10.145 __wfi intrinsic

This intrinsic inserts a WFI instruction into the instruction stream generated by the compiler.

In some architectures, for example the v6T2 architecture, the WFI instruction executes as a NOP instruction.


void __wfi(void)


The compiler does not recognize the __wfi intrinsic when compiling for a target that does not support the WFI instruction. The compiler generates either a warning or an error in this case, depending on the source language:

  • In C code: Warning: #223-D: function "__wfi" declared implicitly.
  • In C++ code: Error: #20: identifier "__wfi" is undefined.
Related reference
10.135 __sev intrinsic
10.121  __nop intrinsic
10.144 __wfe intrinsic
10.146 __yield intrinsic
Related information
Non-Confidential PDF file icon PDF version ARM DUI0472J
Copyright © 2010-2013 ARM. All rights reserved.