On Fri, 4 Dec 2015, Jakub Jelinek wrote:
> On Fri, Dec 04, 2015 at 10:30:38AM +0100, Richard Biener wrote:
> > > The following patch has been bootstrapped/regtested on x86_64-linux and
> > > i686-linux.
> >
> > The patch is ok - it looks like you could have removed the
> > __builtin_alloca strcmp with it though.
>
> Ok, will remove the strcmp then.
>
> > Does the patch mean we inlined __builtin_alloca_with_align ()
> > functions? We might run into the issue Eric fixed lately with
>
> Yes, see testcase below. 4.7+ inlines it. As for tail call optimization,
> seems we are just lucky there (f4), as fab pass which is quite late
> turns the __builtin_stack_restore into GIMPLE_NOP and tailc pass does not
> ignore nops. Shall I commit following patch to trunk to fix that up
> (after committing this VLA fix of course)?
Yes please.
Thanks,
Richard.
> int f1 (char *);
>
> static inline void
> f2 (int x)
> {
> char a[x];
> f1 (a);
> }
>
> void
> f3 (int x)
> {
> f2 (x);
> f2 (x);
> f2 (x);
> f2 (x);
> }
>
> int
> f4 (int x)
> {
> char a[x];
> return f1 (a);
> }
>
> 2015-12-04 Jakub Jelinek <[email protected]>
>
> * tree-tailcall.c (find_tail_calls): Ignore GIMPLE_NOPs.
>
> --- gcc/tree-tailcall.c.jj 2015-11-04 11:12:17.000000000 +0100
> +++ gcc/tree-tailcall.c 2015-12-04 11:43:01.296110941 +0100
> @@ -412,9 +412,10 @@ find_tail_calls (basic_block bb, struct
> {
> stmt = gsi_stmt (gsi);
>
> - /* Ignore labels, returns, clobbers and debug stmts. */
> + /* Ignore labels, returns, nops, clobbers and debug stmts. */
> if (gimple_code (stmt) == GIMPLE_LABEL
> || gimple_code (stmt) == GIMPLE_RETURN
> + || gimple_code (stmt) == GIMPLE_NOP
> || gimple_clobber_p (stmt)
> || is_gimple_debug (stmt))
> continue;
> @@ -532,7 +533,8 @@ find_tail_calls (basic_block bb, struct
>
> stmt = gsi_stmt (agsi);
>
> - if (gimple_code (stmt) == GIMPLE_LABEL)
> + if (gimple_code (stmt) == GIMPLE_LABEL
> + || gimple_code (stmt) == GIMPLE_NOP)
> continue;
>
> if (gimple_code (stmt) == GIMPLE_RETURN)
>
>
> Jakub
>
>
--
Richard Biener <[email protected]>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
