sse4

As you know, the first two are AVX-specific intrinsics and the second is a SSE4.1 intrinsic. Both sets of intrinsics can be used to check for equality of 2 floating-point vectors. My specific use case is: _mm_cmpeq_ps or _mm_cmpeq_pd , followed by _mm_testc_ps or _mm_testc_pd on the result, with an appropriate mask But AVX provides equivalents for "legacy" intrinsics, so I might be able to use _mm_testc_si128 , after a cast of the result to __m128i . My questions are, which of the two use cases results in better performance and where I can find out what legacy SSE instructions are provided by

I'm experimenting with SSE42 and STTNI instructions and have got strange result - PcmpEstrM (works with explicit length strings) runs twice slower than PcmpIstrM (implicit length strings). On my i7 3610QM the difference is 2366.2 ms vs. 1202.3 ms - 97% . On i5 3470 difference is not so huge, but is still significant = 3206.2 ms vs. 2623.2 ms - 22% . Both are "Ivy Bridge" - it is strange that they have so different "difference" (at least i can't see any technical differences in their specs - http://www.cpu-world.com/Compare_CPUs/Intel_AW8063801013511,Intel_CM8063701093302/ ). Intel 64 and IA-32

I have a simple test program that loads an xmm register with the movdqu instruction accessing data across a page boundary (OS = Linux). If the following page is mapped, this works just fine. If it's not mapped then I get a SIGSEGV, which is probably expected. However this diminishes the usefulness of the unaligned loads quite a bit. Additionally SSE4.2 instructions (like pcmpistri) which allow for unaligned memory references appear to exhibit this behavior as well. That's all fine -- except there's many an implementation of strcmp using pcmpistri that I've found that don't seem to address this

Here is my code's assembler Can you embed it in c ++ and check against SSE4? At speed I would very much like to see how stepped into the development of SSE4. Or is not worried about him at all? Let's check (I do not have support above SSSE3) { sse2 strcmp WideChar 32 bit } function CmpSee2(const P1, P2: Pointer; len: Integer): Boolean; asm push ebx // Create ebx cmp EAX, EDX // Str = Str2 je @@true // to exit true test eax, eax // not Str je @@false // to exit false test edx, edx // not Str2 je @@false // to exit false sub edx, eax // Str2 := Str2 - Str; mov ebx, [eax] // get Str 4 byte xor

Why in the world was _mm_crc32_u64(...) defined like this? unsigned int64 _mm_crc32_u64( unsigned __int64 crc, unsigned __int64 v ); The "crc32" instruction always accumulates a 32-bit CRC, never a 64-bit CRC (It is, after all, CRC32 not CRC64). If the machine instruction CRC32 happens to have a 64-bit destination operand, the upper 32 bits are ignored, and filled with 0's on completion, so there is NO use to EVER have a 64-bit destination. I understand why Intel allowed a 64-bit destination operand on the instruction (for uniformity), but if I want to process data quickly, I want a source