[PyTorch] Avoid std::string in TORCH_CHECK when possible (#52221)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/52221
The previous code forced a `std::string` to be created even when the default message or a user-provided string literal message was used. Now it's not forced and we don't need an outlined lambda in those cases either.
ghstack-source-id: 121877056
Test Plan:
Compare assembly for
```
#include <c10/util/Exception.h>
void f(bool b) {
TORCH_CHECK(b, "message");
}
void g(bool b) {
TORCH_CHECK(b);
}
void h(bool b) {
TORCH_CHECK(b, "message", random());
}
```
before/after in fbcode optimized build.
Before: P174696735
After: P174696840
For `f()` and `g()`, we go from a call to an outlined lambda that did a bunch of `std::string` creation to a load of a string constant before calling `torchCheckFail`. This is a clear improvement.
For `h()`, results are mixed: we save a bunch of *extra* string goop in the outlined lambda and instead call `c10::detail::_str_wrapper` directly. This is good for overall size. However, we no longer outline the call to `random()`, which is less than ideal. I hope to recover the ability to fully outline the `random()` call in future diffs; this is just thorny enough that I don't want to cram even more into one diff.
Added automated test to make sure `TORCH_CHECK` and `TORCH_INTERNAL_ASSERT` only evaluate their arguments once.
Profiled AdIndexer mergenet benchmark in perf to check that `IValue::toTensor` is still getting inlined.
Reviewed By: bhosmer
Differential Revision: D26380783
fbshipit-source-id: 288860772423994ac739a8f33e2c09f718e8dd38
pytorch
efbb854e - [PyTorch] Avoid std::string in TORCH_CHECK when possible (#52221)
