The following makes sure the languages default of -ffp-contract
is properly transfered to the LTO stage (which defaults to "fast").
Merging different options from different TUs is done conservatively.
LTO bootstrapped and tested on x86_64-unknown-linux-gnu, applied.
Richard.
2013-11-20 Richard Biener <rguent...@suse.de>
PR lto/59035
* lto-opts.c (lto_write_options): Write defaults only if
they were not explicitely specified. Also write
-ffp-contract default.
* lto-wrapper.c (merge_and_complain): Merge -ffp-contract
conservatively.
(run_gcc): Pass through -ffp-contract.
Index: gcc/lto-opts.c
===================================================================
*** gcc/lto-opts.c (revision 205009)
--- gcc/lto-opts.c (working copy)
*************** lto_write_options (void)
*** 85,98 ****
function rather than per compilation unit. */
/* -fexceptions causes the EH machinery to be initialized, enabling
generation of unwind data so that explicit throw() calls work. */
! if (global_options.x_flag_exceptions)
append_to_collect_gcc_options (&temporary_obstack, &first_p,
"-fexceptions");
/* -fnon-call-exceptions changes the generation of exception
regions. It is enabled implicitly by the Go frontend. */
! if (global_options.x_flag_non_call_exceptions)
append_to_collect_gcc_options (&temporary_obstack, &first_p,
"-fnon-call-exceptions");
/* Output explicitly passed options. */
for (i = 1; i < save_decoded_options_count; ++i)
--- 85,119 ----
function rather than per compilation unit. */
/* -fexceptions causes the EH machinery to be initialized, enabling
generation of unwind data so that explicit throw() calls work. */
! if (!global_options_set.x_flag_exceptions
! && global_options.x_flag_exceptions)
append_to_collect_gcc_options (&temporary_obstack, &first_p,
"-fexceptions");
/* -fnon-call-exceptions changes the generation of exception
regions. It is enabled implicitly by the Go frontend. */
! if (!global_options_set.x_flag_non_call_exceptions
! && global_options.x_flag_non_call_exceptions)
append_to_collect_gcc_options (&temporary_obstack, &first_p,
"-fnon-call-exceptions");
+ /* The default -ffp-contract changes depending on the language
+ standard. Pass thru conservative standard settings. */
+ if (!global_options_set.x_flag_fp_contract_mode)
+ switch (global_options.x_flag_fp_contract_mode)
+ {
+ case FP_CONTRACT_OFF:
+ append_to_collect_gcc_options (&temporary_obstack, &first_p,
+ "-ffp-contract=off");
+ break;
+ case FP_CONTRACT_ON:
+ append_to_collect_gcc_options (&temporary_obstack, &first_p,
+ "-ffp-contract=on");
+ break;
+ case FP_CONTRACT_FAST:
+ /* Nothing. That merges conservatively and is the default for LTO. */
+ break;
+ default:
+ gcc_unreachable ();
+ }
/* Output explicitly passed options. */
for (i = 1; i < save_decoded_options_count; ++i)
Index: gcc/lto-wrapper.c
===================================================================
*** gcc/lto-wrapper.c (revision 205009)
--- gcc/lto-wrapper.c (working copy)
*************** merge_and_complain (struct cl_decoded_op
*** 422,427 ****
--- 422,439 ----
append_option (decoded_options, decoded_options_count, foption);
break;
+ case OPT_ffp_contract_:
+ /* For selected options we can merge conservatively. */
+ for (j = 0; j < *decoded_options_count; ++j)
+ if ((*decoded_options)[j].opt_index == foption->opt_index)
+ break;
+ if (j == *decoded_options_count)
+ append_option (decoded_options, decoded_options_count, foption);
+ /* FP_CONTRACT_OFF < FP_CONTRACT_ON < FP_CONTRACT_FAST. */
+ else if (foption->value < (*decoded_options)[j].value)
+ (*decoded_options)[j] = *foption;
+ break;
+
case OPT_freg_struct_return:
case OPT_fpcc_struct_return:
for (j = 0; j < *decoded_options_count; ++j)
*************** run_gcc (unsigned argc, char *argv[])
*** 578,583 ****
--- 590,596 ----
case OPT_fgnu_tm:
case OPT_freg_struct_return:
case OPT_fpcc_struct_return:
+ case OPT_ffp_contract_:
break;
default:
