[PATCH v2 0/2] rs6000: Add support for _mm_minpos_epu16

[PATCH v2 0/2] rs6000: Add support for _mm_minpos_epu16

[Paul A. Clarke]

Added compatible implementation of _mm_minpos_epu16 for powerpc.
Copied, improved, and fixed testcase from i386.
Tested on BE, LE (32 and 64bit).

Paul A. Clarke (2):
  rs6000: Add support for _mm_minpos_epu16
  rs6000: Add test for _mm_minpos_epu16

 gcc/config/rs6000/smmintrin.h                 | 25 +++++++
 .../gcc.target/powerpc/sse4_1-phminposuw.c    | 68 +++++++++++++++++++
 2 files changed, 93 insertions(+)
 create mode 100644 gcc/testsuite/gcc.target/powerpc/sse4_1-phminposuw.c

-- 
2.27.0

[PATCH v2 1/2] rs6000: Add support for _mm_minpos_epu16

[Paul A. Clarke]

Add a naive implementation of the subject x86 intrinsic to
ease porting.

2021-06-08  Paul A. Clarke  <pc@us.ibm.com>

gcc/ChangeLog:
        * config/rs6000/smmintrin.h (_mm_minpos_epu16): New.
---
 gcc/config/rs6000/smmintrin.h | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/gcc/config/rs6000/smmintrin.h b/gcc/config/rs6000/smmintrin.h
index bdf6eb365d88..b7de38763f2b 100644
--- a/gcc/config/rs6000/smmintrin.h
+++ b/gcc/config/rs6000/smmintrin.h
@@ -116,4 +116,29 @@ _mm_blendv_epi8 (__m128i __A, __m128i __B, __m128i __mask)
   return (__m128i) vec_sel ((__v16qu) __A, (__v16qu) __B, __lmask);
 }
 
+/* Return horizontal packed word minimum and its index in bits [15:0]
+   and bits [18:16] respectively.  */
+extern __inline __m128i __attribute__((__gnu_inline__, __always_inline__, __artificial__))
+_mm_minpos_epu16 (__m128i __A)
+{
+  union __u
+    {
+      __m128i __m;
+      __v8hu __uh;
+    };
+  union __u __u = { .__m = __A }, __r = { .__m = {0} };
+  unsigned short __ridx = 0;
+  unsigned short __rmin = __u.__uh[__ridx];
+  for (unsigned long __i = __ridx + 1; __i < 8; __i++)
+    {
+      if (__u.__uh[__i] < __rmin)
+        {
+          __rmin = __u.__uh[__i];
+          __ridx = __i;
+        }
+    }
+  __r.__uh[0] = __rmin;
+  __r.__uh[1] = __ridx;
+  return __r.__m;
+}
 #endif
-- 
2.27.0

Re: [ping PATCH v2 1/2] rs6000: Add support for _mm_minpos_epu16

[Paul A. Clarke]

Gentle ping.

I now realize I forgot to include a blurb about "what changed in v2".

v2:
- Slight formatting changes based on Segher's review (simplified
  condition, single line).

PC

On Tue, Jun 08, 2021 at 02:11:54PM -0500, Paul A. Clarke via Gcc-patches wrote:
> Add a naive implementation of the subject x86 intrinsic to
> ease porting.
> 
> 2021-06-08  Paul A. Clarke  <pc@us.ibm.com>
> 
> gcc/ChangeLog:
>         * config/rs6000/smmintrin.h (_mm_minpos_epu16): New.
> ---
>  gcc/config/rs6000/smmintrin.h | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
> 
> diff --git a/gcc/config/rs6000/smmintrin.h b/gcc/config/rs6000/smmintrin.h
> index bdf6eb365d88..b7de38763f2b 100644
> --- a/gcc/config/rs6000/smmintrin.h
> +++ b/gcc/config/rs6000/smmintrin.h
> @@ -116,4 +116,29 @@ _mm_blendv_epi8 (__m128i __A, __m128i __B, __m128i __mask)
>    return (__m128i) vec_sel ((__v16qu) __A, (__v16qu) __B, __lmask);
>  }
>  
> +/* Return horizontal packed word minimum and its index in bits [15:0]
> +   and bits [18:16] respectively.  */
> +extern __inline __m128i __attribute__((__gnu_inline__, __always_inline__, __artificial__))
> +_mm_minpos_epu16 (__m128i __A)
> +{
> +  union __u
> +    {
> +      __m128i __m;
> +      __v8hu __uh;
> +    };
> +  union __u __u = { .__m = __A }, __r = { .__m = {0} };
> +  unsigned short __ridx = 0;
> +  unsigned short __rmin = __u.__uh[__ridx];
> +  for (unsigned long __i = __ridx + 1; __i < 8; __i++)
> +    {
> +      if (__u.__uh[__i] < __rmin)
> +        {
> +          __rmin = __u.__uh[__i];
> +          __ridx = __i;
> +        }
> +    }
> +  __r.__uh[0] = __rmin;
> +  __r.__uh[1] = __ridx;
> +  return __r.__m;
> +}
>  #endif
> -- 
> 2.27.0
> 

Re: [PATCH v2 1/2] rs6000: Add support for _mm_minpos_epu16

[Bill Schmidt]

Hi Paul,

On 6/8/21 2:11 PM, Paul A. Clarke via Gcc-patches wrote:
> Add a naive implementation of the subject x86 intrinsic to
> ease porting.
"subject" won't be part of eventual commit, so please specify in commit 
blurb.
>
> 2021-06-08  Paul A. Clarke  <pc@us.ibm.com>
>
> gcc/ChangeLog:
>          * config/rs6000/smmintrin.h (_mm_minpos_epu16): New.
> ---
>   gcc/config/rs6000/smmintrin.h | 25 +++++++++++++++++++++++++
>   1 file changed, 25 insertions(+)
>
> diff --git a/gcc/config/rs6000/smmintrin.h b/gcc/config/rs6000/smmintrin.h
> index bdf6eb365d88..b7de38763f2b 100644
> --- a/gcc/config/rs6000/smmintrin.h
> +++ b/gcc/config/rs6000/smmintrin.h
> @@ -116,4 +116,29 @@ _mm_blendv_epi8 (__m128i __A, __m128i __B, __m128i __mask)
>     return (__m128i) vec_sel ((__v16qu) __A, (__v16qu) __B, __lmask);
>   }
>
> +/* Return horizontal packed word minimum and its index in bits [15:0]
> +   and bits [18:16] respectively.  */
> +extern __inline __m128i __attribute__((__gnu_inline__, __always_inline__, __artificial__))
Line too long, please break up.  (I realize this happens throughout this 
file already, but...)
> +_mm_minpos_epu16 (__m128i __A)
> +{
> +  union __u
> +    {
> +      __m128i __m;
> +      __v8hu __uh;
> +    };
> +  union __u __u = { .__m = __A }, __r = { .__m = {0} };
> +  unsigned short __ridx = 0;
> +  unsigned short __rmin = __u.__uh[__ridx];
> +  for (unsigned long __i = __ridx + 1; __i < 8; __i++)
"__ridx + 1" can just be "1"
> +    {
> +      if (__u.__uh[__i] < __rmin)
> +        {
> +          __rmin = __u.__uh[__i];
> +          __ridx = __i;
> +        }
Preceding four lines need tabs, not spaces.
> +    }
> +  __r.__uh[0] = __rmin;
> +  __r.__uh[1] = __ridx;
> +  return __r.__m;
> +}
>   #endif

Otherwise LGTM.  I can't approve, but recommend approval with those 
things fixed.

Thanks,
Bill

[PATCH v2 2/2] rs6000: Add test for _mm_minpos_epu16

[Paul A. Clarke]

Copy the test for _mm_minpos_epu16 from
gcc/testsuite/gcc.target/i386/sse4_1-phminposuw.c, with
a few adjustments:

- Adjust the dejagnu directives for powerpc platform.
- Make the data not be monotonically increasing,
  such that some of the returned values are not
  always the first value (index 0).
- Create a list of input data testing various scenarios
  including more than one minimum value and different
  orders and indicies of the minimum value.
- Fix a masking issue where the index was being truncated
  to 2 bits instead of 3 bits, which wasn't found because
  all of the returned indicies were 0 with the original
  generated data.
- Support big-endian.

2021-06-08  Paul A. Clarke  <pc@us.ibm.com>

gcc/testsuite/ChangeLog:
        * gcc.target/powerpc/sse4_1-phminposuw.c: Copy from
        gcc/testsuite/gcc.target/i386, make more robust.
---
 .../gcc.target/powerpc/sse4_1-phminposuw.c    | 68 +++++++++++++++++++
 1 file changed, 68 insertions(+)
 create mode 100644 gcc/testsuite/gcc.target/powerpc/sse4_1-phminposuw.c

diff --git a/gcc/testsuite/gcc.target/powerpc/sse4_1-phminposuw.c b/gcc/testsuite/gcc.target/powerpc/sse4_1-phminposuw.c
new file mode 100644
index 000000000000..3bb5a2dfe4f5
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/sse4_1-phminposuw.c
@@ -0,0 +1,68 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -mpower8-vector -Wno-psabi" } */
+/* { dg-require-effective-target p8vector_hw } */
+
+#define NO_WARN_X86_INTRINSICS 1
+#ifndef CHECK_H
+#define CHECK_H "sse4_1-check.h"
+#endif
+
+#ifndef TEST
+#define TEST sse4_1_test
+#endif
+
+#include CHECK_H
+
+#include <smmintrin.h>
+
+#define DIM(a) (sizeof (a) / sizeof ((a)[0]))
+
+static void
+TEST (void)
+{
+  union
+    {
+      __m128i x;
+      unsigned short s[8];
+    } src[] =
+    {
+      { .s = { 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000 } },
+      { .s = { 0x0000, 0xffff, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000 } },
+      { .s = { 0xffff, 0xffff, 0x0000, 0xffff, 0xffff, 0xffff, 0x0000, 0xffff } },
+      { .s = { 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007, 0x0008 } },
+      { .s = { 0x0008, 0x0007, 0x0006, 0x0005, 0x0004, 0x0003, 0x0002, 0x0001 } },
+      { .s = { 0xfff4, 0xfff3, 0xfff2, 0xfff1, 0xfff3, 0xfff1, 0xfff2, 0xfff3 } }
+    };
+  unsigned short minVal[DIM (src)];
+  int minInd[DIM (src)];
+  unsigned short minValScalar, minIndScalar;
+  int i, j;
+  union
+    {
+      int i;
+      unsigned short s[2];
+    } res;
+
+  for (i = 0; i < DIM (src); i++)
+    {
+      res.i = _mm_cvtsi128_si32 (_mm_minpos_epu16 (src[i].x));
+      minVal[i] = res.s[0];
+      minInd[i] = res.s[1] & 0b111;
+    }
+
+  for (i = 0; i < DIM (src); i++)
+    {
+      minValScalar = src[i].s[0];
+      minIndScalar = 0;
+
+      for (j = 1; j < 8; j++)
+	if (minValScalar > src[i].s[j])
+	  {
+	    minValScalar = src[i].s[j];
+	    minIndScalar = j;
+	  }
+
+      if (minValScalar != minVal[i] && minIndScalar != minInd[i])
+	abort ();
+    }
+}
-- 
2.27.0

Re: [ping PATCH v2 2/2] rs6000: Add test for _mm_minpos_epu16

[Paul A. Clarke]

Gentle ping.

I now realize I forgot to include a blurb about "what changed in v2".

v2:
- Rewrote input computation into a fixed set of useful input sets:
  - All equal.
  - All but one equal.
  - A couple equal, but not in positions that are endian-identical.
  - Minimum first.
  - Minimum last.
  - Values which are large enough that if considered signed would
    be considered minimums, but not if unsigned.
- Convert "dimension of array" computation to DIM macro.

On Tue, Jun 08, 2021 at 02:11:55PM -0500, Paul A. Clarke via Gcc-patches wrote:
> Copy the test for _mm_minpos_epu16 from
> gcc/testsuite/gcc.target/i386/sse4_1-phminposuw.c, with
> a few adjustments:
> 
> - Adjust the dejagnu directives for powerpc platform.
> - Make the data not be monotonically increasing,
>   such that some of the returned values are not
>   always the first value (index 0).
> - Create a list of input data testing various scenarios
>   including more than one minimum value and different
>   orders and indicies of the minimum value.
> - Fix a masking issue where the index was being truncated
>   to 2 bits instead of 3 bits, which wasn't found because
>   all of the returned indicies were 0 with the original
>   generated data.
> - Support big-endian.
> 
> 2021-06-08  Paul A. Clarke  <pc@us.ibm.com>
> 
> gcc/testsuite/ChangeLog:
>         * gcc.target/powerpc/sse4_1-phminposuw.c: Copy from
>         gcc/testsuite/gcc.target/i386, make more robust.
> ---
>  .../gcc.target/powerpc/sse4_1-phminposuw.c    | 68 +++++++++++++++++++
>  1 file changed, 68 insertions(+)
>  create mode 100644 gcc/testsuite/gcc.target/powerpc/sse4_1-phminposuw.c
> 
> diff --git a/gcc/testsuite/gcc.target/powerpc/sse4_1-phminposuw.c b/gcc/testsuite/gcc.target/powerpc/sse4_1-phminposuw.c
> new file mode 100644
> index 000000000000..3bb5a2dfe4f5
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/powerpc/sse4_1-phminposuw.c
> @@ -0,0 +1,68 @@
> +/* { dg-do run } */
> +/* { dg-options "-O2 -mpower8-vector -Wno-psabi" } */
> +/* { dg-require-effective-target p8vector_hw } */
> +
> +#define NO_WARN_X86_INTRINSICS 1
> +#ifndef CHECK_H
> +#define CHECK_H "sse4_1-check.h"
> +#endif
> +
> +#ifndef TEST
> +#define TEST sse4_1_test
> +#endif
> +
> +#include CHECK_H
> +
> +#include <smmintrin.h>
> +
> +#define DIM(a) (sizeof (a) / sizeof ((a)[0]))
> +
> +static void
> +TEST (void)
> +{
> +  union
> +    {
> +      __m128i x;
> +      unsigned short s[8];
> +    } src[] =
> +    {
> +      { .s = { 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000 } },
> +      { .s = { 0x0000, 0xffff, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000 } },
> +      { .s = { 0xffff, 0xffff, 0x0000, 0xffff, 0xffff, 0xffff, 0x0000, 0xffff } },
> +      { .s = { 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007, 0x0008 } },
> +      { .s = { 0x0008, 0x0007, 0x0006, 0x0005, 0x0004, 0x0003, 0x0002, 0x0001 } },
> +      { .s = { 0xfff4, 0xfff3, 0xfff2, 0xfff1, 0xfff3, 0xfff1, 0xfff2, 0xfff3 } }
> +    };
> +  unsigned short minVal[DIM (src)];
> +  int minInd[DIM (src)];
> +  unsigned short minValScalar, minIndScalar;
> +  int i, j;
> +  union
> +    {
> +      int i;
> +      unsigned short s[2];
> +    } res;
> +
> +  for (i = 0; i < DIM (src); i++)
> +    {
> +      res.i = _mm_cvtsi128_si32 (_mm_minpos_epu16 (src[i].x));
> +      minVal[i] = res.s[0];
> +      minInd[i] = res.s[1] & 0b111;
> +    }
> +
> +  for (i = 0; i < DIM (src); i++)
> +    {
> +      minValScalar = src[i].s[0];
> +      minIndScalar = 0;
> +
> +      for (j = 1; j < 8; j++)
> +	if (minValScalar > src[i].s[j])
> +	  {
> +	    minValScalar = src[i].s[j];
> +	    minIndScalar = j;
> +	  }
> +
> +      if (minValScalar != minVal[i] && minIndScalar != minInd[i])
> +	abort ();
> +    }
> +}
> -- 
> 2.27.0
> 

Re: [PATCH v2 2/2] rs6000: Add test for _mm_minpos_epu16

[Bill Schmidt]

Hi Paul,

On 6/8/21 2:11 PM, Paul A. Clarke via Gcc-patches wrote:
> Copy the test for _mm_minpos_epu16 from
> gcc/testsuite/gcc.target/i386/sse4_1-phminposuw.c, with
> a few adjustments:
>
> - Adjust the dejagnu directives for powerpc platform.
> - Make the data not be monotonically increasing,
>    such that some of the returned values are not
>    always the first value (index 0).
> - Create a list of input data testing various scenarios
>    including more than one minimum value and different
>    orders and indicies of the minimum value.
Typo: indices
> - Fix a masking issue where the index was being truncated
>    to 2 bits instead of 3 bits, which wasn't found because
>    all of the returned indicies were 0 with the original
and here
>    generated data.
> - Support big-endian.
Thank you for attention to detail. :)
>
> 2021-06-08  Paul A. Clarke  <pc@us.ibm.com>
>
> gcc/testsuite/ChangeLog:
>          * gcc.target/powerpc/sse4_1-phminposuw.c: Copy from
>          gcc/testsuite/gcc.target/i386, make more robust.
> ---
>   .../gcc.target/powerpc/sse4_1-phminposuw.c    | 68 +++++++++++++++++++
>   1 file changed, 68 insertions(+)
>   create mode 100644 gcc/testsuite/gcc.target/powerpc/sse4_1-phminposuw.c
>
> diff --git a/gcc/testsuite/gcc.target/powerpc/sse4_1-phminposuw.c b/gcc/testsuite/gcc.target/powerpc/sse4_1-phminposuw.c
> new file mode 100644
> index 000000000000..3bb5a2dfe4f5
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/powerpc/sse4_1-phminposuw.c
> @@ -0,0 +1,68 @@
> +/* { dg-do run } */
> +/* { dg-options "-O2 -mpower8-vector -Wno-psabi" } */
> +/* { dg-require-effective-target p8vector_hw } */
> +
> +#define NO_WARN_X86_INTRINSICS 1
> +#ifndef CHECK_H
> +#define CHECK_H "sse4_1-check.h"
> +#endif
> +
> +#ifndef TEST
> +#define TEST sse4_1_test
> +#endif
> +
> +#include CHECK_H
> +
> +#include <smmintrin.h>
> +
> +#define DIM(a) (sizeof (a) / sizeof ((a)[0]))
> +
> +static void
> +TEST (void)
> +{
> +  union
> +    {
> +      __m128i x;
> +      unsigned short s[8];
> +    } src[] =
> +    {
> +      { .s = { 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000 } },
> +      { .s = { 0x0000, 0xffff, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000 } },
> +      { .s = { 0xffff, 0xffff, 0x0000, 0xffff, 0xffff, 0xffff, 0x0000, 0xffff } },
> +      { .s = { 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007, 0x0008 } },
> +      { .s = { 0x0008, 0x0007, 0x0006, 0x0005, 0x0004, 0x0003, 0x0002, 0x0001 } },
> +      { .s = { 0xfff4, 0xfff3, 0xfff2, 0xfff1, 0xfff3, 0xfff1, 0xfff2, 0xfff3 } }
> +    };
> +  unsigned short minVal[DIM (src)];
> +  int minInd[DIM (src)];
> +  unsigned short minValScalar, minIndScalar;
> +  int i, j;
> +  union
> +    {
> +      int i;

No need to change, but overloading i in another scope is not the 
greatest style.  I assume this came with the original test.

> +      unsigned short s[2];
> +    } res;
> +
> +  for (i = 0; i < DIM (src); i++)
> +    {
> +      res.i = _mm_cvtsi128_si32 (_mm_minpos_epu16 (src[i].x));
> +      minVal[i] = res.s[0];
> +      minInd[i] = res.s[1] & 0b111;
> +    }
> +
> +  for (i = 0; i < DIM (src); i++)
> +    {
> +      minValScalar = src[i].s[0];
> +      minIndScalar = 0;
> +
> +      for (j = 1; j < 8; j++)
> +	if (minValScalar > src[i].s[j])
> +	  {
> +	    minValScalar = src[i].s[j];
> +	    minIndScalar = j;
> +	  }
> +
> +      if (minValScalar != minVal[i] && minIndScalar != minInd[i])
> +	abort ();
> +    }
> +}

LGTM with spelling addressed.  I can't approve, but recommend approval 
with those changes.

Thanks,
Bill