Developer Guide and Reference

Contents

qopt-dynamic-align, Qopt-dynamic-align

Enables or disables dynamic data alignment optimizations.

Syntax

Linux and macOS:
-qopt-dynamic-align
-qno-opt-dynamic-align
Windows:
/Qopt-dynamic-align
/Qopt-dynamic-align-
Arguments
None
Default
-qopt-dynamic-align
or
/Qopt-dynamic-align
The compiler may generate code dynamically dependent on alignment. It may do optimizations based on data location for the best performance. The result of execution on some algorithms may depend on data layout.
Description
This option enables or disables dynamic data alignment optimizations.
If you specify
-qno-opt-dynamic-align
or
/Qopt-dynamic-align-
, the compiler generates no code dynamically dependent on alignment. It will not do any optimizations based on data location and results will depend on the data values themselves.
When you specify
[q or Q]qopt-dynamic-align
, the compiler may implement conditional optimizations based on dynamic alignment of the input data. These dynamic alignment optimizations may result in different bitwise results for aligned and unaligned data with the same values.
Dynamic alignment optimizations can improve the performance of vectorized code, especially for long trip count loops. Disabling such optimizations can decrease performance, but it may improve bitwise reproducibility of results, factoring out data location from possible sources of discrepancy.
Alternate Options
None