+/* Internal state for internal_arg_pointer_based_exp and its helpers. */
+static struct
+{
+ /* Last insn that has been scanned by internal_arg_pointer_based_exp_scan,
+ or NULL_RTX if none has been scanned yet. */
+ rtx scan_start;
+ /* Vector indexed by REGNO - FIRST_PSEUDO_REGISTER, recording if a pseudo is
+ based on crtl->args.internal_arg_pointer. The element is NULL_RTX if the
+ pseudo isn't based on it, a CONST_INT offset if the pseudo is based on it
+ with fixed offset, or PC if this is with variable or unknown offset. */
+ VEC(rtx, heap) *cache;
+} internal_arg_pointer_exp_state;
+
+static rtx internal_arg_pointer_based_exp (rtx, bool);
+
+/* Helper function for internal_arg_pointer_based_exp. Scan insns in
+ the tail call sequence, starting with first insn that hasn't been
+ scanned yet, and note for each pseudo on the LHS whether it is based
+ on crtl->args.internal_arg_pointer or not, and what offset from that
+ that pointer it has. */
+
+static void
+internal_arg_pointer_based_exp_scan (void)
+{
+ rtx insn, scan_start = internal_arg_pointer_exp_state.scan_start;
+
+ if (scan_start == NULL_RTX)
+ insn = get_insns ();
+ else
+ insn = NEXT_INSN (scan_start);
+
+ while (insn)
+ {
+ rtx set = single_set (insn);
+ if (set && REG_P (SET_DEST (set)) && !HARD_REGISTER_P (SET_DEST (set)))
+ {
+ rtx val = NULL_RTX;
+ unsigned int idx = REGNO (SET_DEST (set)) - FIRST_PSEUDO_REGISTER;
+ /* Punt on pseudos set multiple times. */
+ if (idx < VEC_length (rtx, internal_arg_pointer_exp_state.cache)
+ && (VEC_index (rtx, internal_arg_pointer_exp_state.cache, idx)
+ != NULL_RTX))
+ val = pc_rtx;
+ else
+ val = internal_arg_pointer_based_exp (SET_SRC (set), false);
+ if (val != NULL_RTX)
+ {
+ if (idx
+ >= VEC_length (rtx, internal_arg_pointer_exp_state.cache))
+ VEC_safe_grow_cleared (rtx, heap,
+ internal_arg_pointer_exp_state.cache,
+ idx + 1);
+ VEC_replace (rtx, internal_arg_pointer_exp_state.cache,
+ idx, val);
+ }
+ }
+ if (NEXT_INSN (insn) == NULL_RTX)
+ scan_start = insn;
+ insn = NEXT_INSN (insn);
+ }
+
+ internal_arg_pointer_exp_state.scan_start = scan_start;
+}
+
+/* Helper function for internal_arg_pointer_based_exp, called through
+ for_each_rtx. Return 1 if *LOC is a register based on
+ crtl->args.internal_arg_pointer. Return -1 if *LOC is not based on it
+ and the subexpressions need not be examined. Otherwise return 0. */
+
+static int
+internal_arg_pointer_based_exp_1 (rtx *loc, void *data ATTRIBUTE_UNUSED)
+{
+ if (REG_P (*loc) && internal_arg_pointer_based_exp (*loc, false) != NULL_RTX)
+ return 1;
+ if (MEM_P (*loc))
+ return -1;
+ return 0;
+}
+
+/* Compute whether RTL is based on crtl->args.internal_arg_pointer. Return
+ NULL_RTX if RTL isn't based on it, a CONST_INT offset if RTL is based on
+ it with fixed offset, or PC if this is with variable or unknown offset.
+ TOPLEVEL is true if the function is invoked at the topmost level. */
+
+static rtx
+internal_arg_pointer_based_exp (rtx rtl, bool toplevel)
+{
+ if (CONSTANT_P (rtl))
+ return NULL_RTX;
+
+ if (rtl == crtl->args.internal_arg_pointer)
+ return const0_rtx;
+
+ if (REG_P (rtl) && HARD_REGISTER_P (rtl))
+ return NULL_RTX;
+
+ if (GET_CODE (rtl) == PLUS && CONST_INT_P (XEXP (rtl, 1)))
+ {
+ rtx val = internal_arg_pointer_based_exp (XEXP (rtl, 0), toplevel);
+ if (val == NULL_RTX || val == pc_rtx)
+ return val;
+ return plus_constant (val, INTVAL (XEXP (rtl, 1)));
+ }
+
+ /* When called at the topmost level, scan pseudo assignments in between the
+ last scanned instruction in the tail call sequence and the latest insn
+ in that sequence. */
+ if (toplevel)
+ internal_arg_pointer_based_exp_scan ();
+
+ if (REG_P (rtl))
+ {
+ unsigned int idx = REGNO (rtl) - FIRST_PSEUDO_REGISTER;
+ if (idx < VEC_length (rtx, internal_arg_pointer_exp_state.cache))
+ return VEC_index (rtx, internal_arg_pointer_exp_state.cache, idx);
+
+ return NULL_RTX;
+ }
+
+ if (for_each_rtx (&rtl, internal_arg_pointer_based_exp_1, NULL))
+ return pc_rtx;
+
+ return NULL_RTX;
+}
+