Hi!
On the testcase from this PR on AVR (from libgcc, thus not including
it into testsuite/) we ICE, because dead_debug_insert_temp is called
several times on the same insn, for multi-register hard register for each
regno in it (except the first which doesn't seem to be dead).
In the first call dead_debug_insert_temp changes *DF_REF_REAL_LOC
to DEBUG_EXPR, and in the next call for the next consecutive hard register
we set reg variable to *DF_REF_REAL_LOC and rely on it to be a REG,
when it is a DEBUG_EXPR already instead. No change is needed in that case.
Bootstrapped/regtested on x86_64-linux and i686-linux (where this never
kicks in though), tested on the testcase in cross to avr. Ok for trunk?
2012-08-20 Jakub Jelinek <ja...@redhat.com>
PR debug/53923
* valtrack.c (dead_debug_insert_temp): Drop non-reg uses
from the chain.
--- gcc/valtrack.c.jj 2012-08-10 12:57:21.000000000 +0200
+++ gcc/valtrack.c 2012-08-20 14:59:07.609586159 +0200
@@ -336,6 +336,14 @@ dead_debug_insert_temp (struct dead_debu
{
if (DF_REF_REGNO (cur->use) == uregno)
{
+ /* If this loc has been changed e.g. to debug_expr already
+ as part of a multi-register use, just drop it. */
+ if (!REG_P (*DF_REF_REAL_LOC (cur->use)))
+ {
+ *tailp = cur->next;
+ XDELETE (cur);
+ continue;
+ }
*usesp = cur;
usesp = &cur->next;
*tailp = cur->next;
Jakub
