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In optimized mode, don't force Clang to use explicit load/store for _mm_cvtepi16_epi32, only for _mm_cvtepi8_epi32. Adjust comment accordingly.

--- a/celt/x86/x86cpu.h

+++ b/celt/x86/x86cpu.h

@@ -55,21 +55,25 @@

   reference in the PMOVSXWD instruction itself, but gcc is not smart enough to

   optimize this out when optimizations ARE enabled.

-  It appears clang requires us to do this always (which is fair, since

-  technically the compiler is always allowed to do the dereference before

-  invoking the function implementing the intrinsic). I have not investiaged

-  whether it is any smarter than gcc when it comes to eliminating the extra

-  load instruction.*/

+  Clang, in contrast, requires us to do this always for _mm_cvtepi8_epi32

+  (which is fair, since technically the compiler is always allowed to do the

+  dereference before invoking the function implementing the intrinsic).

+  However, it is smart enough to eliminate the extra MOVD instruction.

+  For _mm_cvtepi16_epi32, it does the right thing, though does *not* optimize out

+  the extra MOVQ if it's specified explicitly */

+

 # if defined(__clang__) || !defined(__OPTIMIZE__)

 #  define OP_CVTEPI8_EPI32_M32(x) \

  (_mm_cvtepi8_epi32(_mm_cvtsi32_si128(*(int *)(x))))

-

-#  define OP_CVTEPI16_EPI32_M64(x) \

- (_mm_cvtepi16_epi32(_mm_loadl_epi64((__m128i *)(x))))

 # else

 #  define OP_CVTEPI8_EPI32_M32(x) \

  (_mm_cvtepi8_epi32(*(__m128i *)(x)))

+#endif

+# if !defined(__OPTIMIZE__)

+#  define OP_CVTEPI16_EPI32_M64(x) \

+ (_mm_cvtepi16_epi32(_mm_loadl_epi64((__m128i *)(x))))

+# else

 #  define OP_CVTEPI16_EPI32_M64(x) \

  (_mm_cvtepi16_epi32(*(__m128i *)(x)))

 # endif