Copyright © 2012 Intel Corporation. All Rights Reserved.
Invoke the Intel C compiler for IA32 applications.
You need binutils 2.16.91.0.7 or later with this compiler to support new instructions on Intel Core 2 processors
Invoke the Intel C++ compiler for IA32 and Intel 64 applications.
You need binutils 2.16.91.0.7 or later with this compiler to support new instructions on Intel Core 2 processors
Invoke the Intel Fortran compiler for IA32 and Intel 64 applications.
You need binutils 2.16.91.0.7 or later with this compiler to support new instructions on Intel Core 2 processors
specify source files are in free format. Same as -FR. -nofree indicates fixed format
-mcmodel=
-mcmodel=
enable language support for
Enables O2 optimizations plus more aggressive optimizations,
such as prefetching, scalar replacement, and loop and memory
access transformations. Enables optimizations for maximum speed,
such as:
- Loop unrolling, including instruction scheduling
- Code replication to eliminate branches
- Padding the size of certain power-of-two arrays to allow
more efficient cache use.
On IA-32 and Intel EM64T processors, when O3 is used with options
-ax or -x (Linux) or with options /Qax or /Qx (Windows), the compiler
performs more aggressive data dependency analysis than for O2, which
may result in longer compilation times.
The O3 optimizations may not cause higher performance unless loop and
memory access transformations take place. The optimizations may slow
down code in some cases compared to O2 optimizations.
The O3 option is recommended for applications that have loops that heavily
use floating-point calculations and process large data sets. On IA-32
Windows platforms, -O3 sets the following:
/GF (/Qvc7 and above), /Gf (/Qvc6 and below), and /Ob2
Enable/disable(DEFAULT) use of ANSI aliasing rules in optimizations; user asserts that the program adheres to these rules.
-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.
Enables the parallelizer to generate multi-threaded code based on OpenMP* directives. Option -qopenmp is the replacement option for -openmp, which is deprecated.
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
May generate Intel(R) Advanced Vector Extensions 512 (Intel(R) AVX-512) Foundation instructions, Intel(R) AVX-512 Conflict Detection instructions, Intel(R) AVX-512 Exponential and Reciprocal instructions, Intel(R) AVX-512 Prefetch instructions for Intel(R) processors, and the instructions enabled with CORE-AVX2.
enable
Enables O2 optimizations plus more aggressive optimizations,
such as prefetching, scalar replacement, and loop and memory
access transformations. Enables optimizations for maximum speed,
such as:
- Loop unrolling, including instruction scheduling
- Code replication to eliminate branches
- Padding the size of certain power-of-two arrays to allow
more efficient cache use.
On IA-32 and Intel EM64T processors, when O3 is used with options
-ax or -x (Linux) or with options /Qax or /Qx (Windows), the compiler
performs more aggressive data dependency analysis than for O2, which
may result in longer compilation times.
The O3 optimizations may not cause higher performance unless loop and
memory access transformations take place. The optimizations may slow
down code in some cases compared to O2 optimizations.
The O3 option is recommended for applications that have loops that heavily
use floating-point calculations and process large data sets. On IA-32
Windows platforms, -O3 sets the following:
/GF (/Qvc7 and above), /Gf (/Qvc6 and below), and /Ob2
Enable/disable(DEFAULT) use of ANSI aliasing rules in optimizations; user asserts that the program adheres to these rules.
-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.
Enables the parallelizer to generate multi-threaded code based on OpenMP* directives. Option -qopenmp is the replacement option for -openmp, which is deprecated.
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
May generate Intel(R) Advanced Vector Extensions 512 (Intel(R) AVX-512) Foundation instructions, Intel(R) AVX-512 Conflict Detection instructions, Intel(R) AVX-512 Exponential and Reciprocal instructions, Intel(R) AVX-512 Prefetch instructions for Intel(R) processors, and the instructions enabled with CORE-AVX2.
enable
Enables O2 optimizations plus more aggressive optimizations,
such as prefetching, scalar replacement, and loop and memory
access transformations. Enables optimizations for maximum speed,
such as:
- Loop unrolling, including instruction scheduling
- Code replication to eliminate branches
- Padding the size of certain power-of-two arrays to allow
more efficient cache use.
On IA-32 and Intel EM64T processors, when O3 is used with options
-ax or -x (Linux) or with options /Qax or /Qx (Windows), the compiler
performs more aggressive data dependency analysis than for O2, which
may result in longer compilation times.
The O3 optimizations may not cause higher performance unless loop and
memory access transformations take place. The optimizations may slow
down code in some cases compared to O2 optimizations.
The O3 option is recommended for applications that have loops that heavily
use floating-point calculations and process large data sets. On IA-32
Windows platforms, -O3 sets the following:
/GF (/Qvc7 and above), /Gf (/Qvc6 and below), and /Ob2
-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.
Enables the parallelizer to generate multi-threaded code based on OpenMP* directives. Option -qopenmp is the replacement option for -openmp, which is deprecated.
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
May generate Intel(R) Advanced Vector Extensions 512 (Intel(R) AVX-512) Foundation instructions, Intel(R) AVX-512 Conflict Detection instructions, Intel(R) AVX-512 Exponential and Reciprocal instructions, Intel(R) AVX-512 Prefetch instructions for Intel(R) processors, and the instructions enabled with CORE-AVX2.
enable
This section contains descriptions of flags that were included implicitly by other flags, but which do not have a permanent home at SPEC.
This option enables read only string-pooling optimization.
This option enables read/write string-pooling optimization.
Specifies the level of inline function expansion.
Ob0 - Disables inlining of user-defined functions. Note that statement functions are always inlined.
Ob1 - Enables inlining when an inline keyword or an inline attribute is specified. Also enables inlining according to the C++ language.
Ob2 - Enables inlining of any function at the compiler's discretion.
Enables optimizations for speed. This is the generally recommended
optimization level. This option also enables:
- Inlining of intrinsics
- Intra-file interprocedural optimizations, which include:
- inlining
- constant propagation
- forward substitution
- routine attribute propagation
- variable address-taken analysis
- dead static function elimination
- removal of unreferenced variables
- The following capabilities for performance gain:
- constant propagation
- copy propagation
- dead-code elimination
- global register allocation
- global instruction scheduling and control speculation
- loop unrolling
- optimized code selection
- partial redundancy elimination
- strength reduction/induction variable simplification
- variable renaming
- exception handling optimizations
- tail recursions
- peephole optimizations
- structure assignment lowering and optimizations
- dead store elimination
On IA-32 Windows platforms, -O2 sets the following:
/Og, /Oi-, /Os, /Oy, /Ob2, /GF (/Qvc7 and above), /Gf (/Qvc6 and below), /Gs, and /Gy.
Disables inline expansion of all intrinsic functions.
This option disables stack-checking for routines with 4096 bytes of local variables and compiler temporaries.
Allows use of EBP as a general-purpose register in optimizations.
This option tells the compiler to separate functions into COMDATs for the linker.
This option enables most speed optimizations, but disables some that increase code size for a small speed benefit.
This option enables global optimizations.
Enables optimizations for speed and disables some optimizations that
increase code size and affect speed.
To limit code size, this option:
- Enables global optimization; this includes data-flow analysis,
code motion, strength reduction and test replacement, split-lifetime
analysis, and instruction scheduling.
- Disables intrinsic recognition and intrinsics inlining.
The O1 option may improve performance for applications with very large
code size, many branches, and execution time not dominated by code within loops.
On IA-32 Windows platforms, -O1 sets the following:
/Qunroll0, /Oi-, /Op-, /Oy, /Gy, /Os, /GF (/Qvc7 and above), /Gf (/Qvc6 and below), /Ob2, and /Og
Tells the compiler the maximum number of times to unroll loops.
Disables conformance to the ANSI C and IEEE 754 standards for floating-point arithmetic.
Flag description origin markings:
For questions about the meanings of these flags, please contact the tester.
For other inquiries, please contact webmaster@spec.org
Copyright 2012-2016 Standard Performance Evaluation Corporation
Tested with SPEC OMP2012 v1.1.
Report generated on Wed Oct 26 11:19:51 2016 by SPEC OMP2012 flags formatter v538.