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 ```
This crate contains the core Cranelift code generator. It translates code from an intermediate representation into executable machine code.