diff options
| -rw-r--r-- | src/support/file.h | 2 | ||||
| -rw-r--r-- | src/tools/wasm-split.cpp | 59 | ||||
| -rw-r--r-- | test/lit/wasm-split/call_exports.mjs | 25 | ||||
| -rw-r--r-- | test/lit/wasm-split/profile-guided.wast | 67 |
4 files changed, 151 insertions, 2 deletions
diff --git a/src/support/file.h b/src/support/file.h index ce554acaa..3dc766b2d 100644 --- a/src/support/file.h +++ b/src/support/file.h @@ -15,7 +15,7 @@ */ // -// FIle helpers. +// File helpers. // #ifndef wasm_support_file_h diff --git a/src/tools/wasm-split.cpp b/src/tools/wasm-split.cpp index 61f52d5fa..a363b825b 100644 --- a/src/tools/wasm-split.cpp +++ b/src/tools/wasm-split.cpp @@ -20,6 +20,7 @@ #include "ir/module-splitting.h" #include "ir/module-utils.h" #include "ir/names.h" +#include "support/file.h" #include "support/name.h" #include "support/utilities.h" #include "tool-options.h" @@ -358,6 +359,21 @@ void Instrumenter::instrumentFuncs() { }); } +// wasm-split profile format:: +// +// The wasm-split profile is a binary format designed to be simple to produce +// and consume. It is comprised of: +// +// 1. An 8-byte module hash +// +// 2. A 4-byte timestamp for each defined function +// +// The module hash is meant to guard against bugs where the module that was +// instrumented and the module that is being split are different. The timestamps +// are non-zero for functions that were called during the instrumented run and 0 +// otherwise. Functions with smaller non-zero timestamps were called earlier in +// the instrumented run than funtions with larger timestamps. + void Instrumenter::addProfileExport() { // Create and export a function to dump the profile into a given memory // buffer. The function takes the available address and buffer size as @@ -423,6 +439,8 @@ void Instrumenter::addProfileExport() { wasm->memory.max = pages; } } + + // TODO: export the memory if it is not already exported. } void instrumentModule(Module& wasm, const WasmSplitOptions& options) { @@ -443,12 +461,51 @@ void instrumentModule(Module& wasm, const WasmSplitOptions& options) { writer.write(wasm, options.output); } +// See "wasm-split profile format" above for more information. +std::set<Name> readProfile(Module& wasm, const WasmSplitOptions& options) { + auto profileData = + read_file<std::vector<char>>(options.profileFile, Flags::Binary); + size_t i = 0; + auto readi32 = [&]() { + if (i + 4 > profileData.size()) { + Fatal() << "Unexpected end of profile data"; + } + uint32_t i32 = 0; + i32 |= uint32_t(profileData[i++]); + i32 |= uint32_t(profileData[i++]) << 8; + i32 |= uint32_t(profileData[i++]) << 16; + i32 |= uint32_t(profileData[i++]) << 24; + return i32; + }; + + // TODO: Read and compare the 8-byte module hash. Just skip it for now. + readi32(); + readi32(); + + std::set<Name> keptFuncs; + ModuleUtils::iterDefinedFunctions(wasm, [&](Function* func) { + uint32_t timestamp = readi32(); + // TODO: provide an option to set the timestamp threshold. For now, kee the + // function if the profile shows it being run at all. + if (timestamp > 0) { + keptFuncs.insert(func->name); + } + }); + + if (i != profileData.size()) { + // TODO: Handle concatenated profile data. + Fatal() << "Unexpected extra profile data"; + } + + return keptFuncs; +} + void splitModule(Module& wasm, const WasmSplitOptions& options) { std::set<Name> keepFuncs; if (options.profileFile.size()) { // Use the profile to initialize `keepFuncs` - Fatal() << "TODO: implement reading profiles\n"; + keepFuncs = readProfile(wasm, options); } // Add in the functions specified with --keep-funcs diff --git a/test/lit/wasm-split/call_exports.mjs b/test/lit/wasm-split/call_exports.mjs new file mode 100644 index 000000000..546564d2e --- /dev/null +++ b/test/lit/wasm-split/call_exports.mjs @@ -0,0 +1,25 @@ +// Instantiates an instrumented module, calls the given exports, then collects +// its wasm-split profile and writes it to a given file. +// +// Usage: +// +// node call_exports.mjs <module> <profile> <export>* + +import * as fs from 'fs'; + +let wasm = process.argv[2]; +let outFile = process.argv[3]; + +// Create the Wasm instance +let { _, instance } = await WebAssembly.instantiate(fs.readFileSync(wasm)); + +// Call the specified exports +for (let i = 4; i < process.argv.length; i++) { + console.log('calling', process.argv[i]); + instance.exports[process.argv[i]](); +} + +// Create and read the profile +let profileSize = instance.exports['__write_profile'](0, 2**32 - 1); +let profileData = Buffer.from(instance.exports.memory.buffer, 0, profileSize); +fs.writeFileSync(outFile, profileData); diff --git a/test/lit/wasm-split/profile-guided.wast b/test/lit/wasm-split/profile-guided.wast new file mode 100644 index 000000000..f2d79f99c --- /dev/null +++ b/test/lit/wasm-split/profile-guided.wast @@ -0,0 +1,67 @@ +;; Instrument the binary + +;; RUN: wasm-split --instrument %s -o %t.instrumented.wasm + +;; Create profiles + +;; RUN: node %S/call_exports.mjs %t.instrumented.wasm %t.foo.prof foo +;; RUN: node %S/call_exports.mjs %t.instrumented.wasm %t.bar.prof bar +;; RUN: node %S/call_exports.mjs %t.instrumented.wasm %t.both.prof foo bar +;; RUN: node %S/call_exports.mjs %t.instrumented.wasm %t.none.prof + +;; Create profile-guided splits + +;; RUN: wasm-split %s --profile=%t.foo.prof -v -o1 %t.foo.1.wasm -o2 %t.foo.2.wasm \ +;; RUN: | filecheck %s --check-prefix FOO + +;; FOO: Keeping functions: deep_foo_callee, foo, foo_callee, shared_callee +;; FOO: Splitting out functions: bar, bar_callee, uncalled + +;; RUN: wasm-split %s --profile=%t.bar.prof -v -o1 %t.bar.1.wasm -o2 %t.bar.2.wasm \ +;; RUN: | filecheck %s --check-prefix BAR + +;; BAR: Keeping functions: bar, bar_callee, shared_callee +;; BAR: Splitting out functions: deep_foo_callee, foo, foo_callee, uncalled + +;; RUN: wasm-split %s --profile=%t.both.prof -v -o1 %t.both.1.wasm -o2 %t.both.2.wasm \ +;; RUN: | filecheck %s --check-prefix BOTH + +;; BOTH: Keeping functions: bar, bar_callee, deep_foo_callee, foo, foo_callee, shared_callee +;; BOTH: Splitting out functions: uncalled + +;; RUN: wasm-split %s --profile=%t.none.prof -v -o1 %t.none.1.wasm -o2 %t.none.2.wasm \ +;; RUN: | filecheck %s --check-prefix NONE + +;; NONE: Keeping functions: +;; NONE: Splitting out functions: bar, bar_callee, deep_foo_callee, foo, foo_callee, shared_callee, uncalled + + +(module + (memory $mem 1 1) + (export "memory" (memory $mem)) + (export "foo" (func $foo)) + (export "bar" (func $bar)) + (export "uncalled" (func $uncalled)) + + (func $foo + (call $foo_callee) + (call $shared_callee) + ) + + (func $bar + (call $shared_callee) + (call $bar_callee) + ) + + (func $uncalled) + + (func $foo_callee + (call $deep_foo_callee) + ) + + (func $bar_callee) + + (func $shared_callee) + + (func $deep_foo_callee) +) |