|  | /* | 
|  | * 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. | 
|  | */ | 
|  |  | 
|  | #include "config.h" | 
|  | #include "CallFrameShuffler.h" | 
|  |  | 
|  | #if ENABLE(JIT) && USE(JSVALUE64) | 
|  |  | 
|  | #include "CCallHelpers.h" | 
|  | #include "DataFormat.h" | 
|  | #include "JSCInlines.h" | 
|  |  | 
|  | namespace JSC { | 
|  |  | 
|  | DataFormat CallFrameShuffler::emitStore( | 
|  | CachedRecovery& cachedRecovery, MacroAssembler::Address address) | 
|  | { | 
|  | ASSERT(!cachedRecovery.recovery().isInJSStack()); | 
|  |  | 
|  | switch (cachedRecovery.recovery().technique()) { | 
|  | case InGPR: | 
|  | m_jit.storePtr(cachedRecovery.recovery().gpr(), address); | 
|  | return DataFormatJS; | 
|  | case UnboxedInt32InGPR: | 
|  | m_jit.store32(cachedRecovery.recovery().gpr(), address.withOffset(PayloadOffset)); | 
|  | return DataFormatInt32; | 
|  | case UnboxedInt52InGPR: | 
|  | m_jit.rshift64(MacroAssembler::TrustedImm32(JSValue::int52ShiftAmount), | 
|  | cachedRecovery.recovery().gpr()); | 
|  | FALLTHROUGH; | 
|  | case UnboxedStrictInt52InGPR: | 
|  | m_jit.storePtr(cachedRecovery.recovery().gpr(), address); | 
|  | return DataFormatStrictInt52; | 
|  | case UnboxedBooleanInGPR: | 
|  | m_jit.storePtr(cachedRecovery.recovery().gpr(), address); | 
|  | return DataFormatBoolean; | 
|  | case UnboxedCellInGPR: | 
|  | m_jit.storePtr(cachedRecovery.recovery().gpr(), address); | 
|  | return DataFormatCell; | 
|  | case UnboxedDoubleInFPR: | 
|  | m_jit.storeDouble(cachedRecovery.recovery().fpr(), address); | 
|  | return DataFormatDouble; | 
|  | case InFPR: | 
|  | m_jit.storeDouble(cachedRecovery.recovery().fpr(), address); | 
|  | return DataFormatJS; | 
|  | case Constant: | 
|  | m_jit.storeTrustedValue(cachedRecovery.recovery().constant(), address); | 
|  | return DataFormatJS; | 
|  | default: | 
|  | RELEASE_ASSERT_NOT_REACHED(); | 
|  | } | 
|  | } | 
|  |  | 
|  | void CallFrameShuffler::emitBox(CachedRecovery& cachedRecovery) | 
|  | { | 
|  | ASSERT(canBox(cachedRecovery)); | 
|  | if (cachedRecovery.recovery().isConstant()) | 
|  | return; | 
|  |  | 
|  | if (cachedRecovery.recovery().isInGPR()) { | 
|  | switch (cachedRecovery.recovery().dataFormat()) { | 
|  | case DataFormatInt32: | 
|  | if (verbose) | 
|  | dataLog("   * Boxing ", cachedRecovery.recovery()); | 
|  | m_jit.zeroExtend32ToPtr( | 
|  | cachedRecovery.recovery().gpr(), | 
|  | cachedRecovery.recovery().gpr()); | 
|  | m_lockedRegisters.set(cachedRecovery.recovery().gpr()); | 
|  | if (tryAcquireTagTypeNumber()) | 
|  | m_jit.or64(m_tagTypeNumber, cachedRecovery.recovery().gpr()); | 
|  | else { | 
|  | // We have to do this the hard way | 
|  | m_jit.or64(MacroAssembler::TrustedImm64(TagTypeNumber), | 
|  | cachedRecovery.recovery().gpr()); | 
|  | } | 
|  | m_lockedRegisters.clear(cachedRecovery.recovery().gpr()); | 
|  | cachedRecovery.setRecovery( | 
|  | ValueRecovery::inGPR(cachedRecovery.recovery().gpr(), DataFormatJS)); | 
|  | if (verbose) | 
|  | dataLog(" into ", cachedRecovery.recovery(), "\n"); | 
|  | return; | 
|  | case DataFormatInt52: | 
|  | if (verbose) | 
|  | dataLog("   * Boxing ", cachedRecovery.recovery()); | 
|  | m_jit.rshift64(MacroAssembler::TrustedImm32(JSValue::int52ShiftAmount), | 
|  | cachedRecovery.recovery().gpr()); | 
|  | cachedRecovery.setRecovery( | 
|  | ValueRecovery::inGPR(cachedRecovery.recovery().gpr(), DataFormatStrictInt52)); | 
|  | if (verbose) | 
|  | dataLog(" into ", cachedRecovery.recovery(), "\n"); | 
|  | FALLTHROUGH; | 
|  | case DataFormatStrictInt52: { | 
|  | if (verbose) | 
|  | dataLog("   * Boxing ", cachedRecovery.recovery()); | 
|  | FPRReg resultFPR = getFreeFPR(); | 
|  | ASSERT(resultFPR != InvalidFPRReg); | 
|  | m_jit.convertInt64ToDouble(cachedRecovery.recovery().gpr(), resultFPR); | 
|  | updateRecovery(cachedRecovery, ValueRecovery::inFPR(resultFPR, DataFormatDouble)); | 
|  | if (verbose) | 
|  | dataLog(" into ", cachedRecovery.recovery(), "\n"); | 
|  | break; | 
|  | } | 
|  | case DataFormatBoolean: | 
|  | if (verbose) | 
|  | dataLog("   * Boxing ", cachedRecovery.recovery()); | 
|  | m_jit.add32(MacroAssembler::TrustedImm32(ValueFalse), | 
|  | cachedRecovery.recovery().gpr()); | 
|  | cachedRecovery.setRecovery( | 
|  | ValueRecovery::inGPR(cachedRecovery.recovery().gpr(), DataFormatJS)); | 
|  | if (verbose) | 
|  | dataLog(" into ", cachedRecovery.recovery(), "\n"); | 
|  | return; | 
|  | default: | 
|  | return; | 
|  | } | 
|  | } | 
|  |  | 
|  | if (cachedRecovery.recovery().isInFPR()) { | 
|  | if (cachedRecovery.recovery().dataFormat() == DataFormatDouble) { | 
|  | if (verbose) | 
|  | dataLog("   * Boxing ", cachedRecovery.recovery()); | 
|  | GPRReg resultGPR = cachedRecovery.wantedJSValueRegs().gpr(); | 
|  | if (resultGPR == InvalidGPRReg || m_registers[resultGPR]) | 
|  | resultGPR = getFreeGPR(); | 
|  | ASSERT(resultGPR != InvalidGPRReg); | 
|  | m_jit.purifyNaN(cachedRecovery.recovery().fpr()); | 
|  | m_jit.moveDoubleTo64(cachedRecovery.recovery().fpr(), resultGPR); | 
|  | m_lockedRegisters.set(resultGPR); | 
|  | if (tryAcquireTagTypeNumber()) | 
|  | m_jit.sub64(m_tagTypeNumber, resultGPR); | 
|  | else | 
|  | m_jit.sub64(MacroAssembler::TrustedImm64(TagTypeNumber), resultGPR); | 
|  | m_lockedRegisters.clear(resultGPR); | 
|  | updateRecovery(cachedRecovery, ValueRecovery::inGPR(resultGPR, DataFormatJS)); | 
|  | if (verbose) | 
|  | dataLog(" into ", cachedRecovery.recovery(), "\n"); | 
|  | return; | 
|  | } | 
|  | ASSERT(cachedRecovery.recovery().dataFormat() == DataFormatJS); | 
|  | return; | 
|  | } | 
|  |  | 
|  | RELEASE_ASSERT_NOT_REACHED(); | 
|  | } | 
|  |  | 
|  | void CallFrameShuffler::emitLoad(CachedRecovery& cachedRecovery) | 
|  | { | 
|  | if (!cachedRecovery.recovery().isInJSStack()) | 
|  | return; | 
|  |  | 
|  | if (verbose) | 
|  | dataLog("   * Loading ", cachedRecovery.recovery(), " into "); | 
|  |  | 
|  | VirtualRegister reg = cachedRecovery.recovery().virtualRegister(); | 
|  | MacroAssembler::Address address { addressForOld(reg) }; | 
|  | bool tryFPR { true }; | 
|  | GPRReg resultGPR { cachedRecovery.wantedJSValueRegs().gpr() }; | 
|  |  | 
|  | // If we want a GPR and it's available, that's better than loading | 
|  | // into an FPR. | 
|  | if (resultGPR != InvalidGPRReg && !m_registers[resultGPR] | 
|  | && !m_lockedRegisters.get(resultGPR) && cachedRecovery.loadsIntoGPR()) | 
|  | tryFPR = false; | 
|  |  | 
|  | // Otherwise, we prefer loading into FPRs if possible | 
|  | if (tryFPR && cachedRecovery.loadsIntoFPR()) { | 
|  | FPRReg resultFPR { cachedRecovery.wantedFPR() }; | 
|  | if (resultFPR == InvalidFPRReg || m_registers[resultFPR] || m_lockedRegisters.get(resultFPR)) | 
|  | resultFPR = getFreeFPR(); | 
|  | if (resultFPR != InvalidFPRReg) { | 
|  | m_jit.loadDouble(address, resultFPR); | 
|  | DataFormat dataFormat = DataFormatJS; | 
|  | // We could be transforming a DataFormatCell into a | 
|  | // DataFormatJS here - but that's OK. | 
|  | if (cachedRecovery.recovery().dataFormat() == DataFormatDouble) | 
|  | dataFormat = DataFormatDouble; | 
|  | updateRecovery(cachedRecovery, | 
|  | ValueRecovery::inFPR(resultFPR, dataFormat)); | 
|  | if (verbose) | 
|  | dataLog(cachedRecovery.recovery(), "\n"); | 
|  | if (reg == newAsOld(dangerFrontier())) | 
|  | updateDangerFrontier(); | 
|  | return; | 
|  | } | 
|  | } | 
|  |  | 
|  | ASSERT(cachedRecovery.loadsIntoGPR()); | 
|  | if (resultGPR == InvalidGPRReg || m_registers[resultGPR] || m_lockedRegisters.get(resultGPR)) | 
|  | resultGPR = getFreeGPR(); | 
|  | ASSERT(resultGPR != InvalidGPRReg); | 
|  | m_jit.loadPtr(address, resultGPR); | 
|  | updateRecovery(cachedRecovery, | 
|  | ValueRecovery::inGPR(resultGPR, cachedRecovery.recovery().dataFormat())); | 
|  | if (verbose) | 
|  | dataLog(cachedRecovery.recovery(), "\n"); | 
|  | if (reg == newAsOld(dangerFrontier())) | 
|  | updateDangerFrontier(); | 
|  | } | 
|  |  | 
|  | bool CallFrameShuffler::canLoad(CachedRecovery& cachedRecovery) | 
|  | { | 
|  | if (!cachedRecovery.recovery().isInJSStack()) | 
|  | return true; | 
|  |  | 
|  | ASSERT(cachedRecovery.loadsIntoFPR() || cachedRecovery.loadsIntoGPR()); | 
|  |  | 
|  | if (cachedRecovery.loadsIntoFPR() && getFreeFPR() != InvalidFPRReg) | 
|  | return true; | 
|  |  | 
|  | if (cachedRecovery.loadsIntoGPR() && getFreeGPR() != InvalidGPRReg) | 
|  | return true; | 
|  |  | 
|  | return false; | 
|  | } | 
|  |  | 
|  | void CallFrameShuffler::emitDisplace(CachedRecovery& cachedRecovery) | 
|  | { | 
|  | Reg wantedReg; | 
|  | if (!(wantedReg = Reg { cachedRecovery.wantedJSValueRegs().gpr() })) | 
|  | wantedReg = Reg { cachedRecovery.wantedFPR() }; | 
|  | ASSERT(wantedReg); | 
|  | ASSERT(!m_lockedRegisters.get(wantedReg)); | 
|  |  | 
|  | if (CachedRecovery* current = m_registers[wantedReg]) { | 
|  | if (current == &cachedRecovery) { | 
|  | if (verbose) | 
|  | dataLog("   + ", wantedReg, " is OK\n"); | 
|  | return; | 
|  | } | 
|  | // We could do a more complex thing by finding cycles | 
|  | // etc. in that case. | 
|  | // However, ending up in this situation will be super | 
|  | // rare, and should actually be outright impossible for | 
|  | // non-FTL tiers, since: | 
|  | //  (a) All doubles have been converted into JSValues with | 
|  | //      ValueRep nodes, so FPRs are initially free | 
|  | // | 
|  | //  (b) The only recoveries with wanted registers are the | 
|  | //      callee (which always starts out in a register) and | 
|  | //      the callee-save registers | 
|  | // | 
|  | //  (c) The callee-save registers are the first things we | 
|  | //      load (after the return PC), and they are loaded as JSValues | 
|  | // | 
|  | //  (d) We prefer loading JSValues into FPRs if their | 
|  | //      wanted GPR is not available | 
|  | // | 
|  | //  (e) If we end up spilling some registers with a | 
|  | //      target, we won't load them again before the very | 
|  | //      end of the algorithm | 
|  | // | 
|  | // Combined, this means that we will never load a recovery | 
|  | // with a wanted GPR into any GPR other than its wanted | 
|  | // GPR. The callee could however have been initially in | 
|  | // one of the callee-save registers - but since the wanted | 
|  | // GPR for the callee is always regT0, it will be the | 
|  | // first one to be displaced, and we won't see it when | 
|  | // handling any of the callee-save registers. | 
|  | // | 
|  | // Thus, the only way we could ever reach this path is in | 
|  | // the FTL, when there is so much pressure that we | 
|  | // absolutely need to load the callee-save registers into | 
|  | // different GPRs initially but not enough pressure to | 
|  | // then have to spill all of them. And even in that case, | 
|  | // depending on the order in which B3 saves the | 
|  | // callee-saves, we will probably still be safe. Anyway, | 
|  | // the couple extra move instructions compared to an | 
|  | // efficient cycle-based algorithm are not going to hurt | 
|  | // us. | 
|  | if (wantedReg.isFPR()) { | 
|  | FPRReg tempFPR = getFreeFPR(); | 
|  | if (verbose) | 
|  | dataLog("  * Moving ", wantedReg, " into ", tempFPR, "\n"); | 
|  | m_jit.moveDouble(wantedReg.fpr(), tempFPR); | 
|  | updateRecovery(*current, | 
|  | ValueRecovery::inFPR(tempFPR, current->recovery().dataFormat())); | 
|  | } else { | 
|  | GPRReg tempGPR = getFreeGPR(); | 
|  | if (verbose) | 
|  | dataLog("  * Moving ", wantedReg.gpr(), " into ", tempGPR, "\n"); | 
|  | m_jit.move(wantedReg.gpr(), tempGPR); | 
|  | updateRecovery(*current, | 
|  | ValueRecovery::inGPR(tempGPR, current->recovery().dataFormat())); | 
|  | } | 
|  | } | 
|  | ASSERT(!m_registers[wantedReg]); | 
|  |  | 
|  | if (cachedRecovery.recovery().isConstant()) { | 
|  | // We only care about callee saves for wanted FPRs, and those are never constants | 
|  | ASSERT(wantedReg.isGPR()); | 
|  | if (verbose) | 
|  | dataLog("   * Loading ", cachedRecovery.recovery().constant(), " into ", wantedReg, "\n"); | 
|  | m_jit.moveTrustedValue(cachedRecovery.recovery().constant(), JSValueRegs { wantedReg.gpr() }); | 
|  | updateRecovery( | 
|  | cachedRecovery, | 
|  | ValueRecovery::inRegister(wantedReg, DataFormatJS)); | 
|  | } else if (cachedRecovery.recovery().isInGPR()) { | 
|  | if (verbose) | 
|  | dataLog("   * Moving ", cachedRecovery.recovery(), " into ", wantedReg, "\n"); | 
|  | if (wantedReg.isGPR()) | 
|  | m_jit.move(cachedRecovery.recovery().gpr(), wantedReg.gpr()); | 
|  | else | 
|  | m_jit.move64ToDouble(cachedRecovery.recovery().gpr(), wantedReg.fpr()); | 
|  | RELEASE_ASSERT(cachedRecovery.recovery().dataFormat() == DataFormatJS); | 
|  | updateRecovery(cachedRecovery, | 
|  | ValueRecovery::inRegister(wantedReg, DataFormatJS)); | 
|  | } else { | 
|  | ASSERT(cachedRecovery.recovery().isInFPR()); | 
|  | if (cachedRecovery.recovery().dataFormat() == DataFormatDouble) { | 
|  | // We only care about callee saves for wanted FPRs, and those are always DataFormatJS | 
|  | ASSERT(wantedReg.isGPR()); | 
|  | // This will automatically pick the wanted GPR | 
|  | emitBox(cachedRecovery); | 
|  | } else { | 
|  | if (verbose) | 
|  | dataLog("   * Moving ", cachedRecovery.recovery().fpr(), " into ", wantedReg, "\n"); | 
|  | if (wantedReg.isGPR()) | 
|  | m_jit.moveDoubleTo64(cachedRecovery.recovery().fpr(), wantedReg.gpr()); | 
|  | else | 
|  | m_jit.moveDouble(cachedRecovery.recovery().fpr(), wantedReg.fpr()); | 
|  | RELEASE_ASSERT(cachedRecovery.recovery().dataFormat() == DataFormatJS); | 
|  | updateRecovery(cachedRecovery, | 
|  | ValueRecovery::inRegister(wantedReg, DataFormatJS)); | 
|  | } | 
|  | } | 
|  |  | 
|  | ASSERT(m_registers[wantedReg] == &cachedRecovery); | 
|  | } | 
|  |  | 
|  | bool CallFrameShuffler::tryAcquireTagTypeNumber() | 
|  | { | 
|  | if (m_tagTypeNumber != InvalidGPRReg) | 
|  | return true; | 
|  |  | 
|  | m_tagTypeNumber = getFreeGPR(); | 
|  |  | 
|  | if (m_tagTypeNumber == InvalidGPRReg) | 
|  | return false; | 
|  |  | 
|  | m_lockedRegisters.set(m_tagTypeNumber); | 
|  | m_jit.move(MacroAssembler::TrustedImm64(TagTypeNumber), m_tagTypeNumber); | 
|  | return true; | 
|  | } | 
|  |  | 
|  | } // namespace JSC | 
|  |  | 
|  | #endif // ENABLE(JIT) && USE(JSVALUE64) |