AuroraMiddleware/v8
1
0
Fork 0
Code Issues 2 Pull Requests Releases Wiki Activity

[wasm][tail-call] Fix CanTailCall check

Browse Source 
The CanTailCall check only passes if the return locations are the
same in the caller and the callee. However, stack returns are expected
to be at a different offset depending on the stack space reserved for
parameters.

R=clemensb@chromium.org

Bug: v8:7431
Change-Id: Iaac15fce889d6cd7d1ac88f320a872202281fb5a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2289789
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Thibaud Michaud <thibaudm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68933}
This commit is contained in:
Thibaud Michaud 2020-07-10 11:49:15 +02:00 committed by Commit Bot
parent 9df54e0767
commit 69553feaab
2 changed files with 53 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
src/compiler/linkage.cc
View File

@ -125,10 +125,18 @@ int CallDescriptor::GetTaggedParameterSlots() const {
bool CallDescriptor::CanTailCall(const CallDescriptor* callee) const {
if (ReturnCount() != callee->ReturnCount()) return false;
const int stack_param_delta = callee->GetStackParameterDelta(this);
for (size_t i = 0; i < ReturnCount(); ++i) {
if (!LinkageLocation::IsSameLocation(GetReturnLocation(i),
callee->GetReturnLocation(i)))
if (GetReturnLocation(i).IsCallerFrameSlot() &&
callee->GetReturnLocation(i).IsCallerFrameSlot()) {
if (GetReturnLocation(i).AsCallerFrameSlot() - stack_param_delta !=
callee->GetReturnLocation(i).AsCallerFrameSlot()) {
return false;
}
} else if (!LinkageLocation::IsSameLocation(GetReturnLocation(i),
callee->GetReturnLocation(i))) {
return false;
}
}
return true;
}

43
test/mjsunit/wasm/return-calls.js
View File

@ -159,3 +159,46 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
print(" --right--");
assertEquals(3, module.exports.main(0, -2, 3));
})();
(function TestMultiReturnCallWithLongSig() {
print(arguments.callee.name);
const callee_inputs = 10;
// Tail call from a function with less, as many, or more parameters than the
// callee.
for (caller_inputs = 9; caller_inputs <= 11; ++caller_inputs) {
let builder = new WasmModuleBuilder();
// f just returns its arguments in reverse order.
const f_params = new Array(callee_inputs).fill(kWasmI32);
const f_returns = f_params;
const f_sig = builder.addType(makeSig(f_params, f_returns));
let f_body = [];
for (i = 0; i < callee_inputs; ++i) {
f_body.push(kExprLocalGet, callee_inputs - i - 1);
}
const f = builder.addFunction("f", f_sig).addBody(f_body);
// Slice or pad the caller inputs to match the callee.
const main_params = new Array(caller_inputs).fill(kWasmI32);
const main_sig = builder.addType(makeSig(main_params, f_returns));
let main_body = [];
for (i = 0; i < callee_inputs; ++i) {
main_body.push(kExprLocalGet, Math.min(caller_inputs - 1, i));
}
main_body.push(kExprReturnCall, f.index);
builder.addFunction("main", main_sig).addBody(main_body).exportFunc();
let module = builder.instantiate();
inputs = [];
for (i = 0; i < caller_inputs; ++i) {
inputs.push(i);
}
let expect = inputs.slice(0, callee_inputs);
while (expect.length < callee_inputs) {
expect.push(inputs[inputs.length - 1]);
}
expect.reverse();
assertEquals(expect, module.exports.main(...inputs));
}
})();