Intel Compiler, Optimization and Other flags for use by SPEChpc

Intel_compiler_flags Intel Compiler, Optimization and Other flags for use by SPEChpc

Compilers: Intel Fortran/C/C++

Operating systems: Linux

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The OpenMPI Fortran driver configured for use with the Intel Fortran compiler.

]]> mpifort The OpenMPI C++ driver configured for use with the Intel C++ compiler.

]]> mpicxx The OpenMPI C driver configured for use with the Intel C compiler.

]]> mpicc The Intel MPI Fortran driver configured for use with the Intel oneAPI Fortran compiler.

]]> The Intel MPI C++ driver configured for use with the Intel oneAPI C++ compiler.

]]> The Intel MPI C driver configured for use with the Intel oneAPI C compiler.

]]> The Intel oneAPI Fortran compiler.

]]> The Intel oneAPI C++ compiler.

]]> The Intel oneAPI C compiler.

]]> The Intel MPI Fortran driver configured for use with the Intel Classic Fortran compiler.

]]> mpiifort The Intel MPI C++ driver configured for use with the Intel Classic C++ compiler.

]]> mpiicpc The Intel MPI C driver configured for use with the Intel Classic C compiler.

]]> mpiicc USE std C++ libs on Linker

]]> !!!!!!!!!!!!!!!!!!!!!!!!!.

]]> Disable use of reduction with variable array reduction variable (OpenMP 4.5, OpenACC 2.7) even if compiler reports support.

]]> Mandatory flag enabling MPI by default.

]]> Use C99 language features.

]]> Use C++ 14 language features.

]]> -std=c++14 Use C++ 17 language features.

]]> --c++17 Use C++ 14 language features.

]]> --c++14 FPORTABILITY flag No Fortran main method exists, use C equivalent instead. link Intel provided libraries dynamically Pass the comma separated arguments to the linker use a specific memory model to generate code and store data
small - Restricts code and data to the first 2GB of address space (DEFAULT)
medium - Restricts code to the first 2GB; it places no memory restriction on data
large - Places no memory restriction on code or data

]]> -align array32byte specifies that analyzed arrays should be aligned to 32byte boundaries The align toggle changes how data elements are aligned. Variables and arrays are analyzed and memory layout can be altered. Specifying array64byte will look for opportunities to transform and reailgn arrays to 32byte boundaries.

]]> -align array64byte specifies that analyzed arrays should be aligned to 64byte boundaries The align toggle changes how data elements are aligned. Variables and arrays are analyzed and memory layout can be altered. Specifying array64byte will look for opportunities to transform and reailgn arrays to 64byte boundaries.

]]> Determines whether the compiler uses the current Fortran Standard rules or the old Fortran 2003 rules when interpreting assignment statements. Option standard-realloc-lhs (the default), tells the compiler that when the left-hand side of an assignment is an allocatable object, it should be reallocated to the shape of the right-hand side of the assignment before the assignment occurs. This is the current Fortran Standard definition. This feature may cause extra overhead at run time. This option has the same effect as option assume realloc_lhs.

If you specify nostandard-realloc-lhs, the compiler uses the old Fortran 2003 rules when interpreting assignment statements. The left-hand side is assumed to be allocated with the correct shape to hold the right-hand side. If it is not, incorrect behavior will occur. This option has the same effect as option assume norealloc_lhs.

]]> Causes all local, non-SAVEd variables to be allocated to the runtime stack. This option places local variables (scalars and arrays of all types), except those declared as SAVE, on the runtime stack. It is as if the variables were declared with the AUTOMATIC attribute. It does not affect variables that have the SAVE attribute or ALLOCATABLE attribute, or variables that appear in an EQUIVALENCE statement or in a common block. This option may provide a performance gain for your program, but if your program depends on variables having the same value as the last time the routine was invoked, your program may not function properly. If you want to cause variables to be placed in static memory, specify option [Q]save. If you want only scalar variables of certain intrinsic types to be placed on the runtime stack, specify option auto-scalar.

]]> -qopt-zmm-usage=
Specifies the level of zmm registers usage. You can specify one of the following:
low - Tells the compiler that the compiled program is unlikely to benefit from zmm registers usage. It specifies that the compiler should avoid using zmm registers unless it can prove the gain from their usage.
high - Tells the compiler to generate zmm code without restrictions

]]> Specifies preferred 512b vector width for auto-vectorization. Defaults to 'none' which allows target specific decisions.

]]> Multi-file ip optimizations that includes:
- inline function expansion
- interprocedural constant propogation
- dead code elimination
- propagation of function characteristics
- passing arguments in registers
- loop-invariant code motion

]]> (disable/enable[default] -[no-]prec-div) -prec-div improves precision of floating-point divides. It has a slight impact on speed. -no-prec-div disables this option and enables optimizations that give slightly less precise results than full IEEE division.

When you specify -no-prec-div along with some optimizations, such as -xN and -xB (Linux) or /QxN and /QxB (Windows), the compiler may change floating-point division computations into multiplication by the reciprocal of the denominator. For example, A/B is computed as A * (1/B) to improve the speed of the computation.

However, sometimes the value produced by this transformation is not as accurate as full IEEE division. When it is important to have fully precise IEEE division, do not use -no-prec-div which will enable the default -prec-div and the result is more accurate, with some loss of performance.

]]> -fimf-precision=value[:funclist]
defines the accuracy (precision) for math library functions
value - defined as one of the following values
high - equivalent to max-error = 0.6
medium - equivalent to max-error = 4 (DEFAULT)
low - equivalent to accuracy-bits = 11 (single precision); accuracy-bits = 26 (double precision)
funclist - optional comma separated list of one or more math library functions to which the attribute should be applied

]]> Define the relative error, measured by the number of correct bits,for math library function results Enable peeling to optimize alignment for vectorization. Enables peel loop vectorization. Enable/disable(DEFAULT) use of ANSI aliasing rules in optimizations; user asserts that the program adheres to these rules. TODO Assume that a scalar declare target variable with implicit data-mapping referenced in a 'target' construct has the same value in the host and device environment Pass argument to clang -cc1 Pass arg to the OpenMP based target backend.
-device <arch> - set target device.
-revision_id <revision_id> - Target stepping. Can be decimal or hexadecimal value.
-cl-fast-relaxed-math - Sets the optimization options -cl-finite-math-only and -cl-unsafe-math-optimizations, which enable optimizations for floating-point arithmetic that may violate the IEEE 754 standard and the OpenCL numerical compliance requirements.
The device and revision_id options are only needed for AOT mode.

]]> Enables offloading to a specified GPU target if OpenMP features have been enabled.
Is a target triple device name. The following triplets are supported.
spir64 - Tells the compiler to enable offloading to SPIR64-based devices.
spir64_x86_64 - Tells the compiler to enable offloading to Intel CPUs.
spir64_gen - Tells the compiler to enable offloading to Intel Proessor Graphics.

]]> Enables the loop optimizer and auto-vectorization for OpenMP offloading device compilation when option O2 or higher is set or specified. -ftarget-register-alloc-mode=device-name:reg-mode[, device-name:reg-mode][,...]
device-name - Is the device name. Currently, you can only specify the following: pvc Indicates a Ponte Vecchio (PVC) device.
reg-mode - Is the register allocation mode. It can be any of the following:
default - Tells the target backend to not impose any specification when choosing a register allocation mode.
small - Tells the target backend to select small register allocation mode (for PVC, this means to use the 128 register file).
large - Tells the target backend to select large register allocation mode (for PVC, this means to use the 256 register file).
auto - Tells the target backend to use internal heuristics to select a register allocation mode based on kernel analysis.

]]> When using the collapse clause on a loop nest the default behavior is to automatically extend the representation of the loop counter to 64 bits for the cases where the sizes of the collapsed loops are not known at compile time. To prevent this conservative choice and use at most 32 bits, compile your program with the -fopenmp-optimistic-collapse.

]]> May generate Intel® AVX2, AVX, SSE4.2, SSE4.1, SSSE3, SSE3, SSE2 and SSE instructions for Intel® procesr. Optimizes for 4th, 5th and 6th generation Intel® Co processors and the Intel® Xeon® Processor E3 v3, E5 v3, E7 v3, E3 v4, E5 v4 and E7 v4 familie Available in compiler versions 13 and later.

]]> Code is optimized for Intel(R) processors with support for AVX instructions. May generate Intel® AVX-12 Foundation instructions,Intel® AVX-512 Conflict Detectio instructions, Intel® AVX-512 Doubleword and Quadword instructions, Intel® AVX-51 Byte and Word instructions, Intel® AVX-512 Vector Length extensions, Intel® AVX2,VX SSE4.2, SSE4.1, SSSE3, SSE3, SSE2 and SSE instructions for Intel® processors. Optimizes for a future Intel® processor. Available in compiler version 15 update 1 and later.

]]> Parse OpenMP pragmas and generate parallel code. Advanced users who prefer to use OpenMP* as it is implemented by the LLVM community can get most of that functionality by using -fopenmp.

]]> Enable the compiler to generate multi-threaded code based on the OpenMP* directives. Similar behavior was granted by -qopenmp in previous versions.

]]> Enable OpenMP compilation for hpc2021.

]]> Enable OPENMP programming model for hpc2021.

]]> Definition of this macro indicates that the MPI implementation supports accelerator device-to-device transfers. Used in conjuction when using OpenACC or OpenMP w/ target offload.

]]> AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA.

]]> Enable -O3 -no-prec-div -fp-model fast=2 optimizations.

]]> -Ofast Determine if certain square root optimizations are enabled. Specifies whether streaming stores are generated:

always - enables generation of streaming stores under the assumption that the application is memory bound

auto - compiler decides when streaming stores are used (DEFAULT)

never - disables generation of streaming stores

]]> Enable LTO (Link Time Optimization) in 'full' mode.

]]> Allow aggressive, lossy floating-point optimizations.

]]> Turn on loop unroller.

]]> Enable the specified warning.

]]> -Wno-incompatible-function-pointer-types