Updated documentation to tell users to delete persistent cache is the…

…ir compiler changes.

README.md

@@ -83,14 +83,16 @@ An example cmake step can be:
 CXX=/opt/rocm/hcc/bin/hcc cmake -DMIOPEN_BACKEND=HIP -DCMAKE_PREFIX_PATH="/opt/rocm/hcc;/opt/rocm/hip" ..
 ```
 
-#### Setting up locations
+#### Setting Up Locations
 
 By default the install location is set to '/opt/rocm', this can be set by using `CMAKE_INSTALL_PREFIX`:
 
 ```
 cmake -DMIOPEN_BACKEND=OpenCL -DCMAKE_INSTALL_PREFIX=<miopen-installed-path> ..
 ```
 
+##### System Performance Database and User Database
+
 The default path to the System PerfDb is `miopen/share/miopen/db/` within install location. The default path to the User PerfDb is `~/.config/miopen/`. For development purposes, setting `BUILD_DEV` will change default path to both database files to the source directory:
 
 ```
@@ -99,6 +101,16 @@ cmake -DMIOPEN_BACKEND=OpenCL -DBUILD_DEV=On ..
 
 Database paths can be explicitly customized by means of `MIOPEN_DB_PATH` (System PerfDb) and `MIOPEN_USER_DB_PATH` (User PerfDb) cmake variables.
 
+##### Persistent Program Cache
+
+MIOpen by default caches the device programs in the location `~/.cache/miopen/`. In the cache directory there exists a directory for each version of MIOpen. Users change the location of the cache directory during configuration using the flag `-DMIOPEN_CACHE_DIR=<cache-directory-path>`. 
+
+Users can also disable the cache during runtime using the environmental variable set as `MIOPEN_DISABLE_CACHE=1`. 
+
+If the compiler changes, or the user modifies the kernels then the cache must be deleted for the MIOpen version in use; e.g., `rm -rf ~/.cache/miopen/<miopen-version-number>`.
+
+
+
 #### Changing the cmake configuration
 
 The configuration can be changed after running cmake by using `ccmake`: