why does _mm_mulhrs_epi16() always do biased rounding to positive infinity?
Does anyone know why the pmulhrsw instruction or_mm_mulhrs_epi16(x) := RoundDown((x * y + 16384) / 32768)always rounds towards positive infinity? To me, this is terribly biased for negative numbers,...
View ArticleMeasuring Core Voltage
I am using an Atom N2600 processor. The intel software developer's manual says that a p-state can be requested by writing to MSR 0x199 and the locked p-state can be seen in MSR 0x198. The way to...
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SSE ucomiss/comiss strange behavior
Hello. When I run this code :#include <cmath> // for NAN c++11 and up #include <iostream> #include <xmmintrin.h> int main(int argc, char ** argv) { float nan_value = NAN; __m128 const...
View ArticleSDE 7.15 for Linux has no 64-bit libs
The recently released SDE 7.15 for Linux seem to have 32-bit libraries instead of 64-bit in intel64/pin_ext_lib and intel64/xed_ext_lib. Is this an oversight or am I missing something?
View ArticleTSX example code doesn't work
I have intel xeon cpu E3-1230 v3 machine which has TSX.I just want to test that TSX runs well.From manual, i got this example pseucodevoid rtm_wrapped_lock(lock) { if (_xbegin() == _XBEGIN_STARTED) {...
View ArticleIs profiling information running on SDE accurate and trustable?
Hi, I am trying to look at AVX 512 performance, currently, I wrote a simple function for evaluation as below, I configured the optimization and enabled AVX-512 etc in the project properties...
View ArticleHow to work with AVX on windows
Hi,I am interested in AVX instructions set using in my application for speed up.But i am new to AVX.How can i know whether my system processor is able to support AVX or not?My System Configurations...
View ArticleIntel 64 documentation bug
This is for Intel 64 and IA-32 Architectures Software Developer’s Manual, Order Number: 325462-053 US January 2015. Page Vol. 1 5-29.5.19 64-BIT MODE INSTRUCTIONS ... MOVZX (64-bits) Move doubleword to...
View ArticlePointer Arithmetic using Intel AVX2
Hi,is there an opportunity to operate on pointers in 256 bit AVX2 registers (e.g. incrementing, border check, masking operations) and load from pointer, stored in a vector register?Thank you in...
View Articlepin-2.14-71313 and WinSock library
Hi, I have a problem trying to start my pintool built with WinSock library (ws2_32.lib) - it immediately exits with message "Failure to open DLL file WS2_32.dll". I've prepared a simple pintool to...
View ArticleHow to compile avx intrinsics in linux device driver?
My setup: Linux 3.13 kernel, gcc 4.8.2. Ubuntu on core i7How to compile avx intrinsics in linux device driver? Any exact gcc compiler flags (makefile) and what header files to include in c source?Thanks
View ArticleCan AVX instruction be executed in parallel
Hi,Can two avx instrcutions can be executed in parallel?For example,Version1: a1= _mm256_load_ps((Rin +offset)); a2= _mm256_load_ps((Gin +offset)); a3=...
View ArticleA Question about MSR ？
Hi，I am a grean-hand，I have a question about msr：when i reboot the computer，will The MSR register reset？or not？，if i write some infomation to the msr register ，when the cpu reboot ，I need rewrite？
View Articlequestion about DAA(opcode 0x27) instruction's operation
Hi,I'm currently writing a x86 code emulator.So I need to know detailed instruction's operation. I was writing a DAA instruction, detailed operation is like this, old_AL ← AL; old_CF ← CF; CF ← 0; IF...
View ArticleQ on memory comparison optimization
Hi All,I am using AVX/SSE instructions to replace memcmp and our workload includes comparing 64 bytes and occasionally 64 and 128 bytes. I am using following function cmp32 for 32byte comparisons and...
View ArticleInclude all intrinsics
I would like to see the Intel Intrinsics Guide include all of the intrinsics, not just the SSE-based intrinsics. It would be helpful if the 'interlocked' and other intrinsics were also included,...
View ArticleHaswell and crosslan
Hello,I build a code for Integralimage computation with SSE and its quite good. But I have serious problems making use of AVX/AVX2. I run my code on an i5-4460.What is the basis: For integral image I...
View ArticleIntel SDE and VS2013
Hello,I try using Intel® Software Development Emulator with Visual Studio 2013 but I have troubles.Try to start a debug session with SDE Debugger fails, saying my programme (of the visual studio...
View ArticleIntel SDE and Windows 10 Preview
I am trying to run SDE on a Windows 10 Preview machine (running build 10074) and I get the following error:C:\Users\user\Downloads\sde-external-7.21.0-2015-04-01-win>sde -- cmd E: DBG_TRACE:...
View ArticleCache and _mm_prefetch
Hello,I have some code, where I iterate over an array in reverse order. I already use SSE,AVX (depending on what CPU supports). Normally prefetching of CPU should be finde, if I iterate over an arry...
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