[Bug rtl-optimization/65912] New: x_rtl.x_frame_offset not updated after frame related insn deleted

[Bug rtl-optimization/65912] New: x_rtl.x_frame_offset not updated after frame related insn deleted

[jiwang at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65912

            Bug ID: 65912
           Summary: x_rtl.x_frame_offset not updated after frame related
                    insn deleted
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jiwang at gcc dot gnu.org
  Target Milestone: ---

given the following simple test.c

typedef unsigned long int uint64_t;
typedef __Uint8x8_t uint8x8_t;

typedef struct uint8x8x4_t
{
  uint8x8_t val[4];
} uint8x8x4_t;

__inline uint8x8_t
bar (uint64_t __a)
{
  return (uint8x8_t) __a;
}

uint8x8x4_t foo(uint8x8x4_t v1, uint8x8x4_t v2)
{
  return (uint8x8x4_t){{bar(0), bar(0), bar(0), bar(0)}};
}

on aarch64, compile it with "./cc1-aarch64 -std=c99 -Wall -O3
-ftree-vectorizer-verbose=3"

foo:
        movi    v0.2s, 0
        sub     sp, sp, #128  <== useless stack adjustment
        add     sp, sp, 128   <== useless stack adjustment
        ...

There are useless stack adjustment. A quick investigation shows it's caued by
we first decide to put the return value on stack, then later optimized them
into registers, and all those store to stack are deleted by dse1, but stack
space required kept in x_rtl->x_frame_offset is not updated accordingly.

Although I run into this issue on AArch64, I highly suspect it's a generic
issue when the type of return value is very complex.

Has anyone run into this issue on other architecture like MIPS, PPC?

Re: [Bug rtl-optimization/65912] New: x_rtl.x_frame_offset not updated after frame related insn deleted

[pinskia]

> On Apr 27, 2015, at 9:10 PM, jiwang at gcc dot gnu.org <gcc-bugzilla@gcc.gnu.org> wrote:
> 
> Has anyone run into this issue on other architecture like MIPS, PPC?

Yes on both. 
>From gcc-bugs-return-484877-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org Tue Apr 28 16:26:30 2015
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Subject: [Bug rtl-optimization/65912] x_rtl.x_frame_offset not updated after frame related insn deleted
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https://gcc.gnu.org/bugzilla/show_bug.cgi?ide912

--- Comment #1 from pinskia at gmail dot com <pinskia at gmail dot com> ---
> On Apr 27, 2015, at 9:10 PM, jiwang at gcc dot gnu.org <gcc-bugzilla@gcc.gnu.org> wrote:
>
> Has anyone run into this issue on other architecture like MIPS, PPC?

Yes on both.

[Bug rtl-optimization/65912] x_rtl.x_frame_offset not updated after frame related insn deleted

[ramana at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65912

Ramana Radhakrishnan <ramana at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Blocks|                            |47562

--- Comment #3 from Ramana Radhakrishnan <ramana at gcc dot gnu.org> ---
Technically blocks 47562 as this is another intrinsics related issue.


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47562
[Bug 47562] [meta-bug] keep track of Neon Intrinsics enhancements

[Bug rtl-optimization/65912] x_rtl.x_frame_offset not updated after frame related insn deleted

[ramana at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65912

Ramana Radhakrishnan <ramana at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |missed-optimization
             Target|                            |aarch64*-*-*
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2015-06-25
                 CC|                            |ramana at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #2 from Ramana Radhakrishnan <ramana at gcc dot gnu.org> ---
Confirmed then.

[Bug middle-end/65912] x_rtl.x_frame_offset not updated after frame related insn deleted

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65912

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
   Target Milestone|---                         |6.0
             Status|NEW                         |RESOLVED

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This aarch64 testcase was fixed in GCC 6. There are already many more bug
reports about this issue really, see PR 101926.

So closing as fixed for GCC 6.