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wasmtime/cranelift/filetests
Chris Fallin 1faff8c2ce Enable egraph-based optimization by default. (#5587)
This PR follows up on #5382 and #5391, which rebuilt the egraph-based optimization framework to be more performant, by enabling it by default.

Based on performance results in #5382 (my measurements on SpiderMonkey and bjorn3's independent confirmation with cg_clif), it seems that this is reasonable to enable. Now that we have been fuzzing compiler configurations with egraph opts (#5388) for 6 weeks, having fixed a few fuzzbugs that came up (#5409, #5420, #5438) and subsequently received no further reports from OSS-Fuzz, I believe it is stable enough to rely on.

This PR enables `use_egraphs`, and also normalizes its meaning: previously it forced optimization (it basically meant "turn on the egraph optimization machinery"), now it runs egraph opts if the opt level indicates (it means "use egraphs to optimize if we are going to optimize"). The conditionals in the top-level pass driver are a little subtle, but will get simpler once we can remove the non-egraph path (which we plan to do eventually!).

Fixes #5181.
2023-01-19 15:46:53 -08:00
..

filetests

Filetests is a crate that contains multiple test suites for testing various parts of cranelift. Each folder under cranelift/filetests/filetests is a different test suite that tests different parts.

Adding a runtest

One of the available testsuites is the "runtest" testsuite. Its goal is to compile some piece of clif code, run it and ensure that what comes out is what we expect.

To build a run test you can add the following to a file:

test interpret
test run
target x86_64
target aarch64
target s390x

function %band_f32(f32, f32) -> f32 {
block0(v0: f32, v1: f32):
    v2 = band v0, v1
    return v2
}
; run: %band_f32(0x0.5, 0x1.0) == 0x1.5

Since this is a run test for band we can put it in: runtests/band.clif. Once we have the file in the test suite we can run it by invoking: cargo run -- test filetests/filetests/runtests/band.clif from the cranelift directory.

The first lines tell clif-util what kind of tests we want to run on this file. test interpret invokes the interpreter and checks if the conditions in the ; run comments pass. test run does the same, but compiles the file and runs it as a native binary.

For more information about testing see testing.md.