[Bug c++/111306] New: macro-fusion makes error on conjugate complex multiplication

[Bug c++/111306] New: macro-fusion makes error on conjugate complex multiplication

[joony.wie at samsung dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111306

            Bug ID: 111306
           Summary: macro-fusion makes error on conjugate complex
                    multiplication
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: joony.wie at samsung dot com
  Target Milestone: ---

It seems that the operands src1 and src2 of "_mm512_fcmul_pch" are swapped for
macro-fusion with optimize option.

If the operands are swapped, the imag value of result will have incorrect sign
bit.

So, the operands should not be swapped in these conjugate complex
multiplication intrinsics.

Let me show the example and the output.

output: 
3.000000 -4.000000 // w/o optimize.
3.000000 4.000000 // w/ optimize.

https://godbolt.org/z/df9Gz18hc // but may not executable
```
#include <immintrin.h>
#include <cstdio>

__attribute__((optimize("O0")))
auto func0(_Float16 *a, _Float16 *b, int n, _Float16 *c) {
  __m512h rA = _mm512_loadu_ph(a);
  for (int i = 0; i < n; i += 32) {
    __m512h rB = _mm512_loadu_ph(b + i);
    _mm512_storeu_ph(c + i, _mm512_fcmul_pch(rB, rA));
  }
}

__attribute__((optimize("O")))
auto func1(_Float16 *a, _Float16 *b, int n, _Float16 *c) {
  __m512h rA = _mm512_loadu_ph(a);
  for (int i = 0; i < n; i += 32) {
    __m512h rB = _mm512_loadu_ph(b + i);
    _mm512_storeu_ph(c + i, _mm512_fcmul_pch(rB, rA));
  }
}

int main() {
  int n = 32;

  _Float16 a[n], b[n], c[n];
  for (int i = 1; i <= n; i++) {
    a[i - 1] = i & 1 ? -i : i;
    b[i - 1] = i;
  }

  func0(a, b, n, c);
    for (int i = 0; i < n / 32 * 2; i++) {
      printf("%f ", (float)c[i]);
    }
    printf("\n");

  func1(a, b, n, c);
    for (int i = 0; i < n / 32 * 2; i++) {
      printf("%f ", (float)c[i]);
    }
    printf("\n");

  return 0;
}
```

[Bug target/111306] [12,13] macro-fusion makes error on conjugate complex multiplication fp16

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111306

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |crazylht at gmail dot com

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
*** Bug 111333 has been marked as a duplicate of this bug. ***

[Bug target/111306] [12,13] macro-fusion makes error on conjugate complex multiplication fp16

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111306

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2023-09-08
             Status|UNCONFIRMED                 |NEW

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
.

[Bug target/111306] [12,13] macro-fusion makes error on conjugate complex multiplication fp16

[crazylht at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111306

--- Comment #3 from Hongtao.liu <crazylht at gmail dot com> ---
A patch is posted at
https://gcc.gnu.org/pipermail/gcc-patches/2023-September/629650.html

[Bug target/111306] [12,13] macro-fusion makes error on conjugate complex multiplication fp16

[crazylht at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111306

--- Comment #4 from Hongtao.liu <crazylht at gmail dot com> ---
A related PR111335 for fmaddcph , similar but not the same, PR111335 is due to
precision difference for complex _Float16 fma, fmaddcph a, b, c is not equal to
fmaddcph b, a, c

[Bug target/111306] [12,13] macro-fusion makes error on conjugate complex multiplication fp16

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111306

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

https://gcc.gnu.org/g:f197392a16ffb1327f1d12ff8ff05f9295e015cb

commit r14-3831-gf197392a16ffb1327f1d12ff8ff05f9295e015cb
Author: liuhongt <hongtao.liu@intel.com>
Date:   Fri Sep 8 09:22:43 2023 +0800

    Remove constraint modifier % for fcmaddcph/fmaddcph/fcmulcph since there're
not commutative.

    gcc/ChangeLog:

            PR target/111306
            PR target/111335
            * config/i386/sse.md (int_comm): New int_attr.
            (fma_<complexopname>_<mode><sdc_maskz_name><round_name>):
            Remove % for Complex conjugate operations since they're not
            commutative.
            (fma_<complexpairopname>_<mode>_pair): Ditto.
            (<avx512>_<complexopname>_<mode>_mask<round_name>): Ditto.
            (cmul<conj_op><mode>3): Ditto.

    gcc/testsuite/ChangeLog:

            * gcc.target/i386/pr111306.c: New test.

[Bug target/111306] [12,13] macro-fusion makes error on conjugate complex multiplication fp16

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111306

--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-13 branch has been updated by hongtao Liu
<liuhongt@gcc.gnu.org>:

https://gcc.gnu.org/g:162731529e4dd10970880c369471229735dc3e9b

commit r13-7789-g162731529e4dd10970880c369471229735dc3e9b
Author: liuhongt <hongtao.liu@intel.com>
Date:   Fri Sep 8 09:22:43 2023 +0800

    Remove constraint modifier % for fcmaddcph/fmaddcph/fcmulcph since there're
not commutative.

    gcc/ChangeLog:

            PR target/111306
            PR target/111335
            * config/i386/sse.md (int_comm): New int_attr.
            (fma_<complexopname>_<mode><sdc_maskz_name><round_name>):
            Remove % for Complex conjugate operations since they're not
            commutative.
            (fma_<complexpairopname>_<mode>_pair): Ditto.
            (<avx512>_<complexopname>_<mode>_mask<round_name>): Ditto.
            (cmul<conj_op><mode>3): Ditto.

    gcc/testsuite/ChangeLog:

            * gcc.target/i386/pr111306.c: New test.

    (cherry picked from commit f197392a16ffb1327f1d12ff8ff05f9295e015cb)

[Bug target/111306] [12,13] macro-fusion makes error on conjugate complex multiplication fp16

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111306

--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-12 branch has been updated by hongtao Liu
<liuhongt@gcc.gnu.org>:

https://gcc.gnu.org/g:82c1ff396e49b706d5baa11f4c884810f6350e95

commit r12-9852-g82c1ff396e49b706d5baa11f4c884810f6350e95
Author: liuhongt <hongtao.liu@intel.com>
Date:   Fri Sep 8 09:22:43 2023 +0800

    Remove constraint modifier % for fcmaddcph/fmaddcph/fcmulcph since there're
not commutative.

    gcc/ChangeLog:

            PR target/111306
            PR target/111335
            * config/i386/sse.md (int_comm): New int_attr.
            (fma_<complexopname>_<mode><sdc_maskz_name><round_name>):
            Remove % for Complex conjugate operations since they're not
            commutative.
            (fma_<complexpairopname>_<mode>_pair): Ditto.
            (<avx512>_<complexopname>_<mode>_mask<round_name>): Ditto.
            (cmul<conj_op><mode>3): Ditto.

    gcc/testsuite/ChangeLog:

            * gcc.target/i386/pr111306.c: New test.

    (cherry picked from commit f197392a16ffb1327f1d12ff8ff05f9295e015cb)

[Bug target/111306] [12,13] macro-fusion makes error on conjugate complex multiplication fp16

[crazylht at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111306

--- Comment #8 from Hongtao.liu <crazylht at gmail dot com> ---
Fixed in GCC14.1 GCC13.3 GCC12.4

[Bug target/111306] [12,13] macro-fusion makes error on conjugate complex multiplication fp16

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111306

Richard Biener <rguenth at gcc dot gnu.org> changed:

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

--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed.