Changeset 216058 in webkit for trunk/Source/JavaScriptCore/b3/testb3.cpp

Timestamp:

May 1, 2017, 9:32:08 PM (8 years ago)

Author:

[email protected]

Message:

[aarch64][Linux] m_allowScratchRegister assert hit in MacroAssemblerARM64 under B3::Air::CCallSpecial::generate()
​https://bugs.webkit.org/show_bug.cgi?id=170672

Reviewed by Filip Pizlo.

In Air::CCallSpecial::admitsStack() we reject admitting the callee argument on
the stack for ARM64 because that can lead to disallowed usage of the scratch
register in MacroAssemblerARM64 when generating a call with an address Arg
in Air::CCallSpecial::generate().

The testLinearScanWithCalleeOnStack test is added to testb3. It reproduces the
original issue by force-spilling everything on the stack and enforcing the use
of the linear scan register allocation by using an optimization level of 1.

• b3/air/AirCCallSpecial.cpp:

(JSC::B3::Air::CCallSpecial::admitsStack):

• b3/testb3.cpp:

(JSC::B3::testLinearScanWithCalleeOnStack):
(JSC::B3::run):

File:

• trunk/Source/JavaScriptCore/b3/testb3.cpp (modified) (2 diffs)

trunk/Source/JavaScriptCore/b3/testb3.cpp

@@ -10426 +10426 @@
 
     CHECK(compileAndRun<float>(proc) == functionWithHellaFloatArguments(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26));
+}
+
+void testLinearScanWithCalleeOnStack()
+{
+    // This tests proper CCall generation when compiling with a lower optimization
+    // level and operating with a callee argument that's spilt on the stack.
+    // On ARM64, this caused an assert in MacroAssemblerARM64 because of disallowed
+    // use of the scratch register.
+    // https://bugs.webkit.org/show_bug.cgi?id=170672
+
+    Procedure proc;
+    BasicBlock* root = proc.addBlock();
+
+    root->appendNewControlValue(
+        proc, Return, Origin(),
+        root->appendNew<CCallValue>(
+            proc, Int32, Origin(),
+            root->appendNew<ConstPtrValue>(proc, Origin(), bitwise_cast<void*>(simpleFunction)),
+            root->appendNew<ArgumentRegValue>(proc, Origin(), GPRInfo::argumentGPR0),
+            root->appendNew<ArgumentRegValue>(proc, Origin(), GPRInfo::argumentGPR1)));
+
+    // Force the linear scan algorithm to spill everything.
+    auto original = Options::airLinearScanSpillsEverything();
+    Options::airLinearScanSpillsEverything() = true;
+
+    // Compiling with 1 as the optimization level enforces the use of linear scan
+    // for register allocation.
+    auto code = compileProc(proc, 1);
+    CHECK_EQ(invoke<int>(*code, 41, 1), 42);
+
+    Options::airLinearScanSpillsEverything() = original;
 }
 
@@ -16319 +16350 @@
     RUN_BINARY(testCallSimpleFloat, floatingPointOperands<float>(), floatingPointOperands<float>());
     RUN(testCallFunctionWithHellaFloatArguments());
+
+    RUN(testLinearScanWithCalleeOnStack());
 
     RUN(testChillDiv(4, 2, 2));