package org.jruby.ir.transformations.inlining;
import org.jruby.RubyModule;
import org.jruby.ir.IRClosure;
import org.jruby.ir.IRScope;
import org.jruby.ir.Tuple;
import org.jruby.ir.instructions.*;
import org.jruby.ir.operands.*;
import org.jruby.ir.representations.BasicBlock;
import org.jruby.ir.representations.CFG;
import org.jruby.ir.representations.CFG.EdgeType;
import org.jruby.ir.util.Edge;
import java.util.ArrayList;
import java.util.List;
public class CFGInliner {
private final CFG cfg;
public CFGInliner(CFG build) {
this.cfg = build;
}
private SimpleCloneInfo cloneHostInstrs(CFG cfg) {
cfg.getScope().initNestedClosures();
SimpleCloneInfo ii = new SimpleCloneInfo(cfg.getScope(), false);
for (BasicBlock b : cfg.getBasicBlocks()) {
b.cloneInstrs(ii);
}
return ii;
}
private CFG cloneSelf(InlineCloneInfo ii) {
CFG selfClone = new CFG(cfg.getScope());
// clone bbs
for (BasicBlock b : cfg.getBasicBlocks()) {
if (!b.isEntryBB() && !b.isExitBB()) selfClone.addBasicBlock(b.cloneForInlining(ii));
}
// clone edges
for (BasicBlock b: cfg.getBasicBlocks()) {
if (b.isEntryBB() || b.isExitBB()) continue;
BasicBlock rb = ii.getRenamedBB(b);
for (Edge<BasicBlock> e : cfg.getOutgoingEdges(b)) {
BasicBlock destination = e.getDestination().getData();
if (!destination.isExitBB()) selfClone.addEdge(rb, ii.getRenamedBB(destination), e.getType());
}
}
return selfClone;
}
public void inlineMethod(IRScope scope, RubyModule implClass, int classToken, BasicBlock callBB, CallBase call, boolean cloneHost) {
// Temporarily turn off inlining of recursive methods
// Conservative turning off for inlining of a method in a closure nested within the same method
IRScope hostScope = cfg.getScope();
if (hostScope.getNearestMethod() == scope) return;
/*
System.out.println("Looking for: " + call.getIPC() + ": " + call);
System.out.println("host cfg :" + cfg.toStringGraph());
System.out.println("host instrs:" + cfg.toStringInstrs());
System.out.println("source cfg :" + scope.getCFG().toStringGraph());
System.out.println("source instrs:" + scope.getCFG().toStringInstrs());
*/
// Find callBB
if (callBB == null) {
for (BasicBlock x: cfg.getBasicBlocks()) {
for (Instr i: x.getInstrs()) {
// System.out.println("IPC " + i.getIPC() + " = " + i);
if (i.getIPC() == call.getIPC()) {
// System.out.println("Found it!!!! -- " + call);
callBB = x;
break;
}
}
}
}
if (callBB == null) {
System.out.println("----------------------------------");
System.out.println("Did not find BB with call: " + call);
System.out.println("Host cfg :" + cfg.toStringGraph());
System.out.println("Host instrs:" + cfg.toStringInstrs());
System.out.println("----------------------------------");
return;
}
// Split callsite bb, move outbound edges from callsite bb to split bb, and unhook call bb
Label splitBBLabel = hostScope.getNewLabel();
BasicBlock splitBB = callBB.splitAtInstruction(call, splitBBLabel, false);
cfg.addBasicBlock(splitBB);
for (Edge<BasicBlock> e : cfg.getOutgoingEdges(callBB)) {
cfg.addEdge(splitBB, e.getDestination().getData(), e.getType());
}
cfg.removeAllOutgoingEdgesForBB(callBB);
SimpleCloneInfo hostCloneInfo = cloneHost ? cloneHostInstrs(cfg) : null;
// Host method data init
Operand callReceiver = call.getReceiver();
Variable callReceiverVar;
if (callReceiver instanceof Variable) {
callReceiverVar = (Variable)callReceiver;
} else {
callReceiverVar = hostScope.createTemporaryVariable();
}
InlineCloneInfo ii = new InlineCloneInfo(call, cfg, callReceiverVar);
// Inlinee method data init
CFG methodCFG = scope.getCFG();
List<BasicBlock> methodBBs = new ArrayList<BasicBlock>();
for (BasicBlock b: methodCFG.getBasicBlocks()) methodBBs.add(b);
// Check if we are inlining a recursive method
if (hostScope.getNearestMethod() == scope) {
// 1. clone self
// SSS: FIXME: We need a clone-graph api method in cfg and graph
CFG selfClone = cloneSelf(ii);
// 2. add callee bbs and their edges
// SSS: FIXME: We need a swallow-graph api method in cfg and graph
for (BasicBlock b : selfClone.getBasicBlocks()) {
cfg.addBasicBlock(b);
for (Edge<BasicBlock> e : selfClone.getOutgoingEdges(b)) {
cfg.addEdge(b, e.getDestination().getData(), e.getType());
}
}
} else {
// clone callee and add it to the host cfg
for (BasicBlock b : methodCFG.getBasicBlocks()) {
if (!b.isEntryBB() && !b.isExitBB()) cfg.addBasicBlock(b.cloneForInlining(ii));
}
for (BasicBlock x : methodCFG.getBasicBlocks()) {
if (x.isEntryBB() || x.isExitBB()) continue;
BasicBlock rx = ii.getRenamedBB(x);
for (Edge<BasicBlock> e : methodCFG.getOutgoingEdges(x)) {
BasicBlock b = e.getDestination().getData();
if (!b.isExitBB()) cfg.addEdge(rx, ii.getRenamedBB(b), e.getType());
}
}
}
// Hook up entry edges
assert methodCFG.outDegree(methodCFG.getEntryBB()) == 2: "Entry BB of inlinee method does not have outdegree 2: " + methodCFG.toStringGraph();
for (BasicBlock destination : methodCFG.getOutgoingDestinations(methodCFG.getEntryBB())) {
if (destination.isExitBB()) continue;
BasicBlock dstBB = ii.getRenamedBB(destination);
if (callReceiver != callReceiverVar) {
dstBB.insertInstr(new CopyInstr(callReceiverVar, callReceiver));
}
if (!ii.canMapArgsStatically()) {
// SSS FIXME: This is buggy!
// This code has to mimic whatever CallBase.prepareArguments does!
// We may need a special instruction that takes care of this.
Operand args;
Operand[] callArgs = call.cloneCallArgs(hostCloneInfo);
if (callArgs.length == 1 && callArgs[0] instanceof Splat) {
args = callArgs[0];
} else {
args = new Array(callArgs);
}
dstBB.insertInstr(new CopyInstr((Variable)ii.getArgs(), args));
}
cfg.addEdge(callBB, dstBB, CFG.EdgeType.FALL_THROUGH);
}
// Hook up exit edges
for (Edge<BasicBlock> e : methodCFG.getIncomingEdges(methodCFG.getExitBB())) {
BasicBlock source = e.getSource().getData();
if (source.isEntryBB()) continue;
BasicBlock clonedSource = ii.getRenamedBB(source);
if (e.getType() == EdgeType.EXCEPTION) {
// e._src has an explicit throw that returns from the callee
// after inlining, if the caller instruction has a rescuer, then the
// throw has to be captured by the rescuer as well.
BasicBlock rescuerOfSplitBB = cfg.getRescuerBBFor(splitBB);
if (rescuerOfSplitBB != null) {
cfg.addEdge(clonedSource, rescuerOfSplitBB, EdgeType.EXCEPTION);
} else {
cfg.addEdge(clonedSource, cfg.getExitBB(), EdgeType.EXIT);
}
} else {
cfg.addEdge(clonedSource, splitBB, e.getType());
}
}
// Update bb rescuer map
// splitBB will be protected by the same bb as callBB
BasicBlock callBBrescuer = cfg.getRescuerBBFor(callBB);
if (callBBrescuer != null) cfg.setRescuerBB(splitBB, callBBrescuer);
// Remap existing protections for bbs in mcfg to their renamed bbs.
// bbs in mcfg that aren't protected by an existing bb will be protected by callBBrescuer.
for (BasicBlock x : methodBBs) {
if (x.isEntryBB() || x.isExitBB()) continue;
BasicBlock xRenamed = ii.getRenamedBB(x);
BasicBlock xProtector = methodCFG.getRescuerBBFor(x);
if (xProtector != null) {
cfg.setRescuerBB(xRenamed, ii.getRenamedBB(xProtector));
} else if (callBBrescuer != null) {
cfg.setRescuerBB(xRenamed, callBBrescuer);
}
}
// Add inline guard that verifies that the method inlined is the same
// that gets called in future invocations. In addition to the guard, add
// a failure path code.
Label failurePathLabel = hostScope.getNewLabel();
callBB.addInstr(new ModuleVersionGuardInstr(implClass, classToken, call.getReceiver(), failurePathLabel));
BasicBlock failurePathBB = new BasicBlock(cfg, failurePathLabel);
cfg.addBasicBlock(failurePathBB);
failurePathBB.addInstr(call);
failurePathBB.addInstr(new JumpInstr(hostCloneInfo == null ? splitBBLabel : hostCloneInfo.getRenamedLabel(splitBBLabel)));
call.blockInlining();
cfg.addEdge(callBB, failurePathBB, CFG.EdgeType.REGULAR);
cfg.addEdge(failurePathBB, splitBB, CFG.EdgeType.REGULAR);
// Inline any closure argument passed into the call.
Operand closureArg = call.getClosureArg(null);
List yieldSites = ii.getYieldSites();
if (closureArg != null && !yieldSites.isEmpty()) {
// Detect unlikely but contrived scenarios where there are far too many yield sites that could lead to code blowup
// if we inline the closure at all those yield sites!
if (yieldSites.size() > 1) {
throw new RuntimeException("Encountered " + yieldSites.size() + " yield sites. Convert the yield to a call by converting the closure into a dummy method (have to convert all frame vars to call arguments, or at least convert the frame into a call arg");
}
if (!(closureArg instanceof WrappedIRClosure)) {
throw new RuntimeException("Encountered a dynamic closure arg. Cannot inline it here! Convert the yield to a call by converting the closure into a dummy method (have to convert all frame vars to call arguments, or at least convert the frame into a call arg");
}
Tuple t = (Tuple) yieldSites.get(0);
inlineClosureAtYieldSite(ii, ((WrappedIRClosure) closureArg).getClosure(), (BasicBlock) t.a, (YieldInstr) t.b);
}
// Optimize cfg by merging straight-line bbs
cfg.collapseStraightLineBBs();
/*
System.out.println("final cfg :" + cfg.toStringGraph());
System.out.println("final instrs:" + cfg.toStringInstrs());
*/
}
private void inlineClosureAtYieldSite(InlineCloneInfo ii, IRClosure cl, BasicBlock yieldBB, YieldInstr yield) {
// 1. split yield site bb and move outbound edges from yield site bb to split bb.
BasicBlock splitBB = yieldBB.splitAtInstruction(yield, cfg.getScope().getNewLabel(), false);
cfg.addBasicBlock(splitBB);
for (Edge<BasicBlock> e : cfg.getOutgoingEdges(yieldBB)) {
cfg.addEdge(splitBB, e.getDestination().getData(), e.getType());
}
cfg.removeAllOutgoingEdgesForBB(yieldBB);
// Allocate new inliner object to reset variable and label rename maps
ii = ii.cloneForInliningClosure();
ii.setupYieldArgsAndYieldResult(yield, yieldBB, cl.getBlockBody().arity());
// 2. Merge closure cfg into the current cfg
CFG closureCFG = cl.getCFG();
for (BasicBlock b : closureCFG.getBasicBlocks()) {
if (!b.isEntryBB() && !b.isExitBB()) cfg.addBasicBlock(b.cloneForInlining(ii));
}
for (BasicBlock b : closureCFG.getBasicBlocks()) {
if (b.isEntryBB() || b.isExitBB()) continue;
BasicBlock bClone = ii.getRenamedBB(b);
for (Edge<BasicBlock> e : closureCFG.getOutgoingEdges(b)) {
BasicBlock edst = e.getDestination().getData();
if (!edst.isExitBB()) cfg.addEdge(bClone, ii.getRenamedBB(edst), e.getType());
}
}
// Hook up entry edges
for (Edge<BasicBlock> e : closureCFG.getOutgoingEdges(closureCFG.getEntryBB())) {
BasicBlock destination = e.getDestination().getData();
if (!destination.isExitBB()) {
cfg.addEdge(yieldBB, ii.getRenamedBB(destination), CFG.EdgeType.FALL_THROUGH);
}
}
// Hook up exit edges
for (Edge<BasicBlock> e : closureCFG.getIncomingEdges(closureCFG.getExitBB())) {
BasicBlock source = e.getSource().getData();
if (source.isEntryBB()) continue;
BasicBlock clonedSource = ii.getRenamedBB(source);
if (e.getType() == EdgeType.EXCEPTION) {
// e._src has an explicit throw that returns from the closure.
// After inlining, if the yield instruction has a rescuer, then the
// throw has to be captured by the rescuer as well.
BasicBlock rescuerOfSplitBB = cfg.getRescuerBBFor(splitBB);
if (rescuerOfSplitBB != null) {
cfg.addEdge(clonedSource, rescuerOfSplitBB, EdgeType.EXCEPTION);
} else {
cfg.addEdge(clonedSource, cfg.getExitBB(), EdgeType.EXIT);
}
} else {
cfg.addEdge(clonedSource, splitBB, e.getType());
}
}
// 6. Update bb rescuer map
// 6a. splitBB will be protected by the same bb as yieldB
BasicBlock yieldBBrescuer = cfg.getRescuerBBFor(yieldBB);
if (yieldBBrescuer != null) cfg.setRescuerBB(splitBB, yieldBBrescuer);
// 6b. remap existing protections for bbs in mcfg to their renamed bbs.
// 6c. bbs in mcfg that aren't protected by an existing bb will be protected by yieldBBrescuer/yieldBBensurer
for (BasicBlock cb : closureCFG.getBasicBlocks()) {
if (cb.isEntryBB() || cb.isExitBB()) continue;
BasicBlock cbProtector = ii.getRenamedBB(closureCFG.getRescuerBBFor(cb));
if (cbProtector != null) {
cfg.setRescuerBB(cb, cbProtector);
} else if (yieldBBrescuer != null) {
cfg.setRescuerBB(cb, yieldBBrescuer);
}
}
}
}