Debug tips and tricks

To inspect the IR generated use the --dump-compilation-phases-to=<dir-name> parameter.
To see the full stack trace when an errors is generated use the --mlir-print-stacktrace-on-diagnostic parameter.
To see the full IR when an error occour --mlir-print-ir-after-failure.
To avoid dumping huge attributes (for instance constants) : --mlir-elide-elementsattrs-if-larger=SIZE
To generate the debugging info in a directory instead of stderr: --mlir-print-ir-tree-dir=<dirname>
To print line numbers (locations) in the source input when printing IRs use --mlir-print-debuginfo --mlir-pretty-debuginfo --mlir-print-local-scope
To view more debug information during execution pass the parameter --torq_debug to iree-run-module

A VMFB file can be inspected using zip. For example to inspect a Torq flat buffer install flatc on your host and then run a command like the following:

unzip  -p ../mobilenetv2.vmfb main_dispatch_0_torq_fb.fb > dump.bin
flatc -t -o . \
    runtime/schemas/torq_executable_def.fbs -- dump.bin
cat dump.json

To convert a tosa file (which is actually a binary MLIR file) to the text representation::
```
iree-opt model.tosa  -o model.mlir
```
To debug a hang on the runtime perform the following steps:
1. Compile the test network until the executable-targets phase:
```
torq-compile --compile-to=executable-targets -o test.hw.mlir test.mlir
```
2. Compile the resulting dump from the executable-targets phase:
```
torq-compile --compile-from=executable-targets -o test.vmfb test.hw.mlir
```
3. Run the model with the --torq_debug option:
```
iree-run-module .... --torq_debug
```
4. In the debug log the line where the hardware gets stuck
To analyze the intermediate files used to create the CSS binary images append the option --torq-keep-css-linking-artifacts to the compiler invocation. With this command the compiler will also print the linking command line used to generate the binary file. By executing the command line without the --oformat=binary parameter it is possible to get a elf binary.
To debug an instruction fault in a CSS task you can add the flag --torq_qemu_trace_instructions to the runtime and then inspect the /tmp/qemu_trace_XXXX produced during the execution.
To print additional logs during execution of qemu based emulation use the flag --torq_qemu_verbose.
To kill an execution that hang during CSS emulation on qemu use the keystrokes Ctrl-A X (these keystrokes are consumed by qemu emulator).
To run the compiler in single threaded mode we add the option --mlir-disable-threading