The pass generate-runtime-verification generates additional runtime op
verification checks.
Currently, the pass is extremely expensive. For example, with a
mobilenet v2 ssd network(converted to mlir), running this pass alone in
debug mode will take 30 minutes. The same observation has been made to
other networks as small as 5 Mb.
The culprit is this line "op->print(stream, flags);" in function
"RuntimeVerifiableOpInterface::generateErrorMessage" in File
mlir/lib/Interfaces/RuntimeVerifiableOpInterface.cpp.
As we are printing the op with all the names of the operands in the
middle end, we are constructing a new SSANameState for each
op->print(...) call. Thus, we are doing a new SSA analysis for each
error message printed.
Perf profiling shows that 98% percent of the time is spent in the
constructor of SSANameState.
This change refactored the message generator. We use a toplevel
AsmState, and reuse it with all the op-print(stream, asmState). With a
release build, this change reduces the pass exeuction time from ~160
seconds to 0.3 seconds on my machine.
This change also adds verbose options to generate-runtime-verification
pass.
verbose 0: print only source location with error message.
verbose 1: print the full op, including the name of the operands.
As specified in the docs,
1) raw_string_ostream is always unbuffered and
2) the underlying buffer may be used directly
( 65b13610a5226b84889b923bae884ba395ad084d for further reference )
* Don't call raw_string_ostream::flush(), which is essentially a no-op.
* Avoid unneeded calls to raw_string_ostream::str(), to avoid excess indirection.
This commit implements runtime verification for LinalgStructuredOps
using the existing `RuntimeVerifiableOpInterface`. The verification
checks that the runtime sizes of the operands match the runtime sizes
inferred by composing the loop ranges with the op's indexing maps.
This commit implements runtime verification for LinalgStructuredOps
using the existing `RuntimeVerifiableOpInterface`. The verification
checks that the runtime sizes of the operands match the runtime sizes
inferred by composing the loop ranges with the op's indexing maps.
Static op verification cannot detect cases where an op is valid at compile time but may be invalid at runtime.
An example of such an op is `memref::ExpandShapeOp`.
Invalid at compile time: `memref.expand_shape %m [[0, 1]] : memref<11xf32> into memref<2x5xf32>`
Valid at compile time (because we do not know any better): `memref.expand_shape %m [[0, 1]] : memref<?xf32> into memref<?x5xf32>`. This op may or may not be valid at runtime depending on the runtime shape of `%m`.
Invalid runtime ops such as the one above are hard to debug because they can crash the program execution at a seemingly unrelated position or (even worse) compute an invalid result without crashing.
This revision adds a new op interface `RuntimeVerifiableOpInterface` that can be implemented by ops that provide additional runtime verification. Such runtime verification can be computationally expensive, so it is only generated on an opt-in basis by running `-generate-runtime-verification`. A simple runtime verifier for `memref::ExpandShapeOp` is provided as an example.
Differential Revision: https://reviews.llvm.org/D138576
