Modified: trunk/Source/_javascript_Core/ChangeLog (241253 => 241254)
--- trunk/Source/_javascript_Core/ChangeLog 2019-02-11 00:29:36 UTC (rev 241253)
+++ trunk/Source/_javascript_Core/ChangeLog 2019-02-11 03:25:52 UTC (rev 241254)
@@ -1,3 +1,16 @@
+2019-02-10 Saam barati <[email protected]>
+
+ BBQ-Air: Emit better code for switch
+ https://bugs.webkit.org/show_bug.cgi?id=194053
+
+ Reviewed by Yusuke Suzuki.
+
+ Instead of emitting a linear set of jumps for Switch, this patch
+ makes the BBQ-Air backend emit a binary switch.
+
+ * wasm/WasmAirIRGenerator.cpp:
+ (JSC::Wasm::AirIRGenerator::addSwitch):
+
2019-02-09 Yusuke Suzuki <[email protected]>
Unreviewed, Lexer should use isLatin1 implementation in WTF
Modified: trunk/Source/_javascript_Core/wasm/WasmAirIRGenerator.cpp (241253 => 241254)
--- trunk/Source/_javascript_Core/wasm/WasmAirIRGenerator.cpp 2019-02-11 00:29:36 UTC (rev 241253)
+++ trunk/Source/_javascript_Core/wasm/WasmAirIRGenerator.cpp 2019-02-11 03:25:52 UTC (rev 241254)
@@ -39,6 +39,7 @@
#include "B3PatchpointSpecial.h"
#include "B3Procedure.h"
#include "B3ProcedureInlines.h"
+#include "BinarySwitch.h"
#include "ScratchRegisterAllocator.h"
#include "VirtualRegister.h"
#include "WasmCallingConvention.h"
@@ -1523,27 +1524,61 @@
auto AirIRGenerator::addSwitch(ExpressionType condition, const Vector<ControlData*>& targets, ControlData& defaultTarget, const ExpressionList& expressionStack) -> PartialResult
{
- for (size_t i = 0; i < targets.size(); ++i)
- unifyValuesWithBlock(expressionStack, targets[i]->resultForBranch());
+ auto& successors = m_currentBlock->successors();
+ ASSERT(successors.isEmpty());
+ for (const auto& target : targets) {
+ unifyValuesWithBlock(expressionStack, target->resultForBranch());
+ successors.append(target->targetBlockForBranch());
+ }
unifyValuesWithBlock(expressionStack, defaultTarget.resultForBranch());
+ successors.append(defaultTarget.targetBlockForBranch());
- // FIXME: Emit either a jump table or a binary switch here.
- // https://bugs.webkit.org/show_bug.cgi?id=194053
+ ASSERT(condition.type() == Type::I32);
- for (size_t i = 0; i < targets.size(); ++i) {
- BasicBlock* target = targets[i]->targetBlockForBranch();
- BasicBlock* continuation = m_code.addBlock();
- auto constant = g64();
- append(Move, Arg::bigImm(i), constant);
- append(Branch32, Arg::relCond(MacroAssembler::Equal), constant, condition);
- m_currentBlock->setSuccessors(target, continuation);
+ // FIXME: We should consider dynamically switching between a jump table
+ // and a binary switch depending on the number of successors.
+ // https://bugs.webkit.org/show_bug.cgi?id=194477
- m_currentBlock = continuation;
- }
+ size_t numTargets = targets.size();
- append(Jump);
- m_currentBlock->setSuccessors(defaultTarget.targetBlockForBranch());
+ auto* patchpoint = addPatchpoint(B3::Void);
+ patchpoint->effects = B3::Effects::none();
+ patchpoint->effects.terminal = true;
+ patchpoint->setGenerator([=] (CCallHelpers& jit, const B3::StackmapGenerationParams& params) {
+ Vector<int64_t> cases;
+ cases.reserveInitialCapacity(numTargets);
+ for (size_t i = 0; i < numTargets; ++i)
+ cases.uncheckedAppend(i);
+
+ GPRReg valueReg = params[0].gpr();
+ BinarySwitch binarySwitch(valueReg, cases, BinarySwitch::Int32);
+
+ Vector<CCallHelpers::Jump> caseJumps;
+ caseJumps.resize(numTargets);
+
+ while (binarySwitch.advance(jit)) {
+ unsigned value = binarySwitch.caseValue();
+ unsigned index = binarySwitch.caseIndex();
+ ASSERT_UNUSED(value, value == index);
+ ASSERT(index < numTargets);
+ caseJumps[index] = jit.jump();
+ }
+
+ CCallHelpers::JumpList fallThrough = binarySwitch.fallThrough();
+
+ Vector<Box<CCallHelpers::Label>> successorLabels = params.successorLabels();
+ ASSERT(successorLabels.size() == caseJumps.size() + 1);
+
+ params.addLatePath([=, caseJumps = WTFMove(caseJumps), successorLabels = WTFMove(successorLabels)] (CCallHelpers& jit) {
+ for (size_t i = 0; i < numTargets; ++i)
+ caseJumps[i].linkTo(*successorLabels[i], &jit);
+ fallThrough.linkTo(*successorLabels[numTargets], &jit);
+ });
+ });
+
+ emitPatchpoint(patchpoint, TypedTmp(), condition);
+
return { };
}
