The matched MPI Send/Recv pairs are mixed up
Hi,Each MPI process has dedicated thread for each send/receive operation (I use MPI_Send/MPI_Recv calls). Because the data size is too big, I made each thread iterate over a for loop sending fixed...
View ArticleIs there any performance or space overheads for using 'tag' in MPI?
Hi, I wonder if there can be any performance or space overheads for using 'tag' in MPI.It would depend on how it is implemented, but I guess if it used a sort of hash map and keep (possible) multiple...
View ArticleICC 17.0.0: MPX pass incorrectly treats C99 VLA arrays
Hello,I use icc (ICC) version 17.0.0 (20160721). I found a bug in the way its MPX transformation pass treats code with VLAs (variable-length arrays allocated on stack). My computer has an Intel Skylake...
View Articleicc 17.0.0 crashes on valid C code at -O3 on x86_64-linux-gnu (segfault)
Compiler version and platform: Intel(R) C Intel(R) 64 Compiler for applications running on Intel(R) 64, Version 17.0.0.098 Build 20160721$ icc -O2 small.c $ ./a.out $ $ icc -O3 small.c": internal...
View Articleicc 17.0.0 miscompiles valid C code (compiled code hangs) at -O1 and above on...
Compiler version and platform: Intel(R) C Intel(R) 64 Compiler for applications running on Intel(R) 64, Version 17.0.0.098 Build 20160721$ icc -O0 small.c; ./a.out $ $ icc -O1 small.c $ timeout -s 9 10...
View ArticleVS2015 Editor does not work after installing Intel C++ 2017 Update 1
I just installed Intel C++ 2017 Update 1. After doing that, any file I try to display in the Visual Studio 2015 Update 3 editor does not appear. The file appears to be opened, but the content window...
View ArticleCompiler Optimizations (Settings)
Hello there,I'm wondering why for example, "Interprocedural Optimizations" aren't enabled by default since they include important things like "dead call deletion" / "inlining" / whole program analysis....
View Articleicc-16.0.3 not respecting no-ansi-alias flag?
Compiling a.c with icc -O2 results in reordering of memory accesses, even when -no-ansi-alias flag is used.We are using icc version 16.0.3$ cat a.c#include "stdlib.h"char *foo(size_t size);struct list...
View ArticleError in example (15.0 compiler online manual)
The page at https://software.intel.com/en-us/node/524530 (Description of omp simd) has an example that is wrong (or weird) in two ways.The example is #pragma omp simd collapse(2) for(i=0; i<N; i++)...
View ArticleCompiler Optimization Flag /Ot
So i am working on porting an existing windows code to a Unix code. In visual studio i used the option /Ot but this does not exist in the unix system. Many of the other optimization flags in the...
View Articleicc 17.0.0 crashes on valid C++ code on x86_64-linux-gnu (internal error:...
Compiler version and platform: Intel(R) C Intel(R) 64 Compiler for applications running on Intel(R) 64, Version 17.0.0.098 Build 20160721$ icc -c small.cpp small.cpp(5) (col. 3): internal error:...
View ArticleExtremely slow compilation time with insanely big expressions
Hello everybody Here's my problem. I'm generating a C++ file with large arithmetic expressions (mostly adds and muls) from a high level specification of a numerical problem. Basically, I have a loop...
View Articleicc-16.0.3 not respecting fno-strict-overflow flag?
$ icc -v icc version 16.0.3 (gcc version 4.8.0 compatibility) $ cat b.c void foo(int fl) { long i; for (i = 0; i < fl + 1; i++) { printf("%d\n", i); } } $ cat main.c #include <limits.h> void...
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spill avoidance (register pressure from loop fusion)
In the attached screen snip from VTune running on KNL, there appear to be stalls due to spills, mostly using AVX-512 moves to copy data chunks from (OpenMP shared) data arrays to stack. I wondered if...
View ArticleICC missing bmi2 target
GCC (and clang) support __attribute__((__target__("bmi2"))), ICC doesn't, which can cause compile failures due to ICC masquerading as GCC (defining __GNUC__ and friends).Reproducible by simply adding...
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internal compiler error 101004_111
Hi, I am trying to compile ParaView 5.2.0 RC3 (http://www.paraview.org) with GUI support. The GUI is written in QT and the compiler gives error like following,[ 88%] Building CXX object...
View ArticleCompiler error while creating an union (icc15, icc14, icc13)
We ran into this internal compiler error with our open source code, described here: https://github.com/manodeep/Corrfunc/issues/100. We have fixed it for the repo but figured it might be helpful for...
View Articleicc 17.0.0 crashes on valid C++ code on x86_64-linux-gnu (internal error:...
Compiler version and platform: Intel(R) C Intel(R) 64 Compiler for applications running on Intel(R) 64, Version 17.0.0.098 Build 20160721The code compiles successfully with -std=c++11, but crashes the...
View Articleicc 17.0.0 accepts illegal C++ code with shadowed template parameters
Compiler version and platform: Intel(R) C Intel(R) 64 Compiler for applications running on Intel(R) 64, Version 17.0.0.098 Build 20160721According to the C++ standard, it is illegal to have a...
View Articleicc 17.0.0 rejects valid C++ code with template friend function
Compiler version and platform: Intel(R) C Intel(R) 64 Compiler for applications running on Intel(R) 64, Version 17.0.0.098 Build 20160721$ g++-6.2 small.cpp $ clang++-3.8 small.cpp $ $ icc small.cpp...
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