[PATCH 1/2] rs6000: Support _mm_insert_epi{8,32,64}

[Paul A. Clarke]

On Thu, Sep 24, 2020 at 06:22:10PM -0500, Segher Boessenkool wrote:
> On Wed, Sep 23, 2020 at 05:12:44PM -0500, Paul A. Clarke wrote:
> > +extern __inline __m128i __attribute__((__gnu_inline__, __always_inline__, __artificial__))
> > +_mm_insert_epi8 (__m128i const __A, int const __D, int const __N)
> > +{
> > +  __v16qi result = (__v16qi)__A;
> > +
> > +  result [(__N & 0b1111)] = __D;
> 
> Hrm, GCC supports binary constants like this since 2007, so okay.  But I
> have to wonder if this improves anything over hex (or decimal even!)
> The parens are superfluous (and only hinder legibility), fwiw.
> 
> > +_mm_insert_epi64 (__m128i const __A, long long const __D, int const __N)
> > +{
> > +  __v2di result = (__v2di)__A;
> > +
> > +  result [(__N & 0b1)] = __D;
> 
> Especially single-digit numbers look really goofy (like 0x0, but even
> worse for binary somehow).
> 
> Anyway, okay for trunk, with or without those things improved.  Thanks!

I was trying to obviously and consistently convey the sizes of the masks,
but I really want to convey _why_ there are masks, so let me try a
different approach, below.

--

Add compatibility implementations for SSE4.1 intrinsics
_mm_insert_epi8, _mm_insert_epi32, _mm_insert_epi64.

2020-09-25  Paul A. Clarke  <pc@us.ibm.com>

gcc/
	* config/rs6000/smmintrin.h (_mm_insert_epi8): New.
	(_mm_insert_epi32): New.
	(_mm_insert_epi64): New.
---
 gcc/config/rs6000/smmintrin.h | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/gcc/config/rs6000/smmintrin.h b/gcc/config/rs6000/smmintrin.h
index d78ddba99d9..8128c417978 100644
--- a/gcc/config/rs6000/smmintrin.h
+++ b/gcc/config/rs6000/smmintrin.h
@@ -42,6 +42,36 @@
 #include <altivec.h>
 #include <tmmintrin.h>
 
+extern __inline __m128i __attribute__((__gnu_inline__, __always_inline__, __artificial__))
+_mm_insert_epi8 (__m128i const __A, int const __D, int const __N)
+{
+  __v16qi result = (__v16qi)__A;
+
+  result [__N % (sizeof result / sizeof result[0])] = __D;
+
+  return (__m128i) result;
+}
+
+extern __inline __m128i __attribute__((__gnu_inline__, __always_inline__, __artificial__))
+_mm_insert_epi32 (__m128i const __A, int const __D, int const __N)
+{
+  __v4si result = (__v4si)__A;
+
+  result [__N % (sizeof result / sizeof result[0])] = __D;
+
+  return (__m128i) result;
+}
+
+extern __inline __m128i __attribute__((__gnu_inline__, __always_inline__, __artificial__))
+_mm_insert_epi64 (__m128i const __A, long long const __D, int const __N)
+{
+  __v2di result = (__v2di)__A;
+
+  result [__N % (sizeof result / sizeof result[0])] = __D;
+
+  return (__m128i) result;
+}
+
 extern __inline int __attribute__((__gnu_inline__, __always_inline__, __artificial__))
 _mm_extract_epi8 (__m128i __X, const int __N)
 {
-- 
2.18.4