cfcf04a6ba
From-SVN: r3284
1661 lines
52 KiB
C
1661 lines
52 KiB
C
/* Allocate registers for pseudo-registers that span basic blocks.
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Copyright (C) 1987, 1988, 1991 Free Software Foundation, Inc.
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This file is part of GNU CC.
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GNU CC is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GNU CC is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GNU CC; see the file COPYING. If not, write to
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the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
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#include <stdio.h>
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#include "config.h"
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#include "rtl.h"
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#include "flags.h"
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#include "basic-block.h"
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#include "hard-reg-set.h"
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#include "regs.h"
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#include "insn-config.h"
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#include "output.h"
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/* This pass of the compiler performs global register allocation.
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It assigns hard register numbers to all the pseudo registers
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that were not handled in local_alloc. Assignments are recorded
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in the vector reg_renumber, not by changing the rtl code.
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(Such changes are made by final). The entry point is
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the function global_alloc.
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After allocation is complete, the reload pass is run as a subroutine
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of this pass, so that when a pseudo reg loses its hard reg due to
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spilling it is possible to make a second attempt to find a hard
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reg for it. The reload pass is independent in other respects
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and it is run even when stupid register allocation is in use.
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1. count the pseudo-registers still needing allocation
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and assign allocation-numbers (allocnos) to them.
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Set up tables reg_allocno and allocno_reg to map
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reg numbers to allocnos and vice versa.
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max_allocno gets the number of allocnos in use.
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2. Allocate a max_allocno by max_allocno conflict bit matrix and clear it.
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Allocate a max_allocno by FIRST_PSEUDO_REGISTER conflict matrix
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for conflicts between allocnos and explicit hard register use
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(which includes use of pseudo-registers allocated by local_alloc).
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3. for each basic block
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walk forward through the block, recording which
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unallocated registers and which hardware registers are live.
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Build the conflict matrix between the unallocated registers
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and another of unallocated registers versus hardware registers.
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Also record the preferred hardware registers
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for each unallocated one.
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4. Sort a table of the allocnos into order of
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desirability of the variables.
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5. Allocate the variables in that order; each if possible into
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a preferred register, else into another register. */
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/* Number of pseudo-registers still requiring allocation
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(not allocated by local_allocate). */
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static int max_allocno;
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/* Indexed by (pseudo) reg number, gives the allocno, or -1
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for pseudo registers already allocated by local_allocate. */
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static int *reg_allocno;
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/* Indexed by allocno, gives the reg number. */
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static int *allocno_reg;
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/* A vector of the integers from 0 to max_allocno-1,
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sorted in the order of first-to-be-allocated first. */
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static int *allocno_order;
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/* Indexed by an allocno, gives the number of consecutive
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hard registers needed by that pseudo reg. */
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static int *allocno_size;
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/* Indexed by (pseudo) reg number, gives the number of another
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lower-numbered pseudo reg which can share a hard reg with this pseudo
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*even if the two pseudos would otherwise appear to conflict*. */
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static int *reg_may_share;
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/* Define the number of bits in each element of `conflicts' and what
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type that element has. We use the largest integer format on the
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host machine. */
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#define INT_BITS HOST_BITS_PER_WIDE_INT
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#define INT_TYPE HOST_WIDE_INT
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/* max_allocno by max_allocno array of bits,
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recording whether two allocno's conflict (can't go in the same
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hardware register).
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`conflicts' is not symmetric; a conflict between allocno's i and j
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is recorded either in element i,j or in element j,i. */
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static INT_TYPE *conflicts;
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/* Number of ints require to hold max_allocno bits.
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This is the length of a row in `conflicts'. */
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static int allocno_row_words;
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/* Two macros to test or store 1 in an element of `conflicts'. */
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#define CONFLICTP(I, J) \
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(conflicts[(I) * allocno_row_words + (J) / INT_BITS] \
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& ((INT_TYPE) 1 << ((J) % INT_BITS)))
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#define SET_CONFLICT(I, J) \
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(conflicts[(I) * allocno_row_words + (J) / INT_BITS] \
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|= ((INT_TYPE) 1 << ((J) % INT_BITS)))
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/* Set of hard regs currently live (during scan of all insns). */
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static HARD_REG_SET hard_regs_live;
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/* Indexed by N, set of hard regs conflicting with allocno N. */
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static HARD_REG_SET *hard_reg_conflicts;
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/* Indexed by N, set of hard regs preferred by allocno N.
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This is used to make allocnos go into regs that are copied to or from them,
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when possible, to reduce register shuffling. */
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static HARD_REG_SET *hard_reg_preferences;
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/* Similar, but just counts register preferences made in simple copy
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operations, rather than arithmetic. These are given priority because
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we can always eliminate an insn by using these, but using a register
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in the above list won't always eliminate an insn. */
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static HARD_REG_SET *hard_reg_copy_preferences;
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/* Similar to hard_reg_preferences, but includes bits for subsequent
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registers when an allocno is multi-word. The above variable is used for
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allocation while this is used to build reg_someone_prefers, below. */
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static HARD_REG_SET *hard_reg_full_preferences;
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/* Indexed by N, set of hard registers that some later allocno has a
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preference for. */
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static HARD_REG_SET *regs_someone_prefers;
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/* Set of registers that global-alloc isn't supposed to use. */
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static HARD_REG_SET no_global_alloc_regs;
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/* Set of registers used so far. */
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static HARD_REG_SET regs_used_so_far;
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/* Number of calls crossed by each allocno. */
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static int *allocno_calls_crossed;
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/* Number of refs (weighted) to each allocno. */
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static int *allocno_n_refs;
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/* Guess at live length of each allocno.
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This is actually the max of the live lengths of the regs. */
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static int *allocno_live_length;
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/* Number of refs (weighted) to each hard reg, as used by local alloc.
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It is zero for a reg that contains global pseudos or is explicitly used. */
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static int local_reg_n_refs[FIRST_PSEUDO_REGISTER];
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/* Guess at live length of each hard reg, as used by local alloc.
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This is actually the sum of the live lengths of the specific regs. */
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static int local_reg_live_length[FIRST_PSEUDO_REGISTER];
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/* Test a bit in TABLE, a vector of HARD_REG_SETs,
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for vector element I, and hard register number J. */
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#define REGBITP(TABLE, I, J) TEST_HARD_REG_BIT (TABLE[I], J)
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/* Set to 1 a bit in a vector of HARD_REG_SETs. Works like REGBITP. */
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#define SET_REGBIT(TABLE, I, J) SET_HARD_REG_BIT (TABLE[I], J)
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/* Bit mask for allocnos live at current point in the scan. */
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static INT_TYPE *allocnos_live;
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/* Test, set or clear bit number I in allocnos_live,
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a bit vector indexed by allocno. */
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#define ALLOCNO_LIVE_P(I) \
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(allocnos_live[(I) / INT_BITS] & ((INT_TYPE) 1 << ((I) % INT_BITS)))
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#define SET_ALLOCNO_LIVE(I) \
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(allocnos_live[(I) / INT_BITS] |= ((INT_TYPE) 1 << ((I) % INT_BITS)))
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#define CLEAR_ALLOCNO_LIVE(I) \
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(allocnos_live[(I) / INT_BITS] &= ~((INT_TYPE) 1 << ((I) % INT_BITS)))
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/* This is turned off because it doesn't work right for DImode.
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(And it is only used for DImode, so the other cases are worthless.)
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The problem is that it isn't true that there is NO possibility of conflict;
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only that there is no conflict if the two pseudos get the exact same regs.
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If they were allocated with a partial overlap, there would be a conflict.
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We can't safely turn off the conflict unless we have another way to
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prevent the partial overlap.
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Idea: change hard_reg_conflicts so that instead of recording which
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hard regs the allocno may not overlap, it records where the allocno
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may not start. Change both where it is used and where it is updated.
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Then there is a way to record that (reg:DI 108) may start at 10
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but not at 9 or 11. There is still the question of how to record
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this semi-conflict between two pseudos. */
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#if 0
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/* Reg pairs for which conflict after the current insn
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is inhibited by a REG_NO_CONFLICT note.
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If the table gets full, we ignore any other notes--that is conservative. */
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#define NUM_NO_CONFLICT_PAIRS 4
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/* Number of pairs in use in this insn. */
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int n_no_conflict_pairs;
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static struct { int allocno1, allocno2;}
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no_conflict_pairs[NUM_NO_CONFLICT_PAIRS];
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#endif /* 0 */
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/* Record all regs that are set in any one insn.
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Communication from mark_reg_{store,clobber} and global_conflicts. */
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static rtx *regs_set;
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static int n_regs_set;
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/* All register that can be eliminated. */
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static HARD_REG_SET eliminable_regset;
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static int allocno_compare ();
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static void mark_reg_store ();
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static void mark_reg_clobber ();
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static void mark_reg_conflicts ();
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static void mark_reg_live_nc ();
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static void mark_reg_death ();
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static void dump_conflicts ();
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void dump_global_regs ();
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static void find_reg ();
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static void global_conflicts ();
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static void expand_preferences ();
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static void prune_preferences ();
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static void record_conflicts ();
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static void set_preference ();
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/* Perform allocation of pseudo-registers not allocated by local_alloc.
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FILE is a file to output debugging information on,
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or zero if such output is not desired.
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Return value is nonzero if reload failed
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and we must not do any more for this function. */
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int
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global_alloc (file)
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FILE *file;
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{
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#ifdef ELIMINABLE_REGS
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static struct {int from, to; } eliminables[] = ELIMINABLE_REGS;
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#endif
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register int i;
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rtx x;
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max_allocno = 0;
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/* A machine may have certain hard registers that
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are safe to use only within a basic block. */
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CLEAR_HARD_REG_SET (no_global_alloc_regs);
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#ifdef OVERLAPPING_REGNO_P
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for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
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if (OVERLAPPING_REGNO_P (i))
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SET_HARD_REG_BIT (no_global_alloc_regs, i);
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#endif
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/* Build the regset of all eliminable registers and show we can't use those
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that we already know won't be eliminated. */
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#ifdef ELIMINABLE_REGS
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for (i = 0; i < sizeof eliminables / sizeof eliminables[0]; i++)
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{
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SET_HARD_REG_BIT (eliminable_regset, eliminables[i].from);
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if (! CAN_ELIMINATE (eliminables[i].from, eliminables[i].to)
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|| (eliminables[i].from == FRAME_POINTER_REGNUM
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&& (! flag_omit_frame_pointer || FRAME_POINTER_REQUIRED)))
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SET_HARD_REG_BIT (no_global_alloc_regs, eliminables[i].from);
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}
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#else
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SET_HARD_REG_BIT (eliminable_regset, FRAME_POINTER_REGNUM);
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/* If we know we will definitely not be eliminating the frame pointer,
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don't allocate it. */
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if (! flag_omit_frame_pointer || FRAME_POINTER_REQUIRED)
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SET_HARD_REG_BIT (no_global_alloc_regs, FRAME_POINTER_REGNUM);
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#endif
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/* Track which registers have already been used. Start with registers
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explicitly in the rtl, then registers allocated by local register
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allocation. */
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CLEAR_HARD_REG_SET (regs_used_so_far);
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#ifdef LEAF_REGISTERS
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/* If we are doing the leaf function optimization, and this is a leaf
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function, it means that the registers that take work to save are those
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that need a register window. So prefer the ones that can be used in
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a leaf function. */
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{
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char *cheap_regs;
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static char leaf_regs[] = LEAF_REGISTERS;
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if (only_leaf_regs_used () && leaf_function_p ())
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cheap_regs = leaf_regs;
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else
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cheap_regs = call_used_regs;
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for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
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if (regs_ever_live[i] || cheap_regs[i])
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SET_HARD_REG_BIT (regs_used_so_far, i);
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}
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#else
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/* We consider registers that do not have to be saved over calls as if
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they were already used since there is no cost in using them. */
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for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
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if (regs_ever_live[i] || call_used_regs[i])
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SET_HARD_REG_BIT (regs_used_so_far, i);
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#endif
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for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
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if (reg_renumber[i] >= 0)
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SET_HARD_REG_BIT (regs_used_so_far, reg_renumber[i]);
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/* Establish mappings from register number to allocation number
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and vice versa. In the process, count the allocnos. */
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reg_allocno = (int *) alloca (max_regno * sizeof (int));
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for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
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reg_allocno[i] = -1;
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/* Initialize the shared-hard-reg mapping
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from the list of pairs that may share. */
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reg_may_share = (int *) alloca (max_regno * sizeof (int));
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bzero (reg_may_share, max_regno * sizeof (int));
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for (x = regs_may_share; x; x = XEXP (XEXP (x, 1), 1))
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{
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int r1 = REGNO (XEXP (x, 0));
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int r2 = REGNO (XEXP (XEXP (x, 1), 0));
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if (r1 > r2)
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reg_may_share[r1] = r2;
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else
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reg_may_share[r2] = r1;
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}
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for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
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/* Note that reg_live_length[i] < 0 indicates a "constant" reg
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that we are supposed to refrain from putting in a hard reg.
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-2 means do make an allocno but don't allocate it. */
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if (reg_n_refs[i] != 0 && reg_renumber[i] < 0 && reg_live_length[i] != -1
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/* Don't allocate pseudos that cross calls,
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if this function receives a nonlocal goto. */
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&& (! current_function_has_nonlocal_label
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|| reg_n_calls_crossed[i] == 0))
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{
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if (reg_may_share[i] && reg_allocno[reg_may_share[i]] >= 0)
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reg_allocno[i] = reg_allocno[reg_may_share[i]];
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else
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reg_allocno[i] = max_allocno++;
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if (reg_live_length[i] == 0)
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abort ();
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}
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else
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reg_allocno[i] = -1;
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allocno_reg = (int *) alloca (max_allocno * sizeof (int));
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allocno_size = (int *) alloca (max_allocno * sizeof (int));
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allocno_calls_crossed = (int *) alloca (max_allocno * sizeof (int));
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allocno_n_refs = (int *) alloca (max_allocno * sizeof (int));
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allocno_live_length = (int *) alloca (max_allocno * sizeof (int));
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bzero (allocno_size, max_allocno * sizeof (int));
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bzero (allocno_calls_crossed, max_allocno * sizeof (int));
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bzero (allocno_n_refs, max_allocno * sizeof (int));
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bzero (allocno_live_length, max_allocno * sizeof (int));
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for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
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if (reg_allocno[i] >= 0)
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{
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int allocno = reg_allocno[i];
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allocno_reg[allocno] = i;
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allocno_size[allocno] = PSEUDO_REGNO_SIZE (i);
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allocno_calls_crossed[allocno] += reg_n_calls_crossed[i];
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allocno_n_refs[allocno] += reg_n_refs[i];
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if (allocno_live_length[allocno] < reg_live_length[i])
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allocno_live_length[allocno] = reg_live_length[i];
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}
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/* Calculate amount of usage of each hard reg by pseudos
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allocated by local-alloc. This is to see if we want to
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override it. */
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bzero (local_reg_live_length, sizeof local_reg_live_length);
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bzero (local_reg_n_refs, sizeof local_reg_n_refs);
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for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
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if (reg_allocno[i] < 0 && reg_renumber[i] >= 0)
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{
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int regno = reg_renumber[i];
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int endregno = regno + HARD_REGNO_NREGS (regno, PSEUDO_REGNO_MODE (i));
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int j;
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for (j = regno; j < endregno; j++)
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{
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local_reg_n_refs[j] += reg_n_refs[i];
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local_reg_live_length[j] += reg_live_length[i];
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}
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}
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/* We can't override local-alloc for a reg used not just by local-alloc. */
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for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
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if (regs_ever_live[i])
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local_reg_n_refs[i] = 0;
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/* Allocate the space for the conflict and preference tables and
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initialize them. */
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hard_reg_conflicts
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= (HARD_REG_SET *) alloca (max_allocno * sizeof (HARD_REG_SET));
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bzero (hard_reg_conflicts, max_allocno * sizeof (HARD_REG_SET));
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hard_reg_preferences
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= (HARD_REG_SET *) alloca (max_allocno * sizeof (HARD_REG_SET));
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bzero (hard_reg_preferences, max_allocno * sizeof (HARD_REG_SET));
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hard_reg_copy_preferences
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= (HARD_REG_SET *) alloca (max_allocno * sizeof (HARD_REG_SET));
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bzero (hard_reg_copy_preferences, max_allocno * sizeof (HARD_REG_SET));
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hard_reg_full_preferences
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= (HARD_REG_SET *) alloca (max_allocno * sizeof (HARD_REG_SET));
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bzero (hard_reg_full_preferences, max_allocno * sizeof (HARD_REG_SET));
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regs_someone_prefers
|
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= (HARD_REG_SET *) alloca (max_allocno * sizeof (HARD_REG_SET));
|
||
bzero (regs_someone_prefers, max_allocno * sizeof (HARD_REG_SET));
|
||
|
||
allocno_row_words = (max_allocno + INT_BITS - 1) / INT_BITS;
|
||
|
||
conflicts = (INT_TYPE *) alloca (max_allocno * allocno_row_words
|
||
* sizeof (INT_TYPE));
|
||
bzero (conflicts, max_allocno * allocno_row_words
|
||
* sizeof (INT_TYPE));
|
||
|
||
allocnos_live = (INT_TYPE *) alloca (allocno_row_words * sizeof (INT_TYPE));
|
||
|
||
/* If there is work to be done (at least one reg to allocate),
|
||
perform global conflict analysis and allocate the regs. */
|
||
|
||
if (max_allocno > 0)
|
||
{
|
||
/* Scan all the insns and compute the conflicts among allocnos
|
||
and between allocnos and hard regs. */
|
||
|
||
global_conflicts ();
|
||
|
||
/* Eliminate conflicts between pseudos and eliminable registers. If
|
||
the register is not eliminated, the pseudo won't really be able to
|
||
live in the eliminable register, so the conflict doesn't matter.
|
||
If we do eliminate the register, the conflict will no longer exist.
|
||
So in either case, we can ignore the conflict. Likewise for
|
||
preferences. */
|
||
|
||
for (i = 0; i < max_allocno; i++)
|
||
{
|
||
AND_COMPL_HARD_REG_SET (hard_reg_conflicts[i], eliminable_regset);
|
||
AND_COMPL_HARD_REG_SET (hard_reg_copy_preferences[i],
|
||
eliminable_regset);
|
||
AND_COMPL_HARD_REG_SET (hard_reg_preferences[i], eliminable_regset);
|
||
}
|
||
|
||
/* Try to expand the preferences by merging them between allocnos. */
|
||
|
||
expand_preferences ();
|
||
|
||
/* Determine the order to allocate the remaining pseudo registers. */
|
||
|
||
allocno_order = (int *) alloca (max_allocno * sizeof (int));
|
||
for (i = 0; i < max_allocno; i++)
|
||
allocno_order[i] = i;
|
||
|
||
/* Default the size to 1, since allocno_compare uses it to divide by.
|
||
Also convert allocno_live_length of zero to -1. A length of zero
|
||
can occur when all the registers for that allocno have reg_live_length
|
||
equal to -2. In this case, we want to make an allocno, but not
|
||
allocate it. So avoid the divide-by-zero and set it to a low
|
||
priority. */
|
||
|
||
for (i = 0; i < max_allocno; i++)
|
||
{
|
||
if (allocno_size[i] == 0)
|
||
allocno_size[i] = 1;
|
||
if (allocno_live_length[i] == 0)
|
||
allocno_live_length[i] = -1;
|
||
}
|
||
|
||
qsort (allocno_order, max_allocno, sizeof (int), allocno_compare);
|
||
|
||
prune_preferences ();
|
||
|
||
if (file)
|
||
dump_conflicts (file);
|
||
|
||
/* Try allocating them, one by one, in that order,
|
||
except for parameters marked with reg_live_length[regno] == -2. */
|
||
|
||
for (i = 0; i < max_allocno; i++)
|
||
if (reg_live_length[allocno_reg[allocno_order[i]]] >= 0)
|
||
{
|
||
/* If we have more than one register class,
|
||
first try allocating in the class that is cheapest
|
||
for this pseudo-reg. If that fails, try any reg. */
|
||
if (N_REG_CLASSES > 1)
|
||
{
|
||
find_reg (allocno_order[i], HARD_CONST (0), 0, 0, 0);
|
||
if (reg_renumber[allocno_reg[allocno_order[i]]] >= 0)
|
||
continue;
|
||
}
|
||
if (reg_alternate_class (allocno_reg[allocno_order[i]]) != NO_REGS)
|
||
find_reg (allocno_order[i], HARD_CONST (0), 1, 0, 0);
|
||
}
|
||
}
|
||
|
||
/* Do the reloads now while the allocno data still exist, so that we can
|
||
try to assign new hard regs to any pseudo regs that are spilled. */
|
||
|
||
#if 0 /* We need to eliminate regs even if there is no rtl code,
|
||
for the sake of debugging information. */
|
||
if (n_basic_blocks > 0)
|
||
#endif
|
||
return reload (get_insns (), 1, file);
|
||
}
|
||
|
||
/* Sort predicate for ordering the allocnos.
|
||
Returns -1 (1) if *v1 should be allocated before (after) *v2. */
|
||
|
||
static int
|
||
allocno_compare (v1, v2)
|
||
int *v1, *v2;
|
||
{
|
||
/* Note that the quotient will never be bigger than
|
||
the value of floor_log2 times the maximum number of
|
||
times a register can occur in one insn (surely less than 100).
|
||
Multiplying this by 10000 can't overflow. */
|
||
register int pri1
|
||
= (((double) (floor_log2 (allocno_n_refs[*v1]) * allocno_n_refs[*v1])
|
||
/ (allocno_live_length[*v1] * allocno_size[*v1]))
|
||
* 10000);
|
||
register int pri2
|
||
= (((double) (floor_log2 (allocno_n_refs[*v2]) * allocno_n_refs[*v2])
|
||
/ (allocno_live_length[*v2] * allocno_size[*v2]))
|
||
* 10000);
|
||
if (pri2 - pri1)
|
||
return pri2 - pri1;
|
||
|
||
/* If regs are equally good, sort by allocno,
|
||
so that the results of qsort leave nothing to chance. */
|
||
return *v1 - *v2;
|
||
}
|
||
|
||
/* Scan the rtl code and record all conflicts and register preferences in the
|
||
conflict matrices and preference tables. */
|
||
|
||
static void
|
||
global_conflicts ()
|
||
{
|
||
register int b, i;
|
||
register rtx insn;
|
||
short *block_start_allocnos;
|
||
|
||
/* Make a vector that mark_reg_{store,clobber} will store in. */
|
||
regs_set = (rtx *) alloca (max_parallel * sizeof (rtx) * 2);
|
||
|
||
block_start_allocnos = (short *) alloca (max_allocno * sizeof (short));
|
||
|
||
for (b = 0; b < n_basic_blocks; b++)
|
||
{
|
||
bzero (allocnos_live, allocno_row_words * sizeof (INT_TYPE));
|
||
|
||
/* Initialize table of registers currently live
|
||
to the state at the beginning of this basic block.
|
||
This also marks the conflicts among them.
|
||
|
||
For pseudo-regs, there is only one bit for each one
|
||
no matter how many hard regs it occupies.
|
||
This is ok; we know the size from PSEUDO_REGNO_SIZE.
|
||
For explicit hard regs, we cannot know the size that way
|
||
since one hard reg can be used with various sizes.
|
||
Therefore, we must require that all the hard regs
|
||
implicitly live as part of a multi-word hard reg
|
||
are explicitly marked in basic_block_live_at_start. */
|
||
|
||
{
|
||
register int offset;
|
||
REGSET_ELT_TYPE bit;
|
||
register regset old = basic_block_live_at_start[b];
|
||
int ax = 0;
|
||
|
||
#ifdef HARD_REG_SET
|
||
hard_regs_live = old[0];
|
||
#else
|
||
COPY_HARD_REG_SET (hard_regs_live, old);
|
||
#endif
|
||
for (offset = 0, i = 0; offset < regset_size; offset++)
|
||
if (old[offset] == 0)
|
||
i += REGSET_ELT_BITS;
|
||
else
|
||
for (bit = 1; bit; bit <<= 1, i++)
|
||
{
|
||
if (i >= max_regno)
|
||
break;
|
||
if (old[offset] & bit)
|
||
{
|
||
register int a = reg_allocno[i];
|
||
if (a >= 0)
|
||
{
|
||
SET_ALLOCNO_LIVE (a);
|
||
block_start_allocnos[ax++] = a;
|
||
}
|
||
else if ((a = reg_renumber[i]) >= 0)
|
||
mark_reg_live_nc (a, PSEUDO_REGNO_MODE (i));
|
||
}
|
||
}
|
||
|
||
/* Record that each allocno now live conflicts with each other
|
||
allocno now live, and with each hard reg now live. */
|
||
|
||
record_conflicts (block_start_allocnos, ax);
|
||
}
|
||
|
||
insn = basic_block_head[b];
|
||
|
||
/* Scan the code of this basic block, noting which allocnos
|
||
and hard regs are born or die. When one is born,
|
||
record a conflict with all others currently live. */
|
||
|
||
while (1)
|
||
{
|
||
register RTX_CODE code = GET_CODE (insn);
|
||
register rtx link;
|
||
|
||
/* Make regs_set an empty set. */
|
||
|
||
n_regs_set = 0;
|
||
|
||
if (code == INSN || code == CALL_INSN || code == JUMP_INSN)
|
||
{
|
||
int i = 0;
|
||
|
||
#if 0
|
||
for (link = REG_NOTES (insn);
|
||
link && i < NUM_NO_CONFLICT_PAIRS;
|
||
link = XEXP (link, 1))
|
||
if (REG_NOTE_KIND (link) == REG_NO_CONFLICT)
|
||
{
|
||
no_conflict_pairs[i].allocno1
|
||
= reg_allocno[REGNO (SET_DEST (PATTERN (insn)))];
|
||
no_conflict_pairs[i].allocno2
|
||
= reg_allocno[REGNO (XEXP (link, 0))];
|
||
i++;
|
||
}
|
||
#endif /* 0 */
|
||
|
||
/* Mark any registers clobbered by INSN as live,
|
||
so they conflict with the inputs. */
|
||
|
||
note_stores (PATTERN (insn), mark_reg_clobber);
|
||
|
||
/* Mark any registers dead after INSN as dead now. */
|
||
|
||
for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
|
||
if (REG_NOTE_KIND (link) == REG_DEAD)
|
||
mark_reg_death (XEXP (link, 0));
|
||
|
||
/* Mark any registers set in INSN as live,
|
||
and mark them as conflicting with all other live regs.
|
||
Clobbers are processed again, so they conflict with
|
||
the registers that are set. */
|
||
|
||
note_stores (PATTERN (insn), mark_reg_store);
|
||
|
||
#ifdef AUTO_INC_DEC
|
||
for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
|
||
if (REG_NOTE_KIND (link) == REG_INC)
|
||
mark_reg_store (XEXP (link, 0), NULL_RTX);
|
||
#endif
|
||
|
||
/* If INSN has multiple outputs, then any reg that dies here
|
||
and is used inside of an output
|
||
must conflict with the other outputs. */
|
||
|
||
if (GET_CODE (PATTERN (insn)) == PARALLEL && !single_set (insn))
|
||
for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
|
||
if (REG_NOTE_KIND (link) == REG_DEAD)
|
||
{
|
||
int used_in_output = 0;
|
||
int i;
|
||
rtx reg = XEXP (link, 0);
|
||
|
||
for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
|
||
{
|
||
rtx set = XVECEXP (PATTERN (insn), 0, i);
|
||
if (GET_CODE (set) == SET
|
||
&& GET_CODE (SET_DEST (set)) != REG
|
||
&& !rtx_equal_p (reg, SET_DEST (set))
|
||
&& reg_overlap_mentioned_p (reg, SET_DEST (set)))
|
||
used_in_output = 1;
|
||
}
|
||
if (used_in_output)
|
||
mark_reg_conflicts (reg);
|
||
}
|
||
|
||
/* Mark any registers set in INSN and then never used. */
|
||
|
||
while (n_regs_set > 0)
|
||
if (find_regno_note (insn, REG_UNUSED,
|
||
REGNO (regs_set[--n_regs_set])))
|
||
mark_reg_death (regs_set[n_regs_set]);
|
||
}
|
||
|
||
if (insn == basic_block_end[b])
|
||
break;
|
||
insn = NEXT_INSN (insn);
|
||
}
|
||
}
|
||
}
|
||
/* Expand the preference information by looking for cases where one allocno
|
||
dies in an insn that sets an allocno. If those two allocnos don't conflict,
|
||
merge any preferences between those allocnos. */
|
||
|
||
static void
|
||
expand_preferences ()
|
||
{
|
||
rtx insn;
|
||
rtx link;
|
||
rtx set;
|
||
|
||
/* We only try to handle the most common cases here. Most of the cases
|
||
where this wins are reg-reg copies. */
|
||
|
||
for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
|
||
if (GET_RTX_CLASS (GET_CODE (insn)) == 'i'
|
||
&& (set = single_set (insn)) != 0
|
||
&& GET_CODE (SET_DEST (set)) == REG
|
||
&& reg_allocno[REGNO (SET_DEST (set))] >= 0)
|
||
for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
|
||
if (REG_NOTE_KIND (link) == REG_DEAD
|
||
&& GET_CODE (XEXP (link, 0)) == REG
|
||
&& reg_allocno[REGNO (XEXP (link, 0))] >= 0
|
||
&& ! CONFLICTP (reg_allocno[REGNO (SET_DEST (set))],
|
||
reg_allocno[REGNO (XEXP (link, 0))])
|
||
&& ! CONFLICTP (reg_allocno[REGNO (XEXP (link, 0))],
|
||
reg_allocno[REGNO (SET_DEST (set))]))
|
||
{
|
||
int a1 = reg_allocno[REGNO (SET_DEST (set))];
|
||
int a2 = reg_allocno[REGNO (XEXP (link, 0))];
|
||
|
||
if (XEXP (link, 0) == SET_SRC (set))
|
||
{
|
||
IOR_HARD_REG_SET (hard_reg_copy_preferences[a1],
|
||
hard_reg_copy_preferences[a2]);
|
||
IOR_HARD_REG_SET (hard_reg_copy_preferences[a2],
|
||
hard_reg_copy_preferences[a1]);
|
||
}
|
||
|
||
IOR_HARD_REG_SET (hard_reg_preferences[a1],
|
||
hard_reg_preferences[a2]);
|
||
IOR_HARD_REG_SET (hard_reg_preferences[a2],
|
||
hard_reg_preferences[a1]);
|
||
IOR_HARD_REG_SET (hard_reg_full_preferences[a1],
|
||
hard_reg_full_preferences[a2]);
|
||
IOR_HARD_REG_SET (hard_reg_full_preferences[a2],
|
||
hard_reg_full_preferences[a1]);
|
||
}
|
||
}
|
||
|
||
/* Prune the preferences for global registers to exclude registers that cannot
|
||
be used.
|
||
|
||
Compute `regs_someone_prefers', which is a bitmask of the hard registers
|
||
that are preferred by conflicting registers of lower priority. If possible,
|
||
we will avoid using these registers. */
|
||
|
||
static void
|
||
prune_preferences ()
|
||
{
|
||
int i, j;
|
||
int allocno;
|
||
|
||
/* Scan least most important to most important.
|
||
For each allocno, remove from preferences registers that cannot be used,
|
||
either because of conflicts or register type. Then compute all registers
|
||
preferred by each lower-priority register that conflicts. */
|
||
|
||
for (i = max_allocno - 1; i >= 0; i--)
|
||
{
|
||
HARD_REG_SET temp;
|
||
|
||
allocno = allocno_order[i];
|
||
COPY_HARD_REG_SET (temp, hard_reg_conflicts[allocno]);
|
||
|
||
if (allocno_calls_crossed[allocno] == 0)
|
||
IOR_HARD_REG_SET (temp, fixed_reg_set);
|
||
else
|
||
IOR_HARD_REG_SET (temp, call_used_reg_set);
|
||
|
||
IOR_COMPL_HARD_REG_SET
|
||
(temp,
|
||
reg_class_contents[(int) reg_preferred_class (allocno_reg[allocno])]);
|
||
|
||
AND_COMPL_HARD_REG_SET (hard_reg_preferences[allocno], temp);
|
||
AND_COMPL_HARD_REG_SET (hard_reg_copy_preferences[allocno], temp);
|
||
AND_COMPL_HARD_REG_SET (hard_reg_full_preferences[allocno], temp);
|
||
|
||
CLEAR_HARD_REG_SET (regs_someone_prefers[allocno]);
|
||
|
||
/* Merge in the preferences of lower-priority registers (they have
|
||
already been pruned). If we also prefer some of those registers,
|
||
don't exclude them unless we are of a smaller size (in which case
|
||
we want to give the lower-priority allocno the first chance for
|
||
these registers). */
|
||
for (j = i + 1; j < max_allocno; j++)
|
||
if (CONFLICTP (allocno, allocno_order[j]))
|
||
{
|
||
COPY_HARD_REG_SET (temp,
|
||
hard_reg_full_preferences[allocno_order[j]]);
|
||
if (allocno_size[allocno_order[j]] <= allocno_size[allocno])
|
||
AND_COMPL_HARD_REG_SET (temp,
|
||
hard_reg_full_preferences[allocno]);
|
||
|
||
IOR_HARD_REG_SET (regs_someone_prefers[allocno], temp);
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Assign a hard register to ALLOCNO; look for one that is the beginning
|
||
of a long enough stretch of hard regs none of which conflicts with ALLOCNO.
|
||
The registers marked in PREFREGS are tried first.
|
||
|
||
LOSERS, if non-zero, is a HARD_REG_SET indicating registers that cannot
|
||
be used for this allocation.
|
||
|
||
If ALT_REGS_P is zero, consider only the preferred class of ALLOCNO's reg.
|
||
Otherwise ignore that preferred class and use the alternate class.
|
||
|
||
If ACCEPT_CALL_CLOBBERED is nonzero, accept a call-clobbered hard reg that
|
||
will have to be saved and restored at calls.
|
||
|
||
RETRYING is nonzero if this is called from retry_global_alloc.
|
||
|
||
If we find one, record it in reg_renumber.
|
||
If not, do nothing. */
|
||
|
||
static void
|
||
find_reg (allocno, losers, alt_regs_p, accept_call_clobbered, retrying)
|
||
int allocno;
|
||
HARD_REG_SET losers;
|
||
int alt_regs_p;
|
||
int accept_call_clobbered;
|
||
int retrying;
|
||
{
|
||
register int i, best_reg, pass;
|
||
#ifdef HARD_REG_SET
|
||
register /* Declare it register if it's a scalar. */
|
||
#endif
|
||
HARD_REG_SET used, used1, used2;
|
||
|
||
enum reg_class class = (alt_regs_p
|
||
? reg_alternate_class (allocno_reg[allocno])
|
||
: reg_preferred_class (allocno_reg[allocno]));
|
||
enum machine_mode mode = PSEUDO_REGNO_MODE (allocno_reg[allocno]);
|
||
|
||
if (accept_call_clobbered)
|
||
COPY_HARD_REG_SET (used1, call_fixed_reg_set);
|
||
else if (allocno_calls_crossed[allocno] == 0)
|
||
COPY_HARD_REG_SET (used1, fixed_reg_set);
|
||
else
|
||
COPY_HARD_REG_SET (used1, call_used_reg_set);
|
||
|
||
/* Some registers should not be allocated in global-alloc. */
|
||
IOR_HARD_REG_SET (used1, no_global_alloc_regs);
|
||
if (losers)
|
||
IOR_HARD_REG_SET (used1, losers);
|
||
|
||
IOR_COMPL_HARD_REG_SET (used1, reg_class_contents[(int) class]);
|
||
COPY_HARD_REG_SET (used2, used1);
|
||
|
||
IOR_HARD_REG_SET (used1, hard_reg_conflicts[allocno]);
|
||
|
||
/* Try each hard reg to see if it fits. Do this in two passes.
|
||
In the first pass, skip registers that are preferred by some other pseudo
|
||
to give it a better chance of getting one of those registers. Only if
|
||
we can't get a register when excluding those do we take one of them.
|
||
However, we never allocate a register for the first time in pass 0. */
|
||
|
||
COPY_HARD_REG_SET (used, used1);
|
||
IOR_COMPL_HARD_REG_SET (used, regs_used_so_far);
|
||
IOR_HARD_REG_SET (used, regs_someone_prefers[allocno]);
|
||
|
||
best_reg = -1;
|
||
for (i = FIRST_PSEUDO_REGISTER, pass = 0;
|
||
pass <= 1 && i >= FIRST_PSEUDO_REGISTER;
|
||
pass++)
|
||
{
|
||
if (pass == 1)
|
||
COPY_HARD_REG_SET (used, used1);
|
||
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
|
||
{
|
||
#ifdef REG_ALLOC_ORDER
|
||
int regno = reg_alloc_order[i];
|
||
#else
|
||
int regno = i;
|
||
#endif
|
||
if (! TEST_HARD_REG_BIT (used, regno)
|
||
&& HARD_REGNO_MODE_OK (regno, mode))
|
||
{
|
||
register int j;
|
||
register int lim = regno + HARD_REGNO_NREGS (regno, mode);
|
||
for (j = regno + 1;
|
||
(j < lim
|
||
&& ! TEST_HARD_REG_BIT (used, j));
|
||
j++);
|
||
if (j == lim)
|
||
{
|
||
best_reg = regno;
|
||
break;
|
||
}
|
||
#ifndef REG_ALLOC_ORDER
|
||
i = j; /* Skip starting points we know will lose */
|
||
#endif
|
||
}
|
||
}
|
||
}
|
||
|
||
/* See if there is a preferred register with the same class as the register
|
||
we allocated above. Making this restriction prevents register
|
||
preferencing from creating worse register allocation.
|
||
|
||
Remove from the preferred registers and conflicting registers. Note that
|
||
additional conflicts may have been added after `prune_preferences' was
|
||
called.
|
||
|
||
First do this for those register with copy preferences, then all
|
||
preferred registers. */
|
||
|
||
AND_COMPL_HARD_REG_SET (hard_reg_copy_preferences[allocno], used);
|
||
GO_IF_HARD_REG_SUBSET (hard_reg_copy_preferences[allocno],
|
||
reg_class_contents[(int) NO_REGS], no_copy_prefs);
|
||
|
||
if (best_reg >= 0)
|
||
{
|
||
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
|
||
if (TEST_HARD_REG_BIT (hard_reg_copy_preferences[allocno], i)
|
||
&& HARD_REGNO_MODE_OK (i, mode)
|
||
&& (REGNO_REG_CLASS (i) == REGNO_REG_CLASS (best_reg)
|
||
|| reg_class_subset_p (REGNO_REG_CLASS (i),
|
||
REGNO_REG_CLASS (best_reg))
|
||
|| reg_class_subset_p (REGNO_REG_CLASS (best_reg),
|
||
REGNO_REG_CLASS (i))))
|
||
{
|
||
register int j;
|
||
register int lim = i + HARD_REGNO_NREGS (i, mode);
|
||
for (j = i + 1;
|
||
(j < lim
|
||
&& ! TEST_HARD_REG_BIT (used, j)
|
||
&& (REGNO_REG_CLASS (j)
|
||
== REGNO_REG_CLASS (best_reg + (j - i))
|
||
|| reg_class_subset_p (REGNO_REG_CLASS (j),
|
||
REGNO_REG_CLASS (best_reg + (j - i)))
|
||
|| reg_class_subset_p (REGNO_REG_CLASS (best_reg + (j - i)),
|
||
REGNO_REG_CLASS (j))));
|
||
j++);
|
||
if (j == lim)
|
||
{
|
||
best_reg = i;
|
||
goto no_prefs;
|
||
}
|
||
}
|
||
}
|
||
no_copy_prefs:
|
||
|
||
AND_COMPL_HARD_REG_SET (hard_reg_preferences[allocno], used);
|
||
GO_IF_HARD_REG_SUBSET (hard_reg_preferences[allocno],
|
||
reg_class_contents[(int) NO_REGS], no_prefs);
|
||
|
||
if (best_reg >= 0)
|
||
{
|
||
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
|
||
if (TEST_HARD_REG_BIT (hard_reg_preferences[allocno], i)
|
||
&& HARD_REGNO_MODE_OK (i, mode)
|
||
&& (REGNO_REG_CLASS (i) == REGNO_REG_CLASS (best_reg)
|
||
|| reg_class_subset_p (REGNO_REG_CLASS (i),
|
||
REGNO_REG_CLASS (best_reg))
|
||
|| reg_class_subset_p (REGNO_REG_CLASS (best_reg),
|
||
REGNO_REG_CLASS (i))))
|
||
{
|
||
register int j;
|
||
register int lim = i + HARD_REGNO_NREGS (i, mode);
|
||
for (j = i + 1;
|
||
(j < lim
|
||
&& ! TEST_HARD_REG_BIT (used, j)
|
||
&& (REGNO_REG_CLASS (j)
|
||
== REGNO_REG_CLASS (best_reg + (j - i))
|
||
|| reg_class_subset_p (REGNO_REG_CLASS (j),
|
||
REGNO_REG_CLASS (best_reg + (j - i)))
|
||
|| reg_class_subset_p (REGNO_REG_CLASS (best_reg + (j - i)),
|
||
REGNO_REG_CLASS (j))));
|
||
j++);
|
||
if (j == lim)
|
||
{
|
||
best_reg = i;
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
no_prefs:
|
||
|
||
/* If we haven't succeeded yet, try with caller-saves.
|
||
We need not check to see if the current function has nonlocal
|
||
labels because we don't put any pseudos that are live over calls in
|
||
registers in that case. */
|
||
|
||
if (flag_caller_saves && best_reg < 0)
|
||
{
|
||
/* Did not find a register. If it would be profitable to
|
||
allocate a call-clobbered register and save and restore it
|
||
around calls, do that. */
|
||
if (! accept_call_clobbered
|
||
&& allocno_calls_crossed[allocno] != 0
|
||
&& CALLER_SAVE_PROFITABLE (allocno_n_refs[allocno],
|
||
allocno_calls_crossed[allocno]))
|
||
{
|
||
find_reg (allocno, losers, alt_regs_p, 1, retrying);
|
||
if (reg_renumber[allocno_reg[allocno]] >= 0)
|
||
{
|
||
caller_save_needed = 1;
|
||
return;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* If we haven't succeeded yet,
|
||
see if some hard reg that conflicts with us
|
||
was utilized poorly by local-alloc.
|
||
If so, kick out the regs that were put there by local-alloc
|
||
so we can use it instead. */
|
||
if (best_reg < 0 && !retrying
|
||
/* Let's not bother with multi-reg allocnos. */
|
||
&& allocno_size[allocno] == 1)
|
||
{
|
||
/* Count from the end, to find the least-used ones first. */
|
||
for (i = FIRST_PSEUDO_REGISTER - 1; i >= 0; i--)
|
||
if (local_reg_n_refs[i] != 0
|
||
/* Don't use a reg no good for this pseudo. */
|
||
&& ! TEST_HARD_REG_BIT (used2, i)
|
||
&& HARD_REGNO_MODE_OK (i, mode)
|
||
&& ((double) local_reg_n_refs[i] / local_reg_live_length[i]
|
||
< ((double) allocno_n_refs[allocno]
|
||
/ allocno_live_length[allocno])))
|
||
{
|
||
/* Hard reg I was used less in total by local regs
|
||
than it would be used by this one allocno! */
|
||
int k;
|
||
for (k = 0; k < max_regno; k++)
|
||
if (reg_renumber[k] >= 0)
|
||
{
|
||
int regno = reg_renumber[k];
|
||
int endregno
|
||
= regno + HARD_REGNO_NREGS (regno, PSEUDO_REGNO_MODE (k));
|
||
|
||
if (i >= regno && i < endregno)
|
||
reg_renumber[k] = -1;
|
||
}
|
||
|
||
best_reg = i;
|
||
break;
|
||
}
|
||
}
|
||
|
||
/* Did we find a register? */
|
||
|
||
if (best_reg >= 0)
|
||
{
|
||
register int lim, j;
|
||
HARD_REG_SET this_reg;
|
||
|
||
/* Yes. Record it as the hard register of this pseudo-reg. */
|
||
reg_renumber[allocno_reg[allocno]] = best_reg;
|
||
/* Also of any pseudo-regs that share with it. */
|
||
if (reg_may_share[allocno_reg[allocno]])
|
||
for (j = FIRST_PSEUDO_REGISTER; j < max_regno; j++)
|
||
if (reg_allocno[j] == allocno)
|
||
reg_renumber[j] = best_reg;
|
||
|
||
/* Make a set of the hard regs being allocated. */
|
||
CLEAR_HARD_REG_SET (this_reg);
|
||
lim = best_reg + HARD_REGNO_NREGS (best_reg, mode);
|
||
for (j = best_reg; j < lim; j++)
|
||
{
|
||
SET_HARD_REG_BIT (this_reg, j);
|
||
SET_HARD_REG_BIT (regs_used_so_far, j);
|
||
/* This is no longer a reg used just by local regs. */
|
||
local_reg_n_refs[j] = 0;
|
||
}
|
||
/* For each other pseudo-reg conflicting with this one,
|
||
mark it as conflicting with the hard regs this one occupies. */
|
||
lim = allocno;
|
||
for (j = 0; j < max_allocno; j++)
|
||
if (CONFLICTP (lim, j) || CONFLICTP (j, lim))
|
||
{
|
||
IOR_HARD_REG_SET (hard_reg_conflicts[j], this_reg);
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Called from `reload' to look for a hard reg to put pseudo reg REGNO in.
|
||
Perhaps it had previously seemed not worth a hard reg,
|
||
or perhaps its old hard reg has been commandeered for reloads.
|
||
FORBIDDEN_REGS indicates certain hard regs that may not be used, even if
|
||
they do not appear to be allocated.
|
||
If FORBIDDEN_REGS is zero, no regs are forbidden. */
|
||
|
||
void
|
||
retry_global_alloc (regno, forbidden_regs)
|
||
int regno;
|
||
HARD_REG_SET forbidden_regs;
|
||
{
|
||
int allocno = reg_allocno[regno];
|
||
if (allocno >= 0)
|
||
{
|
||
/* If we have more than one register class,
|
||
first try allocating in the class that is cheapest
|
||
for this pseudo-reg. If that fails, try any reg. */
|
||
if (N_REG_CLASSES > 1)
|
||
find_reg (allocno, forbidden_regs, 0, 0, 1);
|
||
if (reg_renumber[regno] < 0
|
||
&& reg_alternate_class (regno) != NO_REGS)
|
||
find_reg (allocno, forbidden_regs, 1, 0, 1);
|
||
|
||
/* If we found a register, modify the RTL for the register to
|
||
show the hard register, and mark that register live. */
|
||
if (reg_renumber[regno] >= 0)
|
||
{
|
||
REGNO (regno_reg_rtx[regno]) = reg_renumber[regno];
|
||
mark_home_live (regno);
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Record a conflict between register REGNO
|
||
and everything currently live.
|
||
REGNO must not be a pseudo reg that was allocated
|
||
by local_alloc; such numbers must be translated through
|
||
reg_renumber before calling here. */
|
||
|
||
static void
|
||
record_one_conflict (regno)
|
||
int regno;
|
||
{
|
||
register int j;
|
||
|
||
if (regno < FIRST_PSEUDO_REGISTER)
|
||
/* When a hard register becomes live,
|
||
record conflicts with live pseudo regs. */
|
||
for (j = 0; j < max_allocno; j++)
|
||
{
|
||
if (ALLOCNO_LIVE_P (j))
|
||
SET_HARD_REG_BIT (hard_reg_conflicts[j], regno);
|
||
}
|
||
else
|
||
/* When a pseudo-register becomes live,
|
||
record conflicts first with hard regs,
|
||
then with other pseudo regs. */
|
||
{
|
||
register int ialloc = reg_allocno[regno];
|
||
register int ialloc_prod = ialloc * allocno_row_words;
|
||
IOR_HARD_REG_SET (hard_reg_conflicts[ialloc], hard_regs_live);
|
||
for (j = allocno_row_words - 1; j >= 0; j--)
|
||
{
|
||
#if 0
|
||
int k;
|
||
for (k = 0; k < n_no_conflict_pairs; k++)
|
||
if (! ((j == no_conflict_pairs[k].allocno1
|
||
&& ialloc == no_conflict_pairs[k].allocno2)
|
||
||
|
||
(j == no_conflict_pairs[k].allocno2
|
||
&& ialloc == no_conflict_pairs[k].allocno1)))
|
||
#endif /* 0 */
|
||
conflicts[ialloc_prod + j] |= allocnos_live[j];
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Record all allocnos currently live as conflicting
|
||
with each other and with all hard regs currently live.
|
||
ALLOCNO_VEC is a vector of LEN allocnos, all allocnos that
|
||
are currently live. Their bits are also flagged in allocnos_live. */
|
||
|
||
static void
|
||
record_conflicts (allocno_vec, len)
|
||
register short *allocno_vec;
|
||
register int len;
|
||
{
|
||
register int allocno;
|
||
register int j;
|
||
register int ialloc_prod;
|
||
|
||
while (--len >= 0)
|
||
{
|
||
allocno = allocno_vec[len];
|
||
ialloc_prod = allocno * allocno_row_words;
|
||
IOR_HARD_REG_SET (hard_reg_conflicts[allocno], hard_regs_live);
|
||
for (j = allocno_row_words - 1; j >= 0; j--)
|
||
conflicts[ialloc_prod + j] |= allocnos_live[j];
|
||
}
|
||
}
|
||
|
||
/* Handle the case where REG is set by the insn being scanned,
|
||
during the forward scan to accumulate conflicts.
|
||
Store a 1 in regs_live or allocnos_live for this register, record how many
|
||
consecutive hardware registers it actually needs,
|
||
and record a conflict with all other registers already live.
|
||
|
||
Note that even if REG does not remain alive after this insn,
|
||
we must mark it here as live, to ensure a conflict between
|
||
REG and any other regs set in this insn that really do live.
|
||
This is because those other regs could be considered after this.
|
||
|
||
REG might actually be something other than a register;
|
||
if so, we do nothing.
|
||
|
||
SETTER is 0 if this register was modified by an auto-increment (i.e.,
|
||
a REG_INC note was found for it).
|
||
|
||
CLOBBERs are processed here by calling mark_reg_clobber. */
|
||
|
||
static void
|
||
mark_reg_store (orig_reg, setter)
|
||
rtx orig_reg, setter;
|
||
{
|
||
register int regno;
|
||
register rtx reg = orig_reg;
|
||
|
||
/* WORD is which word of a multi-register group is being stored.
|
||
For the case where the store is actually into a SUBREG of REG.
|
||
Except we don't use it; I believe the entire REG needs to be
|
||
made live. */
|
||
int word = 0;
|
||
|
||
if (GET_CODE (reg) == SUBREG)
|
||
{
|
||
word = SUBREG_WORD (reg);
|
||
reg = SUBREG_REG (reg);
|
||
}
|
||
|
||
if (GET_CODE (reg) != REG)
|
||
return;
|
||
|
||
if (setter && GET_CODE (setter) == CLOBBER)
|
||
{
|
||
/* A clobber of a register should be processed here too. */
|
||
mark_reg_clobber (orig_reg, setter);
|
||
return;
|
||
}
|
||
|
||
regs_set[n_regs_set++] = reg;
|
||
|
||
if (setter)
|
||
set_preference (reg, SET_SRC (setter));
|
||
|
||
regno = REGNO (reg);
|
||
|
||
if (reg_renumber[regno] >= 0)
|
||
regno = reg_renumber[regno] /* + word */;
|
||
|
||
/* Either this is one of the max_allocno pseudo regs not allocated,
|
||
or it is or has a hardware reg. First handle the pseudo-regs. */
|
||
if (regno >= FIRST_PSEUDO_REGISTER)
|
||
{
|
||
if (reg_allocno[regno] >= 0)
|
||
{
|
||
SET_ALLOCNO_LIVE (reg_allocno[regno]);
|
||
record_one_conflict (regno);
|
||
}
|
||
}
|
||
/* Handle hardware regs (and pseudos allocated to hard regs). */
|
||
else if (! fixed_regs[regno])
|
||
{
|
||
register int last = regno + HARD_REGNO_NREGS (regno, GET_MODE (reg));
|
||
while (regno < last)
|
||
{
|
||
record_one_conflict (regno);
|
||
SET_HARD_REG_BIT (hard_regs_live, regno);
|
||
regno++;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Like mark_reg_set except notice just CLOBBERs; ignore SETs. */
|
||
|
||
static void
|
||
mark_reg_clobber (reg, setter)
|
||
rtx reg, setter;
|
||
{
|
||
register int regno;
|
||
|
||
/* WORD is which word of a multi-register group is being stored.
|
||
For the case where the store is actually into a SUBREG of REG.
|
||
Except we don't use it; I believe the entire REG needs to be
|
||
made live. */
|
||
int word = 0;
|
||
|
||
if (GET_CODE (setter) != CLOBBER)
|
||
return;
|
||
|
||
if (GET_CODE (reg) == SUBREG)
|
||
{
|
||
word = SUBREG_WORD (reg);
|
||
reg = SUBREG_REG (reg);
|
||
}
|
||
|
||
if (GET_CODE (reg) != REG)
|
||
return;
|
||
|
||
regs_set[n_regs_set++] = reg;
|
||
|
||
regno = REGNO (reg);
|
||
|
||
if (reg_renumber[regno] >= 0)
|
||
regno = reg_renumber[regno] /* + word */;
|
||
|
||
/* Either this is one of the max_allocno pseudo regs not allocated,
|
||
or it is or has a hardware reg. First handle the pseudo-regs. */
|
||
if (regno >= FIRST_PSEUDO_REGISTER)
|
||
{
|
||
if (reg_allocno[regno] >= 0)
|
||
{
|
||
SET_ALLOCNO_LIVE (reg_allocno[regno]);
|
||
record_one_conflict (regno);
|
||
}
|
||
}
|
||
/* Handle hardware regs (and pseudos allocated to hard regs). */
|
||
else if (! fixed_regs[regno])
|
||
{
|
||
register int last = regno + HARD_REGNO_NREGS (regno, GET_MODE (reg));
|
||
while (regno < last)
|
||
{
|
||
record_one_conflict (regno);
|
||
SET_HARD_REG_BIT (hard_regs_live, regno);
|
||
regno++;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Record that REG has conflicts with all the regs currently live.
|
||
Do not mark REG itself as live. */
|
||
|
||
static void
|
||
mark_reg_conflicts (reg)
|
||
rtx reg;
|
||
{
|
||
register int regno;
|
||
|
||
if (GET_CODE (reg) == SUBREG)
|
||
reg = SUBREG_REG (reg);
|
||
|
||
if (GET_CODE (reg) != REG)
|
||
return;
|
||
|
||
regno = REGNO (reg);
|
||
|
||
if (reg_renumber[regno] >= 0)
|
||
regno = reg_renumber[regno];
|
||
|
||
/* Either this is one of the max_allocno pseudo regs not allocated,
|
||
or it is or has a hardware reg. First handle the pseudo-regs. */
|
||
if (regno >= FIRST_PSEUDO_REGISTER)
|
||
{
|
||
if (reg_allocno[regno] >= 0)
|
||
record_one_conflict (regno);
|
||
}
|
||
/* Handle hardware regs (and pseudos allocated to hard regs). */
|
||
else if (! fixed_regs[regno])
|
||
{
|
||
register int last = regno + HARD_REGNO_NREGS (regno, GET_MODE (reg));
|
||
while (regno < last)
|
||
{
|
||
record_one_conflict (regno);
|
||
regno++;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Mark REG as being dead (following the insn being scanned now).
|
||
Store a 0 in regs_live or allocnos_live for this register. */
|
||
|
||
static void
|
||
mark_reg_death (reg)
|
||
rtx reg;
|
||
{
|
||
register int regno = REGNO (reg);
|
||
|
||
/* For pseudo reg, see if it has been assigned a hardware reg. */
|
||
if (reg_renumber[regno] >= 0)
|
||
regno = reg_renumber[regno];
|
||
|
||
/* Either this is one of the max_allocno pseudo regs not allocated,
|
||
or it is a hardware reg. First handle the pseudo-regs. */
|
||
if (regno >= FIRST_PSEUDO_REGISTER)
|
||
{
|
||
if (reg_allocno[regno] >= 0)
|
||
CLEAR_ALLOCNO_LIVE (reg_allocno[regno]);
|
||
}
|
||
/* Handle hardware regs (and pseudos allocated to hard regs). */
|
||
else if (! fixed_regs[regno])
|
||
{
|
||
/* Pseudo regs already assigned hardware regs are treated
|
||
almost the same as explicit hardware regs. */
|
||
register int last = regno + HARD_REGNO_NREGS (regno, GET_MODE (reg));
|
||
while (regno < last)
|
||
{
|
||
CLEAR_HARD_REG_BIT (hard_regs_live, regno);
|
||
regno++;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Mark hard reg REGNO as currently live, assuming machine mode MODE
|
||
for the value stored in it. MODE determines how many consecutive
|
||
registers are actually in use. Do not record conflicts;
|
||
it is assumed that the caller will do that. */
|
||
|
||
static void
|
||
mark_reg_live_nc (regno, mode)
|
||
register int regno;
|
||
enum machine_mode mode;
|
||
{
|
||
register int last = regno + HARD_REGNO_NREGS (regno, mode);
|
||
while (regno < last)
|
||
{
|
||
SET_HARD_REG_BIT (hard_regs_live, regno);
|
||
regno++;
|
||
}
|
||
}
|
||
|
||
/* Try to set a preference for an allocno to a hard register.
|
||
We are passed DEST and SRC which are the operands of a SET. It is known
|
||
that SRC is a register. If SRC or the first operand of SRC is a register,
|
||
try to set a preference. If one of the two is a hard register and the other
|
||
is a pseudo-register, mark the preference.
|
||
|
||
Note that we are not as aggressive as local-alloc in trying to tie a
|
||
pseudo-register to a hard register. */
|
||
|
||
static void
|
||
set_preference (dest, src)
|
||
rtx dest, src;
|
||
{
|
||
int src_regno, dest_regno;
|
||
/* Amount to add to the hard regno for SRC, or subtract from that for DEST,
|
||
to compensate for subregs in SRC or DEST. */
|
||
int offset = 0;
|
||
int i;
|
||
int copy = 1;
|
||
|
||
if (GET_RTX_FORMAT (GET_CODE (src))[0] == 'e')
|
||
src = XEXP (src, 0), copy = 0;
|
||
|
||
/* Get the reg number for both SRC and DEST.
|
||
If neither is a reg, give up. */
|
||
|
||
if (GET_CODE (src) == REG)
|
||
src_regno = REGNO (src);
|
||
else if (GET_CODE (src) == SUBREG && GET_CODE (SUBREG_REG (src)) == REG)
|
||
{
|
||
src_regno = REGNO (SUBREG_REG (src));
|
||
offset += SUBREG_WORD (src);
|
||
}
|
||
else
|
||
return;
|
||
|
||
if (GET_CODE (dest) == REG)
|
||
dest_regno = REGNO (dest);
|
||
else if (GET_CODE (dest) == SUBREG && GET_CODE (SUBREG_REG (dest)) == REG)
|
||
{
|
||
dest_regno = REGNO (SUBREG_REG (dest));
|
||
offset -= SUBREG_WORD (dest);
|
||
}
|
||
else
|
||
return;
|
||
|
||
/* Convert either or both to hard reg numbers. */
|
||
|
||
if (reg_renumber[src_regno] >= 0)
|
||
src_regno = reg_renumber[src_regno];
|
||
|
||
if (reg_renumber[dest_regno] >= 0)
|
||
dest_regno = reg_renumber[dest_regno];
|
||
|
||
/* Now if one is a hard reg and the other is a global pseudo
|
||
then give the other a preference. */
|
||
|
||
if (dest_regno < FIRST_PSEUDO_REGISTER && src_regno >= FIRST_PSEUDO_REGISTER
|
||
&& reg_allocno[src_regno] >= 0)
|
||
{
|
||
dest_regno -= offset;
|
||
if (dest_regno >= 0 && dest_regno < FIRST_PSEUDO_REGISTER)
|
||
{
|
||
if (copy)
|
||
SET_REGBIT (hard_reg_copy_preferences,
|
||
reg_allocno[src_regno], dest_regno);
|
||
|
||
SET_REGBIT (hard_reg_preferences,
|
||
reg_allocno[src_regno], dest_regno);
|
||
for (i = dest_regno;
|
||
i < dest_regno + HARD_REGNO_NREGS (dest_regno, GET_MODE (dest));
|
||
i++)
|
||
SET_REGBIT (hard_reg_full_preferences, reg_allocno[src_regno], i);
|
||
}
|
||
}
|
||
|
||
if (src_regno < FIRST_PSEUDO_REGISTER && dest_regno >= FIRST_PSEUDO_REGISTER
|
||
&& reg_allocno[dest_regno] >= 0)
|
||
{
|
||
src_regno += offset;
|
||
if (src_regno >= 0 && src_regno < FIRST_PSEUDO_REGISTER)
|
||
{
|
||
if (copy)
|
||
SET_REGBIT (hard_reg_copy_preferences,
|
||
reg_allocno[dest_regno], src_regno);
|
||
|
||
SET_REGBIT (hard_reg_preferences,
|
||
reg_allocno[dest_regno], src_regno);
|
||
for (i = src_regno;
|
||
i < src_regno + HARD_REGNO_NREGS (src_regno, GET_MODE (src));
|
||
i++)
|
||
SET_REGBIT (hard_reg_full_preferences, reg_allocno[dest_regno], i);
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Indicate that hard register number FROM was eliminated and replaced with
|
||
an offset from hard register number TO. The status of hard registers live
|
||
at the start of a basic block is updated by replacing a use of FROM with
|
||
a use of TO. */
|
||
|
||
void
|
||
mark_elimination (from, to)
|
||
int from, to;
|
||
{
|
||
int i;
|
||
|
||
for (i = 0; i < n_basic_blocks; i++)
|
||
if ((basic_block_live_at_start[i][from / REGSET_ELT_BITS]
|
||
& ((REGSET_ELT_TYPE) 1 << (from % REGSET_ELT_BITS))) != 0)
|
||
{
|
||
basic_block_live_at_start[i][from / REGSET_ELT_BITS]
|
||
&= ~ ((REGSET_ELT_TYPE) 1 << (from % REGSET_ELT_BITS));
|
||
basic_block_live_at_start[i][to / REGSET_ELT_BITS]
|
||
|= ((REGSET_ELT_TYPE) 1 << (to % REGSET_ELT_BITS));
|
||
}
|
||
}
|
||
|
||
/* Print debugging trace information if -greg switch is given,
|
||
showing the information on which the allocation decisions are based. */
|
||
|
||
static void
|
||
dump_conflicts (file)
|
||
FILE *file;
|
||
{
|
||
register int i;
|
||
register int has_preferences;
|
||
fprintf (file, ";; %d regs to allocate:", max_allocno);
|
||
for (i = 0; i < max_allocno; i++)
|
||
{
|
||
int j;
|
||
fprintf (file, " %d", allocno_reg[allocno_order[i]]);
|
||
for (j = 0; j < max_regno; j++)
|
||
if (reg_allocno[j] == allocno_order[i]
|
||
&& j != allocno_reg[allocno_order[i]])
|
||
fprintf (file, "+%d", j);
|
||
if (allocno_size[allocno_order[i]] != 1)
|
||
fprintf (file, " (%d)", allocno_size[allocno_order[i]]);
|
||
}
|
||
fprintf (file, "\n");
|
||
|
||
for (i = 0; i < max_allocno; i++)
|
||
{
|
||
register int j;
|
||
fprintf (file, ";; %d conflicts:", allocno_reg[i]);
|
||
for (j = 0; j < max_allocno; j++)
|
||
if (CONFLICTP (i, j) || CONFLICTP (j, i))
|
||
fprintf (file, " %d", allocno_reg[j]);
|
||
for (j = 0; j < FIRST_PSEUDO_REGISTER; j++)
|
||
if (TEST_HARD_REG_BIT (hard_reg_conflicts[i], j))
|
||
fprintf (file, " %d", j);
|
||
fprintf (file, "\n");
|
||
|
||
has_preferences = 0;
|
||
for (j = 0; j < FIRST_PSEUDO_REGISTER; j++)
|
||
if (TEST_HARD_REG_BIT (hard_reg_preferences[i], j))
|
||
has_preferences = 1;
|
||
|
||
if (! has_preferences)
|
||
continue;
|
||
fprintf (file, ";; %d preferences:", allocno_reg[i]);
|
||
for (j = 0; j < FIRST_PSEUDO_REGISTER; j++)
|
||
if (TEST_HARD_REG_BIT (hard_reg_preferences[i], j))
|
||
fprintf (file, " %d", j);
|
||
fprintf (file, "\n");
|
||
}
|
||
fprintf (file, "\n");
|
||
}
|
||
|
||
void
|
||
dump_global_regs (file)
|
||
FILE *file;
|
||
{
|
||
register int i, j;
|
||
|
||
fprintf (file, ";; Register dispositions:\n");
|
||
for (i = FIRST_PSEUDO_REGISTER, j = 0; i < max_regno; i++)
|
||
if (reg_renumber[i] >= 0)
|
||
{
|
||
fprintf (file, "%d in %d ", i, reg_renumber[i]);
|
||
if (++j % 6 == 0)
|
||
fprintf (file, "\n");
|
||
}
|
||
|
||
fprintf (file, "\n\n;; Hard regs used: ");
|
||
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
|
||
if (regs_ever_live[i])
|
||
fprintf (file, " %d", i);
|
||
fprintf (file, "\n\n");
|
||
}
|