SPEC_MPI_CASE_FLAG may be used in SPEC MPI2007.
This macro indicates that the benchmark is being compiled on a Linux system.
This macro indicates that Fortran functions called from C should have their names lower-cased.
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 Intel Itanium processors, the O3 option enables optimizations
for technical computing applications (loop-intensive code):
loop optimizations and data prefetch.
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.
Enables optimizations that give slightly less precise results than full IEEE division. With some optimizations, such as -xN and -xB, the compiler may change floating-point division compu- tations into multiplication by the reciprocal of the denomina- tor. For example, A/B is computed as A * (1/B) to improve the speed of the computation. The default is -prec-div, which provides fully precise IEEE division. It improves precision of floating-point divides by disabling floating-point division-to-multiplication optimiza- tions, resulting in greater accuracy with some loss of perfor- mance.
Flushes denormal floating point results to zero when the application is in gradual underflow mode.
Tells the compiler not to assume aliasing in the program (DEFAULT = -falias).
Generates specialized code to run exclusively on processors with the extensions T. This option can generate SSSE3, SSE3, SSE2, and SSE instructions for Intel processors, and it can optimize for the Intel (R) Core (TM) 2 Duo processor family.
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 Intel Itanium processors, the O3 option enables optimizations
for technical computing applications (loop-intensive code):
loop optimizations and data prefetch.
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.
Enables optimizations that give slightly less precise results than full IEEE division. With some optimizations, such as -xN and -xB, the compiler may change floating-point division compu- tations into multiplication by the reciprocal of the denomina- tor. For example, A/B is computed as A * (1/B) to improve the speed of the computation. The default is -prec-div, which provides fully precise IEEE division. It improves precision of floating-point divides by disabling floating-point division-to-multiplication optimiza- tions, resulting in greater accuracy with some loss of perfor- mance.
Flushes denormal floating point results to zero when the application is in gradual underflow mode.
Tells the compiler not to assume aliasing in the program (DEFAULT = -falias).
Generates specialized code to run exclusively on processors with the extensions T. This option can generate SSSE3, SSE3, SSE2, and SSE instructions for Intel processors, and it can optimize for the Intel (R) Core (TM) 2 Duo processor family.
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 Intel Itanium processors, the O3 option enables optimizations
for technical computing applications (loop-intensive code):
loop optimizations and data prefetch.
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.
Enables optimizations that give slightly less precise results than full IEEE division. With some optimizations, such as -xN and -xB, the compiler may change floating-point division compu- tations into multiplication by the reciprocal of the denomina- tor. For example, A/B is computed as A * (1/B) to improve the speed of the computation. The default is -prec-div, which provides fully precise IEEE division. It improves precision of floating-point divides by disabling floating-point division-to-multiplication optimiza- tions, resulting in greater accuracy with some loss of perfor- mance.
Flushes denormal floating point results to zero when the application is in gradual underflow mode.
Tells the compiler not to assume aliasing in the program (DEFAULT = -falias).
Generates specialized code to run exclusively on processors with the extensions T. This option can generate SSSE3, SSE3, SSE2, and SSE instructions for Intel processors, and it can optimize for the Intel (R) Core (TM) 2 Duo processor family.
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 Intel Itanium processors, the O3 option enables optimizations
for technical computing applications (loop-intensive code):
loop optimizations and data prefetch.
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.
Enables optimizations that give slightly less precise results than full IEEE division. With some optimizations, such as -xN and -xB, the compiler may change floating-point division compu- tations into multiplication by the reciprocal of the denomina- tor. For example, A/B is computed as A * (1/B) to improve the speed of the computation. The default is -prec-div, which provides fully precise IEEE division. It improves precision of floating-point divides by disabling floating-point division-to-multiplication optimiza- tions, resulting in greater accuracy with some loss of perfor- mance.
Flushes denormal floating point results to zero when the application is in gradual underflow mode.
Tells the compiler not to assume aliasing in the program (DEFAULT = -falias).
Generates specialized code to run exclusively on processors with the extensions T. This option can generate SSSE3, SSE3, SSE2, and SSE instructions for Intel processors, and it can optimize for the Intel (R) Core (TM) 2 Duo processor family.
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 Intel Itanium processors, the O3 option enables optimizations
for technical computing applications (loop-intensive code):
loop optimizations and data prefetch.
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.
Enables optimizations that give slightly less precise results than full IEEE division. With some optimizations, such as -xN and -xB, the compiler may change floating-point division compu- tations into multiplication by the reciprocal of the denomina- tor. For example, A/B is computed as A * (1/B) to improve the speed of the computation. The default is -prec-div, which provides fully precise IEEE division. It improves precision of floating-point divides by disabling floating-point division-to-multiplication optimiza- tions, resulting in greater accuracy with some loss of perfor- mance.
Flushes denormal floating point results to zero when the application is in gradual underflow mode.
Tells the compiler not to assume aliasing in the program (DEFAULT = -falias).
Generates specialized code to run exclusively on processors with the extensions T. This option can generate SSSE3, SSE3, SSE2, and SSE instructions for Intel processors, and it can optimize for the Intel (R) Core (TM) 2 Duo processor family.
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 Intel Itanium processors, the O3 option enables optimizations
for technical computing applications (loop-intensive code):
loop optimizations and data prefetch.
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.
Enables optimizations that give slightly less precise results than full IEEE division. With some optimizations, such as -xN and -xB, the compiler may change floating-point division compu- tations into multiplication by the reciprocal of the denomina- tor. For example, A/B is computed as A * (1/B) to improve the speed of the computation. The default is -prec-div, which provides fully precise IEEE division. It improves precision of floating-point divides by disabling floating-point division-to-multiplication optimiza- tions, resulting in greater accuracy with some loss of perfor- mance.
Flushes denormal floating point results to zero when the application is in gradual underflow mode.
Tells the compiler not to assume aliasing in the program (DEFAULT = -falias).
Generates specialized code to run exclusively on processors with the extensions T. This option can generate SSSE3, SSE3, SSE2, and SSE instructions for Intel processors, and it can optimize for the Intel (R) Core (TM) 2 Duo processor family.
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 Intel Itanium processors, the O3 option enables optimizations
for technical computing applications (loop-intensive code):
loop optimizations and data prefetch.
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.
Enables optimizations that give slightly less precise results than full IEEE division. With some optimizations, such as -xN and -xB, the compiler may change floating-point division compu- tations into multiplication by the reciprocal of the denomina- tor. For example, A/B is computed as A * (1/B) to improve the speed of the computation. The default is -prec-div, which provides fully precise IEEE division. It improves precision of floating-point divides by disabling floating-point division-to-multiplication optimiza- tions, resulting in greater accuracy with some loss of perfor- mance.
Flushes denormal floating point results to zero when the application is in gradual underflow mode.
Tells the compiler not to assume aliasing in the program (DEFAULT = -falias).
Generates specialized code to run exclusively on processors with the extensions T. This option can generate SSSE3, SSE3, SSE2, and SSE instructions for Intel processors, and it can optimize for the Intel (R) Core (TM) 2 Duo processor family.
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 Intel Itanium processors, the O3 option enables optimizations
for technical computing applications (loop-intensive code):
loop optimizations and data prefetch.
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.
Enables optimizations that give slightly less precise results than full IEEE division. With some optimizations, such as -xN and -xB, the compiler may change floating-point division compu- tations into multiplication by the reciprocal of the denomina- tor. For example, A/B is computed as A * (1/B) to improve the speed of the computation. The default is -prec-div, which provides fully precise IEEE division. It improves precision of floating-point divides by disabling floating-point division-to-multiplication optimiza- tions, resulting in greater accuracy with some loss of perfor- mance.
Flushes denormal floating point results to zero when the application is in gradual underflow mode.
Tells the compiler not to assume aliasing in the program (DEFAULT = -falias).
Generates specialized code to run exclusively on processors with the extensions T. This option can generate SSSE3, SSE3, SSE2, and SSE instructions for Intel processors, and it can optimize for the Intel (R) Core (TM) 2 Duo processor family.
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 Intel Itanium processors, the O3 option enables optimizations
for technical computing applications (loop-intensive code):
loop optimizations and data prefetch.
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.
Enables optimizations that give slightly less precise results than full IEEE division. With some optimizations, such as -xN and -xB, the compiler may change floating-point division compu- tations into multiplication by the reciprocal of the denomina- tor. For example, A/B is computed as A * (1/B) to improve the speed of the computation. The default is -prec-div, which provides fully precise IEEE division. It improves precision of floating-point divides by disabling floating-point division-to-multiplication optimiza- tions, resulting in greater accuracy with some loss of perfor- mance.
Flushes denormal floating point results to zero when the application is in gradual underflow mode.
Tells the compiler not to assume aliasing in the program (DEFAULT = -falias).
Generates specialized code to run exclusively on processors with the extensions T. This option can generate SSSE3, SSE3, SSE2, and SSE instructions for Intel processors, and it can optimize for the Intel (R) Core (TM) 2 Duo processor family.
This section contains descriptions of flags that were included implicitly by other flags, but which do not have a permanent home at SPEC.
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
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 Linux64 platforms, -O1 disable software pipelining and global code scheduling.
On Intel Itanium processors, this option also enables optimizations for server applications
(straight-line and branch-like code with a flat profile).
-unroll0, -fbuiltin, -mno-ieee-fp, -fomit-frame-pointer (same as -fp), -ffunction-sections
Tells the compiler the maximum number of times (n) to unroll loops.
Enables inline expansion of all intrinsic functions.
Disables conformance to the ANSI C and IEEE 754 standards for floating-point arithmetic.
Allows use of EBP as a general-purpose register in optimizations.
Places each function in its own COMDAT section.
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 2006-2010 Standard Performance Evaluation Corporation
Tested with SPEC MPI2007 v59.
Report generated on Tue Jul 22 13:32:37 2014 by SPEC MPI2007 flags formatter v1445.