On 10/16/2017 10:38 PM, Vladimir Makarov wrote:
This is another version of the patch to fix
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82353
The patch was successfully bootstrapped on x86-64 with Go and Ada.
Committed as rev. 253796.
Hi Vladimir,
AFAIU this bit of the patch makes sure that the flags register show up
in the bb_livein of the bb in which it's used (and not defined before
the use), but not in the bb_liveout of the predecessors of that bb.
I wonder if that's a compile-speed optimization, or an oversight.
[ I ran into a similar problem for target gcn here (
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83327 ) with the
spill_class hook. I've posted a tentative fix in that PR, which
piggybacks on this fix, but needed a few extra bits to make sure that
inter-bb propagation was done:
- a bit at the end of process_bb_lives to detect the liveness change and
then set live_change_p which make sure the propagation is run.
- a bit in lra_create_live_ranges_1 to unmask the registers we want to
propagate in all_hard_regs_bitmap.
]
Thanks,
- Tom
Index: lra-lives.c
===================================================================
--- lra-lives.c (revision 253685)
+++ lra-lives.c (working copy)
@@ -220,6 +220,9 @@ lra_intersected_live_ranges_p (lra_live_
return false;
}
+/* The corresponding bitmaps of BB currently being processed. */
+static bitmap bb_killed_pseudos, bb_gen_pseudos;
+
/* The function processing birth of hard register REGNO. It updates
living hard regs, START_LIVING, and conflict hard regs for living
pseudos. Conflict hard regs for the pic pseudo is not updated if
@@ -243,6 +246,8 @@ make_hard_regno_born (int regno, bool ch
|| i != REGNO (pic_offset_table_rtx))
#endif
SET_HARD_REG_BIT (lra_reg_info[i].conflict_hard_regs, regno);
+ if (fixed_regs[regno])
+ bitmap_set_bit (bb_gen_pseudos, regno);
}
/* Process the death of hard register REGNO. This updates
@@ -255,6 +260,11 @@ make_hard_regno_dead (int regno)
return;
sparseset_set_bit (start_dying, regno);
CLEAR_HARD_REG_BIT (hard_regs_live, regno);
+ if (fixed_regs[regno])
+ {
+ bitmap_clear_bit (bb_gen_pseudos, regno);
+ bitmap_set_bit (bb_killed_pseudos, regno);
+ }
}
/* Mark pseudo REGNO as living at program point POINT, update conflicting
@@ -299,9 +309,6 @@ mark_pseudo_dead (int regno, int point)
}
}
-/* The corresponding bitmaps of BB currently being processed. */
-static bitmap bb_killed_pseudos, bb_gen_pseudos;
-
/* Mark register REGNO (pseudo or hard register) in MODE as live at
program point POINT. Update BB_GEN_PSEUDOS.
Return TRUE if the liveness tracking sets were modified, or FALSE
