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-rw-r--r--gcc/sched.c24
1 files changed, 22 insertions, 2 deletions
diff --git a/gcc/sched.c b/gcc/sched.c
index 1d81407c3f4..e27f70e28ea 100644
--- a/gcc/sched.c
+++ b/gcc/sched.c
@@ -4174,8 +4174,28 @@ update_flow_info (notes, first, last, orig_insn)
}
else if (! found_orig_dest)
{
- /* This should never happen. */
- abort ();
+ int i, regno;
+
+ /* Should never reach here for a pseudo reg. */
+ if (REGNO (orig_dest) >= FIRST_PSEUDO_REGISTER)
+ abort ();
+
+ /* This can happen for a hard register, if the splitter
+ does not bother to emit instructions which would be no-ops.
+ We try to verify that this is the case by checking to see if
+ the original instruction uses all of the registers that it
+ set. This case is OK, because deleting a no-op can not affect
+ REG_DEAD notes on other insns. If this is not the case, then
+ abort. */
+
+ regno = REGNO (orig_dest);
+ for (i = HARD_REGNO_NREGS (regno, GET_MODE (orig_dest)) - 1;
+ i >= 0; i--)
+ if (! refers_to_regno_p (regno + i, regno + i + 1, orig_insn,
+ NULL_PTR))
+ break;
+ if (i >= 0)
+ abort ();
}
}