CODE (insn) == INSN
+ && GET_CODE (PATTERN (insn)) != USE
+ && GET_CODE (PATTERN (insn)) != CLOBBER
+ && GET_CODE (PATTERN (insn)) != ASM_INPUT)
+ || (GET_CODE (insn) == JUMP_INSN
+ && GET_CODE (PATTERN (insn)) != ADDR_VEC
+ && GET_CODE (PATTERN (insn)) != ADDR_DIFF_VEC)
+ || GET_CODE (insn) == CALL_INSN)
+ {
+ if (GET_CODE (insn) == INSN && asm_noperands (PATTERN (insn)) >= 0)
+ {
+ int noperands = asm_noperands (PATTERN (insn));
+ /* We don't use alloca because alloca would not free
+ any of the space until this function returns. */
+ rtx *operands = (rtx *) oballoc (noperands * sizeof (rtx));
+ char **constraints
+ = (char **) oballoc (noperands * sizeof (char *));
+
+ decode_asm_operands (PATTERN (insn), operands, 0, constraints, 0);
+
+ for (i = noperands - 1; i >= 0; i--)
+ reg_class_record (operands[i], i, constraints);
+
+ obfree (operands);
+ }
+ else
+ {
+ int insn_code_number = recog_memoized (insn);
+ rtx set = single_set (insn);
+
+ insn_extract (insn);
+
+ for (i = insn_n_operands[insn_code_number] - 1; i >= 0; i--)
+ reg_class_record (recog_operand[i], i,
+ insn_operand_constraint[insn_code_number]);
+
+ /* If this insn loads a parameter from its stack slot,
+ then it represents a savings, rather than a cost,
+ if the parameter is stored in memory. Record this fact. */
+ if (set != 0 && GET_CODE (SET_DEST (set)) == REG
+ && GET_CODE (SET_SRC (set)) == MEM)
+ {
+ rtx note = find_reg_note (insn, REG_EQUIV, 0);
+ if (note != 0 && GET_CODE (XEXP (note, 0)) == MEM)
+ savings[REGNO (SET_DEST (set))].memcost
+ -= (MEMORY_MOVE_COST (GET_MODE (SET_DEST (set)))
+ * loop_depth);
+ }
+
+ /* Improve handling of two-address insns such as
+ (set X (ashift CONST Y)) where CONST must be made to match X.
+ Change it into two insns: (set X CONST) (set X (ashift X Y)).
+ If we left this for reloading, it would probably get three
+ insns because X and Y might go in the same place.
+ This prevents X and Y from receiving the same hard reg.
+
+ We can only do this if the modes of operands 0 and 1 (which
+ might not be the same) are tieable. */
+
+ if (optimize
+ && insn_n_operands[insn_code_number] >= 3
+ && insn_operand_constraint[insn_code_number][1][0] == '0'
+ && insn_operand_constraint[insn_code_number][1][1] == 0
+ && CONSTANT_P (recog_operand[1])
+ && ! rtx_equal_p (recog_operand[0], recog_operand[1])
+ && ! rtx_equal_p (recog_operand[0], recog_operand[2])
+ && GET_CODE (recog_operand[0]) == REG
+ && MODES_TIEABLE_P (GET_MODE (recog_operand[0]),
+ insn_operand_mode[insn_code_number][1]))
+ {
+ rtx previnsn = prev_real_insn (insn);
+ rtx dest
+ = gen_lowpart (insn_operand_mode[insn_code_number][1],
+ recog_operand[0]);
+ rtx newinsn
+ = emit_insn_before (gen_move_insn (dest, recog_operand[1]),
+ insn);
+
+ /* If this insn was the start of a basic block,
+ include the new insn in that block. */
+ if (previnsn == 0 || GET_CODE (previnsn) == JUMP_INSN)
+ {
+ int b;
+ for (b = 0; b < n_basic_blocks; b++)
+ if (insn == basic_block_head[b])
+ basic_block_head[b] = newinsn;
+ }
+
+ /* This makes one more setting of new insns's destination. */
+ reg_n_sets[REGNO (recog_operand[0])]++;
+
+ *recog_operand_loc[1] = recog_operand[0];
+ for (i = insn_n_dups[insn_code_number] - 1; i >= 0; i--)
+ if (recog_dup_num[i] == 1)
+ *recog_dup_loc[i] = recog_operand[0];
+ }
+ }
+ }
+ }
+
+ /* Now for each register look at how desirable each class is
+ and find which class is preferred. Store that in `prefclass[REGNO]'. */
+
+ prefclass = (char *) oballoc (nregs);
+
+ preferred_or_nothing = (char *) oballoc (nregs);
+
+ for (i = FIRST_PSEUDO_REGISTER; i < nregs; i++)
+ {
+ register int best_savings = 0;
+ enum reg_class best = ALL_REGS;
+
+ /* This is an enum reg_class, but we call it an int
+ to save lots of casts. */
+ register int class;
+ register struct savings *p = &savings[i];
+
+ for (class = (int) ALL_REGS - 1; class > 0; class--)
+ {
+ if (p->savings[class] > best_savings)
+ {
+ best_savings = p->savings[class];
+ best = (enum reg_class) class;
+ }
+ else if (p->savings[class] == best_savings)
+ {
+ best = reg_class_subunion[(int)best][class];
+ }
+ }
+
+#if 0
+ /* Note that best_savings is twice number of places something
+ is saved. */
+ if ((best_savings - p->savings[(int) GENERAL_REGS]) * 5 < reg_n_refs[i])
+ prefclass[i] = (int) GENERAL_REGS;
+ else
+ prefclass[i] = (int) best;
+#else
+ /* We cast to (int) because (char) hits bugs in some compilers. */
+ prefclass[i] = (int) best;
+#endif
+
+ /* reg_n_refs + p->memcost measures the cost of putting in memory.
+ If a GENERAL_REG is no better, don't even try for one.
+ Since savings and memcost are 2 * number of refs,
+ this effectively counts each memory operand not needing reloading
+ as costing 1/2 of a reload insn. */
+ if (reg_n_refs != 0)
+ preferred_or_nothing[i]
+ = ((best_savings - p->savings[(int) GENERAL_REGS])
+ >= p->nrefs + p->memcost);
+ }
+#endif /* REGISTER_CONSTRAINTS */
+}
+\f
+#ifdef REGISTER_CONSTRAINTS
+
+/* Scan an operand OP for register class preferences.
+ OPNO is the operand number, and CONSTRAINTS is the constraint
+ vector for the insn.
+
+ Record the preferred register classes from the constraint for OP
+ if OP is a register. If OP is a memory reference, record suitable
+ preferences for registers used in the address. */
+
+void
+reg_class_record (op, opno, constraints)
+ rtx op;
+ int opno;
+ char **constraints;
+{
+ char *constraint = constraints[opno];
+ register char *p;
+ register enum reg_class class = NO_REGS;
+ char *next = 0;
+ int memok = 0;
+ int double_cost = 0;
+
+ if (op == 0)
+ return;
+
+ while (1)
+ {
+ if (GET_CODE (op) == SUBREG)
+ op = SUBREG_REG (op);
+ else break;
+ }
+
+ /* Memory reference: scan the address. */
+
+ if (GET_CODE (op) == MEM)
+ record_address_regs (XEXP (op, 0), 2, 0);
+
+ if (GET_CODE (op) != REG)
+ {
+ /* If the constraint says the operand is supposed to BE an address,
+ scan it as one. */
+
+ if (constraint != 0 && constraint[0] == 'p')
+ record_address_regs (op, 2, 0);
+ return;
+ }
+
+ /* Operand is a register: examine the constraint for specified classes. */
+
+ for (p = constraint; *p || next; p++)
+ {
+ enum reg_class new_class = NO_REGS;
+
+ if (*p == 0)
+ {
+ p = next;
+ next = 0;
+ }
+ switch (*p)
+ {
+ case '=':
+ case '?':
+ case '#':
+ case '&':
+ case '!':
+ case '%':
+ case 'E':
+ case 'F':
+ case 'G':
+ case 'H':
+ case 'i':
+ case 'n':
+ case 's':
+ case 'p':
+ case ',':
+ case 'I':
+ case 'J':
+ case 'K':
+ case 'L':
+ case 'M':
+ case 'N':
+ case 'O':
+ case 'P':
+#ifdef EXTRA_CONSTRAINT
+ case 'Q':
+ case 'R':
+ case 'S':
+ case 'T':
+ case 'U':
+#endif
+ case 'V':
+ case 'X':
+ break;
+
+ case '+':
+ /* An input-output operand is twice as costly if it loses. */
+ double_cost = 1;
+ break;
+
+ case 'm':
+ case 'o':
+ memok = 1;
+ break;
+
+ /* * means ignore following letter
+ when choosing register preferences. */
+ case '*':
+ p++;
+ break;
+
+ case 'g':
+ case 'r':
+ new_class = GENERAL_REGS;
+ break;
+
+ case '0':
+ case '1':
+ case '2':
+ case '3':
+ case '4':
+ /* If constraint says "match another operand",
+ use that operand's constraint to choose preferences. */
+ next = constraints[*p - '0'];
+ break;
+
+ default:
+ new_class = REG_CLASS_FROM_LETTER (*p);
+ break;
+ }
+
+ /* If this object can fit into the class requested, compute the subunion
+ of the requested class and classes found so far. */
+ if (CLASS_MAX_NREGS (new_class, GET_MODE (op))
+ <= reg_class_size[(int) new_class])
+ class = reg_class_subunion[(int) class][(int) new_class];
+ }
+
+ {
+ register int i;
+ register struct savings *pp;
+ register enum reg_class class1;
+ int cost = 2 * (1 + double_cost) * loop_depth;
+ pp = &savings[REGNO (op)];
+
+ /* Increment the savings for this reg
+ for each class contained in the one the constraint asks for. */
+
+ if (class != NO_REGS && class != ALL_REGS)
+ {
+ int extracost;
+
+ pp->savings[(int) class] += cost;
+ for (i = 0; ; i++)
+ {
+ class1 = reg_class_subclasses[(int)class][i];
+ if (class1 == LIM_REG_CLASSES)
+ break;
+ pp->savings[(int) class1] += cost;
+ }
+ /* If it's slow to move data between this class and GENERAL_REGS,
+ record that fact. */
+ extracost = (REGISTER_MOVE_COST (class, GENERAL_REGS) - 2) * loop_depth;
+ if (extracost > 0)
+ {
+ /* Check that this class and GENERAL_REGS don't overlap.
+ REGISTER_MOVE_COST is meaningless if there is overlap. */
+ HARD_REG_SET temp;
+ COMPL_HARD_REG_SET (temp, reg_class_contents[(int) class]);
+ GO_IF_HARD_REG_SUBSET (reg_class_contents[(int) GENERAL_REGS],
+ temp, label1);
+ /* Overlap. */
+ goto label2;
+
+ label1: /* No overlap. */
+ /* Charge this extra cost to GENERAL_REGS
+ and all its subclasses (none of which overlap this class). */
+ extracost = extracost * cost / (2 * loop_depth);
+ pp->savings[(int) GENERAL_REGS] -= extracost;
+ for (i = 0; ; i++)
+ {
+ class1 = reg_class_subclasses[(int)GENERAL_REGS][i];
+ if (class1 == LIM_REG_CLASSES)
+ break;
+ pp->savings[(int) class1] -= extracost;
+ }
+
+ label2: ;
+ }
+ }
+
+ if (! memok)
+ pp->memcost += (MEMORY_MOVE_COST (GET_MODE (op)) * (1 + double_cost)
+ - 1) * loop_depth;
+ pp->nrefs += loop_depth;
+ }
+}
+
+/* Record the pseudo registers we must reload into hard registers
+ in a subexpression of a memory address, X.
+ BCOST is the cost if X is a register and it fails to be in BASE_REG_CLASS.
+ ICOST is the cost if it fails to be in INDEX_REG_CLASS. */
+
+void
+record_address_regs (x, bcost, icost)
+ rtx x;
+ int bcost, icost;
+{
+ register enum rtx_code code = GET_CODE (x);
+
+ switch (code)
+ {
+ case CONST_INT:
+ case CONST:
+ case CC0:
+ case PC:
+ case SYMBOL_REF:
+ case LABEL_REF:
+ return;
+
+ case PLUS:
+ /* When we have an address that is a sum,
+ we must determine whether registers are "base" or "index" regs.
+ If there is a sum of two registers, we must choose one to be
+ the "base". Luckily, we can use the REGNO_POINTER_FLAG
+ to make a good choice most of the time. */
+ {
+ rtx arg0 = XEXP (x, 0);
+ rtx arg1 = XEXP (x, 1);
+ register enum rtx_code code0 = GET_CODE (arg0);
+ register enum rtx_code code1 = GET_CODE (arg1);
+ int icost0 = 0;
+ int icost1 = 0;
+ int suppress1 = 0;
+ int suppress0 = 0;
+
+ /* Look inside subregs. */
+ while (code0 == SUBREG)
+ arg0 = SUBREG_REG (arg0), code0 = GET_CODE (arg0);
+ while (code1 == SUBREG)
+ arg1 = SUBREG_REG (arg1), code1 = GET_CODE (arg1);
+
+ if (code0 == MULT || code1 == MEM)
+ icost0 = 2;
+ else if (code1 == MULT || code0 == MEM)
+ icost1 = 2;
+ else if (code0 == CONST_INT)
+ suppress0 = 1;
+ else if (code1 == CONST_INT)
+ suppress1 = 1;
+ else if (code0 == REG && code1 == REG)
+ {
+ if (REGNO_POINTER_FLAG (REGNO (arg0)))
+ icost1 = 2;
+ else if (REGNO_POINTER_FLAG (REGNO (arg1)))
+ icost0 = 2;
+ else
+ icost0 = icost1 = 1;
+ }
+ else if (code0 == REG)
+ {
+ if (code1 == PLUS
+ && ! REGNO_POINTER_FLAG (REGNO (arg0)))
+ icost0 = 2;
+ else
+ REGNO_POINTER_FLAG (REGNO (arg0)) = 1;
+ }
+ else if (code1 == REG)
+ {
+ if (code0 == PLUS
+ && ! REGNO_POINTER_FLAG (REGNO (arg1)))
+ icost1 = 2;
+ else
+ REGNO_POINTER_FLAG (REGNO (arg1)) = 1;
+ }
+
+ /* ICOST0 determines whether we are treating operand 0
+ as a base register or as an index register.
+ SUPPRESS0 nonzero means it isn't a register at all.
+ ICOST1 and SUPPRESS1 are likewise for operand 1. */
+
+ if (! suppress0)
+ record_address_regs (arg0, 2 - icost0, icost0);
+ if (! suppress1)
+ record_address_regs (arg1, 2 - icost1, icost1);
+ }
+ break;
+
+ case POST_INC:
+ case PRE_INC:
+ case POST_DEC:
+ case PRE_DEC:
+ /* Double the importance of a pseudo register that is incremented
+ or decremented, since it would take two extra insns
+ if it ends up in the wrong place. */
+ record_address_regs (XEXP (x, 0), 2 * bcost, 2 * icost);
+ break;
+
+ case REG:
+ {
+ register struct savings *pp;
+ register enum reg_class class, class1;
+ pp = &savings[REGNO (x)];
+ pp->nrefs += loop_depth;
+
+ /* We have an address (or part of one) that is just one register. */
+
+ /* Record BCOST worth of savings for classes contained
+ in BASE_REG_CLASS. */
+
+ class = BASE_REG_CLASS;
+ if (class != NO_REGS && class != ALL_REGS)
+ {
+ register int i;
+ pp->savings[(int) class] += bcost * loop_depth;
+ for (i = 0; ; i++)
+ {
+ class1 = reg_class_subclasses[(int)class][i];
+ if (class1 == LIM_REG_CLASSES)
+ break;
+ pp->savings[(int) class1] += bcost * loop_depth;
+ }
+ }
+
+ /* Record ICOST worth of savings for classes contained
+ in INDEX_REG_CLASS. */
+
+ class = INDEX_REG_CLASS;
+ if (icost != 0 && class != NO_REGS && class != ALL_REGS)
+ {
+ register int i;
+ pp->savings[(int) class] += icost * loop_depth;
+ for (i = 0; ; i++)
+ {
+ class1 = reg_class_subclasses[(int)class][i];
+ if (class1 == LIM_REG_CLASSES)
+ break;
+ pp->savings[(int) class1] += icost * loop_depth;
+ }
+ }
+ }
+ break;
+
+ default:
+ {
+ register char *fmt = GET_RTX_FORMAT (code);
+ register int i;
+ for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
+ if (fmt[i] == 'e')
+ record_address_regs (XEXP (x, i), bcost, icost);
+ }
+ }
+}
+#endif /* REGISTER_CONSTRAINTS */
+\f
+/* This is the `regscan' pass of the compiler, run just before cse
+ and again just before loop.
+
+ It finds the first and last use of each pseudo-register
+ and records them in the vectors regno_first_uid, regno_last_uid
+ and counts the number of sets in the vector reg_n_sets.
+
+ REPEAT is nonzero the second time this is called. */
+
+/* Indexed by pseudo register number, gives uid of first insn using the reg
+ (as of the time reg_scan is called). */
+
+short *regno_first_uid;
+
+/* Indexed by pseudo register number, gives uid of last insn using the reg
+ (as of the time reg_scan is called). */
+
+short *regno_last_uid;
+
+/* Record the number of registers we used when we allocated the above two
+ tables. If we are called again with more than this, we must re-allocate
+ the tables. */
+
+static int highest_regno_in_uid_map;
+
+/* Maximum number of parallel sets and clobbers in any insn in this fn.
+ Always at least 3, since the combiner could put that many togetherm
+ and we want this to remain correct for all the remaining passes. */
+
+int max_parallel;
+
+void reg_scan_mark_refs ();
+
+void
+reg_scan (f, nregs, repeat)
+ rtx f;
+ int nregs;
+ int repeat;
+{
+ register rtx insn;
+
+ if (!repeat || nregs > highest_regno_in_uid_map)
+ {
+ /* Leave some spare space in case more regs are allocated. */
+ highest_regno_in_uid_map = nregs + nregs / 20;
+ regno_first_uid
+ = (short *) oballoc (highest_regno_in_uid_map * sizeof (short));
+ regno_last_uid
+ = (short *) oballoc (highest_regno_in_uid_map * sizeof (short));
+ reg_n_sets
+ = (short *) oballoc (highest_regno_in_uid_map * sizeof (short));
+ }
+
+ bzero (regno_first_uid, highest_regno_in_uid_map * sizeof (short));
+ bzero (regno_last_uid, highest_regno_in_uid_map * sizeof (short));
+ bzero (reg_n_sets, highest_regno_in_uid_map * sizeof (short));
+
+ max_parallel = 3;
+
+ for (insn = f; insn; insn = NEXT_INSN (insn))
+ if (GET_CODE (insn) == INSN
+ || GET_CODE (insn) == CALL_INSN
+ || GET_CODE (insn) == JUMP_INSN)
+ {
+ if (GET_CODE (PATTERN (insn)) == PARALLEL
+ && XVECLEN (PATTERN (insn), 0) > max_parallel)
+ max_parallel = XVECLEN (PATTERN (insn), 0);
+ reg_scan_mark_refs (PATTERN (insn), INSN_UID (insn));
+ }
+}
+
+void
+reg_scan_mark_refs (x, uid)
+ rtx x;
+ int uid;
+{
+ register enum rtx_code code = GET_CODE (x);
+ register rtx dest;
+
+ switch (code)
+ {
+ case CONST_INT:
+ case CONST:
+ case CONST_DOUBLE:
+ case CC0:
+ case PC:
+ case SYMBOL_REF:
+ case LABEL_REF:
+ case ADDR_VEC:
+ case ADDR_DIFF_VEC:
+ return;
+
+ case REG:
+ {
+ register int regno = REGNO (x);
+
+ regno_last_uid[regno] = uid;
+ if (regno_first_uid[regno] == 0)
+ regno_first_uid[regno] = uid;
+ }
+ break;
+
+ case SET:
+ /* Count a set of the destination if it is a register. */
+ for (dest = SET_DEST (x);
+ GET_CODE (dest) == SUBREG || GET_CODE (dest) == STRICT_LOW_PART
+ || GET_CODE (dest) == ZERO_EXTEND;
+ dest = XEXP (dest, 0))
+ ;
+
+ if (GET_CODE (dest) == REG)
+ reg_n_sets[REGNO (dest)]++;
+
+ /* ... fall through ... */
+
+ default:
+ {
+ register char *fmt = GET_RTX_FORMAT (code);
+ register int i;
+ for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
+ {
+ if (fmt[i] == 'e')
+ reg_scan_mark_refs (XEXP (x, i), uid);
+ else if (fmt[i] == 'E' && XVEC (x, i) != 0)
+ {
+ register int j;
+ for (j = XVECLEN (x, i) - 1; j >= 0; j--)
+ reg_scan_mark_refs (XVECEXP (x, i, j), uid);
+ }
+ }
+ }
+ }
+}
+\f
+/* Return nonzero if C1 is a subset of C2, i.e., if every register in C1
+ is also in C2. */
+
+int
+reg_class_subset_p (c1, c2)
+ register enum reg_class c1;
+ register enum reg_class c2;
+{
+ if (c1 == c2) return 1;
+
+ if (c2 == ALL_REGS)
+ win:
+ return 1;
+ GO_IF_HARD_REG_SUBSET (reg_class_contents[(int)c1],
+ reg_class_contents[(int)c2],
+ win);
+ return 0;
+}
+
+/* Return nonzero if there is a register that is in both C1 and C2. */
+
+int
+reg_classes_intersect_p (c1, c2)
+ register enum reg_class c1;
+ register enum reg_class c2;
+{
+#ifdef HARD_REG_SET
+ register
+#endif
+ HARD_REG_SET c;
+
+ if (c1 == c2) return 1;
+
+ if (c1 == ALL_REGS || c2 == ALL_REGS)
+ return 1;
+
+ COPY_HARD_REG_SET (c, reg_class_contents[(int) c1]);
+ AND_HARD_REG_SET (c, reg_class_contents[(int) c2]);
+
+ GO_IF_HARD_REG_SUBSET (c, reg_class_contents[(int) NO_REGS], lose);
+ return 1;
+
+ lose:
+ return 0;
+}
+
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