937601c7c3
* Cranelift: Make spectre guards GVN-able While these instructions have a side effect that is otherwise invisible to the optimizer, the side effect in question is idempotent, so it can be de-duplicated by GVN. * Cranelift: Run redundant load replacement and GVN twice This allows us to actually replace redundant Wasm loads with dynamic memories. While this improves our hand-crafted test sequences, it doesn't seem to have any improvement on sightglass benchmarks run with dynamic memories, however it also isn't a hit to compilation times, so seems generally good to land anyways: ``` $ cargo run --release -- benchmark -e ~/scratch/once.so -e ~/scratch/twice.so -m insts-retired --processes 20 --iterations-per-process 3 --engine-flags="--static-memory-maximum-size 0" -- benchmarks/default.suite compilation :: instructions-retired :: benchmarks/spidermonkey/benchmark.wasm No difference in performance. [683595240 683768610.53 684097577] once.so [683597068 700115966.83 1664907164] twice.so instantiation :: instructions-retired :: benchmarks/spidermonkey/benchmark.wasm No difference in performance. [44107 60411.07 92785] once.so [44138 59552.32 92097] twice.so compilation :: instructions-retired :: benchmarks/bz2/benchmark.wasm No difference in performance. [17369916 17404839.78 17471458] once.so [17369935 17625713.87 30700150] twice.so compilation :: instructions-retired :: benchmarks/pulldown-cmark/benchmark.wasm No difference in performance. [126523640 126566170.80 126648265] once.so [126523076 127174580.30 163145149] twice.so instantiation :: instructions-retired :: benchmarks/pulldown-cmark/benchmark.wasm No difference in performance. [34569 35686.25 36513] once.so [34651 35749.97 36953] twice.so instantiation :: instructions-retired :: benchmarks/bz2/benchmark.wasm No difference in performance. [35146 36639.10 37707] once.so [34472 36580.82 38431] twice.so execution :: instructions-retired :: benchmarks/spidermonkey/benchmark.wasm No difference in performance. [7055720115 7055841324.82 7056180024] once.so [7055717681 7055877095.85 7056225217] twice.so execution :: instructions-retired :: benchmarks/pulldown-cmark/benchmark.wasm No difference in performance. [46436881 46437081.28 46437691] once.so [46436883 46437127.68 46437766] twice.so execution :: instructions-retired :: benchmarks/bz2/benchmark.wasm No difference in performance. [653010530 653010533.27 653010539] once.so [653010531 653010532.95 653010538] twice.so ```
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.