/* The number of nop instructions in frv_nops[]. */
static unsigned int frv_num_nops;
+/* Information about one __builtin_read or __builtin_write access, or
+ the combination of several such accesses. The most general value
+ is all-zeros (an unknown access to an unknown address). */
+struct frv_io {
+ /* The type of access. FRV_IO_UNKNOWN means the access can be either
+ a read or a write. */
+ enum { FRV_IO_UNKNOWN, FRV_IO_READ, FRV_IO_WRITE } type;
+
+ /* The constant address being accessed, or zero if not known. */
+ HOST_WIDE_INT const_address;
+
+ /* The run-time address, as used in operand 0 of the membar pattern. */
+ rtx var_address;
+};
+
/* Return true if instruction INSN should be packed with the following
instruction. */
#define PACKING_FLAG_P(INSN) (GET_MODE (INSN) == TImode)
REG < REGNO (X) + HARD_REGNO_NREGS (REGNO (X), GET_MODE (X)); \
REG++)
+/* This structure contains machine specific function data. */
+struct machine_function GTY(())
+{
+ /* True if we have created an rtx that relies on the stack frame. */
+ int frame_needed;
+
+ /* True if this function contains at least one __builtin_{read,write}*. */
+ bool has_membar_p;
+};
+
/* Temporary register allocation support structure. */
typedef struct frv_tmp_reg_struct
{
if ((target_flags_explicit & MASK_LINKED_FP) == 0)
target_flags |= MASK_LINKED_FP;
+ if ((target_flags_explicit & MASK_OPTIMIZE_MEMBAR) == 0)
+ target_flags |= MASK_OPTIMIZE_MEMBAR;
+
for (i = 0; i < ARRAY_SIZE (frv_unit_names); i++)
frv_unit_codes[i] = get_cpu_unit_code (frv_unit_names[i]);
if (join_bb)
{
- int regno;
+ unsigned int regno;
/* Remove anything live at the beginning of the join block from being
available for allocation. */
{
rtx last_insn = BB_END (bb[j]);
rtx insn = BB_HEAD (bb[j]);
- int regno;
+ unsigned int regno;
if (dump_file)
fprintf (dump_file, "Scanning %s block %d, start %d, end %d\n",
frv_insert_nop_in_packet (packet_group->nop);
}
+/* Return true if accesses IO1 and IO2 refer to the same doubleword. */
+
+static bool
+frv_same_doubleword_p (const struct frv_io *io1, const struct frv_io *io2)
+{
+ if (io1->const_address != 0 && io2->const_address != 0)
+ return io1->const_address == io2->const_address;
+
+ if (io1->var_address != 0 && io2->var_address != 0)
+ return rtx_equal_p (io1->var_address, io2->var_address);
+
+ return false;
+}
+
+/* Return true if operations IO1 and IO2 are guaranteed to complete
+ in order. */
+
+static bool
+frv_io_fixed_order_p (const struct frv_io *io1, const struct frv_io *io2)
+{
+ /* The order of writes is always preserved. */
+ if (io1->type == FRV_IO_WRITE && io2->type == FRV_IO_WRITE)
+ return true;
+
+ /* The order of reads isn't preserved. */
+ if (io1->type != FRV_IO_WRITE && io2->type != FRV_IO_WRITE)
+ return false;
+
+ /* One operation is a write and the other is (or could be) a read.
+ The order is only guaranteed if the accesses are to the same
+ doubleword. */
+ return frv_same_doubleword_p (io1, io2);
+}
+
+/* Generalize I/O operation X so that it covers both X and Y. */
+
+static void
+frv_io_union (struct frv_io *x, const struct frv_io *y)
+{
+ if (x->type != y->type)
+ x->type = FRV_IO_UNKNOWN;
+ if (!frv_same_doubleword_p (x, y))
+ {
+ x->const_address = 0;
+ x->var_address = 0;
+ }
+}
+
+/* Fill IO with information about the load or store associated with
+ membar instruction INSN. */
+
+static void
+frv_extract_membar (struct frv_io *io, rtx insn)
+{
+ extract_insn (insn);
+ io->type = INTVAL (recog_data.operand[2]);
+ io->const_address = INTVAL (recog_data.operand[1]);
+ io->var_address = XEXP (recog_data.operand[0], 0);
+}
+
+/* A note_stores callback for which DATA points to an rtx. Nullify *DATA
+ if X is a register and *DATA depends on X. */
+
+static void
+frv_io_check_address (rtx x, rtx pat ATTRIBUTE_UNUSED, void *data)
+{
+ rtx *other = data;
+
+ if (REG_P (x) && *other != 0 && reg_overlap_mentioned_p (x, *other))
+ *other = 0;
+}
+
+/* A note_stores callback for which DATA points to a HARD_REG_SET.
+ Remove every modified register from the set. */
+
+static void
+frv_io_handle_set (rtx x, rtx pat ATTRIBUTE_UNUSED, void *data)
+{
+ HARD_REG_SET *set = data;
+ unsigned int regno;
+
+ if (REG_P (x))
+ FOR_EACH_REGNO (regno, x)
+ CLEAR_HARD_REG_BIT (*set, regno);
+}
+
+/* A for_each_rtx callback for which DATA points to a HARD_REG_SET.
+ Add every register in *X to the set. */
+
+static int
+frv_io_handle_use_1 (rtx *x, void *data)
+{
+ HARD_REG_SET *set = data;
+ unsigned int regno;
+
+ if (REG_P (*x))
+ FOR_EACH_REGNO (regno, *x)
+ SET_HARD_REG_BIT (*set, regno);
+
+ return 0;
+}
+
+/* A note_stores callback that applies frv_io_handle_use_1 to an
+ entire rhs value. */
+
+static void
+frv_io_handle_use (rtx *x, void *data)
+{
+ for_each_rtx (x, frv_io_handle_use_1, data);
+}
+
+/* Go through block BB looking for membars to remove. There are two
+ cases where intra-block analysis is enough:
+
+ - a membar is redundant if it occurs between two consecutive I/O
+ operations and if those operations are guaranteed to complete
+ in order.
+
+ - a membar for a __builtin_read is redundant if the result is
+ used before the next I/O operation is issued.
+
+ If the last membar in the block could not be removed, and there
+ are guaranteed to be no I/O operations between that membar and
+ the end of the block, store the membar in *LAST_MEMBAR, otherwise
+ store null.
+
+ Describe the block's first I/O operation in *NEXT_IO. Describe
+ an unknown operation if the block doesn't do any I/O. */
+
+static void
+frv_optimize_membar_local (basic_block bb, struct frv_io *next_io,
+ rtx *last_membar)
+{
+ HARD_REG_SET used_regs;
+ rtx next_membar, set, insn;
+ bool next_is_end_p;
+
+ /* NEXT_IO is the next I/O operation to be performed after the current
+ instruction. It starts off as being an unknown operation. */
+ memset (next_io, 0, sizeof (*next_io));
+
+ /* NEXT_IS_END_P is true if NEXT_IO describes the end of the block. */
+ next_is_end_p = true;
+
+ /* If the current instruction is a __builtin_read or __builtin_write,
+ NEXT_MEMBAR is the membar instruction associated with it. NEXT_MEMBAR
+ is null if the membar has already been deleted.
+
+ Note that the initialization here should only be needed to
+ supress warnings. */
+ next_membar = 0;
+
+ /* USED_REGS is the set of registers that are used before the
+ next I/O instruction. */
+ CLEAR_HARD_REG_SET (used_regs);
+
+ for (insn = BB_END (bb); insn != BB_HEAD (bb); insn = PREV_INSN (insn))
+ if (GET_CODE (insn) == CALL_INSN)
+ {
+ /* We can't predict what a call will do to volatile memory. */
+ memset (next_io, 0, sizeof (struct frv_io));
+ next_is_end_p = false;
+ CLEAR_HARD_REG_SET (used_regs);
+ }
+ else if (INSN_P (insn))
+ switch (recog_memoized (insn))
+ {
+ case CODE_FOR_optional_membar_qi:
+ case CODE_FOR_optional_membar_hi:
+ case CODE_FOR_optional_membar_si:
+ case CODE_FOR_optional_membar_di:
+ next_membar = insn;
+ if (next_is_end_p)
+ {
+ /* Local information isn't enough to decide whether this
+ membar is needed. Stash it away for later. */
+ *last_membar = insn;
+ frv_extract_membar (next_io, insn);
+ next_is_end_p = false;
+ }
+ else
+ {
+ /* Check whether the I/O operation before INSN could be
+ reordered with one described by NEXT_IO. If it can't,
+ INSN will not be needed. */
+ struct frv_io prev_io;
+
+ frv_extract_membar (&prev_io, insn);
+ if (frv_io_fixed_order_p (&prev_io, next_io))
+ {
+ if (dump_file)
+ fprintf (dump_file,
+ ";; [Local] Removing membar %d since order"
+ " of accesses is guaranteed\n",
+ INSN_UID (next_membar));
+
+ insn = NEXT_INSN (insn);
+ delete_insn (next_membar);
+ next_membar = 0;
+ }
+ *next_io = prev_io;
+ }
+ break;
+
+ default:
+ /* Invalidate NEXT_IO's address if it depends on something that
+ is clobbered by INSN. */
+ if (next_io->var_address)
+ note_stores (PATTERN (insn), frv_io_check_address,
+ &next_io->var_address);
+
+ /* If the next membar is associated with a __builtin_read,
+ see if INSN reads from that address. If it does, and if
+ the destination register is used before the next I/O access,
+ there is no need for the membar. */
+ set = PATTERN (insn);
+ if (next_io->type == FRV_IO_READ
+ && next_io->var_address != 0
+ && next_membar != 0
+ && GET_CODE (set) == SET
+ && GET_CODE (SET_DEST (set)) == REG
+ && TEST_HARD_REG_BIT (used_regs, REGNO (SET_DEST (set))))
+ {
+ rtx src;
+
+ src = SET_SRC (set);
+ if (GET_CODE (src) == ZERO_EXTEND)
+ src = XEXP (src, 0);
+
+ if (GET_CODE (src) == MEM
+ && rtx_equal_p (XEXP (src, 0), next_io->var_address))
+ {
+ if (dump_file)
+ fprintf (dump_file,
+ ";; [Local] Removing membar %d since the target"
+ " of %d is used before the I/O operation\n",
+ INSN_UID (next_membar), INSN_UID (insn));
+
+ if (next_membar == *last_membar)
+ *last_membar = 0;
+
+ delete_insn (next_membar);
+ next_membar = 0;
+ }
+ }
+
+ /* If INSN has volatile references, forget about any registers
+ that are used after it. Otherwise forget about uses that
+ are (or might be) defined by INSN. */
+ if (volatile_refs_p (PATTERN (insn)))
+ CLEAR_HARD_REG_SET (used_regs);
+ else
+ note_stores (PATTERN (insn), frv_io_handle_set, &used_regs);
+
+ note_uses (&PATTERN (insn), frv_io_handle_use, &used_regs);
+ break;
+ }
+}
+
+/* See if MEMBAR, the last membar instruction in BB, can be removed.
+ FIRST_IO[X] describes the first operation performed by basic block X. */
+
+static void
+frv_optimize_membar_global (basic_block bb, struct frv_io *first_io,
+ rtx membar)
+{
+ struct frv_io this_io, next_io;
+ edge succ;
+ edge_iterator ei;
+
+ /* We need to keep the membar if there is an edge to the exit block. */
+ FOR_EACH_EDGE (succ, ei, bb->succs)
+ /* for (succ = bb->succ; succ != 0; succ = succ->succ_next) */
+ if (succ->dest == EXIT_BLOCK_PTR)
+ return;
+
+ /* Work out the union of all successor blocks. */
+ ei = ei_start (bb->succs);
+ ei_cond (ei, &succ);
+ /* next_io = first_io[bb->succ->dest->index]; */
+ next_io = first_io[succ->dest->index];
+ ei = ei_start (bb->succs);
+ if (ei_cond (ei, &succ))
+ {
+ for (ei_next (&ei); ei_cond (ei, &succ); ei_next (&ei))
+ /*for (succ = bb->succ->succ_next; succ != 0; succ = succ->succ_next)*/
+ frv_io_union (&next_io, &first_io[succ->dest->index]);
+ }
+ else
+ gcc_unreachable ();
+
+ frv_extract_membar (&this_io, membar);
+ if (frv_io_fixed_order_p (&this_io, &next_io))
+ {
+ if (dump_file)
+ fprintf (dump_file,
+ ";; [Global] Removing membar %d since order of accesses"
+ " is guaranteed\n", INSN_UID (membar));
+
+ delete_insn (membar);
+ }
+}
+
+/* Remove redundant membars from the current function. */
+
+static void
+frv_optimize_membar (void)
+{
+ basic_block bb;
+ struct frv_io *first_io;
+ rtx *last_membar;
+
+ compute_bb_for_insn ();
+ first_io = xcalloc (last_basic_block, sizeof (struct frv_io));
+ last_membar = xcalloc (last_basic_block, sizeof (rtx));
+
+ FOR_EACH_BB (bb)
+ frv_optimize_membar_local (bb, &first_io[bb->index],
+ &last_membar[bb->index]);
+
+ FOR_EACH_BB (bb)
+ if (last_membar[bb->index] != 0)
+ frv_optimize_membar_global (bb, first_io, last_membar[bb->index]);
+
+ free (first_io);
+ free (last_membar);
+}
+\f
/* Used by frv_reorg to keep track of the current packet's address. */
static unsigned int frv_packet_address;
static void
frv_reorg (void)
{
+ if (optimize > 0 && TARGET_OPTIMIZE_MEMBAR && cfun->machine->has_membar_p)
+ frv_optimize_membar ();
+
frv_num_nops = 0;
frv_register_nop (gen_nop ());
if (TARGET_MEDIA)
{ CODE_FOR_mdasaccs, "__MDASACCS", FRV_BUILTIN_MDASACCS, 0, 0 }
};
-/* Intrinsics that load a value and then issue a MEMBAR.
- The FLAGS field is the icode for the membar. */
+/* Intrinsics that load a value and then issue a MEMBAR. The load is
+ a normal move and the ICODE is for the membar. */
static struct builtin_description bdesc_loads[] =
{
- { CODE_FOR_builtin_read_qi, "__builtin_read8", FRV_BUILTIN_READ8, 0,
- CODE_FOR_optional_membar_qi },
- { CODE_FOR_builtin_read_hi, "__builtin_read16", FRV_BUILTIN_READ16, 0,
- CODE_FOR_optional_membar_hi },
- { CODE_FOR_builtin_read_si, "__builtin_read32", FRV_BUILTIN_READ32, 0,
- CODE_FOR_optional_membar_si },
- { CODE_FOR_builtin_read_di, "__builtin_read64", FRV_BUILTIN_READ64, 0,
- CODE_FOR_optional_membar_di }
+ { CODE_FOR_optional_membar_qi, "__builtin_read8",
+ FRV_BUILTIN_READ8, 0, 0 },
+ { CODE_FOR_optional_membar_hi, "__builtin_read16",
+ FRV_BUILTIN_READ16, 0, 0 },
+ { CODE_FOR_optional_membar_si, "__builtin_read32",
+ FRV_BUILTIN_READ32, 0, 0 },
+ { CODE_FOR_optional_membar_di, "__builtin_read64",
+ FRV_BUILTIN_READ64, 0, 0 }
};
/* Likewise stores. */
static struct builtin_description bdesc_stores[] =
{
- { CODE_FOR_builtin_write_qi, "__builtin_write8", FRV_BUILTIN_WRITE8, 0,
- CODE_FOR_optional_membar_qi },
- { CODE_FOR_builtin_write_hi, "__builtin_write16", FRV_BUILTIN_WRITE16, 0,
- CODE_FOR_optional_membar_hi },
- { CODE_FOR_builtin_write_si, "__builtin_write32", FRV_BUILTIN_WRITE32, 0,
- CODE_FOR_optional_membar_si },
- { CODE_FOR_builtin_write64, "__builtin_write64", FRV_BUILTIN_WRITE64, 0,
- CODE_FOR_optional_membar_di }
+ { CODE_FOR_optional_membar_qi, "__builtin_write8",
+ FRV_BUILTIN_WRITE8, 0, 0 },
+ { CODE_FOR_optional_membar_hi, "__builtin_write16",
+ FRV_BUILTIN_WRITE16, 0, 0 },
+ { CODE_FOR_optional_membar_si, "__builtin_write32",
+ FRV_BUILTIN_WRITE32, 0, 0 },
+ { CODE_FOR_optional_membar_di, "__builtin_write64",
+ FRV_BUILTIN_WRITE64, 0, 0 },
};
/* Initialize media builtins. */
}
}
+/* Given that a __builtin_read or __builtin_write function is accessing
+ address ADDRESS, return the value that should be used as operand 1
+ of the membar. */
+
+static rtx
+frv_io_address_cookie (rtx address)
+{
+ return (GET_CODE (address) == CONST_INT
+ ? GEN_INT (INTVAL (address) / 8 * 8)
+ : const0_rtx);
+}
+
/* Return the accumulator guard that should be paired with accumulator
register ACC. The mode of the returned register is in the same
class as ACC, but is four times smaller. */
return NULL_RTX;
}
-/* Expand a __builtin_read* function. ICODE is the instruction code for
- the load and MEMBAR_ICODE is the instruction code of the "membar". */
+/* Expand a __builtin_read* function. ICODE is the instruction code for the
+ membar and TARGET_MODE is the mode that the loaded value should have. */
static rtx
-frv_expand_load_builtin (enum insn_code icode, enum insn_code membar_icode,
- tree arglist, rtx target)
+frv_expand_load_builtin (enum insn_code icode, enum machine_mode target_mode,
+ tree arglist, rtx target)
{
- rtx op0 = frv_read_argument (& arglist);
-
- target = frv_legitimize_target (icode, target);
- op0 = frv_volatile_memref (insn_data[membar_icode].operand[0].mode, op0);
- emit_insn (GEN_FCN (icode) (target, op0));
- emit_insn (GEN_FCN (membar_icode) (copy_rtx (op0)));
+ rtx op0 = frv_read_argument (&arglist);
+ rtx cookie = frv_io_address_cookie (op0);
+
+ if (target == 0 || !REG_P (target))
+ target = gen_reg_rtx (target_mode);
+ op0 = frv_volatile_memref (insn_data[icode].operand[0].mode, op0);
+ convert_move (target, op0, 1);
+ emit_insn (GEN_FCN (icode) (copy_rtx (op0), cookie, GEN_INT (FRV_IO_READ)));
+ cfun->machine->has_membar_p = 1;
return target;
}
-/* Likewise __builtin_write* functions, with ICODE being the instruction
- code of the store. */
+/* Likewise __builtin_write* functions. */
static rtx
-frv_expand_store_builtin (enum insn_code icode, enum insn_code membar_icode,
- tree arglist)
+frv_expand_store_builtin (enum insn_code icode, tree arglist)
{
- rtx op0 = frv_read_argument (& arglist);
- rtx op1 = frv_read_argument (& arglist);
+ rtx op0 = frv_read_argument (&arglist);
+ rtx op1 = frv_read_argument (&arglist);
+ rtx cookie = frv_io_address_cookie (op0);
- op0 = frv_volatile_memref (insn_data[membar_icode].operand[0].mode, op0);
- op1 = frv_legitimize_argument (icode, 1, op1);
- emit_insn (GEN_FCN (icode) (op0, op1));
- emit_insn (GEN_FCN (membar_icode) (copy_rtx (op0)));
+ op0 = frv_volatile_memref (insn_data[icode].operand[0].mode, op0);
+ convert_move (op0, force_reg (insn_data[icode].operand[0].mode, op1), 1);
+ emit_insn (GEN_FCN (icode) (copy_rtx (op0), cookie, GEN_INT (FRV_IO_WRITE)));
+ cfun->machine->has_membar_p = 1;
return NULL_RTX;
}
for (i = 0, d = bdesc_loads; i < ARRAY_SIZE (bdesc_loads); i++, d++)
if (d->code == fcode)
- return frv_expand_load_builtin (d->icode, d->flag, arglist, target);
+ return frv_expand_load_builtin (d->icode, TYPE_MODE (TREE_TYPE (exp)),
+ arglist, target);
for (i = 0, d = bdesc_stores; i < ARRAY_SIZE (bdesc_stores); i++, d++)
if (d->code == fcode)
- return frv_expand_store_builtin (d->icode, d->flag, arglist);
+ return frv_expand_store_builtin (d->icode, arglist);
return 0;
}
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