c2a7ea7e24
* Cranelift: Add the `DataFlowGraph::display_value_inst` convenience method * Cranelift: Add some `trace!` logs to some parts of legalization * Cranelift: de-duplicate bounds checks in legalizations When both (1) "dynamic" memories that need explicit bounds checks and (2) spectre mitigations that perform bounds checks are enabled, reuse the same bounds checks between the two legalizations. This reduces the overhead of explicit bounds checks and spectre mitigations over using virtual memory guard pages with spectre mitigations from ~1.9-2.1x overhead to ~1.6-1.8x overhead. That is about a 14-19% speed up for when dynamic memories and spectre mitigations are enabled. <details> ``` execution :: instructions-retired :: benchmarks/spidermonkey/benchmark.wasm Δ = 3422455129.47 ± 120159.49 (confidence = 99%) virtual-memory-guards.so is 2.09x to 2.09x faster than bounds-checks.so! [6563931659 6564063496.07 6564301535] bounds-checks.so [3141492675 3141608366.60 3141895249] virtual-memory-guards.so execution :: instructions-retired :: benchmarks/bz2/benchmark.wasm Δ = 338716136.87 ± 1.38 (confidence = 99%) virtual-memory-guards.so is 2.08x to 2.08x faster than bounds-checks.so! [651961494 651961495.47 651961497] bounds-checks.so [313245357 313245358.60 313245362] virtual-memory-guards.so execution :: instructions-retired :: benchmarks/pulldown-cmark/benchmark.wasm Δ = 22742944.07 ± 331.73 (confidence = 99%) virtual-memory-guards.so is 1.87x to 1.87x faster than bounds-checks.so! [48841295 48841567.33 48842139] bounds-checks.so [26098439 26098623.27 26099479] virtual-memory-guards.so ``` </details> <details> ``` execution :: instructions-retired :: benchmarks/spidermonkey/benchmark.wasm Δ = 2465900207.27 ± 146476.61 (confidence = 99%) virtual-memory-guards.so is 1.78x to 1.78x faster than de-duped-bounds-checks.so! [5607275431 5607442989.13 5607838342] de-duped-bounds-checks.so [3141445345 3141542781.87 3141711213] virtual-memory-guards.so execution :: instructions-retired :: benchmarks/bz2/benchmark.wasm Δ = 234253620.20 ± 2.33 (confidence = 99%) virtual-memory-guards.so is 1.75x to 1.75x faster than de-duped-bounds-checks.so! [547498977 547498980.93 547498985] de-duped-bounds-checks.so [313245357 313245360.73 313245363] virtual-memory-guards.so execution :: instructions-retired :: benchmarks/pulldown-cmark/benchmark.wasm Δ = 16605659.13 ± 315.78 (confidence = 99%) virtual-memory-guards.so is 1.64x to 1.64x faster than de-duped-bounds-checks.so! [42703971 42704284.40 42704787] de-duped-bounds-checks.so [26098432 26098625.27 26099234] virtual-memory-guards.so ``` </details> <details> ``` execution :: instructions-retired :: benchmarks/bz2/benchmark.wasm Δ = 104462517.13 ± 7.32 (confidence = 99%) de-duped-bounds-checks.so is 1.19x to 1.19x faster than bounds-checks.so! [651961493 651961500.80 651961532] bounds-checks.so [547498981 547498983.67 547498989] de-duped-bounds-checks.so execution :: instructions-retired :: benchmarks/spidermonkey/benchmark.wasm Δ = 956556982.80 ± 103034.59 (confidence = 99%) de-duped-bounds-checks.so is 1.17x to 1.17x faster than bounds-checks.so! [6563930590 6564019842.40 6564243651] bounds-checks.so [5607307146 5607462859.60 5607677763] de-duped-bounds-checks.so execution :: instructions-retired :: benchmarks/pulldown-cmark/benchmark.wasm Δ = 6137307.87 ± 247.75 (confidence = 99%) de-duped-bounds-checks.so is 1.14x to 1.14x faster than bounds-checks.so! [48841303 48841472.93 48842000] bounds-checks.so [42703965 42704165.07 42704718] de-duped-bounds-checks.so ``` </details> * Update test expectations * Add a test for deduplicating bounds checks between dynamic memories and spectre mitigations * Define a struct for the Spectre comparison instead of using a tuple * More trace logging for heap legalization
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.