[Bug target/96968] New: aarch64 : ICE in vregs pass lowering __builtin_aarch64_get_fpcr

[Bug target/96968] New: aarch64 : ICE in vregs pass lowering __builtin_aarch64_get_fpcr

[iains at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96968

            Bug ID: 96968
           Summary: aarch64 : ICE in vregs pass lowering
                    __builtin_aarch64_get_fpcr
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: iains at gcc dot gnu.org
  Target Milestone: ---

Testcase from FX:

int main (void) {
  unsigned int fpcr;
  fpcr = __builtin_aarch64_get_fpcr ();
}

gcc11 / master r11-3035.

$ ./gcc/xgcc -Bgcc ~/fpcr-test-a.c -S
.../fpcr-test-a.c: In function ‘main’:
.../fpcr-test-a.c:7:1: error: unrecognizable insn:
    7 | }
      | ^
(insn 5 2 6 2 (set (mem/c:SI (plus:DI (reg/f:DI 87 virtual-stack-vars)
                (const_int -4 [0xfffffffffffffffc])) [1 fpcr+0 S4 A32])
        (unspec_volatile:SI [
                (const_int 0 [0])
            ] UNSPECV_GET_FPCR)) ".../fpcr-test-a.c":5:10 -1
     (nil))
during RTL pass: vregs
.../fpcr-test-a.c:7:1: internal compiler error: in extract_insn, at
recog.c:2294
0x61cf73 _fatal_insn(char const*, rtx_def const*, char const*, int, char
const*)
        ../../src/gcc/rtl-error.c:108
0x61cfa7 _fatal_insn_not_found(rtx_def const*, char const*, int, char const*)
        ../../src/gcc/rtl-error.c:116
0xbdd5ef extract_insn(rtx_insn*)
        ../../src/gcc/recog.c:2294
0x96407b instantiate_virtual_regs_in_insn
        ../../src/gcc/function.c:1607
0x96407b instantiate_virtual_regs
        ../../src/gcc/function.c:1977
0x96407b execute
        ../../src/gcc/function.c:2026

[Bug target/96968] aarch64 : ICE in vregs pass lowering __builtin_aarch64_get_fpcr

[iains at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96968

Iain Sandoe <iains at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |ice-on-valid-code
             Target|                            |aarch64-linux-gnu,
                   |                            |aarch64-darwin
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2020-09-08
             Status|UNCONFIRMED                 |NEW

[Bug target/96968] aarch64 : ICE in vregs pass lowering __builtin_aarch64_get_fpcr

[fxcoudert at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96968

Francois-Xavier Coudert <fxcoudert at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |fxcoudert at gcc dot gnu.org

--- Comment #1 from Francois-Xavier Coudert <fxcoudert at gcc dot gnu.org> ---
Exact same issue also occurs with __builtin_aarch64_get_fpsr().

With __builtin_aarch64_get_fpsr64() and __builtin_aarch64_get_fpcr64(), I get
"error: unrecognizable insn" at -O0, and "internal compiler error: Segmentation
fault" at -O1.

[Bug target/96968] aarch64 : ICE in vregs pass lowering __builtin_aarch64_get_fpcr

[iains at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96968

--- Comment #2 from Iain Sandoe <iains at gcc dot gnu.org> ---

for __builtin_aarch64_get_fpcr64 () O1 the fail is:

$ ./gcc/xgcc -Bgcc ~/fpcr-test-a.c -S -O
during RTL pass: expand
.../fpcr-test-a.c: In function ‘main’:
.../fpcr-test-a.c:7:1: internal compiler error: Segmentation fault
    7 | }
      | ^
0xc7d9c3 crash_signal
        ../../src/gcc/toplev.c:327
0xab6a84 mark_jump_label_1
        ../../src/gcc/jump.c:1087
0xab6c23 mark_jump_label_1
        ../../src/gcc/jump.c:1211
0xab7033 mark_all_labels
        ../../src/gcc/jump.c:332
0xab7223 rebuild_jump_labels_1
        ../../src/gcc/jump.c:74
0xab7223 rebuild_jump_labels(rtx_insn*)
        ../../src/gcc/jump.c:98
0x7d35a3 execute
        ../../src/gcc/cfgexpand.c:6619

[Bug target/96968] aarch64 : ICE in vregs or expand pass, lowering __builtin_aarch64_get_{fpcr,fpsr,fpcr64,fpsr64}

[akrl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96968

--- Comment #3 from akrl at gcc dot gnu.org ---
Confirm this was introduced by:

0d7e5fa655e59c99035bf94a46c912e369bb9fa0
"aarch64: Add 64 bit setter getter fpsr fpcr"

I'll have a look as soon as I have a slot of time.

Re: [Bug target/96968] aarch64 : ICE in vregs or expand pass, lowering __builtin_aarch64_get_{fpcr,fpsr,fpcr64,fpsr64}

[Andrea Corallo]

Patch posted at:

https://gcc.gnu.org/pipermail/gcc-patches/2020-September/553882.html

[Bug target/96968] aarch64 : ICE in vregs or expand pass, lowering __builtin_aarch64_get_{fpcr,fpsr,fpcr64,fpsr64}

[andrea.corallo at arm dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96968

--- Comment #4 from Andrea Corallo <andrea.corallo at arm dot com> ---
Patch posted at:

https://gcc.gnu.org/pipermail/gcc-patches/2020-September/553882.html

[Bug target/96968] aarch64 : ICE in vregs or expand pass, lowering __builtin_aarch64_get_{fpcr,fpsr,fpcr64,fpsr64}

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96968

--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Andrea Corallo <akrl@gcc.gnu.org>:

https://gcc.gnu.org/g:f5e73de00e9c853ce65333efada7409b0d00f758

commit r11-3317-gf5e73de00e9c853ce65333efada7409b0d00f758
Author: Andrea Corallo <andrea.corallo@arm.com>
Date:   Mon Sep 14 14:47:24 2020 +0100

    aarch64: Fix ICE on fpsr fpcr getters [PR96968]

    gcc/ChangeLog

    2020-09-14  Andrea Corallo  <andrea.corallo@arm.com>

            PR target/96968
            * config/aarch64/aarch64-builtins.c
            (aarch64_expand_fpsr_fpcr_setter): Fix comment nit.
            (aarch64_expand_fpsr_fpcr_getter): New function, expand these
            getters using expand_insn machinery.
            (aarch64_general_expand_builtin): Make use of.

    gcc/testsuite/ChangeLog

    2020-09-14  Andrea Corallo  <andrea.corallo@arm.com>

            PR target/96968
            * gcc.target/aarch64/pr96968.c: New test.

Re: [Bug target/96968] aarch64 : ICE in vregs or expand pass, lowering __builtin_aarch64_get_{fpcr,fpsr,fpcr64,fpsr64}

[Andrea Corallo]

I believe f5e73de00e9c853ce65333efada7409b0d00f758 should have fixed
this.

Okay to close?

Thanks

  Andrea

[Bug target/96968] aarch64 : ICE in vregs or expand pass, lowering __builtin_aarch64_get_{fpcr,fpsr,fpcr64,fpsr64}

[andrea.corallo at arm dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96968

--- Comment #6 from Andrea Corallo <andrea.corallo at arm dot com> ---
I believe f5e73de00e9c853ce65333efada7409b0d00f758 should have fixed
this.

Okay to close?

Thanks

  Andrea

[Bug target/96968] aarch64 : ICE in vregs or expand pass, lowering __builtin_aarch64_get_{fpcr,fpsr,fpcr64,fpsr64}

[iains at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96968

--- Comment #7 from Iain Sandoe <iains at gcc dot gnu.org> ---
(In reply to Andrea Corallo from comment #6)
> I believe f5e73de00e9c853ce65333efada7409b0d00f758 should have fixed
> this.
> 
> Okay to close?

unfortunately, I've not been able to test since you applied this - currently
bootstrap is broken on aarch64-darwin for reasons outside our control (new
security provisions stopping the gcc/build/gen* programs from running).  If it
could stay open for a few more days, while we try to find a fix for that - (or
close it and we can reopen if needed).

Re: [Bug target/96968] aarch64 : ICE in vregs or expand pass, lowering __builtin_aarch64_get_{fpcr,fpsr,fpcr64,fpsr64}

[Andrea Corallo]

"iains at gcc dot gnu.org via Gcc-bugs" <gcc-bugs@gcc.gnu.org> writes:
[...]
> unfortunately, I've not been able to test since you applied this - currently
> bootstrap is broken on aarch64-darwin for reasons outside our control (new
> security provisions stopping the gcc/build/gen* programs from running).  If it
> could stay open for a few more days, while we try to find a fix for that - (or
> close it and we can reopen if needed).

Sure no rush, thanks for testing it!

[Bug target/96968] aarch64 : ICE in vregs or expand pass, lowering __builtin_aarch64_get_{fpcr,fpsr,fpcr64,fpsr64}

[andrea.corallo at arm dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96968

--- Comment #8 from Andrea Corallo <andrea.corallo at arm dot com> ---
"iains at gcc dot gnu.org via Gcc-bugs" <gcc-bugs@gcc.gnu.org> writes:
[...]
> unfortunately, I've not been able to test since you applied this - currently
> bootstrap is broken on aarch64-darwin for reasons outside our control (new
> security provisions stopping the gcc/build/gen* programs from running).  If it
> could stay open for a few more days, while we try to find a fix for that - (or
> close it and we can reopen if needed).

Sure no rush, thanks for testing it!

[Bug target/96968] aarch64 : ICE in vregs or expand pass, lowering __builtin_aarch64_get_{fpcr,fpsr,fpcr64,fpsr64}

[iains at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96968

--- Comment #9 from Iain Sandoe <iains at gcc dot gnu.org> ---
(In reply to Andrea Corallo from comment #8)
> "iains at gcc dot gnu.org via Gcc-bugs" <gcc-bugs@gcc.gnu.org> writes:
> [...]
> > unfortunately, I've not been able to test since you applied this - currently
> > bootstrap is broken on aarch64-darwin for reasons outside our control (new
> > security provisions stopping the gcc/build/gen* programs from running).  If it
> > could stay open for a few more days, while we try to find a fix for that - (or
> > close it and we can reopen if needed).
> 
> Sure no rush, thanks for testing it!

I managed to do a manual build on arm64-darwin, and the ICE is gone.  Not sure
if the flags are supported by the hardware but that's a different issue.  Fine
to close this from my pov.

We get this for the simple test-case (mach-o/darwin format object):
        .arch armv8-a
        .text
        .align  2
        .globl _main
_main:
LFB0:
        .cfi_startproc
        sub     sp, sp, #16
        .cfi_def_cfa_offset 16
        mrs     x0, fpcr
        str     w0, [sp, 12]
        mov     w0, 0
        add     sp, sp, 16
        .cfi_def_cfa_offset 0
        ret
        .cfi_endproc
LFE0:
        .ident  "GCC: (GNU) 11.0.0 20200929 (experimental)"
        .subsections_via_symbols

[Bug target/96968] aarch64 : ICE in vregs or expand pass, lowering __builtin_aarch64_get_{fpcr,fpsr,fpcr64,fpsr64}

[akrl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96968

akrl at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |FIXED

--- Comment #10 from akrl at gcc dot gnu.org ---
Thanks, closing.