(allocate_dynamic_stack_space): Call probe_stack_range.
(emit_stack_probe, probe_stack_range): New functions. From-SVN: r14469
This commit is contained in:
Richard Kenner
parent
bf1c53323f
commit
edff249168
134
gcc/explow.c
134
gcc/explow.c
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@ -31,7 +31,7 @@ Boston, MA 02111-1307, USA. */
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#include "insn-codes.h"
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static rtx break_out_memory_refs PROTO((rtx));
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static void emit_stack_probe PROTO((rtx));
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/* Return an rtx for the sum of X and the integer C.
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This function should be used via the `plus_constant' macro. */
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@ -1077,6 +1077,11 @@ allocate_dynamic_stack_space (size, target, known_align)
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do_pending_stack_adjust ();
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/* If needed, check that we have the required amount of stack. Take into
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account what has already been checked. */
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if (flag_stack_check && ! STACK_CHECK_BUILTIN)
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probe_stack_range (STACK_CHECK_MAX_FRAME_SIZE + STACK_CHECK_PROTECT, size);
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/* Don't use a TARGET that isn't a pseudo. */
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if (target == 0 || GET_CODE (target) != REG
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|| REGNO (target) < FIRST_PSEUDO_REGISTER)
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@ -1147,6 +1152,133 @@ allocate_dynamic_stack_space (size, target, known_align)
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return target;
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}
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/* Emit one stack probe at ADDRESS, an address within the stack. */
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static void
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emit_stack_probe (address)
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rtx address;
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{
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rtx memref = gen_rtx (MEM, word_mode, address);
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MEM_VOLATILE_P (memref) = 1;
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if (STACK_CHECK_PROBE_LOAD)
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emit_move_insn (gen_reg_rtx (word_mode), memref);
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else
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emit_move_insn (memref, const0_rtx);
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}
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/* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
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FIRST is a constant and size is a Pmode RTX. These are offsets from the
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current stack pointer. STACK_GROWS_DOWNWARD says whether to add or
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subtract from the stack. If SIZE is constant, this is done
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with a fixed number of probes. Otherwise, we must make a loop. */
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#ifdef STACK_GROWS_DOWNWARD
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#define STACK_GROW_OP MINUS
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#else
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#define STACK_GROW_OP PLUS
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#endif
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void
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probe_stack_range (first, size)
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HOST_WIDE_INT first;
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rtx size;
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{
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/* First see if we have an insn to check the stack. Use it if so. */
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#ifdef HAVE_check_stack
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if (HAVE_check_stack)
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{
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rtx last_addr = force_operand (gen_rtx (STACK_GROW_OP, Pmode,
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stack_pointer_rtx,
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plus_constant (size, first)),
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NULL_RTX);
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if (insn_operand_predicate[(int) CODE_FOR_check_stack][0]
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&& ! ((*insn_operand_predicate[(int) CODE_FOR_check_stack][0])
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(last_address, Pmode)))
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last_address = copy_to_mode_reg (Pmode, last_address);
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emit_insn (gen_check_stack (last_address));
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return;
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}
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#endif
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/* If we have to generate explicit probes, see if we have a constant
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number of them to generate. If so, that's the easy case. */
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if (GET_CODE (size) == CONST_INT)
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{
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HOST_WIDE_INT offset;
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/* Start probing at FIRST + N * STACK_CHECK_PROBE_INTERVAL
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for values of N from 1 until it exceeds LAST. If only one
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probe is needed, this will not generate any code. Then probe
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at LAST. */
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for (offset = first + STACK_CHECK_PROBE_INTERVAL;
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offset < INTVAL (size);
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offset = offset + STACK_CHECK_PROBE_INTERVAL)
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emit_stack_probe (gen_rtx (STACK_GROW_OP, Pmode,
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stack_pointer_rtx, GEN_INT (offset)));
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emit_stack_probe (gen_rtx (STACK_GROW_OP, Pmode, stack_pointer_rtx,
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plus_constant (size, first)));
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}
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/* In the variable case, do the same as above, but in a loop. We emit loop
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notes so that loop optimization can be done. */
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else
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{
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rtx test_addr
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= force_operand (gen_rtx (STACK_GROW_OP, Pmode, stack_pointer_rtx,
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GEN_INT (first
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+ STACK_CHECK_PROBE_INTERVAL)),
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NULL_RTX);
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rtx last_addr
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= force_operand (gen_rtx (STACK_GROW_OP, Pmode, stack_pointer_rtx,
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plus_constant (size, first)),
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NULL_RTX);
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rtx incr = GEN_INT (STACK_CHECK_PROBE_INTERVAL);
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rtx loop_lab = gen_label_rtx ();
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rtx test_lab = gen_label_rtx ();
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rtx end_lab = gen_label_rtx ();
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rtx temp;
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if (GET_CODE (test_addr) != REG
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|| REGNO (test_addr) < FIRST_PSEUDO_REGISTER)
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test_addr = force_reg (Pmode, test_addr);
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emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
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emit_jump (test_lab);
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emit_label (loop_lab);
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emit_stack_probe (test_addr);
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emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
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#ifdef STACK_GROWS_DOWNWARD
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#define CMP_OPCODE GTU
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temp = expand_binop (Pmode, sub_optab, test_addr, incr, test_addr,
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1, OPTAB_WIDEN);
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#else
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#define CMP_OPCODE LTU
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temp = expand_binop (Pmode, add_optab, test_addr, incr, test_addr,
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1, OPTAB_WIDEN);
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#endif
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if (temp != test_addr)
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abort ();
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emit_label (test_lab);
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emit_cmp_insn (test_addr, last_addr, CMP_OPCODE, NULL_RTX, Pmode, 1, 0);
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emit_jump_insn ((*bcc_gen_fctn[(int) CMP_OPCODE]) (loop_lab));
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emit_jump (end_lab);
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emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
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emit_label (end_lab);
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emit_stack_probe (last_addr);
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}
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}
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/* Return an rtx representing the register or memory location
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in which a scalar value of data type VALTYPE
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was returned by a function call to function FUNC.
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