Developer Guide and Reference

Contents

U

Undefines any definition currently in effect for the specified
macro
.

Syntax

Linux:
-U
name
macOS:
-U
name
Windows:
/U
name
Arguments
name
Is the name of the
macro
to be undefined.
Default
OFF
Macro
definitions are in effect until they are undefined.
Description
This option undefines any definition currently in effect for the specified
macro
.
It is equivalent to an #undef preprocessing directive.
On Windows systems, use the
/u
option to undefine all previously defined preprocessor values.
Alternate Options
None
To undefine a macro, enter the following command:
On Windows* systems:
icl -Uia64 prog1.cpp
On Linux* systems:
icpc -Uia64 prog1.cpp
On
macOS*
systems:
icpc -Uia64 prog1.cpp
If you attempt to undefine an ANSI C macro, the compiler will emit an error:
invalid macro undefinition: <name of macro>

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