-\f
-/* Try to find a hard register of mode MODE, matching the register class in
- CLASS_STR, which is available at the beginning of insn CURRENT_INSN and
- remains available until the end of LAST_INSN. LAST_INSN may be NULL_RTX,
- in which case the only condition is that the register must be available
- before CURRENT_INSN.
- Registers that already have bits set in REG_SET will not be considered.
-
- If an appropriate register is available, it will be returned and the
- corresponding bit(s) in REG_SET will be set; otherwise, NULL_RTX is
- returned. */
-
-rtx
-find_free_register (current_insn, last_insn, class_str, mode, reg_set)
- rtx current_insn, last_insn;
- const char *class_str;
- int mode;
- HARD_REG_SET *reg_set;
-{
- int i, j;
- struct resources used;
- unsigned char clet = class_str[0];
- enum reg_class class
- = (clet == 'r' ? GENERAL_REGS : REG_CLASS_FROM_LETTER (clet));
-
- mark_target_live_regs (get_insns (), current_insn, &used);
- if (last_insn)
- while (current_insn != last_insn)
- {
- /* Exclude anything set in this insn. */
- mark_set_resources (PATTERN (current_insn), &used, 0, 1);
- current_insn = next_nonnote_insn (current_insn);
- }
-
-
- for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
- {
- int regno;
- int success;
-
-#ifdef REG_ALLOC_ORDER
- regno = reg_alloc_order [i];
-#else
- regno = i;
-#endif
-
- /* Don't allocate fixed registers. */
- if (fixed_regs[regno])
- continue;
- /* Make sure the register is of the right class. */
- if (! TEST_HARD_REG_BIT (reg_class_contents[class], regno))
- continue;
- /* And can support the mode we need. */
- if (! HARD_REGNO_MODE_OK (regno, mode))
- continue;
- /* And that we don't create an extra save/restore. */
- if (! call_used_regs[regno] && ! regs_ever_live[regno])
- continue;
- /* And we don't clobber traceback for noreturn functions. */
- if ((regno == FRAME_POINTER_REGNUM || regno == HARD_FRAME_POINTER_REGNUM)
- && (! reload_completed || frame_pointer_needed))
- continue;
-
- success = 1;
- for (j = HARD_REGNO_NREGS (regno, mode) - 1; j >= 0; j--)
- {
- if (TEST_HARD_REG_BIT (*reg_set, regno + j)
- || TEST_HARD_REG_BIT (used.regs, regno + j))
- {
- success = 0;
- break;
- }
- }
- if (success)
- {
- for (j = HARD_REGNO_NREGS (regno, mode) - 1; j >= 0; j--)
- {
- SET_HARD_REG_BIT (*reg_set, regno + j);
- }
- return gen_rtx_REG (mode, regno);
- }
- }
- return NULL_RTX;
-}
-
-/* Return true if REG is dead at CURRENT_INSN. */
-
-int
-reg_dead_p (current_insn, reg)
- rtx current_insn, reg;
-{
- struct resources used;
- int regno, j;
-
- mark_target_live_regs (get_insns (), current_insn, &used);
-
- regno = REGNO (reg);
- for (j = HARD_REGNO_NREGS (regno, GET_MODE (reg)) - 1; j >= 0; j--)
- {
- if (TEST_HARD_REG_BIT (used.regs, regno + j))
- return 0;
- }
-
- return 1;
-}