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[Memory64] preamble JS changes for 64-bit #15225

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Merged
aardappel merged 1 commit into from
Oct 7, 2021
Merged

[Memory64] preamble JS changes for 64-bit #15225

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56 changes: 54 additions & 2 deletions src/preamble.js
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Original file line number Diff line number Diff line change
Expand Up @@ -263,8 +263,10 @@ var HEAP_DATA_VIEW;
#endif

#if WASM_BIGINT
var HEAP64;
var HEAPU64;
/** @type {BigInt64Array} */
var HEAP64,
/** @type {BigUint64Array} */
HEAPU64;
#endif

#if USE_PTHREADS
Expand Down Expand Up @@ -736,6 +738,7 @@ function instrumentWasmTableWithAbort() {
var realGet = wasmTable.get;
var wrapperCache = {};
wasmTable.get = function(i) {
{{{ from64('i') }}}
var func = realGet.call(wasmTable, i);
var cached = wrapperCache[i];
if (!cached || cached.func !== func) {
Expand All @@ -749,6 +752,51 @@ function instrumentWasmTableWithAbort() {
}
#endif

#if MEMORY64
// In memory64 mode wasm pointers are 64-bit. To support that in JS we must use
// BigInts. For now we keep JS as much the same as it always was, that is,
// stackAlloc() receives and returns a Number from the JS point of view -
// we translate BigInts automatically for that.
// TODO: support minified export names
function instrumentWasmExportsForMemory64(exports) {
var instExports = {};
for (var name in exports) {
(function(name) {
var original = exports[name];
var replacement = original;
if (name === 'stackAlloc' || name === 'malloc') {

@kripken kripken Oct 4, 2021

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This method won't work if we minify the names of exports, which we do in -O3 etc. For now, please add a comment // TODO: support minified export names, and in a later PR we should disable that minification for MEMORY64 for now (that would be in minify_wasm_imports_and_exports in tools/building.py)

@aardappel aardappel Oct 7, 2021

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Ok, will do.

@aardappel aardappel Oct 14, 2021

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Addressed here: #15305

// get one i64, return an i64
replacement = function(x) {
var r = Number(original(BigInt(x)));
return r;
};
} else if (name === 'free') {
// get one i64
replacement = function(x) {
original(BigInt(x));
};
} else if (name === 'emscripten_stack_get_end' ||
name === 'emscripten_stack_get_base' ||
name === 'emscripten_stack_get_current') {
// return an i64
replacement = function() {
var r = Number(original());
return r;
};
} else if (name === 'main') {
// get a i64 as second arg
replacement = function(x, y) {
var r = original(x, BigInt(y));
return r;
};
}
instExports[name] = replacement;
})(name);
}
return instExports;
}
#endif MEMORY64

var wasmBinaryFile;
#if EXPORT_ES6 && USE_ES6_IMPORT_META && !SINGLE_FILE
if (Module['locateFile']) {
Expand Down Expand Up @@ -968,6 +1016,10 @@ function createWasm() {
exports = relocateExports(exports, {{{ GLOBAL_BASE }}});
#endif

#if MEMORY64
exports = instrumentWasmExportsForMemory64(exports);
#endif

#if ASYNCIFY
exports = Asyncify.instrumentWasmExports(exports);
#endif
Expand Down