The following patch should fix Go bootstrap. We need to preserve
virtual SSA form properly during EH cleanup and for the
cleanup_empty_eh_merge_phis the same arguments that hold for
real variables should hold for virtual operands - they are not
changed by empty EH handlers and thus we can simply re-use them.
Bootstrap / regtest pending on x86_64-unknown-linux-gnu.
Richard.
Index: gcc/tree-eh.c
===================================================================
*** gcc/tree-eh.c (revision 198522)
--- gcc/tree-eh.c (working copy)
*************** cleanup_empty_eh_merge_phis (basic_block
*** 3949,3955 ****
gimple_stmt_iterator ngsi, ogsi;
edge_iterator ei;
edge e;
- bitmap rename_virts;
bitmap ophi_handled;
/* The destination block must not be a regular successor for any
--- 3949,3954 ----
*************** cleanup_empty_eh_merge_phis (basic_block
*** 3972,3978 ****
redirect_edge_var_map_clear (e);
ophi_handled = BITMAP_ALLOC (NULL);
- rename_virts = BITMAP_ALLOC (NULL);
/* First, iterate through the PHIs on NEW_BB and set up the edge_var_map
for the edges we're going to move. */
--- 3971,3976 ----
*************** cleanup_empty_eh_merge_phis (basic_block
*** 4025,4035 ****
redirect_edge_var_map_add (e, nresult, oop, oloc);
}
}
! /* If we didn't find the PHI, but it's a VOP, remember to rename
! it later, assuming all other tests succeed. */
! else if (virtual_operand_p (nresult))
! bitmap_set_bit (rename_virts, SSA_NAME_VERSION (nresult));
! /* If we didn't find the PHI, and it's a real variable, we know
from the fact that OLD_BB is tree_empty_eh_handler_p that the
variable is unchanged from input to the block and we can simply
re-use the input to NEW_BB from the OLD_BB_OUT edge. */
--- 4023,4029 ----
redirect_edge_var_map_add (e, nresult, oop, oloc);
}
}
! /* If we didn't find the PHI, if it's a real variable or a VOP, we know
from the fact that OLD_BB is tree_empty_eh_handler_p that the
variable is unchanged from input to the block and we can simply
re-use the input to NEW_BB from the OLD_BB_OUT edge. */
*************** cleanup_empty_eh_merge_phis (basic_block
*** 4052,4075 ****
goto fail;
}
- /* At this point we know that the merge will succeed. Remove the PHI
- nodes for the virtuals that we want to rename. */
- if (!bitmap_empty_p (rename_virts))
- {
- for (ngsi = gsi_start_phis (new_bb); !gsi_end_p (ngsi); )
- {
- gimple nphi = gsi_stmt (ngsi);
- tree nresult = gimple_phi_result (nphi);
- if (bitmap_bit_p (rename_virts, SSA_NAME_VERSION (nresult)))
- {
- mark_virtual_phi_result_for_renaming (nphi);
- remove_phi_node (&ngsi, true);
- }
- else
- gsi_next (&ngsi);
- }
- }
-
/* Finally, move the edges and update the PHIs. */
for (ei = ei_start (old_bb->preds); (e = ei_safe_edge (ei)); )
if (e->flags & EDGE_EH)
--- 4046,4051 ----
*************** cleanup_empty_eh_merge_phis (basic_block
*** 4097,4110 ****
ei_next (&ei);
BITMAP_FREE (ophi_handled);
- BITMAP_FREE (rename_virts);
return true;
fail:
FOR_EACH_EDGE (e, ei, old_bb->preds)
redirect_edge_var_map_clear (e);
BITMAP_FREE (ophi_handled);
- BITMAP_FREE (rename_virts);
return false;
}
--- 4073,4084 ----
*************** struct gimple_opt_pass pass_cleanup_eh =
*** 4467,4473 ****
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
! 0 /* todo_flags_finish */
}
};
--- 4441,4447 ----
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
! TODO_verify_ssa /* todo_flags_finish */
}
};
