On Mon, Nov 26, 2012 at 11:54 PM, Dehao Chen <de...@google.com> wrote:
> The new patch is attached. Bootstrapped and passed gcc regression test.
>
> Ok for trunk?
Hmm ... this merely avoids some UNKNOWN_LOCATIONs which should
be ok. I think the issue is that gimplify_expr does:
saved_location = input_location;
if (save_expr != error_mark_node
&& EXPR_HAS_LOCATION (*expr_p))
input_location = EXPR_LOCATION (*expr_p);
thus it retains input_location from previous recursive invocations (that's ok).
But it doesn't seem to be the case that input_location is UNKNOWN_LOCATION
during GIMPLE passes (which it really should be ...). So to fix the
gimplification
issue I think that gimplify_ctx should have a location (initialized to
UNKNOWN_LOCATION), which it saves/restores across its push/pop
operation.
Or of course that inside the pass manager before executing passes assert
that input_location is UNKNOWN_LOCATION and fix up things according
to that. First offender is in cgraphunit.c in cgraph_analyze_function:
location_t saved_loc = input_location;
input_location = DECL_SOURCE_LOCATION (decl);
that should be totally unnecessary (input_location shoud be and stay
UNKNOWN_LOCATION). And finalize_compilation_unit (the last thing
the frontends should call) should have input_location = UNKNOWN_LOCATION
right at the point it clears current_function_decl / cfun.
I'd prefer the 2nd approach (maybe without the assert as we are in stage3
already, but the assert would certainly help). And places in the middle-end
that set input_location for purpose of (re-)gimplifying should use the location
in the gimplify ctx (which would need to be added) instead of setting
input_location.
Maybe as a first try set input_location to UNKNOWN_LOCATION in
finalize_compilation_unit.
Thanks,
Richard.
> Thanks,
> Dehao
>
> gcc/ChangeLog:
> 2010-11-05 Dehao Chen <de...@google.com>
>
> * ipa-prop.c (ipa_modify_call_arguments): Set loc correctly.
> * emit-rtl.c (last_location): Remove unused variable.
>
> Index: gcc/emit-rtl.c
> ===================================================================
> --- gcc/emit-rtl.c (revision 193203)
> +++ gcc/emit-rtl.c (working copy)
> @@ -5937,7 +5937,7 @@ location_t epilogue_location;
> /* Hold current location information and last location information, so the
> datastructures are built lazily only when some instructions in given
> place are needed. */
> -static location_t curr_location, last_location;
> +static location_t curr_location;
>
> /* Allocate insn location datastructure. */
> void
> @@ -5945,7 +5945,6 @@ insn_locations_init (void)
> {
> prologue_location = epilogue_location = 0;
> curr_location = UNKNOWN_LOCATION;
> - last_location = UNKNOWN_LOCATION;
> }
>
> /* At the end of emit stage, clear current location. */
> Index: gcc/ipa-prop.c
> ===================================================================
> --- gcc/ipa-prop.c (revision 193203)
> +++ gcc/ipa-prop.c (working copy)
> @@ -2870,7 +2870,8 @@ ipa_modify_call_arguments (struct cgraph_edge *cs,
>
> gcc_checking_assert (adj->offset % BITS_PER_UNIT == 0);
> base = gimple_call_arg (stmt, adj->base_index);
> - loc = EXPR_LOCATION (base);
> + loc = DECL_P (base) ? DECL_SOURCE_LOCATION (base)
> + : EXPR_LOCATION (base);
>
> if (TREE_CODE (base) != ADDR_EXPR
> && POINTER_TYPE_P (TREE_TYPE (base)))
