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Bug 1533890: Add simulator support for IgnoresReturnValue version of native functions r=mgaudet

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Native calls in the simulator have to be redirected to a special swi instruction. In the old implementation, this redirection did not support calling the IgnoresReturnValue version of a native function. This patch fixes that problem in the new implementation.

Differential Revision: https://phabricator.services.mozilla.com/D22775

--HG--
extra : moz-landing-system : lando
This commit is contained in:
Iain Ireland 2019-03-19 22:57:44 +00:00
parent 777a20a753
commit 97c1196748
1 changed files with 15 additions and 5 deletions
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20
js/src/jit/CacheIR.h
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@ -1125,18 +1125,28 @@ class MOZ_RAII CacheIRWriter : public JS::CustomAutoRooter {
bool isCrossRealm = cx_->realm() != calleeFunc->realm();
buffer_.writeByte(uint32_t(isCrossRealm));
// Some native functions can be implemented faster if we know that
// the return value is ignored.
bool ignoresReturnValue =
op == JSOP_CALL_IGNORES_RV && calleeFunc->hasJitInfo() &&
calleeFunc->jitInfo()->type() == JSJitInfo::IgnoresReturnValueNative;
#ifdef JS_SIMULATOR
// The simulator requires VM calls to be redirected to a special
// swi instruction to handle them, so we store the redirected
// pointer in the stub and use that instead of the original one.
// If we are calling the ignoresReturnValue version of a native
// function, we bake it into the redirected pointer.
// (See BaselineCacheIRCompiler::emitCallNativeFunction.)
void* target = JS_FUNC_TO_DATA_PTR(void*, calleeFunc->native());
void* redirected = Simulator::RedirectNativeFunction(target, Args_General3);
JSNative target = ignoresReturnValue
? calleeFunc->jitInfo()->ignoresReturnValueMethod
: calleeFunc->native();
void* rawPtr = JS_FUNC_TO_DATA_PTR(void*, target);
void* redirected = Simulator::RedirectNativeFunction(rawPtr, Args_General3);
addStubField(uintptr_t(redirected), StubField::Type::RawWord);
#else
bool ignoresReturnValue =
op == JSOP_CALL_IGNORES_RV && calleeFunc->hasJitInfo() &&
calleeFunc->jitInfo()->type() == JSJitInfo::IgnoresReturnValueNative;
// If we are not running in the simulator, we generate different jitcode
// to find the ignoresReturnValue version of a native function.
buffer_.writeByte(ignoresReturnValue);
#endif
}