Enable LTO optimization by default for runtime releases.

[stellaraccident]

This is done by generalizing the primordial IREE_SIZE_OPTIMIZED flag into a IREE_RUNTIME_OPTIMIZATION_PROFILE that:

• Can enable 'lto' or 'size'.
• Is scoped to just the runtime targets.
• Minimally does the right thing for 'size' on Linux vs just on Windows (not the goal of this patch but drops ~300KB from binary sizes when enabled).

The compile time delta for a clean build of the runtime in full LTO vs regular mode was not measured precisely but is in the noise (i.e. <1m). As such, just enabling by default for Python release binaries.

Others can be enabled via: -DIREE_RUNTIME_OPTIMIZATION_PROFILE=lto, which is recommended for benchmarking, etc.

Note that this removes the use of the CMake option IREE_SIZE_OPTIMIZED. It was never even declared properly as an option and didn't do the same class of thing across Windows/Linux. This has been fixed and it can be enabled via -DIREE_RUNTIME_OPTIMIZATION_PROFILE=size. Note that as on Windows, this implies LTO. If old behavior without LTO is desired, we can add a profile for that.

Progress on #898.

[stellaraccident]

@ScottTodd I expect that the change of the linking mode has effectively just fuzzed execution a bit and caused a latent bug to surface in the tooling. I'm going to squash this branch for easy access but could use your help to resolve/land.

[ScottTodd]

@ScottTodd I expect that the change of the linking mode has effectively just fuzzed execution a bit and caused a latent bug to surface in the tooling. I'm going to squash this branch for easy access but could use your help to resolve/land.

Interesting. I can help tomorrow. A few thoughts from a quick look:

• Are the failure consistent, or flaky?

• If the failures are in the same tests each run, could exclude or mark XFAIL

• Could run a few times at HEAD to see if the PR itself is changing behavior

• I've seen what look like system (driver/hardware/OS/etc.) flakes on the AMDGPU runners (mostly for ROCm, but also for Vulkan). Not sure if I've seen CPU flakes. Reducing parallelism helped with some classes of flakes (resource exhaustion or multithreaded compilation across dozens of runs at once hitting race conditions... idk)

• Diagnostics are lacking... wonder if that's from not having debug symbols or what. Would really like more info from the tests...

  https://github.com/openxla/iree/actions/runs/8319107825/job/22761993141?pr=16811#step:10:45

  =================================== FAILURES ===================================
  _____ IREE compile and run: test_constantofshape_float_ones::cpu_llvm_sync _____
  [gw88] linux -- Python 3.11.8 /runner-root/actions-runner/_work/iree/iree/venv/bin/python
  Error invoking iree-run-module
  Error code: 245
  Stderr diagnostics:
  
  Stdout diagnostics:
  EXEC @test_constantofshape_float_ones
  
  Compiled with:
    cd /runner-root/actions-runner/_work/iree/iree/SHARK-TestSuite/iree_tests/onnx/node/generated/test_constantofshape_float_ones && iree-compile model.mlir --iree-hal-target-backends=llvm-cpu -o model_cpu_llvm_sync.vmfb
  
  Run with:
    cd /runner-root/actions-runner/_work/iree/iree/SHARK-TestSuite/iree_tests/onnx/node/generated/test_constantofshape_float_ones && iree-run-module --module=model_cpu_llvm_sync.vmfb --device=local-sync --flagfile=test_data_flags.txt
  

[ScottTodd]

Retried the failing jobs... same test failures on both CPU and Vulkan. So could mark as XFAIL to unblock this. Should still investigate though.

[ScottTodd]

On my Windows machine I see the compiler crashing on these test cases at tip of tree and with this PR:

FAILED onnx/node/generated/test_shape_end_1/model.mlir::cpu_llvm_sync
FAILED onnx/node/generated/test_shape_start_1_end_negative_1/model.mlir::cpu_llvm_sync
FAILED onnx/node/generated/test_shape_start_1/model.mlir::cpu_llvm_sync
FAILED onnx/node/generated/test_shape_start_negative_1/model.mlir::cpu_llvm_sync
FAILED onnx/node/generated/test_shape_start_1_end_2/model.mlir::cpu_llvm_sync
FAILED onnx/node/generated/test_shape_end_negative_1/model.mlir::cpu_llvm_sync

So the CPU failures on CI here are strange... Could skip them instead of XFAIL to keep the same set of tests running across platforms.

[ScottTodd]

Would really help to have asserts enabled in the pkgci build that these tests use. That is disabled right now: https://github.com/openxla/iree/blob/ee32fc7b74b4aad49fc46d67ea6c1f617416c4d4/.github/workflows/pkgci_build_packages.yml#L81-L83

[stellaraccident]

Would really help to have asserts enabled in the pkgci build that these tests use. That is disabled right now:

https://github.com/openxla/iree/blob/ee32fc7b74b4aad49fc46d67ea6c1f617416c4d4/.github/workflows/pkgci_build_packages.yml#L81-L83

Fwiw, I think I fixed the issue behind that todo un another setup. But yeah.

Ok, I'm taking all of this as orthogonal to this patch (but still needs addressing). How do I mark those tests? (Sorry, running a few things here...)

[ScottTodd]

How do I mark those tests?

https://github.com/openxla/iree/tree/main/experimental/regression_suite/external_test_suite the CPU and Vulkan JSON files. Can add to either skip_compile_tests to exclude entirely or expected_run_failures.

CPU should add these:

test_constantofshape_float_ones
test_dropout_default_mask_ratio
test_reduce_min_empty_set

Vulkan should add these:

test_constantofshape_float_ones
test_dropout_default_mask_ratio

[ScottTodd]

Okay, CI is happy now.