ira: Skip some pseudos in move_unallocated_pseudos

This patch is to make move_unallocated_pseudos consistent
to what we have in function find_moveable_pseudos, where we
record the original pseudo into pseudo_replaced_reg only if
validate_change succeeds with newreg.  To ensure every
unallocated pseudo in move_unallocated_pseudos has expected
information, it's better to add a check and skip it if it's
unexpected.  This avoids possible ICEs in future.

gcc/ChangeLog:

	* ira.c (move_unallocated_pseudos): Check other_reg and skip if
	it isn't set.

diff --git a/gcc/ira.c b/gcc/ira.c
index eb88f1e..725b0ff 100644 (file)
--- a/gcc/ira.c
+++ b/gcc/ira.c
@@ -5111,6 +5111,15 @@ move_unallocated_pseudos (void)
       {
        int idx = i - first_moveable_pseudo;
        rtx other_reg = pseudo_replaced_reg[idx];
+       /* The iterating range [first_moveable_pseudo, last_moveable_pseudo)
+          covers every new pseudo created in find_moveable_pseudos,
+          regardless of the validation with it is successful or not.
+          So we need to skip the pseudos which were used in those failed
+          validations to avoid unexpected DF info and consequent ICE.
+          We only set pseudo_replaced_reg[] when the validation is successful
+          in find_moveable_pseudos, it's enough to check it here.  */
+       if (!other_reg)
+         continue;
        rtx_insn *def_insn = DF_REF_INSN (DF_REG_DEF_CHAIN (i));
        /* The use must follow all definitions of OTHER_REG, so we can
           insert the new definition immediately after any of them.  */