On Tue, 6 Oct 2015, H.J. Lu wrote:
> On Tue, Oct 6, 2015 at 8:01 AM, H.J. Lu <hjl.to...@gmail.com> wrote:
> > On Tue, Oct 6, 2015 at 6:39 AM, Richard Biener <rguent...@suse.de> wrote:
> >> On Tue, 6 Oct 2015, H.J. Lu wrote:
> >>
> >>> On Tue, Oct 06, 2015 at 02:30:59PM +0200, Richard Biener wrote:
> >>> > On Tue, Oct 6, 2015 at 1:43 PM, H.J. Lu <hongjiu...@intel.com> wrote:
> >>> > > Since targetm.expand_to_rtl_hook may be called to switch ABI, it
> >>> > > should
> >>> > > be called for each function before expanding to RTL. Otherwise, we
> >>> > > may
> >>> > > use the stale information from compilation of the previous function.
> >>> > > aggregate_value_p uses call_used_regs. aggregate_value_p is used by
> >>> > > IPA and return value optimization, which are called before
> >>> > > pass_expand::execute after RTL expansion starts. We need to call
> >>> > > targetm.expand_to_rtl_hook early enough in cgraph_node::expand to make
> >>> > > sure that everything is in sync when RTL expansion starts.
> >>> > >
> >>> > > Tested on Linux/x86-64. OK for trunk?
> >>> >
> >>> > Hmm, I think set_cfun hook should handle this. expand_to_rtl_hook
> >>> > shouldn't
> >>> > mess with per-function stuff.
> >>> >
> >>> > Richard.
> >>> >
> >>>
> >>> I am testig this patch. OK for trunk if there is no regresion?
> >>>
> >>>
> >>> H.J.
> >>> --
> >>> ix86_maybe_switch_abi is called to late during RTL expansion and we
> >>> use the stale information from compilation of the previous function.
> >>> aggregate_value_p uses call_used_regs. aggregate_value_p is used by
> >>> IPA and return value optimization, which are called before
> >>> pass_expand::execute after RTL expansion starts. Instead,
> >>> ix86_maybe_switch_abi should be merged with ix86_set_current_function.
> >>>
> >>> PR target/67850
> >>> * config/i386/i386.c (ix86_set_current_function): Renamed
> >>> to ...
> >>> (ix86_set_current_function_1): This.
> >>> (ix86_set_current_function): New. incorporate old
> >>> ix86_set_current_function and ix86_maybe_switch_abi.
> >>> (ix86_maybe_switch_abi): Removed.
> >>> (TARGET_EXPAND_TO_RTL_HOOK): Likewise.
> >>> ---
> >>> gcc/config/i386/i386.c | 33 ++++++++++++++++++---------------
> >>> 1 file changed, 18 insertions(+), 15 deletions(-)
> >>>
> >>> diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
> >>> index d59b59b..a0adf3d 100644
> >>> --- a/gcc/config/i386/i386.c
> >>> +++ b/gcc/config/i386/i386.c
> >>> @@ -6222,7 +6222,7 @@ ix86_reset_previous_fndecl (void)
> >>> FNDECL. The argument might be NULL to indicate processing at top
> >>> level, outside of any function scope. */
> >>> static void
> >>> -ix86_set_current_function (tree fndecl)
> >>> +ix86_set_current_function_1 (tree fndecl)
> >>> {
> >>> /* Only change the context if the function changes. This hook is
> >>> called
> >>> several times in the course of compiling a function, and we don't
> >>> want to
> >>> @@ -6262,6 +6262,23 @@ ix86_set_current_function (tree fndecl)
> >>> ix86_previous_fndecl = fndecl;
> >>> }
> >>>
> >>> +static void
> >>> +ix86_set_current_function (tree fndecl)
> >>> +{
> >>> + ix86_set_current_function_1 (fndecl);
> >>> +
> >>> + if (!cfun)
> >>> + return;
> >>
> >> I think you want to test !fndecl here. Why split this out at all?
> >> The ix86_previous_fndecl caching should still work, no?
> >>
> >>> + /* 64-bit MS and SYSV ABI have different set of call used registers.
> >>> + Avoid expensive re-initialization of init_regs each time we switch
> >>> + function context since this is needed only during RTL expansion. */
> >>
> >> The comment is now wrong (and your bug shows it was wrong previously).
> >>
> >
> > Here is the updated patch. OK for master if there is no
> > regression on Linux/x86-64?
> >
>
> There is no regression. OK for trunk?
Ok with me but I defer to Uros for the approval.
Richard.
