On this page
6.34.11 Nvidia PTX Variable Attributes ¶
These variable attributes are supported by the Nvidia PTX back end:
- shared¶
- 
     Use this attribute to place a variable in the .sharedmemory space. This memory space is private to each cooperative thread array; only threads within one thread block refer to the same instance of the variable. The runtime does not initialize variables in this memory space.
© Free Software Foundation
Licensed under the GNU Free Documentation License, Version 1.3.
 https://gcc.gnu.org/onlinedocs/gcc-13.1.0/gcc/Nvidia-PTX-Variable-Attributes.html