Diff
Modified: trunk/Source/_javascript_Core/ChangeLog (194401 => 194402)
--- trunk/Source/_javascript_Core/ChangeLog 2015-12-24 00:14:13 UTC (rev 194401)
+++ trunk/Source/_javascript_Core/ChangeLog 2015-12-24 00:26:04 UTC (rev 194402)
@@ -1,5 +1,77 @@
2015-12-23 Filip Pizlo <[email protected]>
+ FTL B3 should be able to run crypto-sha1 in eager mode
+ https://bugs.webkit.org/show_bug.cgi?id=152539
+
+ Reviewed by Saam Barati.
+
+ This patch contains one real bug fix and some other fixes that are primarily there for sanity
+ because I don't believe they are symptomatic.
+
+ The real fix is the instruction selector's handling of Phi. It was assuming that the correct
+ lowering of Phi is to do nothing and the correct lowering of Upsilon is to store into the tmp
+ that the Phi uses. But this fails for code patterns like:
+
+ @a = Phi()
+ Upsilon(@x, ^a)
+ use(@a) // this should see the value that @a had at the point that "@a = Phi()" executed.
+
+ This arises when we have a lot of Upsilons in a row and they are trying to perform a
+ shuffling. Prior to this change, "use(@a)" would see the new value of @a, i.e. @x. That's
+ wrong. So, this changes the lowering to make each Phi have a special shadow Tmp, and Upsilon
+ stores to it while Phi loads from it. Most of these assignments get copy-propagated by IRC,
+ so it doesn't really hurt us. I couldn't find any benchmarks that slowed down because of
+ this. In fact, I believe that the only time that this would lead to extra interference or
+ extra assignments is when it's actually needed to be correct.
+
+ This also contains other fixes, which are probably not for real bugs, but they make me feel
+ all warm and fuzzy:
+
+ - spillEverything() works again. Previously, it didn't have all of IRC's smarts for handling
+ a spill of a ZDef. I fixed this by creating a helper phase that finds all subwidth ZDefs
+ to spill slots and amends them with zero-fills of the top bits.
+
+ - IRC no longer requires precise TmpWidth analysis. Previously, if TmpWidth gave pessimistic
+ results, the subwidth ZDef bug would return. That probably means that it was never fixed
+ to begin with, since it's totally cool for just a single def or use of a tmp to cause it
+ to become pessimistic. But there may still have been some subwidth ZDefs. The way that I
+ fixed this bug is to have IRC also run the ZDef fixup code that spillEverything() uses.
+ This is abstracted behind the beautifully named Air::fixSpillSlotZDef().
+
+ - B3::validate() does dominance checks! So, if you shoot yourself in the foot by using
+ something before defining it, validate() will tell you.
+
+ - Air::TmpWidth is now easy to "turn off" - i.e. to make it go fully conservative. It's not
+ an Option; you have to hack code. But that's better than nothing, and it's consistent with
+ what we do for other super-internal compiler options that we use rarely.
+
+ - You can now run spillEverything() without hacking code. Just use
+ Options::airSpillSeverything().
+
+ * _javascript_Core.xcodeproj/project.pbxproj:
+ * b3/B3LowerToAir.cpp:
+ (JSC::B3::Air::LowerToAir::LowerToAir):
+ (JSC::B3::Air::LowerToAir::run):
+ (JSC::B3::Air::LowerToAir::lower):
+ * b3/B3Validate.cpp:
+ * b3/air/AirCode.h:
+ (JSC::B3::Air::Code::specials):
+ (JSC::B3::Air::Code::forAllTmps):
+ (JSC::B3::Air::Code::isFastTmp):
+ * b3/air/AirFixSpillSlotZDef.h: Added.
+ (JSC::B3::Air::fixSpillSlotZDef):
+ * b3/air/AirGenerate.cpp:
+ (JSC::B3::Air::prepareForGeneration):
+ * b3/air/AirIteratedRegisterCoalescing.cpp:
+ * b3/air/AirSpillEverything.cpp:
+ (JSC::B3::Air::spillEverything):
+ * b3/air/AirTmpWidth.cpp:
+ (JSC::B3::Air::TmpWidth::recompute):
+ * jit/JITOperations.cpp:
+ * runtime/Options.h:
+
+2015-12-23 Filip Pizlo <[email protected]>
+
Need a story for platform-specific Args
https://bugs.webkit.org/show_bug.cgi?id=152529
Modified: trunk/Source/_javascript_Core/_javascript_Core.xcodeproj/project.pbxproj (194401 => 194402)
--- trunk/Source/_javascript_Core/_javascript_Core.xcodeproj/project.pbxproj 2015-12-24 00:14:13 UTC (rev 194401)
+++ trunk/Source/_javascript_Core/_javascript_Core.xcodeproj/project.pbxproj 2015-12-24 00:26:04 UTC (rev 194402)
@@ -374,6 +374,7 @@
0F493AFA16D0CAD30084508B /* SourceProvider.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 0F493AF816D0CAD10084508B /* SourceProvider.cpp */; };
0F4B94DC17B9F07500DD03A4 /* TypedArrayInlines.h in Headers */ = {isa = PBXBuildFile; fileRef = 0F4B94DB17B9F07500DD03A4 /* TypedArrayInlines.h */; settings = {ATTRIBUTES = (Private, ); }; };
0F4C91661C29F4F2004341A6 /* B3OriginDump.h in Headers */ = {isa = PBXBuildFile; fileRef = 0F4C91651C29F4F2004341A6 /* B3OriginDump.h */; };
+ 0F4C91681C2B3D68004341A6 /* AirFixSpillSlotZDef.h in Headers */ = {isa = PBXBuildFile; fileRef = 0F4C91671C2B3D68004341A6 /* AirFixSpillSlotZDef.h */; };
0F4F29DF18B6AD1C0057BC15 /* DFGStaticExecutionCountEstimationPhase.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 0F4F29DD18B6AD1C0057BC15 /* DFGStaticExecutionCountEstimationPhase.cpp */; };
0F4F29E018B6AD1C0057BC15 /* DFGStaticExecutionCountEstimationPhase.h in Headers */ = {isa = PBXBuildFile; fileRef = 0F4F29DE18B6AD1C0057BC15 /* DFGStaticExecutionCountEstimationPhase.h */; };
0F50AF3C193E8B3900674EE8 /* DFGStructureClobberState.h in Headers */ = {isa = PBXBuildFile; fileRef = 0F50AF3B193E8B3900674EE8 /* DFGStructureClobberState.h */; };
@@ -2508,6 +2509,7 @@
0F493AF816D0CAD10084508B /* SourceProvider.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = SourceProvider.cpp; sourceTree = "<group>"; };
0F4B94DB17B9F07500DD03A4 /* TypedArrayInlines.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = TypedArrayInlines.h; sourceTree = "<group>"; };
0F4C91651C29F4F2004341A6 /* B3OriginDump.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = B3OriginDump.h; path = b3/B3OriginDump.h; sourceTree = "<group>"; };
+ 0F4C91671C2B3D68004341A6 /* AirFixSpillSlotZDef.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = AirFixSpillSlotZDef.h; path = b3/air/AirFixSpillSlotZDef.h; sourceTree = "<group>"; };
0F4F29DD18B6AD1C0057BC15 /* DFGStaticExecutionCountEstimationPhase.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = DFGStaticExecutionCountEstimationPhase.cpp; path = dfg/DFGStaticExecutionCountEstimationPhase.cpp; sourceTree = "<group>"; };
0F4F29DE18B6AD1C0057BC15 /* DFGStaticExecutionCountEstimationPhase.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = DFGStaticExecutionCountEstimationPhase.h; path = dfg/DFGStaticExecutionCountEstimationPhase.h; sourceTree = "<group>"; };
0F50AF3B193E8B3900674EE8 /* DFGStructureClobberState.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = DFGStructureClobberState.h; path = dfg/DFGStructureClobberState.h; sourceTree = "<group>"; };
@@ -4776,6 +4778,7 @@
0F4570371BE44C910062A629 /* AirEliminateDeadCode.h */,
262D85B41C0D650F006ACB61 /* AirFixPartialRegisterStalls.cpp */,
262D85B51C0D650F006ACB61 /* AirFixPartialRegisterStalls.h */,
+ 0F4C91671C2B3D68004341A6 /* AirFixSpillSlotZDef.h */,
0FEC85521BDACDC70080FF74 /* AirFrequentedBlock.h */,
0FEC85531BDACDC70080FF74 /* AirGenerate.cpp */,
0FEC85541BDACDC70080FF74 /* AirGenerate.h */,
@@ -7216,6 +7219,7 @@
DC00039319D8BE6F00023EB0 /* DFGPreciseLocalClobberize.h in Headers */,
0FBE0F7516C1DB0B0082C5E8 /* DFGPredictionInjectionPhase.h in Headers */,
0FFFC95E14EF90B700C72532 /* DFGPredictionPropagationPhase.h in Headers */,
+ 0F4C91681C2B3D68004341A6 /* AirFixSpillSlotZDef.h in Headers */,
0F3E01AB19D353A500F61B7F /* DFGPrePostNumbering.h in Headers */,
0F2B9CED19D0BA7D00B1D1B5 /* DFGPromotedHeapLocation.h in Headers */,
0FFC92161B94FB3E0071DD66 /* DFGPropertyTypeKey.h in Headers */,
Modified: trunk/Source/_javascript_Core/b3/B3LowerToAir.cpp (194401 => 194402)
--- trunk/Source/_javascript_Core/b3/B3LowerToAir.cpp 2015-12-24 00:14:13 UTC (rev 194401)
+++ trunk/Source/_javascript_Core/b3/B3LowerToAir.cpp 2015-12-24 00:26:04 UTC (rev 194402)
@@ -64,6 +64,7 @@
public:
LowerToAir(Procedure& procedure)
: m_valueToTmp(procedure.values().size())
+ , m_phiToTmp(procedure.values().size())
, m_blockToBlock(procedure.size())
, m_useCounts(procedure)
, m_phiChildren(procedure)
@@ -76,9 +77,21 @@
{
for (B3::BasicBlock* block : m_procedure)
m_blockToBlock[block] = m_code.addBlock(block->frequency());
+
for (Value* value : m_procedure.values()) {
- if (StackSlotValue* stackSlotValue = value->as<StackSlotValue>())
+ switch (value->opcode()) {
+ case Phi: {
+ m_phiToTmp[value] = m_code.newTmp(Arg::typeForB3Type(value->type()));
+ break;
+ }
+ case B3::StackSlot: {
+ StackSlotValue* stackSlotValue = value->as<StackSlotValue>();
m_stackToStack.add(stackSlotValue, m_code.addStackSlot(stackSlotValue));
+ break;
+ }
+ default:
+ break;
+ }
}
m_procedure.resetValueOwners(); // Used by crossesInterference().
@@ -2126,12 +2139,17 @@
Value* value = m_value->child(0);
append(
relaxedMoveForType(value->type()), immOrTmp(value),
- tmp(m_value->as<UpsilonValue>()->phi()));
+ m_phiToTmp[m_value->as<UpsilonValue>()->phi()]);
return;
}
case Phi: {
- // Our semantics are determined by Upsilons, so we have nothing to do here.
+ // Snapshot the value of the Phi. It may change under us because you could do:
+ // a = Phi()
+ // Upsilon(@x, ^a)
+ // @a => this should get the value of the Phi before the Upsilon, i.e. not @x.
+
+ append(relaxedMoveForType(m_value->type()), m_phiToTmp[m_value], tmp(m_value));
return;
}
@@ -2209,6 +2227,7 @@
IndexSet<Value> m_locked; // These are values that will have no Tmp in Air.
IndexMap<Value, Tmp> m_valueToTmp; // These are values that must have a Tmp in Air. We say that a Value* with a non-null Tmp is "pinned".
+ IndexMap<Value, Tmp> m_phiToTmp; // Each Phi gets its own Tmp.
IndexMap<B3::BasicBlock, Air::BasicBlock*> m_blockToBlock;
HashMap<StackSlotValue*, Air::StackSlot*> m_stackToStack;
Modified: trunk/Source/_javascript_Core/b3/B3Validate.cpp (194401 => 194402)
--- trunk/Source/_javascript_Core/b3/B3Validate.cpp 2015-12-24 00:14:13 UTC (rev 194401)
+++ trunk/Source/_javascript_Core/b3/B3Validate.cpp 2015-12-24 00:26:04 UTC (rev 194402)
@@ -30,6 +30,7 @@
#include "B3ArgumentRegValue.h"
#include "B3BasicBlockInlines.h"
+#include "B3Dominators.h"
#include "B3MemoryValue.h"
#include "B3Procedure.h"
#include "B3StackSlotValue.h"
@@ -62,11 +63,17 @@
HashSet<BasicBlock*> blocks;
HashSet<Value*> valueInProc;
HashMap<Value*, unsigned> valueInBlock;
+ HashMap<Value*, BasicBlock*> valueOwner;
+ HashMap<Value*, unsigned> valueIndex;
for (BasicBlock* block : m_procedure) {
blocks.add(block);
- for (Value* value : *block)
+ for (unsigned i = 0; i < block->size(); ++i) {
+ Value* value = block->at(i);
valueInBlock.add(value, 0).iterator->value++;
+ valueOwner.add(value, block);
+ valueIndex.add(value, i);
+ }
}
for (Value* value : m_procedure.values())
@@ -79,10 +86,17 @@
VALIDATE(entry.value == 1, ("At ", *entry.key));
}
+ // Compute dominators ourselves to avoid perturbing Procedure.
+ Dominators dominators(m_procedure);
+
for (Value* value : valueInProc) {
for (Value* child : value->children()) {
VALIDATE(child, ("At ", *value));
VALIDATE(valueInProc.contains(child), ("At ", *value, "->", pointerDump(child)));
+ if (valueOwner.get(child) == valueOwner.get(value))
+ VALIDATE(valueIndex.get(value) > valueIndex.get(child), ("At ", *value, "->", pointerDump(child)));
+ else
+ VALIDATE(dominators.dominates(valueOwner.get(child), valueOwner.get(value)), ("at ", *value, "->", pointerDump(child)));
}
}
Modified: trunk/Source/_javascript_Core/b3/air/AirCode.h (194401 => 194402)
--- trunk/Source/_javascript_Core/b3/air/AirCode.h 2015-12-24 00:14:13 UTC (rev 194401)
+++ trunk/Source/_javascript_Core/b3/air/AirCode.h 2015-12-24 00:26:04 UTC (rev 194402)
@@ -57,6 +57,9 @@
BasicBlock* addBlock(double frequency = 1);
+ // Note that you can rely on stack slots always getting indices that are larger than the index
+ // of any prior stack slot. In fact, all stack slots you create in the future will have an index
+ // that is >= stackSlots().size().
StackSlot* addStackSlot(unsigned byteSize, StackSlotKind, StackSlotValue* = nullptr);
StackSlot* addStackSlot(StackSlotValue*);
@@ -291,6 +294,15 @@
SpecialsCollection specials() const { return SpecialsCollection(*this); }
+ template<typename Callback>
+ void forAllTmps(const Callback& callback) const
+ {
+ for (unsigned i = m_numGPTmps; i--;)
+ callback(Tmp::gpTmpForIndex(i));
+ for (unsigned i = m_numFPTmps; i--;)
+ callback(Tmp::fpTmpForIndex(i));
+ }
+
void addFastTmp(Tmp);
bool isFastTmp(Tmp tmp) const { return m_fastTmps.contains(tmp); }
Added: trunk/Source/_javascript_Core/b3/air/AirFixSpillSlotZDef.h (0 => 194402)
--- trunk/Source/_javascript_Core/b3/air/AirFixSpillSlotZDef.h (rev 0)
+++ trunk/Source/_javascript_Core/b3/air/AirFixSpillSlotZDef.h 2015-12-24 00:26:04 UTC (rev 194402)
@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) 2015 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef AirFixSpillSlotZDef_h
+#define AirFixSpillSlotZDef_h
+
+#include "AirCode.h"
+#include "AirInsertionSet.h"
+#include "AirInstInlines.h"
+
+namespace JSC { namespace B3 { namespace Air {
+
+template<typename IsSpillSlot>
+void fixSpillSlotZDef(Code& code, const IsSpillSlot& isSpillSlot)
+{
+ // We could have introduced ZDef's to StackSlots that are wider than the def. In that case, we
+ // need to emit code to zero-fill the top bits of the StackSlot.
+ InsertionSet insertionSet(code);
+ for (BasicBlock* block : code) {
+ for (unsigned instIndex = 0; instIndex < block->size(); ++instIndex) {
+ Inst& inst = block->at(instIndex);
+
+ inst.forEachArg(
+ [&] (Arg& arg, Arg::Role role, Arg::Type, Arg::Width width) {
+ if (!Arg::isZDef(role))
+ return;
+ if (!arg.isStack())
+ return;
+ if (!isSpillSlot(arg.stackSlot()))
+ return;
+ if (arg.stackSlot()->byteSize() == Arg::bytes(width))
+ return;
+
+ // Currently we only handle this simple case because it's the only one that
+ // arises: ZDef's are only 32-bit right now. So, when we hit these
+ // assertions it means that we need to implement those other kinds of zero
+ // fills.
+ RELEASE_ASSERT(arg.stackSlot()->byteSize() == 8);
+ RELEASE_ASSERT(width == Arg::Width32);
+
+ // We rely on the fact that there must be some way to move zero to a memory
+ // location without first burning a register. On ARM, we would do this using
+ // zr.
+ RELEASE_ASSERT(isValidForm(Move32, Arg::Imm, Arg::Stack));
+ insertionSet.insert(
+ instIndex + 1, Move32, inst.origin, Arg::imm(0), arg.withOffset(4));
+ });
+ }
+ insertionSet.execute(block);
+ }
+}
+
+} } } // namespace JSC::B3::Air
+
+#endif // AirFixSpillSlotZDef_h
+
Modified: trunk/Source/_javascript_Core/b3/air/AirGenerate.cpp (194401 => 194402)
--- trunk/Source/_javascript_Core/b3/air/AirGenerate.cpp 2015-12-24 00:14:13 UTC (rev 194401)
+++ trunk/Source/_javascript_Core/b3/air/AirGenerate.cpp 2015-12-24 00:26:04 UTC (rev 194402)
@@ -74,7 +74,7 @@
// After this phase, every Tmp has a reg.
//
// For debugging, you can use spillEverything() to put everything to the stack between each Inst.
- if (false)
+ if (Options::airSpillsEverything())
spillEverything(code);
else
iteratedRegisterCoalescing(code);
Modified: trunk/Source/_javascript_Core/b3/air/AirIteratedRegisterCoalescing.cpp (194401 => 194402)
--- trunk/Source/_javascript_Core/b3/air/AirIteratedRegisterCoalescing.cpp 2015-12-24 00:14:13 UTC (rev 194401)
+++ trunk/Source/_javascript_Core/b3/air/AirIteratedRegisterCoalescing.cpp 2015-12-24 00:26:04 UTC (rev 194402)
@@ -29,6 +29,7 @@
#if ENABLE(B3_JIT)
#include "AirCode.h"
+#include "AirFixSpillSlotZDef.h"
#include "AirInsertionSet.h"
#include "AirInstInlines.h"
#include "AirLiveness.h"
@@ -1164,6 +1165,7 @@
void addSpillAndFill(const ColoringAllocator<type>& allocator, HashSet<unsigned>& unspillableTmps)
{
HashMap<Tmp, StackSlot*> stackSlots;
+ unsigned newStackSlotThreshold = m_code.stackSlots().size();
for (Tmp tmp : allocator.spilledTmps()) {
// All the spilled values become unspillable.
unspillableTmps.add(AbsoluteTmpMapper<type>::absoluteIndex(tmp));
@@ -1260,6 +1262,12 @@
});
}
}
+
+ fixSpillSlotZDef(
+ m_code,
+ [&] (StackSlot* stackSlot) -> bool {
+ return stackSlot->index() >= newStackSlotThreshold;
+ });
}
Code& m_code;
Modified: trunk/Source/_javascript_Core/b3/air/AirSpillEverything.cpp (194401 => 194402)
--- trunk/Source/_javascript_Core/b3/air/AirSpillEverything.cpp 2015-12-24 00:14:13 UTC (rev 194401)
+++ trunk/Source/_javascript_Core/b3/air/AirSpillEverything.cpp 2015-12-24 00:26:04 UTC (rev 194402)
@@ -29,6 +29,7 @@
#if ENABLE(B3_JIT)
#include "AirCode.h"
+#include "AirFixSpillSlotZDef.h"
#include "AirInsertionSet.h"
#include "AirInstInlines.h"
#include "AirLiveness.h"
@@ -86,6 +87,7 @@
// Allocate a stack slot for each tmp.
Vector<StackSlot*> allStackSlots[Arg::numTypes];
+ unsigned newStackSlotThreshold = code.stackSlots().size();
for (unsigned typeIndex = 0; typeIndex < Arg::numTypes; ++typeIndex) {
Vector<StackSlot*>& stackSlots = allStackSlots[typeIndex];
Arg::Type type = static_cast<Arg::Type>(typeIndex);
@@ -109,7 +111,7 @@
if (arg.isReg())
continue;
- if (inst.admitsStack(i)) {
+ if (inst.admitsStack(i)) {
StackSlot* stackSlot = allStackSlots[arg.type()][arg.tmpIndex()];
arg = Arg::stack(stackSlot);
continue;
@@ -184,6 +186,12 @@
}
insertionSet.execute(block);
}
+
+ fixSpillSlotZDef(
+ code,
+ [&] (StackSlot* stackSlot) -> bool {
+ return stackSlot->index() >= newStackSlotThreshold;
+ });
}
} } } // namespace JSC::B3::Air
Modified: trunk/Source/_javascript_Core/b3/air/AirTmpWidth.cpp (194401 => 194402)
--- trunk/Source/_javascript_Core/b3/air/AirTmpWidth.cpp 2015-12-24 00:14:13 UTC (rev 194401)
+++ trunk/Source/_javascript_Core/b3/air/AirTmpWidth.cpp 2015-12-24 00:26:04 UTC (rev 194402)
@@ -48,17 +48,31 @@
void TmpWidth::recompute(Code& code)
{
+ // Set this to true to cause this analysis to always return pessimistic results.
+ const bool beCareful = false;
+
m_width.clear();
+ auto assumeTheWorst = [&] (Tmp tmp) {
+ Widths& widths = m_width.add(tmp, Widths()).iterator->value;
+ Arg::Type type = Arg(tmp).type();
+ widths.use = Arg::conservativeWidth(type);
+ widths.def = Arg::conservativeWidth(type);
+ };
+
// Assume the worst for registers.
RegisterSet::allRegisters().forEach(
[&] (Reg reg) {
- Widths& widths = m_width.add(Tmp(reg), Widths()).iterator->value;
- Arg::Type type = Arg(Tmp(reg)).type();
- widths.use = Arg::conservativeWidth(type);
- widths.def = Arg::conservativeWidth(type);
+ assumeTheWorst(Tmp(reg));
});
-
+
+ if (beCareful) {
+ code.forAllTmps(assumeTheWorst);
+
+ // We fall through because the fixpoint that follows can only make things even more
+ // conservative. This mode isn't meant to be fast, just safe.
+ }
+
// Now really analyze everything but Move's over Tmp's, but set aside those Move's so we can find
// them quickly during the fixpoint below. Note that we can make this analysis stronger by
// recognizing more kinds of Move's or anything that has Move-like behavior, though it's probably not
Modified: trunk/Source/_javascript_Core/runtime/Options.h (194401 => 194402)
--- trunk/Source/_javascript_Core/runtime/Options.h 2015-12-24 00:14:13 UTC (rev 194401)
+++ trunk/Source/_javascript_Core/runtime/Options.h 2015-12-24 00:26:04 UTC (rev 194402)
@@ -340,6 +340,7 @@
\
v(bool, logB3PhaseTimes, false, nullptr) \
v(double, rareBlockPenalty, 0.001, nullptr) \
+ v(bool, airSpillsEverything, false, nullptr) \
\
v(bool, useDollarVM, false, "installs the $vm debugging tool in global objects") \
v(optionString, functionOverrides, nullptr, "file with debugging overrides for function bodies") \
