Developer Guide and Reference

Contents

qopt-malloc-options

Lets you specify an alternate algorithm for malloc().

Syntax

Linux and macOS:
-qopt-malloc-options
=
n
Windows:
None
Arguments
n
Specifies the algorithm to use for malloc(). Possible values are:
0
Tells the compiler to use the default algorithm for malloc(). This is the default.
1
Causes the following adjustments to the malloc() algorithm: M_MMAP_MAX=2 and M_TRIM_THRESHOLD=0x10000000.
2
Causes the following adjustments to the malloc() algorithm: M_MMAP_MAX=2 and M_TRIM_THRESHOLD=0x40000000.
3
Causes the following adjustments to the malloc() algorithm: M_MMAP_MAX=0 and M_TRIM_THRESHOLD=-1.
4
Causes the following adjustments to the malloc() algorithm: M_MMAP_MAX=0, M_TRIM_THRESHOLD=-1, M_TOP_PAD=4096.
Default
-qopt-malloc-options=0
The compiler uses the default algorithm when malloc() is called. No call is made to mallopt().
Description
This option lets you specify an alternate algorithm for malloc().
If you specify a non-zero value for
n
, it causes alternate configuration parameters to be set for how malloc() allocates and frees memory. It tells the compiler to insert calls to mallopt() to adjust these parameters to malloc() for dynamic memory allocation. This may improve speed.
Alternate Options
None

Product and Performance Information

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804