Hi,
LTO quickly breaks on Ada code involving floating-point comparisons because
the Ada compiler defaults to -fnon-call-exceptions -fno-trapping-math (on most
platforms) and only -fnon-call-exceptions is restored on the LTO side, so you
can end up with the wrong number of edges on FP comparisons during LTRANS.
Tested on x86_64-suse-linux, OK for the mainline?
2014-10-06 Eric Botcazou <ebotca...@adacore.com>
* lto-opts.c (lto_write_options): Handle -fmath-errno, -fsigned-zeros
and -ftrapping-math.
* lto-wrapper.c (merge_and_complain): Likewise.
(run_gcc): Likewise.
2014-10-06 Eric Botcazou <ebotca...@adacore.com>
* gnat.dg/lto16.adb: New test.
* gnat.dg/lto16_pkg.adb: New helper.
--
Eric BotcazouIndex: lto-opts.c
===================================================================
--- lto-opts.c (revision 215843)
+++ lto-opts.c (working copy)
@@ -115,6 +115,24 @@ lto_write_options (void)
default:
gcc_unreachable ();
}
+ /* The default -fmath-errno, -fsigned-zeros and -ftrapping-math change
+ depending on the language (they can be disabled by the Ada and Java
+ front-ends). Pass thru conservative standard settings. */
+ if (!global_options_set.x_flag_errno_math)
+ append_to_collect_gcc_options (&temporary_obstack, &first_p,
+ global_options.x_flag_errno_math
+ ? "-fmath-errno"
+ : "-fno-math-errno");
+ if (!global_options_set.x_flag_signed_zeros)
+ append_to_collect_gcc_options (&temporary_obstack, &first_p,
+ global_options.x_flag_signed_zeros
+ ? "-fsigned-zeros"
+ : "-fno-signed-zeros");
+ if (!global_options_set.x_flag_trapping_math)
+ append_to_collect_gcc_options (&temporary_obstack, &first_p,
+ global_options.x_flag_trapping_math
+ ? "-ftrapping-math"
+ : "-fno-trapping-math");
/* We need to merge -f[no-]strict-overflow, -f[no-]wrapv and -f[no-]trapv
conservatively, so stream out their defaults. */
if (!global_options_set.x_flag_wrapv
Index: lto-wrapper.c
===================================================================
--- lto-wrapper.c (revision 215843)
+++ lto-wrapper.c (working copy)
@@ -261,6 +261,9 @@ merge_and_complain (struct cl_decoded_op
(*decoded_options)[j] = *foption;
break;
+ case OPT_fmath_errno:
+ case OPT_fsigned_zeros:
+ case OPT_ftrapping_math:
case OPT_fwrapv:
/* For selected options we can merge conservatively. */
for (j = 0; j < *decoded_options_count; ++j)
@@ -268,7 +271,10 @@ merge_and_complain (struct cl_decoded_op
break;
if (j == *decoded_options_count)
append_option (decoded_options, decoded_options_count, foption);
- /* -fwrapv > -fno-wrapv. */
+ /* -fmath-errno > -fno-math-errno,
+ -fsigned-zeros > -fno-signed-zeros,
+ -ftrapping-math -> -fno-trapping-math,
+ -fwrapv > -fno-wrapv. */
else if (foption->value > (*decoded_options)[j].value)
(*decoded_options)[j] = *foption;
break;
@@ -502,6 +508,9 @@ run_gcc (unsigned argc, char *argv[])
case OPT_fpcc_struct_return:
case OPT_fshort_double:
case OPT_ffp_contract_:
+ case OPT_fmath_errno:
+ case OPT_fsigned_zeros:
+ case OPT_ftrapping_math:
case OPT_fwrapv:
case OPT_ftrapv:
case OPT_fstrict_overflow:
-- { dg-do link }
-- { dg-options "-O -flto" }
-- { dg-require-effective-target lto }
with Lto16_Pkg; use Lto16_Pkg;
with Text_IO; use Text_IO;
procedure Lto16 is
begin
if F = 0.0 then
Put_Line ("zero");
else
Put_Line ("non-zero");
end if;
exception
when others => Put_Line ("exception");
end;
with Ada.Calendar; use Ada.Calendar;
package body Lto16_Pkg is
function F return Float is
F1 : Float := Float (Seconds (Clock));
F2 : Float := Float (Seconds (Clock));
F : Float;
begin
if F1 > F2 then
F := (F2 - F1) / 2.0;
else
F := (F1 - F2) / 2.0;
end if;
return F;
end;
end Lto16_Pkg;
package Lto16_Pkg is
function F return Float;
end Lto16_Pkg;
