Rework 32-bit SSE loads yet again.

The existing code in vec_avx.h produced
  warning: dereferencing type-punned pointer will break
   strict-aliasing rules
 with gcc 6.4.0.
We already had a macro to work around this within the rules of the
 C standard, but trying to use that here does not get optimized
 into a single MOVD like we were hoping.
Replacing it with memcpy() instead does get optimized correctly,
 but requires switching from a macro to an inline function in order
 to be able to declare a local variable and return a value.
We already have such an inline function in NSQ_del_dec_avx2.c, so
 hoist that out and use it everywhere, and then convert vec_avx.h
 to use it also.

celt/x86/x86cpu.h

@@ -60,18 +60,33 @@
 int opus_select_arch(void);
 # endif
 
+# if defined(OPUS_X86_MAY_HAVE_SSE2)
+#  include "opus_defines.h"
+
 /*MOVD should not impose any alignment restrictions, but the C standard does,
    and UBSan will report errors if we actually make unaligned accesses.
   Use this to work around those restrictions (which should hopefully all get
-   optimized to a single MOVD instruction).*/
+   optimized to a single MOVD instruction).
-#define OP_LOADU_EPI32(x) \
+  GCC implemented _mm_loadu_si32() since GCC 11; HOWEVER, there is a bug!
-  (int)((*(unsigned char *)(x) | *((unsigned char *)(x) + 1) << 8U |\
+  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99754 */
-   *((unsigned char *)(x) + 2) << 16U | (opus_uint32)*((unsigned char *)(x) + 3) << 24U))
+#  if !defined(_MSC_VER) && !OPUS_GNUC_PREREQ(11,3) && !(defined(__clang__) && (__clang_major__ >= 8))
+#   include <string.h>
+#   include <emmintrin.h>
 
-#define OP_CVTEPI8_EPI32_M32(x) \
+#   define _mm_loadu_si32 WORKAROUND_mm_loadu_si32
- (_mm_cvtepi8_epi32(_mm_cvtsi32_si128(OP_LOADU_EPI32(x))))
+static inline __m128i WORKAROUND_mm_loadu_si32(void const* mem_addr) {
+  int val;
+  memcpy(&val, mem_addr, sizeof(val));
+  return _mm_cvtsi32_si128(val);
+}
+#  endif
 
-#define OP_CVTEPI16_EPI32_M64(x) \
+#  define OP_CVTEPI8_EPI32_M32(x) \
+ (_mm_cvtepi8_epi32(_mm_loadu_si32(x)))
+
+#  define OP_CVTEPI16_EPI32_M64(x) \
  (_mm_cvtepi16_epi32(_mm_loadl_epi64((__m128i *)(void*)(x))))
 
+# endif
+
 #endif

dnn/vec_avx.h

@@ -34,7 +34,7 @@
 
 #include <immintrin.h>
 #include <math.h>
-
+#include "celt/x86/x86cpu.h"
 
 #define MAX_INPUTS (2048)
 
@@ -196,6 +196,14 @@ static inline void mm256_storeu_si256(mm256i_emu *dst, mm256i_emu src) {
 #define _mm256_storeu_si256(dst, src) mm256_storeu_si256(dst, src)
 
 
+static inline mm256i_emu mm256_broadcastd_epi32(__m128i x) {
+  mm256i_emu ret;
+  ret.hi = ret.lo = _mm_shuffle_epi32(x, 0);
+  return ret;
+}
+#define _mm256_broadcastd_epi32(x) mm256_broadcastd_epi32(x)
+
+
 static inline mm256i_emu mm256_set1_epi32(int x) {
   mm256i_emu ret;
   ret.lo = _mm_set1_epi32(x);
@@ -786,19 +794,19 @@ static inline void sparse_cgemv8x4(float *_out, const opus_int8 *w, const int *i
       {
          __m256i vxj;
          __m256i vw;
-         vxj = _mm256_set1_epi32(*(int*)(void*)&x[*idx++]);
+         vxj = _mm256_broadcastd_epi32(_mm_loadu_si32(&x[*idx++]));
          vw = _mm256_loadu_si256((const __m256i *)(void*)w);
          vy0 = opus_mm256_dpbusds_epi32(vy0, vxj, vw);
          w += 32;
-         vxj = _mm256_set1_epi32(*(int*)(void*)&x[*idx++]);
+         vxj = _mm256_broadcastd_epi32(_mm_loadu_si32(&x[*idx++]));
          vw = _mm256_loadu_si256((const __m256i *)(void*)w);
          vy0 = opus_mm256_dpbusds_epi32(vy0, vxj, vw);
          w += 32;
-         vxj = _mm256_set1_epi32(*(int*)(void*)&x[*idx++]);
+         vxj = _mm256_broadcastd_epi32(_mm_loadu_si32(&x[*idx++]));
          vw = _mm256_loadu_si256((const __m256i *)(void*)w);
          vy0 = opus_mm256_dpbusds_epi32(vy0, vxj, vw);
          w += 32;
-         vxj = _mm256_set1_epi32(*(int*)(void*)&x[*idx++]);
+         vxj = _mm256_broadcastd_epi32(_mm_loadu_si32(&x[*idx++]));
          vw = _mm256_loadu_si256((const __m256i *)(void*)w);
          vy0 = opus_mm256_dpbusds_epi32(vy0, vxj, vw);
          w += 32;
@@ -808,9 +816,7 @@ static inline void sparse_cgemv8x4(float *_out, const opus_int8 *w, const int *i
       {
          __m256i vxj;
          __m256i vw;
-         int pos;
+         vxj = _mm256_broadcastd_epi32(_mm_loadu_si32(&x[*idx++]));
-         pos = (*idx++);
-         vxj = _mm256_set1_epi32(*(int*)(void*)&x[pos]);
          vw = _mm256_loadu_si256((const __m256i *)(void*)w);
          vy0 = opus_mm256_dpbusds_epi32(vy0, vxj, vw);
          w += 32;
@@ -837,19 +843,19 @@ static inline void cgemv8x4(float *_out, const opus_int8 *w, const float *scale,
       {
          __m256i vxj;
          __m256i vw;
-         vxj = _mm256_set1_epi32(*(int*)(void*)&x[j]);
+         vxj = _mm256_broadcastd_epi32(_mm_loadu_si32(&x[j]));
          vw = _mm256_loadu_si256((const __m256i *)(void*)w);
          vy0 = opus_mm256_dpbusds_epi32(vy0, vxj, vw);
          w += 32;
-         vxj = _mm256_set1_epi32(*(int*)(void*)&x[j+4]);
+         vxj = _mm256_broadcastd_epi32(_mm_loadu_si32(&x[j+4]));
          vw = _mm256_loadu_si256((const __m256i *)(void*)w);
          vy0 = opus_mm256_dpbusds_epi32(vy0, vxj, vw);
          w += 32;
-         vxj = _mm256_set1_epi32(*(int*)(void*)&x[j+8]);
+         vxj = _mm256_broadcastd_epi32(_mm_loadu_si32(&x[j+8]));
          vw = _mm256_loadu_si256((const __m256i *)(void*)w);
          vy0 = opus_mm256_dpbusds_epi32(vy0, vxj, vw);
          w += 32;
-         vxj = _mm256_set1_epi32(*(int*)(void*)&x[j+12]);
+         vxj = _mm256_broadcastd_epi32(_mm_loadu_si32(&x[j+12]));
          vw = _mm256_loadu_si256((const __m256i *)(void*)w);
          vy0 = opus_mm256_dpbusds_epi32(vy0, vxj, vw);
          w += 32;
@@ -859,7 +865,7 @@ static inline void cgemv8x4(float *_out, const opus_int8 *w, const float *scale,
       {
          __m256i vxj;
          __m256i vw;
-         vxj = _mm256_set1_epi32(*(int*)(void*)&x[j]);
+         vxj = _mm256_broadcastd_epi32(_mm_loadu_si32(&x[j]));
          vw = _mm256_loadu_si256((const __m256i *)(void*)w);
          vy0 = opus_mm256_dpbusds_epi32(vy0, vxj, vw);
          w += 32;

silk/x86/NSQ_del_dec_avx2.c

@@ -86,18 +86,6 @@ static inline int __builtin_ctz(unsigned int x)
 }
 #endif
 
-/*
- * GCC implemented _mm_loadu_si32() since GCC 11; HOWEVER, there is a bug!
- * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99754
- */
-#if !defined(_MSC_VER) && !OPUS_GNUC_PREREQ(11,3) && !(defined(__clang__) && (__clang_major__ >= 8))
-#define _mm_loadu_si32 WORKAROUND_mm_loadu_si32
-static inline __m128i WORKAROUND_mm_loadu_si32(void const* mem_addr)
-{
-  return _mm_cvtsi32_si128(OP_LOADU_EPI32(mem_addr));
-}
-#endif
-
 static OPUS_INLINE __m128i silk_cvtepi64_epi32_high(__m256i num)
 {
     return _mm256_castsi256_si128(_mm256_permutevar8x32_epi32(num, _mm256_set_epi32(0, 0, 0, 0, 7, 5, 3, 1)));