r254389 - [X86] Improve codegen for AVX2 gather with an all 1s mask.

[Craig Topper via cfe-commits]

Author: ctopper
Date: Tue Dec  1 01:12:59 2015
New Revision: 254389

URL: http://llvm.org/viewvc/llvm-project?rev=254389&view=rev
Log:
[X86] Improve codegen for AVX2 gather with an all 1s mask.

Use undefined instead of setzero as the pass through input since its going to be fully overwritten. Use cmpeq of two zero vectors to produce the all 1s vector. Casting -1 to a double and vectorizing causes a constant load of a -1.0 floating point value.

Modified:
    cfe/trunk/lib/Headers/avx2intrin.h

Modified: cfe/trunk/lib/Headers/avx2intrin.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Headers/avx2intrin.h?rev=254389&r1=254388&r2=254389&view=diff
==============================================================================
--- cfe/trunk/lib/Headers/avx2intrin.h (original)
+++ cfe/trunk/lib/Headers/avx2intrin.h Tue Dec  1 01:12:59 2015
@@ -1100,103 +1100,112 @@ _mm_srlv_epi64(__m128i __X, __m128i __Y)
                                        (__v4di)(__m256i)(mask), (s)); })
 
 #define _mm_i32gather_pd(m, i, s) __extension__ ({ \
-  (__m128d)__builtin_ia32_gatherd_pd((__v2df)_mm_setzero_pd(), \
+  (__m128d)__builtin_ia32_gatherd_pd((__v2df)_mm_undefined_pd(), \
                                      (double const *)(m), \
                                      (__v4si)(__m128i)(i), \
-                                     (__v2df)_mm_set1_pd( \
-                                       (double)(long long int)-1), \
+                                     (__v2df)_mm_cmpeq_pd(_mm_setzero_pd(), \
+                                                          _mm_setzero_pd()), \
                                      (s)); })
 
 #define _mm256_i32gather_pd(m, i, s) __extension__ ({ \
-  (__m256d)__builtin_ia32_gatherd_pd256((__v4df)_mm256_setzero_pd(), \
+  (__m256d)__builtin_ia32_gatherd_pd256((__v4df)_mm256_undefined_pd(), \
                                         (double const *)(m), \
                                         (__v4si)(__m128i)(i), \
-                                        (__v4df)_mm256_set1_pd( \
-                                          (double)(long long int)-1), \
+                                        (__v4df)_mm256_cmp_pd(_mm256_setzero_pd(), \
+                                                              _mm256_setzero_pd(), \
+                                                              _CMP_EQ_OQ), \
                                         (s)); })
 
 #define _mm_i64gather_pd(m, i, s) __extension__ ({ \
-  (__m128d)__builtin_ia32_gatherq_pd((__v2df)_mm_setzero_pd(), \
+  (__m128d)__builtin_ia32_gatherq_pd((__v2df)_mm_undefined_pd(), \
                                      (double const *)(m), \
                                      (__v2di)(__m128i)(i), \
-                                     (__v2df)_mm_set1_pd( \
-                                       (double)(long long int)-1), \
+                                     (__v2df)_mm_cmpeq_pd(_mm_setzero_pd(), \
+                                                          _mm_setzero_pd()), \
                                      (s)); })
 
 #define _mm256_i64gather_pd(m, i, s) __extension__ ({ \
-  (__m256d)__builtin_ia32_gatherq_pd256((__v4df)_mm256_setzero_pd(), \
+  (__m256d)__builtin_ia32_gatherq_pd256((__v4df)_mm256_undefined_pd(), \
                                         (double const *)(m), \
                                         (__v4di)(__m256i)(i), \
-                                        (__v4df)_mm256_set1_pd( \
-                                          (double)(long long int)-1), \
+                                        (__v4df)_mm256_cmp_pd(_mm256_setzero_pd(), \
+                                                              _mm256_setzero_pd(), \
+                                                              _CMP_EQ_OQ), \
                                         (s)); })
 
 #define _mm_i32gather_ps(m, i, s) __extension__ ({ \
-  (__m128)__builtin_ia32_gatherd_ps((__v4sf)_mm_setzero_ps(), \
-                                    (float const *)(m), (__v4si)(__m128i)(i), \
-                                    (__v4sf)_mm_set1_ps((float)(int)-1), \
+  (__m128)__builtin_ia32_gatherd_ps((__v4sf)_mm_undefined_ps(), \
+                                    (float const *)(m), \
+                                    (__v4si)(__m128i)(i), \
+                                    (__v4sf)_mm_cmpeq_ps(_mm_setzero_ps(), \
+                                                         _mm_setzero_ps()), \
                                     (s)); })
 
 #define _mm256_i32gather_ps(m, i, s) __extension__ ({ \
-  (__m256)__builtin_ia32_gatherd_ps256((__v8sf)_mm256_setzero_ps(), \
+  (__m256)__builtin_ia32_gatherd_ps256((__v8sf)_mm256_undefined_ps(), \
                                        (float const *)(m), \
                                        (__v8si)(__m256i)(i), \
-                                       (__v8sf)_mm256_set1_ps((float)(int)-1), \
+                                       (__v8sf)_mm256_cmp_ps(_mm256_setzero_ps(), \
+                                                             _mm256_setzero_ps(), \
+                                                             _CMP_EQ_OQ), \
                                        (s)); })
 
 #define _mm_i64gather_ps(m, i, s) __extension__ ({ \
-  (__m128)__builtin_ia32_gatherq_ps((__v4sf)_mm_setzero_ps(), \
-                                    (float const *)(m), (__v2di)(__m128i)(i), \
-                                    (__v4sf)_mm_set1_ps((float)(int)-1), \
+  (__m128)__builtin_ia32_gatherq_ps((__v4sf)_mm_undefined_ps(), \
+                                    (float const *)(m), \
+                                    (__v2di)(__m128i)(i), \
+                                    (__v4sf)_mm_cmpeq_ps(_mm_setzero_ps(), \
+                                                         _mm_setzero_ps()), \
                                     (s)); })
 
 #define _mm256_i64gather_ps(m, i, s) __extension__ ({ \
-  (__m128)__builtin_ia32_gatherq_ps256((__v4sf)_mm_setzero_ps(), \
+  (__m128)__builtin_ia32_gatherq_ps256((__v4sf)_mm_undefined_ps(), \
                                        (float const *)(m), \
                                        (__v4di)(__m256i)(i), \
-                                       (__v4sf)_mm_set1_ps((float)(int)-1), \
+                                       (__v4sf)_mm_cmpeq_ps(_mm_setzero_ps(), \
+                                                            _mm_setzero_ps()), \
                                        (s)); })
 
 #define _mm_i32gather_epi32(m, i, s) __extension__ ({ \
-  (__m128i)__builtin_ia32_gatherd_d((__v4si)_mm_setzero_si128(), \
+  (__m128i)__builtin_ia32_gatherd_d((__v4si)_mm_undefined_si128(), \
                                     (int const *)(m), (__v4si)(__m128i)(i), \
                                     (__v4si)_mm_set1_epi32(-1), (s)); })
 
 #define _mm256_i32gather_epi32(m, i, s) __extension__ ({ \
-  (__m256i)__builtin_ia32_gatherd_d256((__v8si)_mm256_setzero_si256(), \
+  (__m256i)__builtin_ia32_gatherd_d256((__v8si)_mm256_undefined_si256(), \
                                        (int const *)(m), (__v8si)(__m256i)(i), \
                                        (__v8si)_mm256_set1_epi32(-1), (s)); })
 
 #define _mm_i64gather_epi32(m, i, s) __extension__ ({ \
-  (__m128i)__builtin_ia32_gatherq_d((__v4si)_mm_setzero_si128(), \
+  (__m128i)__builtin_ia32_gatherq_d((__v4si)_mm_undefined_si128(), \
                                     (int const *)(m), (__v2di)(__m128i)(i), \
                                     (__v4si)_mm_set1_epi32(-1), (s)); })
 
 #define _mm256_i64gather_epi32(m, i, s) __extension__ ({ \
-  (__m128i)__builtin_ia32_gatherq_d256((__v4si)_mm_setzero_si128(), \
+  (__m128i)__builtin_ia32_gatherq_d256((__v4si)_mm_undefined_si128(), \
                                        (int const *)(m), (__v4di)(__m256i)(i), \
                                        (__v4si)_mm_set1_epi32(-1), (s)); })
 
 #define _mm_i32gather_epi64(m, i, s) __extension__ ({ \
-  (__m128i)__builtin_ia32_gatherd_q((__v2di)_mm_setzero_si128(), \
+  (__m128i)__builtin_ia32_gatherd_q((__v2di)_mm_undefined_si128(), \
                                     (long long const *)(m), \
                                     (__v4si)(__m128i)(i), \
                                     (__v2di)_mm_set1_epi64x(-1), (s)); })
 
 #define _mm256_i32gather_epi64(m, i, s) __extension__ ({ \
-  (__m256i)__builtin_ia32_gatherd_q256((__v4di)_mm256_setzero_si256(), \
+  (__m256i)__builtin_ia32_gatherd_q256((__v4di)_mm256_undefined_si256(), \
                                        (long long const *)(m), \
                                        (__v4si)(__m128i)(i), \
                                        (__v4di)_mm256_set1_epi64x(-1), (s)); })
 
 #define _mm_i64gather_epi64(m, i, s) __extension__ ({ \
-  (__m128i)__builtin_ia32_gatherq_q((__v2di)_mm_setzero_si128(), \
+  (__m128i)__builtin_ia32_gatherq_q((__v2di)_mm_undefined_si128(), \
                                     (long long const *)(m), \
                                     (__v2di)(__m128i)(i), \
                                     (__v2di)_mm_set1_epi64x(-1), (s)); })
 
 #define _mm256_i64gather_epi64(m, i, s) __extension__ ({ \
-  (__m256i)__builtin_ia32_gatherq_q256((__v4di)_mm256_setzero_si256(), \
+  (__m256i)__builtin_ia32_gatherq_q256((__v4di)_mm256_undefined_si256(), \
                                        (long long const *)(m), \
                                        (__v4di)(__m256i)(i), \
                                        (__v4di)_mm256_set1_epi64x(-1), (s)); })