- HOST_WIDE_INT last_sp_adjust = 0;
- rtx last_sp_set = NULL_RTX;
- struct csa_memlist *memlist = NULL;
- rtx pending_delete;
- rtx insn, next;
-
- for (insn = bb->head; ; insn = next)
- {
- rtx set;
-
- pending_delete = NULL_RTX;
- next = NEXT_INSN (insn);
-
- if (GET_RTX_CLASS (GET_CODE (insn)) != 'i')
- goto processed;
-
- set = single_set_for_csa (insn);
- if (set)
- {
- rtx dest = SET_DEST (set);
- rtx src = SET_SRC (set);
-
- /* Find constant additions to the stack pointer. */
- if (dest == stack_pointer_rtx
- && GET_CODE (src) == PLUS
- && XEXP (src, 0) == stack_pointer_rtx
- && GET_CODE (XEXP (src, 1)) == CONST_INT)
- {
- HOST_WIDE_INT this_adjust = INTVAL (XEXP (src, 1));
-
- /* If we've not seen an adjustment previously, record
- it now and continue. */
- if (! last_sp_set)
- {
- last_sp_set = insn;
- last_sp_adjust = this_adjust;
- goto processed;
- }
-
- /* If not all recorded memrefs can be adjusted, or the
- adjustment is now too large for a constant addition,
- we cannot merge the two stack adjustments. */
- if (! try_apply_stack_adjustment (last_sp_set, memlist,
- last_sp_adjust + this_adjust,
- this_adjust))
- {
- free_csa_memlist (memlist);
- memlist = NULL;
- last_sp_set = insn;
- last_sp_adjust = this_adjust;
- goto processed;
- }
-
- /* It worked! */
- pending_delete = insn;
- last_sp_adjust += this_adjust;
-
- /* If, by some accident, the adjustments cancel out,
- delete both insns and start from scratch. */
- if (last_sp_adjust == 0)
- {
- if (last_sp_set == bb->head)
- bb->head = NEXT_INSN (last_sp_set);
- flow_delete_insn (last_sp_set);
-
- free_csa_memlist (memlist);
- memlist = NULL;
- last_sp_set = NULL_RTX;
- }
-
- goto processed;
- }
-
- /* Find loads from stack memory and record them. */
- if (last_sp_set && stack_memref_p (src)
- && ! reg_mentioned_p (stack_pointer_rtx, dest))
- {
- memlist = record_one_stack_memref (insn, src, memlist);
- goto processed;
- }
-
- /* Find stores to stack memory and record them. */
- if (last_sp_set && stack_memref_p (dest)
- && ! reg_mentioned_p (stack_pointer_rtx, src))
- {
- memlist = record_one_stack_memref (insn, dest, memlist);
- goto processed;
- }
-
- /* Find a predecrement of exactly the previous adjustment and
- turn it into a direct store. Obviously we can't do this if
- there were any intervening uses of the stack pointer. */
- if (memlist == NULL
- && last_sp_adjust == GET_MODE_SIZE (GET_MODE (dest))
- && GET_CODE (dest) == MEM
- && GET_CODE (XEXP (dest, 0)) == PRE_DEC
- && XEXP (XEXP (dest, 0), 0) == stack_pointer_rtx
- && ! reg_mentioned_p (stack_pointer_rtx, src)
- && memory_address_p (GET_MODE (dest), stack_pointer_rtx)
- && validate_change (insn, &SET_DEST (set),
- change_address (dest, VOIDmode,
- stack_pointer_rtx), 0))
- {
- if (last_sp_set == bb->head)
- bb->head = NEXT_INSN (last_sp_set);
- flow_delete_insn (last_sp_set);
-
- free_csa_memlist (memlist);
- memlist = NULL;
- last_sp_set = NULL_RTX;
- last_sp_adjust = 0;
- goto processed;
- }
- }
-
- /* Otherwise, we were not able to process the instruction.
- Do not continue collecting data across such a one. */
- if (last_sp_set
- && (GET_CODE (insn) == CALL_INSN
- || reg_mentioned_p (stack_pointer_rtx, PATTERN (insn))))
- {
- free_csa_memlist (memlist);
- memlist = NULL;
- last_sp_set = NULL_RTX;
- last_sp_adjust = 0;
- }
-
- processed:
- if (insn == bb->end)
- break;
-
- if (pending_delete)
- flow_delete_insn (pending_delete);
- }