"H.J. Lu" <hjl.to...@gmail.com> writes:
> On Fri, Jun 14, 2019 at 8:31 AM Richard Sandiford
> <richard.sandif...@arm.com> wrote:
>>
>> "H.J. Lu" <hjl.to...@gmail.com> writes:
>> > diff --git a/gcc/calls.c b/gcc/calls.c
>> > index c8a42680041..6ab138e7bb0 100644
>> > --- a/gcc/calls.c
>> > +++ b/gcc/calls.c
>> > @@ -3226,6 +3226,19 @@ can_implement_as_sibling_call_p (tree exp,
>> > return true;
>> > }
>> >
>> > +/* Update stack alignment when the parameter is passed in the stack
>> > + since the outgoing parameter requires extra alignment on the calling
>> > + function side. */
>> > +
>> > +static void
>> > +update_stack_alignment_for_call (struct locate_and_pad_arg_data *locate)
>> > +{
>> > + if (crtl->stack_alignment_needed < locate->boundary)
>> > + crtl->stack_alignment_needed = locate->boundary;
>> > + if (crtl->preferred_stack_boundary < locate->boundary)
>> > + crtl->preferred_stack_boundary = locate->boundary;
>> > +}
>> > +
>> > /* Generate all the code for a CALL_EXPR exp
>> > and return an rtx for its value.
>> > Store the value in TARGET (specified as an rtx) if convenient.
>> > @@ -3703,6 +3716,12 @@ expand_call (tree exp, rtx target, int ignore)
>> > /* Ensure current function's preferred stack boundary is at least
>> > what we need. Stack alignment may also increase preferred stack
>> > boundary. */
>> > + for (i = 0; i < num_actuals; i++)
>> > + if (reg_parm_stack_space > 0
>> > + || args[i].reg == 0
>> > + || args[i].partial != 0
>> > + || args[i].pass_on_stack)
>> > + update_stack_alignment_for_call (&args[i].locate);
>> > if (crtl->preferred_stack_boundary < preferred_stack_boundary)
>> > crtl->preferred_stack_boundary = preferred_stack_boundary;
>> > else
>> > @@ -4961,6 +4980,12 @@ emit_library_call_value_1 (int retval, rtx orgfun,
>> > rtx value,
>> > targetm.calls.function_arg_advance (args_so_far, mode, (tree) 0,
>> > true);
>> > }
>> >
>> > + for (int i = 0; i < nargs; i++)
>> > + if (reg_parm_stack_space > 0
>> > + || argvec[i].reg == 0
>> > + || argvec[i].partial != 0)
>> > + update_stack_alignment_for_call (&argvec[i].locate);
>> > +
>>
>> It's safe to test argvec[i].pass_on_stack here too, since the vector
>
> There is no pass_on_stack in argvec:
>
> struct arg
> {
> rtx value;
> machine_mode mode;
> rtx reg;
> int partial;
> struct locate_and_pad_arg_data locate;
> rtx save_area;
> };
> struct arg *argvec;
>
>> is initialised to zeros. So I think we should move the "if"s into the
>> new function:
>>
>> static void
>> update_stack_alignment_for_call (struct locate_and_pad_arg_data *locate)
>> {
>> if (reg_parm_stack_space > 0
>> || locate->reg == 0
>> || locate->partial != 0
>> || locate->pass_on_stack)
>
> Since we have
>
> struct locate_and_pad_arg_data
> {
> /* Size of this argument on the stack, rounded up for any padding it
> gets. If REG_PARM_STACK_SPACE is defined, then register parms are
> counted here, otherwise they aren't. */
> struct args_size size;
> /* Offset of this argument from beginning of stack-args. */
> struct args_size offset;
> /* Offset to the start of the stack slot. Different from OFFSET
> if this arg pads downward. */
> struct args_size slot_offset;
> /* The amount that the stack pointer needs to be adjusted to
> force alignment for the next argument. */
> struct args_size alignment_pad;
> /* Which way we should pad this arg. */
> pad_direction where_pad;
> /* slot_offset is at least this aligned. */
> unsigned int boundary;
> };
>
> we can't check reg, partial nor pass_on_stack here.
Sorry, missed that they were different structures.
>> {
>> if (crtl->stack_alignment_needed < locate->boundary)
>> crtl->stack_alignment_needed = locate->boundary;
>> if (crtl->preferred_stack_boundary < locate->boundary)
>> crtl->preferred_stack_boundary = locate->boundary;
>> }
>> }
>>
>> OK with that change, thanks.
>>
>
> Is my original patch OK?
Yes, thanks.
Richard
