[PATCH 6/9] [LVU] Allow final_start_function to skip initial insns
Richard Biener
richard.guenther@gmail.com
Thu Oct 19 11:07:00 GMT 2017
On Sat, Sep 30, 2017 at 11:08 AM, Alexandre Oliva <aoliva@redhat.com> wrote:
> This API change will enable final_start_function() to "consume"
> initial insns, and choose the first insn to be passed to final().
>
> Many ports call final_start_function() and final() when creating
> thunks and whatnot, so they needed adjusting.
But for MI thunks (and whatnot) there's no debug info. So why do we care?
Most of them ask for sth very low-level.
That is, almost all the time the sequence is final_start_function immediately
followed by a call to final. So isn't better refactoring the answer here?
Some ports only call final_start_function and never final for their thunks
for example.
That said, what do we lose when you do not adjust these things?
After all final () does more stuff than calling final_scan_insn on all
insns but you only do that for those you handle in final_start_function.
It seems to me that the current split between start/final/end is too
artificial and that the few "raw" building blocks that backends maybe
need should be factored out for them?
That said, it looks like an ugly "layering" violation you are introducing.
But of course I don't know history or details around this part of the
compiler...
That said, all ports invoking final () invoke it in the
start/final/end sequence.
spu, s390, rs6000 (and thus powerpcspe), pa, nds32, i386, cris, arm
invoke final_start_function and not final in the next 3 lines. They all
invoke final_end_function but not final inbetween (all invokers of final
do the 3-line dance).
So, refactor final() to do all three and provide the chunks targets
really care for?
Why can't we do the param locview handling from final ()?
Probably all remanents of targets with text prologues?
Anyway, don't feel like acking in its current state because of this,
maybe somebody else can chime in.
Thanks,
Richard.
> for gcc/ChangeLog
>
> * output.h (final_start_function): Adjust.
> * final.c (final_start_function): Take pointer to FIRST.
> (rest_of_handle_final): Adjust.
> * config/aarch64/aarch64.c (aarch64_output_mi_thunk): Adjust.
> * config/alpha/alpha.c (alpha_output_mi_thunk_osf): Likewise.
> * config/arm/arm.c (arm_thumb1_mi_thunk): Likewise.
> (arm32_output_mi_thunk): Likewise.
> * config/cris/cris.c (cris_asm_output_mi_thunk): Likewise.
> * config/i386/i386.c (ix86_code_end): Likewise.
> (x86_output_mi_thunk): Likewise.
> * config/ia64/ia64.c (ia64_output_mi_thunk): Likewise.
> * config/m68k/m68k.c (m68k_output_mi_thunk): Likewise.
> * config/microblaze/microblaze.c (microblaze_asm_output_mi_thunk):
> Likewise.
> * config/mips/mips.c (mips_output_mi_thunk): Likewise.
> * config/nds32/nds32.c (nds32_asm_output_mi_thunk): Likewise.
> * config/nios2/nios2.c (nios2_asm_output_mi_thunk): Likewise.
> * config/pa/pa.c (pa_asm_output_mi_thunk): Likewise.
> * config/rs6000/rs6000.c (rs6000_output_mi_thunk): Likewise.
> (rs6000_code_end): Likewise.
> * config/s390/s390.c (s390_output_mi_thunk): Likewise.
> * config/sh/sh.c (sh_output_mi_thunk): Likewise.
> * config/sparc/sparc.c (sparc_output_mi_thunk): Likewise.
> * config/spu/spu.c (spu_output_mi_thunk): Likewise.
> * config/tilegx/tilegx.c (tilegx_output_mi_thunk): Likewise.
> * config/tilepro/tilepro.c (tilepro_asm_output_mi_thunk): Likewise.
> ---
> gcc/config/aarch64/aarch64.c | 2 +-
> gcc/config/alpha/alpha.c | 2 +-
> gcc/config/arm/arm.c | 5 +++--
> gcc/config/cris/cris.c | 3 ++-
> gcc/config/i386/i386.c | 5 +++--
> gcc/config/ia64/ia64.c | 2 +-
> gcc/config/m68k/m68k.c | 2 +-
> gcc/config/microblaze/microblaze.c | 2 +-
> gcc/config/mips/mips.c | 2 +-
> gcc/config/nds32/nds32.c | 3 ++-
> gcc/config/nios2/nios2.c | 2 +-
> gcc/config/pa/pa.c | 3 ++-
> gcc/config/rs6000/rs6000.c | 5 +++--
> gcc/config/s390/s390.c | 3 ++-
> gcc/config/sh/sh.c | 2 +-
> gcc/config/sparc/sparc.c | 2 +-
> gcc/config/spu/spu.c | 3 ++-
> gcc/config/tilegx/tilegx.c | 2 +-
> gcc/config/tilepro/tilepro.c | 2 +-
> gcc/final.c | 9 ++++++---
> gcc/output.h | 2 +-
> 21 files changed, 37 insertions(+), 26 deletions(-)
>
> diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
> index 23f5aff..73872dd 100644
> --- a/gcc/config/aarch64/aarch64.c
> +++ b/gcc/config/aarch64/aarch64.c
> @@ -3961,7 +3961,7 @@ aarch64_output_mi_thunk (FILE *file, tree thunk ATTRIBUTE_UNUSED,
>
> insn = get_insns ();
> shorten_branches (insn);
> - final_start_function (insn, file, 1);
> + final_start_function (&insn, file, 1);
> final (insn, file, 1);
> final_end_function ();
>
> diff --git a/gcc/config/alpha/alpha.c b/gcc/config/alpha/alpha.c
> index 41f3e3a..56b6f04 100644
> --- a/gcc/config/alpha/alpha.c
> +++ b/gcc/config/alpha/alpha.c
> @@ -8480,7 +8480,7 @@ alpha_output_mi_thunk_osf (FILE *file, tree thunk_fndecl ATTRIBUTE_UNUSED,
> assemble_start_function and assemble_end_function. */
> insn = get_insns ();
> shorten_branches (insn);
> - final_start_function (insn, file, 1);
> + final_start_function (&insn, file, 1);
> final (insn, file, 1);
> final_end_function ();
> }
> diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
> index 4cddf3b..9301d58 100644
> --- a/gcc/config/arm/arm.c
> +++ b/gcc/config/arm/arm.c
> @@ -26410,7 +26410,8 @@ arm_thumb1_mi_thunk (FILE *file, tree, HOST_WIDE_INT delta,
> if (mi_delta < 0)
> mi_delta = - mi_delta;
>
> - final_start_function (emit_barrier (), file, 1);
> + rtx_insn *first = emit_barrier ();
> + final_start_function (&first, file, 1);
>
> if (TARGET_THUMB1)
> {
> @@ -26587,7 +26588,7 @@ arm32_output_mi_thunk (FILE *file, tree, HOST_WIDE_INT delta,
>
> insn = get_insns ();
> shorten_branches (insn);
> - final_start_function (insn, file, 1);
> + final_start_function (&insn, file, 1);
> final (insn, file, 1);
> final_end_function ();
>
> diff --git a/gcc/config/cris/cris.c b/gcc/config/cris/cris.c
> index fe80a27..3581d2d 100644
> --- a/gcc/config/cris/cris.c
> +++ b/gcc/config/cris/cris.c
> @@ -2755,7 +2755,8 @@ cris_asm_output_mi_thunk (FILE *stream,
> tree funcdecl)
> {
> /* Make sure unwind info is emitted for the thunk if needed. */
> - final_start_function (emit_barrier (), stream, 1);
> + rtx_insn *first = emit_barrier ();
> + final_start_function (&first, stream, 1);
>
> if (delta > 0)
> fprintf (stream, "\tadd%s " HOST_WIDE_INT_PRINT_DEC ",$%s\n",
> diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
> index 98fb1ce..d4d9490 100644
> --- a/gcc/config/i386/i386.c
> +++ b/gcc/config/i386/i386.c
> @@ -12499,8 +12499,9 @@ ix86_code_end (void)
> emitting it directly; tell them we're a thunk, if they care. */
> cfun->is_thunk = true;
> first_function_block_is_cold = false;
> + rtx_insn *first = emit_barrier ();
> /* Make sure unwind info is emitted for the thunk if needed. */
> - final_start_function (emit_barrier (), asm_out_file, 1);
> + final_start_function (&first, asm_out_file, 1);
>
> /* Pad stack IP move with 4 instructions (two NOPs count
> as one instruction). */
> @@ -43001,7 +43002,7 @@ x86_output_mi_thunk (FILE *file, tree, HOST_WIDE_INT delta,
> Note that use_thunk calls assemble_start_function et al. */
> insn = get_insns ();
> shorten_branches (insn);
> - final_start_function (insn, file, 1);
> + final_start_function (&insn, file, 1);
> final (insn, file, 1);
> final_end_function ();
> }
> diff --git a/gcc/config/ia64/ia64.c b/gcc/config/ia64/ia64.c
> index fce3006..a94ab67 100644
> --- a/gcc/config/ia64/ia64.c
> +++ b/gcc/config/ia64/ia64.c
> @@ -11035,7 +11035,7 @@ ia64_output_mi_thunk (FILE *file, tree thunk ATTRIBUTE_UNUSED,
> emit_all_insn_group_barriers (NULL);
> insn = get_insns ();
> shorten_branches (insn);
> - final_start_function (insn, file, 1);
> + final_start_function (&insn, file, 1);
> final (insn, file, 1);
> final_end_function ();
>
> diff --git a/gcc/config/m68k/m68k.c b/gcc/config/m68k/m68k.c
> index cd2e15e..48b9c4a 100644
> --- a/gcc/config/m68k/m68k.c
> +++ b/gcc/config/m68k/m68k.c
> @@ -5142,7 +5142,7 @@ m68k_output_mi_thunk (FILE *file, tree thunk ATTRIBUTE_UNUSED,
> /* Run just enough of rest_of_compilation. */
> insn = get_insns ();
> split_all_insns_noflow ();
> - final_start_function (insn, file, 1);
> + final_start_function (&insn, file, 1);
> final (insn, file, 1);
> final_end_function ();
>
> diff --git a/gcc/config/microblaze/microblaze.c b/gcc/config/microblaze/microblaze.c
> index 53ca016..4ebe023 100644
> --- a/gcc/config/microblaze/microblaze.c
> +++ b/gcc/config/microblaze/microblaze.c
> @@ -3257,7 +3257,7 @@ microblaze_asm_output_mi_thunk (FILE *file, tree thunk_fndecl ATTRIBUTE_UNUSED,
> "borrowed" from rs6000.c. */
> insn = get_insns ();
> shorten_branches (insn);
> - final_start_function (insn, file, 1);
> + final_start_function (&insn, file, 1);
> final (insn, file, 1);
> final_end_function ();
>
> diff --git a/gcc/config/mips/mips.c b/gcc/config/mips/mips.c
> index 4133375..d1f7bd8 100644
> --- a/gcc/config/mips/mips.c
> +++ b/gcc/config/mips/mips.c
> @@ -19394,7 +19394,7 @@ mips_output_mi_thunk (FILE *file, tree thunk_fndecl ATTRIBUTE_UNUSED,
> split_all_insns_noflow ();
> mips16_lay_out_constants (true);
> shorten_branches (insn);
> - final_start_function (insn, file, 1);
> + final_start_function (&insn, file, 1);
> final (insn, file, 1);
> final_end_function ();
>
> diff --git a/gcc/config/nds32/nds32.c b/gcc/config/nds32/nds32.c
> index 65095ff..f6d5f06 100644
> --- a/gcc/config/nds32/nds32.c
> +++ b/gcc/config/nds32/nds32.c
> @@ -1633,7 +1633,8 @@ nds32_asm_output_mi_thunk (FILE *file, tree thunk ATTRIBUTE_UNUSED,
> int this_regno;
>
> /* Make sure unwind info is emitted for the thunk if needed. */
> - final_start_function (emit_barrier (), file, 1);
> + rtx_insn *first = emit_barrier ();
> + final_start_function (&first, file, 1);
>
> this_regno = (aggregate_value_p (TREE_TYPE (TREE_TYPE (function)), function)
> ? 1
> diff --git a/gcc/config/nios2/nios2.c b/gcc/config/nios2/nios2.c
> index 2602605..6ab2c24 100644
> --- a/gcc/config/nios2/nios2.c
> +++ b/gcc/config/nios2/nios2.c
> @@ -4061,7 +4061,7 @@ nios2_asm_output_mi_thunk (FILE *file, tree thunk_fndecl ATTRIBUTE_UNUSED,
> assemble_start_function and assemble_end_function. */
> insn = get_insns ();
> shorten_branches (insn);
> - final_start_function (insn, file, 1);
> + final_start_function (&insn, file, 1);
> final (insn, file, 1);
> final_end_function ();
>
> diff --git a/gcc/config/pa/pa.c b/gcc/config/pa/pa.c
> index 5e945fc..418a017 100644
> --- a/gcc/config/pa/pa.c
> +++ b/gcc/config/pa/pa.c
> @@ -8404,7 +8404,8 @@ pa_asm_output_mi_thunk (FILE *file, tree thunk_fndecl, HOST_WIDE_INT delta,
> xoperands[1] = XEXP (DECL_RTL (thunk_fndecl), 0);
> xoperands[2] = GEN_INT (delta);
>
> - final_start_function (emit_barrier (), file, 1);
> + rtx_insn *first = emit_barrier ();
> + final_start_function (&first, file, 1);
>
> /* Output the thunk. We know that the function is in the same
> translation unit (i.e., the same space) as the thunk, and that
> diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
> index 1e794a0..cf1a7bf 100644
> --- a/gcc/config/rs6000/rs6000.c
> +++ b/gcc/config/rs6000/rs6000.c
> @@ -29699,7 +29699,7 @@ rs6000_output_mi_thunk (FILE *file, tree thunk_fndecl ATTRIBUTE_UNUSED,
> assemble_start_function and assemble_end_function. */
> insn = get_insns ();
> shorten_branches (insn);
> - final_start_function (insn, file, 1);
> + final_start_function (&insn, file, 1);
> final (insn, file, 1);
> final_end_function ();
>
> @@ -38165,7 +38165,8 @@ rs6000_code_end (void)
> init_function_start (decl);
> first_function_block_is_cold = false;
> /* Make sure unwind info is emitted for the thunk if needed. */
> - final_start_function (emit_barrier (), asm_out_file, 1);
> + rtx_insn *first = emit_barrier ();
> + final_start_function (&first, asm_out_file, 1);
>
> fputs ("\tblr\n", asm_out_file);
>
> diff --git a/gcc/config/s390/s390.c b/gcc/config/s390/s390.c
> index 52a82df..0bea709 100644
> --- a/gcc/config/s390/s390.c
> +++ b/gcc/config/s390/s390.c
> @@ -13202,7 +13202,8 @@ s390_output_mi_thunk (FILE *file, tree thunk ATTRIBUTE_UNUSED,
> int nonlocal = 0;
>
> /* Make sure unwind info is emitted for the thunk if needed. */
> - final_start_function (emit_barrier (), file, 1);
> + rtx_insn *first = emit_barrier ();
> + final_start_function (&first, file, 1);
>
> /* Operand 0 is the target function. */
> op[0] = XEXP (DECL_RTL (function), 0);
> diff --git a/gcc/config/sh/sh.c b/gcc/config/sh/sh.c
> index 3c6d525..284fb81 100644
> --- a/gcc/config/sh/sh.c
> +++ b/gcc/config/sh/sh.c
> @@ -10936,7 +10936,7 @@ sh_output_mi_thunk (FILE *file, tree thunk_fndecl ATTRIBUTE_UNUSED,
>
> sh_reorg ();
> shorten_branches (insns);
> - final_start_function (insns, file, 1);
> + final_start_function (&insns, file, 1);
> final (insns, file, 1);
> final_end_function ();
>
> diff --git a/gcc/config/sparc/sparc.c b/gcc/config/sparc/sparc.c
> index d3f002d..9432a66 100644
> --- a/gcc/config/sparc/sparc.c
> +++ b/gcc/config/sparc/sparc.c
> @@ -12140,7 +12140,7 @@ sparc_output_mi_thunk (FILE *file, tree thunk_fndecl ATTRIBUTE_UNUSED,
> assemble_start_function and assemble_end_function. */
> insn = get_insns ();
> shorten_branches (insn);
> - final_start_function (insn, file, 1);
> + final_start_function (&insn, file, 1);
> final (insn, file, 1);
> final_end_function ();
>
> diff --git a/gcc/config/spu/spu.c b/gcc/config/spu/spu.c
> index b9af9a9..d22cf3e 100644
> --- a/gcc/config/spu/spu.c
> +++ b/gcc/config/spu/spu.c
> @@ -7045,7 +7045,8 @@ spu_output_mi_thunk (FILE *file, tree thunk ATTRIBUTE_UNUSED,
> rtx op[8];
>
> /* Make sure unwind info is emitted for the thunk if needed. */
> - final_start_function (emit_barrier (), file, 1);
> + rtx_insn *insn = emit_barrier ();
> + final_start_function (&insn, file, 1);
>
> /* Operand 0 is the target function. */
> op[0] = XEXP (DECL_RTL (function), 0);
> diff --git a/gcc/config/tilegx/tilegx.c b/gcc/config/tilegx/tilegx.c
> index 63fe340..861577eca 100644
> --- a/gcc/config/tilegx/tilegx.c
> +++ b/gcc/config/tilegx/tilegx.c
> @@ -4998,7 +4998,7 @@ tilegx_output_mi_thunk (FILE *file, tree thunk_fndecl ATTRIBUTE_UNUSED,
> */
> insn = get_insns ();
> shorten_branches (insn);
> - final_start_function (insn, file, 1);
> + final_start_function (&insn, file, 1);
> final (insn, file, 1);
> final_end_function ();
>
> diff --git a/gcc/config/tilepro/tilepro.c b/gcc/config/tilepro/tilepro.c
> index ee9bc0a..e261400 100644
> --- a/gcc/config/tilepro/tilepro.c
> +++ b/gcc/config/tilepro/tilepro.c
> @@ -4421,7 +4421,7 @@ tilepro_asm_output_mi_thunk (FILE *file, tree thunk_fndecl ATTRIBUTE_UNUSED,
> */
> insn = get_insns ();
> shorten_branches (insn);
> - final_start_function (insn, file, 1);
> + final_start_function (&insn, file, 1);
> final (insn, file, 1);
> final_end_function ();
>
> diff --git a/gcc/final.c b/gcc/final.c
> index 49cfbfb..d2b8523d 100644
> --- a/gcc/final.c
> +++ b/gcc/final.c
> @@ -1763,9 +1763,11 @@ get_some_local_dynamic_name ()
> test and compare insns. */
>
> void
> -final_start_function (rtx_insn *first, FILE *file,
> +final_start_function (rtx_insn **firstp, FILE *file,
> int optimize_p ATTRIBUTE_UNUSED)
> {
> + rtx_insn *first = *firstp;
> +
> block_depth = 0;
>
> this_is_asm_operands = 0;
> @@ -4536,8 +4538,9 @@ rest_of_handle_final (void)
> variable_tracking_main ();
>
> assemble_start_function (current_function_decl, fnname);
> - final_start_function (get_insns (), asm_out_file, optimize);
> - final (get_insns (), asm_out_file, optimize);
> + rtx_insn *first = get_insns ();
> + final_start_function (&first, asm_out_file, optimize);
> + final (first, asm_out_file, optimize);
> if (flag_ipa_ra
> && !lookup_attribute ("noipa", DECL_ATTRIBUTES (current_function_decl)))
> collect_fn_hard_reg_usage ();
> diff --git a/gcc/output.h b/gcc/output.h
> index e98a911..62a405d 100644
> --- a/gcc/output.h
> +++ b/gcc/output.h
> @@ -59,7 +59,7 @@ const char *get_some_local_dynamic_name ();
> for the new function. The label for the function and associated
> assembler pseudo-ops have already been output in
> `assemble_start_function'. */
> -extern void final_start_function (rtx_insn *, FILE *, int);
> +extern void final_start_function (rtx_insn **, FILE *, int);
>
> /* Output assembler code for the end of a function.
> For clarity, args are same as those of `final_start_function'
> --
> 2.9.5
>
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