Added comment to script and doc

docs/DebuggingNumericalError.md

@@ -72,6 +72,9 @@ Full options are listed under the `--help` flag.
 
 To gain more insight in what the compiler is doing, you may want to print the output of the compiler after each transformation pass. The flags are well documented in the `mlir` literature, and we have written a script that automatically add such flags by using a custom script.
 This script is found here `utils/onnx-mlir-print.sh`, and it is used by adding all desired compiler option, plus one last argument indicating the file in which to save the log of the compiler output.
+Note that this script will list by default all of the compiler passes, regardless of whether they changed anything or not.
+If you want to limit the output to passes that changed the IR, please manually add the `--mlir-print-ir-after-change` flag when invoking `onnx-mlir-print.sh` script.
+
 
 That compiler log may typically have 10-100 passes. We have a tool to isolate a given pass. Use `utils/IsolatePass.py -m <log-file-name> -l` to list the name of all of these passes. You can then decide to investigate the compiler output of a given pass.
 For example, if interested in the transformation of ONNX to Krnl dialect, you can add the `-p "convert-onnx-to-krnl"` option, where the `convert-onnx-to-krnl` is the name of the actual pass. The `-p` option just take a regex matching a pass as listed with the `-l` option. Alternatively, option `-n 34` will isolate the 34th pass as listed with the `-l` option.

utils/onnx-mlir-print.sh

@@ -16,6 +16,10 @@
 # Usage:
 #
 # All but last arguments are mlir arguments; last one is log file name.
+#
+# Note: if a user only want to see passes listed if something happened during
+# that pass, user should add "--mlir-print-ir-after-change" to the list of
+# onnx-mlir options. It is not added by default
 
-onnx-mlir-truncate.sh ${@:1:$#-1} -mlir-print-ir-after-all ${@: -1}
+onnx-mlir-truncate.sh ${@:1:$#-1} --mlir-print-ir-after-all ${@: -1}