Hi!
getopt.c hangs the compiler on h8300-elf with -O2 -g, because the
IL contains addition of constant 0, the first PLUS operand is determined
to have the SP_DERIVED_VALUE_P and the new code in cselib recurses
indefinitely on seeing SP_DERIVED_VALUE_P with locs of
(plus:P SP_DERIVED_VALUE_P (const_int 0)).
Fixed by making sure cselib_subst_to_values canonicalizes it, hashing
already hashes it the same too.
Bootstrapped/regtested on x86_64-linux and i686-linux, tested on the
getopt.i testcase using cross to h8300-elf, approved off-list by Jeff,
committed to trunk.
2020-04-06 Jakub Jelinek <ja...@redhat.com>
* cselib.c (cselib_subst_to_values): For SP_DERIVED_VALUE_P
+ const0_rtx return the SP_DERIVED_VALUE_P.
--- gcc/cselib.c.jj 2020-04-04 10:31:15.409783959 +0200
+++ gcc/cselib.c 2020-04-06 12:05:46.055767835 +0200
@@ -2090,13 +2090,17 @@ cselib_subst_to_values (rtx x, machine_m
{
rtx t = cselib_subst_to_values (XEXP (x, 0), memmode);
if (GET_CODE (t) == VALUE)
- for (struct elt_loc_list *l = CSELIB_VAL_PTR (t)->locs;
- l; l = l->next)
- if (GET_CODE (l->loc) == PLUS
- && GET_CODE (XEXP (l->loc, 0)) == VALUE
- && SP_DERIVED_VALUE_P (XEXP (l->loc, 0))
- && CONST_INT_P (XEXP (l->loc, 1)))
- return plus_constant (Pmode, l->loc, INTVAL (XEXP (x, 1)));
+ {
+ if (SP_DERIVED_VALUE_P (t) && XEXP (x, 1) == const0_rtx)
+ return t;
+ for (struct elt_loc_list *l = CSELIB_VAL_PTR (t)->locs;
+ l; l = l->next)
+ if (GET_CODE (l->loc) == PLUS
+ && GET_CODE (XEXP (l->loc, 0)) == VALUE
+ && SP_DERIVED_VALUE_P (XEXP (l->loc, 0))
+ && CONST_INT_P (XEXP (l->loc, 1)))
+ return plus_constant (Pmode, l->loc, INTVAL (XEXP (x, 1)));
+ }
if (t != XEXP (x, 0))
{
copy = shallow_copy_rtx (x);
Jakub
