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diff --git a/contrib/llvm/lib/Target/X86/X86FloatingPoint.cpp b/contrib/llvm/lib/Target/X86/X86FloatingPoint.cpp
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+//===-- X86FloatingPoint.cpp - Floating point Reg -> Stack converter ------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the pass which converts floating point instructions from
+// pseudo registers into register stack instructions. This pass uses live
+// variable information to indicate where the FPn registers are used and their
+// lifetimes.
+//
+// The x87 hardware tracks liveness of the stack registers, so it is necessary
+// to implement exact liveness tracking between basic blocks. The CFG edges are
+// partitioned into bundles where the same FP registers must be live in
+// identical stack positions. Instructions are inserted at the end of each basic
+// block to rearrange the live registers to match the outgoing bundle.
+//
+// This approach avoids splitting critical edges at the potential cost of more
+// live register shuffling instructions when critical edges are present.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "x86-codegen"
+#include "X86.h"
+#include "X86InstrInfo.h"
+#include "llvm/InlineAsm.h"
+#include "llvm/ADT/DepthFirstIterator.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/CodeGen/EdgeBundles.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Target/TargetMachine.h"
+#include <algorithm>
+using namespace llvm;
+
+STATISTIC(NumFXCH, "Number of fxch instructions inserted");
+STATISTIC(NumFP , "Number of floating point instructions");
+
+namespace {
+ struct FPS : public MachineFunctionPass {
+ static char ID;
+ FPS() : MachineFunctionPass(ID) {
+ initializeEdgeBundlesPass(*PassRegistry::getPassRegistry());
+ // This is really only to keep valgrind quiet.
+ // The logic in isLive() is too much for it.
+ memset(Stack, 0, sizeof(Stack));
+ memset(RegMap, 0, sizeof(RegMap));
+ }
+
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.setPreservesCFG();
+ AU.addRequired<EdgeBundles>();
+ AU.addPreservedID(MachineLoopInfoID);
+ AU.addPreservedID(MachineDominatorsID);
+ MachineFunctionPass::getAnalysisUsage(AU);
+ }
+
+ virtual bool runOnMachineFunction(MachineFunction &MF);
+
+ virtual const char *getPassName() const { return "X86 FP Stackifier"; }
+
+ private:
+ const TargetInstrInfo *TII; // Machine instruction info.
+
+ // Two CFG edges are related if they leave the same block, or enter the same
+ // block. The transitive closure of an edge under this relation is a
+ // LiveBundle. It represents a set of CFG edges where the live FP stack
+ // registers must be allocated identically in the x87 stack.
+ //
+ // A LiveBundle is usually all the edges leaving a block, or all the edges
+ // entering a block, but it can contain more edges if critical edges are
+ // present.
+ //
+ // The set of live FP registers in a LiveBundle is calculated by bundleCFG,
+ // but the exact mapping of FP registers to stack slots is fixed later.
+ struct LiveBundle {
+ // Bit mask of live FP registers. Bit 0 = FP0, bit 1 = FP1, &c.
+ unsigned Mask;
+
+ // Number of pre-assigned live registers in FixStack. This is 0 when the
+ // stack order has not yet been fixed.
+ unsigned FixCount;
+
+ // Assigned stack order for live-in registers.
+ // FixStack[i] == getStackEntry(i) for all i < FixCount.
+ unsigned char FixStack[8];
+
+ LiveBundle() : Mask(0), FixCount(0) {}
+
+ // Have the live registers been assigned a stack order yet?
+ bool isFixed() const { return !Mask || FixCount; }
+ };
+
+ // Numbered LiveBundle structs. LiveBundles[0] is used for all CFG edges
+ // with no live FP registers.
+ SmallVector<LiveBundle, 8> LiveBundles;
+
+ // The edge bundle analysis provides indices into the LiveBundles vector.
+ EdgeBundles *Bundles;
+
+ // Return a bitmask of FP registers in block's live-in list.
+ unsigned calcLiveInMask(MachineBasicBlock *MBB) {
+ unsigned Mask = 0;
+ for (MachineBasicBlock::livein_iterator I = MBB->livein_begin(),
+ E = MBB->livein_end(); I != E; ++I) {
+ unsigned Reg = *I - X86::FP0;
+ if (Reg < 8)
+ Mask |= 1 << Reg;
+ }
+ return Mask;
+ }
+
+ // Partition all the CFG edges into LiveBundles.
+ void bundleCFG(MachineFunction &MF);
+
+ MachineBasicBlock *MBB; // Current basic block
+
+ // The hardware keeps track of how many FP registers are live, so we have
+ // to model that exactly. Usually, each live register corresponds to an
+ // FP<n> register, but when dealing with calls, returns, and inline
+ // assembly, it is sometimes necessary to have live scratch registers.
+ unsigned Stack[8]; // FP<n> Registers in each stack slot...
+ unsigned StackTop; // The current top of the FP stack.
+
+ enum {
+ NumFPRegs = 16 // Including scratch pseudo-registers.
+ };
+
+ // For each live FP<n> register, point to its Stack[] entry.
+ // The first entries correspond to FP0-FP6, the rest are scratch registers
+ // used when we need slightly different live registers than what the
+ // register allocator thinks.
+ unsigned RegMap[NumFPRegs];
+
+ // Pending fixed registers - Inline assembly needs FP registers to appear
+ // in fixed stack slot positions. This is handled by copying FP registers
+ // to ST registers before the instruction, and copying back after the
+ // instruction.
+ //
+ // This is modeled with pending ST registers. NumPendingSTs is the number
+ // of ST registers (ST0-STn) we are tracking. PendingST[n] points to an FP
+ // register that holds the ST value. The ST registers are not moved into
+ // place until immediately before the instruction that needs them.
+ //
+ // It can happen that we need an ST register to be live when no FP register
+ // holds the value:
+ //
+ // %ST0 = COPY %FP4<kill>
+ //
+ // When that happens, we allocate a scratch FP register to hold the ST
+ // value. That means every register in PendingST must be live.
+
+ unsigned NumPendingSTs;
+ unsigned char PendingST[8];
+
+ // Set up our stack model to match the incoming registers to MBB.
+ void setupBlockStack();
+
+ // Shuffle live registers to match the expectations of successor blocks.
+ void finishBlockStack();
+
+ void dumpStack() const {
+ dbgs() << "Stack contents:";
+ for (unsigned i = 0; i != StackTop; ++i) {
+ dbgs() << " FP" << Stack[i];
+ assert(RegMap[Stack[i]] == i && "Stack[] doesn't match RegMap[]!");
+ }
+ for (unsigned i = 0; i != NumPendingSTs; ++i)
+ dbgs() << ", ST" << i << " in FP" << unsigned(PendingST[i]);
+ dbgs() << "\n";
+ }
+
+ /// getSlot - Return the stack slot number a particular register number is
+ /// in.
+ unsigned getSlot(unsigned RegNo) const {
+ assert(RegNo < NumFPRegs && "Regno out of range!");
+ return RegMap[RegNo];
+ }
+
+ /// isLive - Is RegNo currently live in the stack?
+ bool isLive(unsigned RegNo) const {
+ unsigned Slot = getSlot(RegNo);
+ return Slot < StackTop && Stack[Slot] == RegNo;
+ }
+
+ /// getScratchReg - Return an FP register that is not currently in use.
+ unsigned getScratchReg() {
+ for (int i = NumFPRegs - 1; i >= 8; --i)
+ if (!isLive(i))
+ return i;
+ llvm_unreachable("Ran out of scratch FP registers");
+ }
+
+ /// isScratchReg - Returns trus if RegNo is a scratch FP register.
+ bool isScratchReg(unsigned RegNo) {
+ return RegNo > 8 && RegNo < NumFPRegs;
+ }
+
+ /// getStackEntry - Return the X86::FP<n> register in register ST(i).
+ unsigned getStackEntry(unsigned STi) const {
+ if (STi >= StackTop)
+ report_fatal_error("Access past stack top!");
+ return Stack[StackTop-1-STi];
+ }
+
+ /// getSTReg - Return the X86::ST(i) register which contains the specified
+ /// FP<RegNo> register.
+ unsigned getSTReg(unsigned RegNo) const {
+ return StackTop - 1 - getSlot(RegNo) + X86::ST0;
+ }
+
+ // pushReg - Push the specified FP<n> register onto the stack.
+ void pushReg(unsigned Reg) {
+ assert(Reg < NumFPRegs && "Register number out of range!");
+ if (StackTop >= 8)
+ report_fatal_error("Stack overflow!");
+ Stack[StackTop] = Reg;
+ RegMap[Reg] = StackTop++;
+ }
+
+ bool isAtTop(unsigned RegNo) const { return getSlot(RegNo) == StackTop-1; }
+ void moveToTop(unsigned RegNo, MachineBasicBlock::iterator I) {
+ DebugLoc dl = I == MBB->end() ? DebugLoc() : I->getDebugLoc();
+ if (isAtTop(RegNo)) return;
+
+ unsigned STReg = getSTReg(RegNo);
+ unsigned RegOnTop = getStackEntry(0);
+
+ // Swap the slots the regs are in.
+ std::swap(RegMap[RegNo], RegMap[RegOnTop]);
+
+ // Swap stack slot contents.
+ if (RegMap[RegOnTop] >= StackTop)
+ report_fatal_error("Access past stack top!");
+ std::swap(Stack[RegMap[RegOnTop]], Stack[StackTop-1]);
+
+ // Emit an fxch to update the runtime processors version of the state.
+ BuildMI(*MBB, I, dl, TII->get(X86::XCH_F)).addReg(STReg);
+ ++NumFXCH;
+ }
+
+ void duplicateToTop(unsigned RegNo, unsigned AsReg, MachineInstr *I) {
+ DebugLoc dl = I == MBB->end() ? DebugLoc() : I->getDebugLoc();
+ unsigned STReg = getSTReg(RegNo);
+ pushReg(AsReg); // New register on top of stack
+
+ BuildMI(*MBB, I, dl, TII->get(X86::LD_Frr)).addReg(STReg);
+ }
+
+ /// duplicatePendingSTBeforeKill - The instruction at I is about to kill
+ /// RegNo. If any PendingST registers still need the RegNo value, duplicate
+ /// them to new scratch registers.
+ void duplicatePendingSTBeforeKill(unsigned RegNo, MachineInstr *I) {
+ for (unsigned i = 0; i != NumPendingSTs; ++i) {
+ if (PendingST[i] != RegNo)
+ continue;
+ unsigned SR = getScratchReg();
+ DEBUG(dbgs() << "Duplicating pending ST" << i
+ << " in FP" << RegNo << " to FP" << SR << '\n');
+ duplicateToTop(RegNo, SR, I);
+ PendingST[i] = SR;
+ }
+ }
+
+ /// popStackAfter - Pop the current value off of the top of the FP stack
+ /// after the specified instruction.
+ void popStackAfter(MachineBasicBlock::iterator &I);
+
+ /// freeStackSlotAfter - Free the specified register from the register
+ /// stack, so that it is no longer in a register. If the register is
+ /// currently at the top of the stack, we just pop the current instruction,
+ /// otherwise we store the current top-of-stack into the specified slot,
+ /// then pop the top of stack.
+ void freeStackSlotAfter(MachineBasicBlock::iterator &I, unsigned Reg);
+
+ /// freeStackSlotBefore - Just the pop, no folding. Return the inserted
+ /// instruction.
+ MachineBasicBlock::iterator
+ freeStackSlotBefore(MachineBasicBlock::iterator I, unsigned FPRegNo);
+
+ /// Adjust the live registers to be the set in Mask.
+ void adjustLiveRegs(unsigned Mask, MachineBasicBlock::iterator I);
+
+ /// Shuffle the top FixCount stack entries such that FP reg FixStack[0] is
+ /// st(0), FP reg FixStack[1] is st(1) etc.
+ void shuffleStackTop(const unsigned char *FixStack, unsigned FixCount,
+ MachineBasicBlock::iterator I);
+
+ bool processBasicBlock(MachineFunction &MF, MachineBasicBlock &MBB);
+
+ void handleZeroArgFP(MachineBasicBlock::iterator &I);
+ void handleOneArgFP(MachineBasicBlock::iterator &I);
+ void handleOneArgFPRW(MachineBasicBlock::iterator &I);
+ void handleTwoArgFP(MachineBasicBlock::iterator &I);
+ void handleCompareFP(MachineBasicBlock::iterator &I);
+ void handleCondMovFP(MachineBasicBlock::iterator &I);
+ void handleSpecialFP(MachineBasicBlock::iterator &I);
+
+ // Check if a COPY instruction is using FP registers.
+ bool isFPCopy(MachineInstr *MI) {
+ unsigned DstReg = MI->getOperand(0).getReg();
+ unsigned SrcReg = MI->getOperand(1).getReg();
+
+ return X86::RFP80RegClass.contains(DstReg) ||
+ X86::RFP80RegClass.contains(SrcReg);
+ }
+ };
+ char FPS::ID = 0;
+}
+
+FunctionPass *llvm::createX86FloatingPointStackifierPass() { return new FPS(); }
+
+/// getFPReg - Return the X86::FPx register number for the specified operand.
+/// For example, this returns 3 for X86::FP3.
+static unsigned getFPReg(const MachineOperand &MO) {
+ assert(MO.isReg() && "Expected an FP register!");
+ unsigned Reg = MO.getReg();
+ assert(Reg >= X86::FP0 && Reg <= X86::FP6 && "Expected FP register!");
+ return Reg - X86::FP0;
+}
+
+/// runOnMachineFunction - Loop over all of the basic blocks, transforming FP
+/// register references into FP stack references.
+///
+bool FPS::runOnMachineFunction(MachineFunction &MF) {
+ // We only need to run this pass if there are any FP registers used in this
+ // function. If it is all integer, there is nothing for us to do!
+ bool FPIsUsed = false;
+
+ assert(X86::FP6 == X86::FP0+6 && "Register enums aren't sorted right!");
+ for (unsigned i = 0; i <= 6; ++i)
+ if (MF.getRegInfo().isPhysRegUsed(X86::FP0+i)) {
+ FPIsUsed = true;
+ break;
+ }
+
+ // Early exit.
+ if (!FPIsUsed) return false;
+
+ Bundles = &getAnalysis<EdgeBundles>();
+ TII = MF.getTarget().getInstrInfo();
+
+ // Prepare cross-MBB liveness.
+ bundleCFG(MF);
+
+ StackTop = 0;
+
+ // Process the function in depth first order so that we process at least one
+ // of the predecessors for every reachable block in the function.
+ SmallPtrSet<MachineBasicBlock*, 8> Processed;
+ MachineBasicBlock *Entry = MF.begin();
+
+ bool Changed = false;
+ for (df_ext_iterator<MachineBasicBlock*, SmallPtrSet<MachineBasicBlock*, 8> >
+ I = df_ext_begin(Entry, Processed), E = df_ext_end(Entry, Processed);
+ I != E; ++I)
+ Changed |= processBasicBlock(MF, **I);
+
+ // Process any unreachable blocks in arbitrary order now.
+ if (MF.size() != Processed.size())
+ for (MachineFunction::iterator BB = MF.begin(), E = MF.end(); BB != E; ++BB)
+ if (Processed.insert(BB))
+ Changed |= processBasicBlock(MF, *BB);
+
+ LiveBundles.clear();
+
+ return Changed;
+}
+
+/// bundleCFG - Scan all the basic blocks to determine consistent live-in and
+/// live-out sets for the FP registers. Consistent means that the set of
+/// registers live-out from a block is identical to the live-in set of all
+/// successors. This is not enforced by the normal live-in lists since
+/// registers may be implicitly defined, or not used by all successors.
+void FPS::bundleCFG(MachineFunction &MF) {
+ assert(LiveBundles.empty() && "Stale data in LiveBundles");
+ LiveBundles.resize(Bundles->getNumBundles());
+
+ // Gather the actual live-in masks for all MBBs.
+ for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I) {
+ MachineBasicBlock *MBB = I;
+ const unsigned Mask = calcLiveInMask(MBB);
+ if (!Mask)
+ continue;
+ // Update MBB ingoing bundle mask.
+ LiveBundles[Bundles->getBundle(MBB->getNumber(), false)].Mask |= Mask;
+ }
+}
+
+/// processBasicBlock - Loop over all of the instructions in the basic block,
+/// transforming FP instructions into their stack form.
+///
+bool FPS::processBasicBlock(MachineFunction &MF, MachineBasicBlock &BB) {
+ bool Changed = false;
+ MBB = &BB;
+ NumPendingSTs = 0;
+
+ setupBlockStack();
+
+ for (MachineBasicBlock::iterator I = BB.begin(); I != BB.end(); ++I) {
+ MachineInstr *MI = I;
+ uint64_t Flags = MI->getDesc().TSFlags;
+
+ unsigned FPInstClass = Flags & X86II::FPTypeMask;
+ if (MI->isInlineAsm())
+ FPInstClass = X86II::SpecialFP;
+
+ if (MI->isCopy() && isFPCopy(MI))
+ FPInstClass = X86II::SpecialFP;
+
+ if (MI->isImplicitDef() &&
+ X86::RFP80RegClass.contains(MI->getOperand(0).getReg()))
+ FPInstClass = X86II::SpecialFP;
+
+ if (FPInstClass == X86II::NotFP)
+ continue; // Efficiently ignore non-fp insts!
+
+ MachineInstr *PrevMI = 0;
+ if (I != BB.begin())
+ PrevMI = prior(I);
+
+ ++NumFP; // Keep track of # of pseudo instrs
+ DEBUG(dbgs() << "\nFPInst:\t" << *MI);
+
+ // Get dead variables list now because the MI pointer may be deleted as part
+ // of processing!
+ SmallVector<unsigned, 8> DeadRegs;
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ const MachineOperand &MO = MI->getOperand(i);
+ if (MO.isReg() && MO.isDead())
+ DeadRegs.push_back(MO.getReg());
+ }
+
+ switch (FPInstClass) {
+ case X86II::ZeroArgFP: handleZeroArgFP(I); break;
+ case X86II::OneArgFP: handleOneArgFP(I); break; // fstp ST(0)
+ case X86II::OneArgFPRW: handleOneArgFPRW(I); break; // ST(0) = fsqrt(ST(0))
+ case X86II::TwoArgFP: handleTwoArgFP(I); break;
+ case X86II::CompareFP: handleCompareFP(I); break;
+ case X86II::CondMovFP: handleCondMovFP(I); break;
+ case X86II::SpecialFP: handleSpecialFP(I); break;
+ default: llvm_unreachable("Unknown FP Type!");
+ }
+
+ // Check to see if any of the values defined by this instruction are dead
+ // after definition. If so, pop them.
+ for (unsigned i = 0, e = DeadRegs.size(); i != e; ++i) {
+ unsigned Reg = DeadRegs[i];
+ if (Reg >= X86::FP0 && Reg <= X86::FP6) {
+ DEBUG(dbgs() << "Register FP#" << Reg-X86::FP0 << " is dead!\n");
+ freeStackSlotAfter(I, Reg-X86::FP0);
+ }
+ }
+
+ // Print out all of the instructions expanded to if -debug
+ DEBUG(
+ MachineBasicBlock::iterator PrevI(PrevMI);
+ if (I == PrevI) {
+ dbgs() << "Just deleted pseudo instruction\n";
+ } else {
+ MachineBasicBlock::iterator Start = I;
+ // Rewind to first instruction newly inserted.
+ while (Start != BB.begin() && prior(Start) != PrevI) --Start;
+ dbgs() << "Inserted instructions:\n\t";
+ Start->print(dbgs(), &MF.getTarget());
+ while (++Start != llvm::next(I)) {}
+ }
+ dumpStack();
+ );
+ (void)PrevMI;
+
+ Changed = true;
+ }
+
+ finishBlockStack();
+
+ return Changed;
+}
+
+/// setupBlockStack - Use the live bundles to set up our model of the stack
+/// to match predecessors' live out stack.
+void FPS::setupBlockStack() {
+ DEBUG(dbgs() << "\nSetting up live-ins for BB#" << MBB->getNumber()
+ << " derived from " << MBB->getName() << ".\n");
+ StackTop = 0;
+ // Get the live-in bundle for MBB.
+ const LiveBundle &Bundle =
+ LiveBundles[Bundles->getBundle(MBB->getNumber(), false)];
+
+ if (!Bundle.Mask) {
+ DEBUG(dbgs() << "Block has no FP live-ins.\n");
+ return;
+ }
+
+ // Depth-first iteration should ensure that we always have an assigned stack.
+ assert(Bundle.isFixed() && "Reached block before any predecessors");
+
+ // Push the fixed live-in registers.
+ for (unsigned i = Bundle.FixCount; i > 0; --i) {
+ MBB->addLiveIn(X86::ST0+i-1);
+ DEBUG(dbgs() << "Live-in st(" << (i-1) << "): %FP"
+ << unsigned(Bundle.FixStack[i-1]) << '\n');
+ pushReg(Bundle.FixStack[i-1]);
+ }
+
+ // Kill off unwanted live-ins. This can happen with a critical edge.
+ // FIXME: We could keep these live registers around as zombies. They may need
+ // to be revived at the end of a short block. It might save a few instrs.
+ adjustLiveRegs(calcLiveInMask(MBB), MBB->begin());
+ DEBUG(MBB->dump());
+}
+
+/// finishBlockStack - Revive live-outs that are implicitly defined out of
+/// MBB. Shuffle live registers to match the expected fixed stack of any
+/// predecessors, and ensure that all predecessors are expecting the same
+/// stack.
+void FPS::finishBlockStack() {
+ // The RET handling below takes care of return blocks for us.
+ if (MBB->succ_empty())
+ return;
+
+ DEBUG(dbgs() << "Setting up live-outs for BB#" << MBB->getNumber()
+ << " derived from " << MBB->getName() << ".\n");
+
+ // Get MBB's live-out bundle.
+ unsigned BundleIdx = Bundles->getBundle(MBB->getNumber(), true);
+ LiveBundle &Bundle = LiveBundles[BundleIdx];
+
+ // We may need to kill and define some registers to match successors.
+ // FIXME: This can probably be combined with the shuffle below.
+ MachineBasicBlock::iterator Term = MBB->getFirstTerminator();
+ adjustLiveRegs(Bundle.Mask, Term);
+
+ if (!Bundle.Mask) {
+ DEBUG(dbgs() << "No live-outs.\n");
+ return;
+ }
+
+ // Has the stack order been fixed yet?
+ DEBUG(dbgs() << "LB#" << BundleIdx << ": ");
+ if (Bundle.isFixed()) {
+ DEBUG(dbgs() << "Shuffling stack to match.\n");
+ shuffleStackTop(Bundle.FixStack, Bundle.FixCount, Term);
+ } else {
+ // Not fixed yet, we get to choose.
+ DEBUG(dbgs() << "Fixing stack order now.\n");
+ Bundle.FixCount = StackTop;
+ for (unsigned i = 0; i < StackTop; ++i)
+ Bundle.FixStack[i] = getStackEntry(i);
+ }
+}
+
+
+//===----------------------------------------------------------------------===//
+// Efficient Lookup Table Support
+//===----------------------------------------------------------------------===//
+
+namespace {
+ struct TableEntry {
+ uint16_t from;
+ uint16_t to;
+ bool operator<(const TableEntry &TE) const { return from < TE.from; }
+ friend bool operator<(const TableEntry &TE, unsigned V) {
+ return TE.from < V;
+ }
+ friend bool LLVM_ATTRIBUTE_USED operator<(unsigned V,
+ const TableEntry &TE) {
+ return V < TE.from;
+ }
+ };
+}
+
+#ifndef NDEBUG
+static bool TableIsSorted(const TableEntry *Table, unsigned NumEntries) {
+ for (unsigned i = 0; i != NumEntries-1; ++i)
+ if (!(Table[i] < Table[i+1])) return false;
+ return true;
+}
+#endif
+
+static int Lookup(const TableEntry *Table, unsigned N, unsigned Opcode) {
+ const TableEntry *I = std::lower_bound(Table, Table+N, Opcode);
+ if (I != Table+N && I->from == Opcode)
+ return I->to;
+ return -1;
+}
+
+#ifdef NDEBUG
+#define ASSERT_SORTED(TABLE)
+#else
+#define ASSERT_SORTED(TABLE) \
+ { static bool TABLE##Checked = false; \
+ if (!TABLE##Checked) { \
+ assert(TableIsSorted(TABLE, array_lengthof(TABLE)) && \
+ "All lookup tables must be sorted for efficient access!"); \
+ TABLE##Checked = true; \
+ } \
+ }
+#endif
+
+//===----------------------------------------------------------------------===//
+// Register File -> Register Stack Mapping Methods
+//===----------------------------------------------------------------------===//
+
+// OpcodeTable - Sorted map of register instructions to their stack version.
+// The first element is an register file pseudo instruction, the second is the
+// concrete X86 instruction which uses the register stack.
+//
+static const TableEntry OpcodeTable[] = {
+ { X86::ABS_Fp32 , X86::ABS_F },
+ { X86::ABS_Fp64 , X86::ABS_F },
+ { X86::ABS_Fp80 , X86::ABS_F },
+ { X86::ADD_Fp32m , X86::ADD_F32m },
+ { X86::ADD_Fp64m , X86::ADD_F64m },
+ { X86::ADD_Fp64m32 , X86::ADD_F32m },
+ { X86::ADD_Fp80m32 , X86::ADD_F32m },
+ { X86::ADD_Fp80m64 , X86::ADD_F64m },
+ { X86::ADD_FpI16m32 , X86::ADD_FI16m },
+ { X86::ADD_FpI16m64 , X86::ADD_FI16m },
+ { X86::ADD_FpI16m80 , X86::ADD_FI16m },
+ { X86::ADD_FpI32m32 , X86::ADD_FI32m },
+ { X86::ADD_FpI32m64 , X86::ADD_FI32m },
+ { X86::ADD_FpI32m80 , X86::ADD_FI32m },
+ { X86::CHS_Fp32 , X86::CHS_F },
+ { X86::CHS_Fp64 , X86::CHS_F },
+ { X86::CHS_Fp80 , X86::CHS_F },
+ { X86::CMOVBE_Fp32 , X86::CMOVBE_F },
+ { X86::CMOVBE_Fp64 , X86::CMOVBE_F },
+ { X86::CMOVBE_Fp80 , X86::CMOVBE_F },
+ { X86::CMOVB_Fp32 , X86::CMOVB_F },
+ { X86::CMOVB_Fp64 , X86::CMOVB_F },
+ { X86::CMOVB_Fp80 , X86::CMOVB_F },
+ { X86::CMOVE_Fp32 , X86::CMOVE_F },
+ { X86::CMOVE_Fp64 , X86::CMOVE_F },
+ { X86::CMOVE_Fp80 , X86::CMOVE_F },
+ { X86::CMOVNBE_Fp32 , X86::CMOVNBE_F },
+ { X86::CMOVNBE_Fp64 , X86::CMOVNBE_F },
+ { X86::CMOVNBE_Fp80 , X86::CMOVNBE_F },
+ { X86::CMOVNB_Fp32 , X86::CMOVNB_F },
+ { X86::CMOVNB_Fp64 , X86::CMOVNB_F },
+ { X86::CMOVNB_Fp80 , X86::CMOVNB_F },
+ { X86::CMOVNE_Fp32 , X86::CMOVNE_F },
+ { X86::CMOVNE_Fp64 , X86::CMOVNE_F },
+ { X86::CMOVNE_Fp80 , X86::CMOVNE_F },
+ { X86::CMOVNP_Fp32 , X86::CMOVNP_F },
+ { X86::CMOVNP_Fp64 , X86::CMOVNP_F },
+ { X86::CMOVNP_Fp80 , X86::CMOVNP_F },
+ { X86::CMOVP_Fp32 , X86::CMOVP_F },
+ { X86::CMOVP_Fp64 , X86::CMOVP_F },
+ { X86::CMOVP_Fp80 , X86::CMOVP_F },
+ { X86::COS_Fp32 , X86::COS_F },
+ { X86::COS_Fp64 , X86::COS_F },
+ { X86::COS_Fp80 , X86::COS_F },
+ { X86::DIVR_Fp32m , X86::DIVR_F32m },
+ { X86::DIVR_Fp64m , X86::DIVR_F64m },
+ { X86::DIVR_Fp64m32 , X86::DIVR_F32m },
+ { X86::DIVR_Fp80m32 , X86::DIVR_F32m },
+ { X86::DIVR_Fp80m64 , X86::DIVR_F64m },
+ { X86::DIVR_FpI16m32, X86::DIVR_FI16m},
+ { X86::DIVR_FpI16m64, X86::DIVR_FI16m},
+ { X86::DIVR_FpI16m80, X86::DIVR_FI16m},
+ { X86::DIVR_FpI32m32, X86::DIVR_FI32m},
+ { X86::DIVR_FpI32m64, X86::DIVR_FI32m},
+ { X86::DIVR_FpI32m80, X86::DIVR_FI32m},
+ { X86::DIV_Fp32m , X86::DIV_F32m },
+ { X86::DIV_Fp64m , X86::DIV_F64m },
+ { X86::DIV_Fp64m32 , X86::DIV_F32m },
+ { X86::DIV_Fp80m32 , X86::DIV_F32m },
+ { X86::DIV_Fp80m64 , X86::DIV_F64m },
+ { X86::DIV_FpI16m32 , X86::DIV_FI16m },
+ { X86::DIV_FpI16m64 , X86::DIV_FI16m },
+ { X86::DIV_FpI16m80 , X86::DIV_FI16m },
+ { X86::DIV_FpI32m32 , X86::DIV_FI32m },
+ { X86::DIV_FpI32m64 , X86::DIV_FI32m },
+ { X86::DIV_FpI32m80 , X86::DIV_FI32m },
+ { X86::ILD_Fp16m32 , X86::ILD_F16m },
+ { X86::ILD_Fp16m64 , X86::ILD_F16m },
+ { X86::ILD_Fp16m80 , X86::ILD_F16m },
+ { X86::ILD_Fp32m32 , X86::ILD_F32m },
+ { X86::ILD_Fp32m64 , X86::ILD_F32m },
+ { X86::ILD_Fp32m80 , X86::ILD_F32m },
+ { X86::ILD_Fp64m32 , X86::ILD_F64m },
+ { X86::ILD_Fp64m64 , X86::ILD_F64m },
+ { X86::ILD_Fp64m80 , X86::ILD_F64m },
+ { X86::ISTT_Fp16m32 , X86::ISTT_FP16m},
+ { X86::ISTT_Fp16m64 , X86::ISTT_FP16m},
+ { X86::ISTT_Fp16m80 , X86::ISTT_FP16m},
+ { X86::ISTT_Fp32m32 , X86::ISTT_FP32m},
+ { X86::ISTT_Fp32m64 , X86::ISTT_FP32m},
+ { X86::ISTT_Fp32m80 , X86::ISTT_FP32m},
+ { X86::ISTT_Fp64m32 , X86::ISTT_FP64m},
+ { X86::ISTT_Fp64m64 , X86::ISTT_FP64m},
+ { X86::ISTT_Fp64m80 , X86::ISTT_FP64m},
+ { X86::IST_Fp16m32 , X86::IST_F16m },
+ { X86::IST_Fp16m64 , X86::IST_F16m },
+ { X86::IST_Fp16m80 , X86::IST_F16m },
+ { X86::IST_Fp32m32 , X86::IST_F32m },
+ { X86::IST_Fp32m64 , X86::IST_F32m },
+ { X86::IST_Fp32m80 , X86::IST_F32m },
+ { X86::IST_Fp64m32 , X86::IST_FP64m },
+ { X86::IST_Fp64m64 , X86::IST_FP64m },
+ { X86::IST_Fp64m80 , X86::IST_FP64m },
+ { X86::LD_Fp032 , X86::LD_F0 },
+ { X86::LD_Fp064 , X86::LD_F0 },
+ { X86::LD_Fp080 , X86::LD_F0 },
+ { X86::LD_Fp132 , X86::LD_F1 },
+ { X86::LD_Fp164 , X86::LD_F1 },
+ { X86::LD_Fp180 , X86::LD_F1 },
+ { X86::LD_Fp32m , X86::LD_F32m },
+ { X86::LD_Fp32m64 , X86::LD_F32m },
+ { X86::LD_Fp32m80 , X86::LD_F32m },
+ { X86::LD_Fp64m , X86::LD_F64m },
+ { X86::LD_Fp64m80 , X86::LD_F64m },
+ { X86::LD_Fp80m , X86::LD_F80m },
+ { X86::MUL_Fp32m , X86::MUL_F32m },
+ { X86::MUL_Fp64m , X86::MUL_F64m },
+ { X86::MUL_Fp64m32 , X86::MUL_F32m },
+ { X86::MUL_Fp80m32 , X86::MUL_F32m },
+ { X86::MUL_Fp80m64 , X86::MUL_F64m },
+ { X86::MUL_FpI16m32 , X86::MUL_FI16m },
+ { X86::MUL_FpI16m64 , X86::MUL_FI16m },
+ { X86::MUL_FpI16m80 , X86::MUL_FI16m },
+ { X86::MUL_FpI32m32 , X86::MUL_FI32m },
+ { X86::MUL_FpI32m64 , X86::MUL_FI32m },
+ { X86::MUL_FpI32m80 , X86::MUL_FI32m },
+ { X86::SIN_Fp32 , X86::SIN_F },
+ { X86::SIN_Fp64 , X86::SIN_F },
+ { X86::SIN_Fp80 , X86::SIN_F },
+ { X86::SQRT_Fp32 , X86::SQRT_F },
+ { X86::SQRT_Fp64 , X86::SQRT_F },
+ { X86::SQRT_Fp80 , X86::SQRT_F },
+ { X86::ST_Fp32m , X86::ST_F32m },
+ { X86::ST_Fp64m , X86::ST_F64m },
+ { X86::ST_Fp64m32 , X86::ST_F32m },
+ { X86::ST_Fp80m32 , X86::ST_F32m },
+ { X86::ST_Fp80m64 , X86::ST_F64m },
+ { X86::ST_FpP80m , X86::ST_FP80m },
+ { X86::SUBR_Fp32m , X86::SUBR_F32m },
+ { X86::SUBR_Fp64m , X86::SUBR_F64m },
+ { X86::SUBR_Fp64m32 , X86::SUBR_F32m },
+ { X86::SUBR_Fp80m32 , X86::SUBR_F32m },
+ { X86::SUBR_Fp80m64 , X86::SUBR_F64m },
+ { X86::SUBR_FpI16m32, X86::SUBR_FI16m},
+ { X86::SUBR_FpI16m64, X86::SUBR_FI16m},
+ { X86::SUBR_FpI16m80, X86::SUBR_FI16m},
+ { X86::SUBR_FpI32m32, X86::SUBR_FI32m},
+ { X86::SUBR_FpI32m64, X86::SUBR_FI32m},
+ { X86::SUBR_FpI32m80, X86::SUBR_FI32m},
+ { X86::SUB_Fp32m , X86::SUB_F32m },
+ { X86::SUB_Fp64m , X86::SUB_F64m },
+ { X86::SUB_Fp64m32 , X86::SUB_F32m },
+ { X86::SUB_Fp80m32 , X86::SUB_F32m },
+ { X86::SUB_Fp80m64 , X86::SUB_F64m },
+ { X86::SUB_FpI16m32 , X86::SUB_FI16m },
+ { X86::SUB_FpI16m64 , X86::SUB_FI16m },
+ { X86::SUB_FpI16m80 , X86::SUB_FI16m },
+ { X86::SUB_FpI32m32 , X86::SUB_FI32m },
+ { X86::SUB_FpI32m64 , X86::SUB_FI32m },
+ { X86::SUB_FpI32m80 , X86::SUB_FI32m },
+ { X86::TST_Fp32 , X86::TST_F },
+ { X86::TST_Fp64 , X86::TST_F },
+ { X86::TST_Fp80 , X86::TST_F },
+ { X86::UCOM_FpIr32 , X86::UCOM_FIr },
+ { X86::UCOM_FpIr64 , X86::UCOM_FIr },
+ { X86::UCOM_FpIr80 , X86::UCOM_FIr },
+ { X86::UCOM_Fpr32 , X86::UCOM_Fr },
+ { X86::UCOM_Fpr64 , X86::UCOM_Fr },
+ { X86::UCOM_Fpr80 , X86::UCOM_Fr },
+};
+
+static unsigned getConcreteOpcode(unsigned Opcode) {
+ ASSERT_SORTED(OpcodeTable);
+ int Opc = Lookup(OpcodeTable, array_lengthof(OpcodeTable), Opcode);
+ assert(Opc != -1 && "FP Stack instruction not in OpcodeTable!");
+ return Opc;
+}
+
+//===----------------------------------------------------------------------===//
+// Helper Methods
+//===----------------------------------------------------------------------===//
+
+// PopTable - Sorted map of instructions to their popping version. The first
+// element is an instruction, the second is the version which pops.
+//
+static const TableEntry PopTable[] = {
+ { X86::ADD_FrST0 , X86::ADD_FPrST0 },
+
+ { X86::DIVR_FrST0, X86::DIVR_FPrST0 },
+ { X86::DIV_FrST0 , X86::DIV_FPrST0 },
+
+ { X86::IST_F16m , X86::IST_FP16m },
+ { X86::IST_F32m , X86::IST_FP32m },
+
+ { X86::MUL_FrST0 , X86::MUL_FPrST0 },
+
+ { X86::ST_F32m , X86::ST_FP32m },
+ { X86::ST_F64m , X86::ST_FP64m },
+ { X86::ST_Frr , X86::ST_FPrr },
+
+ { X86::SUBR_FrST0, X86::SUBR_FPrST0 },
+ { X86::SUB_FrST0 , X86::SUB_FPrST0 },
+
+ { X86::UCOM_FIr , X86::UCOM_FIPr },
+
+ { X86::UCOM_FPr , X86::UCOM_FPPr },
+ { X86::UCOM_Fr , X86::UCOM_FPr },
+};
+
+/// popStackAfter - Pop the current value off of the top of the FP stack after
+/// the specified instruction. This attempts to be sneaky and combine the pop
+/// into the instruction itself if possible. The iterator is left pointing to
+/// the last instruction, be it a new pop instruction inserted, or the old
+/// instruction if it was modified in place.
+///
+void FPS::popStackAfter(MachineBasicBlock::iterator &I) {
+ MachineInstr* MI = I;
+ DebugLoc dl = MI->getDebugLoc();
+ ASSERT_SORTED(PopTable);
+ if (StackTop == 0)
+ report_fatal_error("Cannot pop empty stack!");
+ RegMap[Stack[--StackTop]] = ~0; // Update state
+
+ // Check to see if there is a popping version of this instruction...
+ int Opcode = Lookup(PopTable, array_lengthof(PopTable), I->getOpcode());
+ if (Opcode != -1) {
+ I->setDesc(TII->get(Opcode));
+ if (Opcode == X86::UCOM_FPPr)
+ I->RemoveOperand(0);
+ } else { // Insert an explicit pop
+ I = BuildMI(*MBB, ++I, dl, TII->get(X86::ST_FPrr)).addReg(X86::ST0);
+ }
+}
+
+/// freeStackSlotAfter - Free the specified register from the register stack, so
+/// that it is no longer in a register. If the register is currently at the top
+/// of the stack, we just pop the current instruction, otherwise we store the
+/// current top-of-stack into the specified slot, then pop the top of stack.
+void FPS::freeStackSlotAfter(MachineBasicBlock::iterator &I, unsigned FPRegNo) {
+ if (getStackEntry(0) == FPRegNo) { // already at the top of stack? easy.
+ popStackAfter(I);
+ return;
+ }
+
+ // Otherwise, store the top of stack into the dead slot, killing the operand
+ // without having to add in an explicit xchg then pop.
+ //
+ I = freeStackSlotBefore(++I, FPRegNo);
+}
+
+/// freeStackSlotBefore - Free the specified register without trying any
+/// folding.
+MachineBasicBlock::iterator
+FPS::freeStackSlotBefore(MachineBasicBlock::iterator I, unsigned FPRegNo) {
+ unsigned STReg = getSTReg(FPRegNo);
+ unsigned OldSlot = getSlot(FPRegNo);
+ unsigned TopReg = Stack[StackTop-1];
+ Stack[OldSlot] = TopReg;
+ RegMap[TopReg] = OldSlot;
+ RegMap[FPRegNo] = ~0;
+ Stack[--StackTop] = ~0;
+ return BuildMI(*MBB, I, DebugLoc(), TII->get(X86::ST_FPrr)).addReg(STReg);
+}
+
+/// adjustLiveRegs - Kill and revive registers such that exactly the FP
+/// registers with a bit in Mask are live.
+void FPS::adjustLiveRegs(unsigned Mask, MachineBasicBlock::iterator I) {
+ unsigned Defs = Mask;
+ unsigned Kills = 0;
+ for (unsigned i = 0; i < StackTop; ++i) {
+ unsigned RegNo = Stack[i];
+ if (!(Defs & (1 << RegNo)))
+ // This register is live, but we don't want it.
+ Kills |= (1 << RegNo);
+ else
+ // We don't need to imp-def this live register.
+ Defs &= ~(1 << RegNo);
+ }
+ assert((Kills & Defs) == 0 && "Register needs killing and def'ing?");
+
+ // Produce implicit-defs for free by using killed registers.
+ while (Kills && Defs) {
+ unsigned KReg = CountTrailingZeros_32(Kills);
+ unsigned DReg = CountTrailingZeros_32(Defs);
+ DEBUG(dbgs() << "Renaming %FP" << KReg << " as imp %FP" << DReg << "\n");
+ std::swap(Stack[getSlot(KReg)], Stack[getSlot(DReg)]);
+ std::swap(RegMap[KReg], RegMap[DReg]);
+ Kills &= ~(1 << KReg);
+ Defs &= ~(1 << DReg);
+ }
+
+ // Kill registers by popping.
+ if (Kills && I != MBB->begin()) {
+ MachineBasicBlock::iterator I2 = llvm::prior(I);
+ while (StackTop) {
+ unsigned KReg = getStackEntry(0);
+ if (!(Kills & (1 << KReg)))
+ break;
+ DEBUG(dbgs() << "Popping %FP" << KReg << "\n");
+ popStackAfter(I2);
+ Kills &= ~(1 << KReg);
+ }
+ }
+
+ // Manually kill the rest.
+ while (Kills) {
+ unsigned KReg = CountTrailingZeros_32(Kills);
+ DEBUG(dbgs() << "Killing %FP" << KReg << "\n");
+ freeStackSlotBefore(I, KReg);
+ Kills &= ~(1 << KReg);
+ }
+
+ // Load zeros for all the imp-defs.
+ while(Defs) {
+ unsigned DReg = CountTrailingZeros_32(Defs);
+ DEBUG(dbgs() << "Defining %FP" << DReg << " as 0\n");
+ BuildMI(*MBB, I, DebugLoc(), TII->get(X86::LD_F0));
+ pushReg(DReg);
+ Defs &= ~(1 << DReg);
+ }
+
+ // Now we should have the correct registers live.
+ DEBUG(dumpStack());
+ assert(StackTop == CountPopulation_32(Mask) && "Live count mismatch");
+}
+
+/// shuffleStackTop - emit fxch instructions before I to shuffle the top
+/// FixCount entries into the order given by FixStack.
+/// FIXME: Is there a better algorithm than insertion sort?
+void FPS::shuffleStackTop(const unsigned char *FixStack,
+ unsigned FixCount,
+ MachineBasicBlock::iterator I) {
+ // Move items into place, starting from the desired stack bottom.
+ while (FixCount--) {
+ // Old register at position FixCount.
+ unsigned OldReg = getStackEntry(FixCount);
+ // Desired register at position FixCount.
+ unsigned Reg = FixStack[FixCount];
+ if (Reg == OldReg)
+ continue;
+ // (Reg st0) (OldReg st0) = (Reg OldReg st0)
+ moveToTop(Reg, I);
+ if (FixCount > 0)
+ moveToTop(OldReg, I);
+ }
+ DEBUG(dumpStack());
+}
+
+
+//===----------------------------------------------------------------------===//
+// Instruction transformation implementation
+//===----------------------------------------------------------------------===//
+
+/// handleZeroArgFP - ST(0) = fld0 ST(0) = flds <mem>
+///
+void FPS::handleZeroArgFP(MachineBasicBlock::iterator &I) {
+ MachineInstr *MI = I;
+ unsigned DestReg = getFPReg(MI->getOperand(0));
+
+ // Change from the pseudo instruction to the concrete instruction.
+ MI->RemoveOperand(0); // Remove the explicit ST(0) operand
+ MI->setDesc(TII->get(getConcreteOpcode(MI->getOpcode())));
+
+ // Result gets pushed on the stack.
+ pushReg(DestReg);
+}
+
+/// handleOneArgFP - fst <mem>, ST(0)
+///
+void FPS::handleOneArgFP(MachineBasicBlock::iterator &I) {
+ MachineInstr *MI = I;
+ unsigned NumOps = MI->getDesc().getNumOperands();
+ assert((NumOps == X86::AddrNumOperands + 1 || NumOps == 1) &&
+ "Can only handle fst* & ftst instructions!");
+
+ // Is this the last use of the source register?
+ unsigned Reg = getFPReg(MI->getOperand(NumOps-1));
+ bool KillsSrc = MI->killsRegister(X86::FP0+Reg);
+
+ if (KillsSrc)
+ duplicatePendingSTBeforeKill(Reg, I);
+
+ // FISTP64m is strange because there isn't a non-popping versions.
+ // If we have one _and_ we don't want to pop the operand, duplicate the value
+ // on the stack instead of moving it. This ensure that popping the value is
+ // always ok.
+ // Ditto FISTTP16m, FISTTP32m, FISTTP64m, ST_FpP80m.
+ //
+ if (!KillsSrc &&
+ (MI->getOpcode() == X86::IST_Fp64m32 ||
+ MI->getOpcode() == X86::ISTT_Fp16m32 ||
+ MI->getOpcode() == X86::ISTT_Fp32m32 ||
+ MI->getOpcode() == X86::ISTT_Fp64m32 ||
+ MI->getOpcode() == X86::IST_Fp64m64 ||
+ MI->getOpcode() == X86::ISTT_Fp16m64 ||
+ MI->getOpcode() == X86::ISTT_Fp32m64 ||
+ MI->getOpcode() == X86::ISTT_Fp64m64 ||
+ MI->getOpcode() == X86::IST_Fp64m80 ||
+ MI->getOpcode() == X86::ISTT_Fp16m80 ||
+ MI->getOpcode() == X86::ISTT_Fp32m80 ||
+ MI->getOpcode() == X86::ISTT_Fp64m80 ||
+ MI->getOpcode() == X86::ST_FpP80m)) {
+ duplicateToTop(Reg, getScratchReg(), I);
+ } else {
+ moveToTop(Reg, I); // Move to the top of the stack...
+ }
+
+ // Convert from the pseudo instruction to the concrete instruction.
+ MI->RemoveOperand(NumOps-1); // Remove explicit ST(0) operand
+ MI->setDesc(TII->get(getConcreteOpcode(MI->getOpcode())));
+
+ if (MI->getOpcode() == X86::IST_FP64m ||
+ MI->getOpcode() == X86::ISTT_FP16m ||
+ MI->getOpcode() == X86::ISTT_FP32m ||
+ MI->getOpcode() == X86::ISTT_FP64m ||
+ MI->getOpcode() == X86::ST_FP80m) {
+ if (StackTop == 0)
+ report_fatal_error("Stack empty??");
+ --StackTop;
+ } else if (KillsSrc) { // Last use of operand?
+ popStackAfter(I);
+ }
+}
+
+
+/// handleOneArgFPRW: Handle instructions that read from the top of stack and
+/// replace the value with a newly computed value. These instructions may have
+/// non-fp operands after their FP operands.
+///
+/// Examples:
+/// R1 = fchs R2
+/// R1 = fadd R2, [mem]
+///
+void FPS::handleOneArgFPRW(MachineBasicBlock::iterator &I) {
+ MachineInstr *MI = I;
+#ifndef NDEBUG
+ unsigned NumOps = MI->getDesc().getNumOperands();
+ assert(NumOps >= 2 && "FPRW instructions must have 2 ops!!");
+#endif
+
+ // Is this the last use of the source register?
+ unsigned Reg = getFPReg(MI->getOperand(1));
+ bool KillsSrc = MI->killsRegister(X86::FP0+Reg);
+
+ if (KillsSrc) {
+ duplicatePendingSTBeforeKill(Reg, I);
+ // If this is the last use of the source register, just make sure it's on
+ // the top of the stack.
+ moveToTop(Reg, I);
+ if (StackTop == 0)
+ report_fatal_error("Stack cannot be empty!");
+ --StackTop;
+ pushReg(getFPReg(MI->getOperand(0)));
+ } else {
+ // If this is not the last use of the source register, _copy_ it to the top
+ // of the stack.
+ duplicateToTop(Reg, getFPReg(MI->getOperand(0)), I);
+ }
+
+ // Change from the pseudo instruction to the concrete instruction.
+ MI->RemoveOperand(1); // Drop the source operand.
+ MI->RemoveOperand(0); // Drop the destination operand.
+ MI->setDesc(TII->get(getConcreteOpcode(MI->getOpcode())));
+}
+
+
+//===----------------------------------------------------------------------===//
+// Define tables of various ways to map pseudo instructions
+//
+
+// ForwardST0Table - Map: A = B op C into: ST(0) = ST(0) op ST(i)
+static const TableEntry ForwardST0Table[] = {
+ { X86::ADD_Fp32 , X86::ADD_FST0r },
+ { X86::ADD_Fp64 , X86::ADD_FST0r },
+ { X86::ADD_Fp80 , X86::ADD_FST0r },
+ { X86::DIV_Fp32 , X86::DIV_FST0r },
+ { X86::DIV_Fp64 , X86::DIV_FST0r },
+ { X86::DIV_Fp80 , X86::DIV_FST0r },
+ { X86::MUL_Fp32 , X86::MUL_FST0r },
+ { X86::MUL_Fp64 , X86::MUL_FST0r },
+ { X86::MUL_Fp80 , X86::MUL_FST0r },
+ { X86::SUB_Fp32 , X86::SUB_FST0r },
+ { X86::SUB_Fp64 , X86::SUB_FST0r },
+ { X86::SUB_Fp80 , X86::SUB_FST0r },
+};
+
+// ReverseST0Table - Map: A = B op C into: ST(0) = ST(i) op ST(0)
+static const TableEntry ReverseST0Table[] = {
+ { X86::ADD_Fp32 , X86::ADD_FST0r }, // commutative
+ { X86::ADD_Fp64 , X86::ADD_FST0r }, // commutative
+ { X86::ADD_Fp80 , X86::ADD_FST0r }, // commutative
+ { X86::DIV_Fp32 , X86::DIVR_FST0r },
+ { X86::DIV_Fp64 , X86::DIVR_FST0r },
+ { X86::DIV_Fp80 , X86::DIVR_FST0r },
+ { X86::MUL_Fp32 , X86::MUL_FST0r }, // commutative
+ { X86::MUL_Fp64 , X86::MUL_FST0r }, // commutative
+ { X86::MUL_Fp80 , X86::MUL_FST0r }, // commutative
+ { X86::SUB_Fp32 , X86::SUBR_FST0r },
+ { X86::SUB_Fp64 , X86::SUBR_FST0r },
+ { X86::SUB_Fp80 , X86::SUBR_FST0r },
+};
+
+// ForwardSTiTable - Map: A = B op C into: ST(i) = ST(0) op ST(i)
+static const TableEntry ForwardSTiTable[] = {
+ { X86::ADD_Fp32 , X86::ADD_FrST0 }, // commutative
+ { X86::ADD_Fp64 , X86::ADD_FrST0 }, // commutative
+ { X86::ADD_Fp80 , X86::ADD_FrST0 }, // commutative
+ { X86::DIV_Fp32 , X86::DIVR_FrST0 },
+ { X86::DIV_Fp64 , X86::DIVR_FrST0 },
+ { X86::DIV_Fp80 , X86::DIVR_FrST0 },
+ { X86::MUL_Fp32 , X86::MUL_FrST0 }, // commutative
+ { X86::MUL_Fp64 , X86::MUL_FrST0 }, // commutative
+ { X86::MUL_Fp80 , X86::MUL_FrST0 }, // commutative
+ { X86::SUB_Fp32 , X86::SUBR_FrST0 },
+ { X86::SUB_Fp64 , X86::SUBR_FrST0 },
+ { X86::SUB_Fp80 , X86::SUBR_FrST0 },
+};
+
+// ReverseSTiTable - Map: A = B op C into: ST(i) = ST(i) op ST(0)
+static const TableEntry ReverseSTiTable[] = {
+ { X86::ADD_Fp32 , X86::ADD_FrST0 },
+ { X86::ADD_Fp64 , X86::ADD_FrST0 },
+ { X86::ADD_Fp80 , X86::ADD_FrST0 },
+ { X86::DIV_Fp32 , X86::DIV_FrST0 },
+ { X86::DIV_Fp64 , X86::DIV_FrST0 },
+ { X86::DIV_Fp80 , X86::DIV_FrST0 },
+ { X86::MUL_Fp32 , X86::MUL_FrST0 },
+ { X86::MUL_Fp64 , X86::MUL_FrST0 },
+ { X86::MUL_Fp80 , X86::MUL_FrST0 },
+ { X86::SUB_Fp32 , X86::SUB_FrST0 },
+ { X86::SUB_Fp64 , X86::SUB_FrST0 },
+ { X86::SUB_Fp80 , X86::SUB_FrST0 },
+};
+
+
+/// handleTwoArgFP - Handle instructions like FADD and friends which are virtual
+/// instructions which need to be simplified and possibly transformed.
+///
+/// Result: ST(0) = fsub ST(0), ST(i)
+/// ST(i) = fsub ST(0), ST(i)
+/// ST(0) = fsubr ST(0), ST(i)
+/// ST(i) = fsubr ST(0), ST(i)
+///
+void FPS::handleTwoArgFP(MachineBasicBlock::iterator &I) {
+ ASSERT_SORTED(ForwardST0Table); ASSERT_SORTED(ReverseST0Table);
+ ASSERT_SORTED(ForwardSTiTable); ASSERT_SORTED(ReverseSTiTable);
+ MachineInstr *MI = I;
+
+ unsigned NumOperands = MI->getDesc().getNumOperands();
+ assert(NumOperands == 3 && "Illegal TwoArgFP instruction!");
+ unsigned Dest = getFPReg(MI->getOperand(0));
+ unsigned Op0 = getFPReg(MI->getOperand(NumOperands-2));
+ unsigned Op1 = getFPReg(MI->getOperand(NumOperands-1));
+ bool KillsOp0 = MI->killsRegister(X86::FP0+Op0);
+ bool KillsOp1 = MI->killsRegister(X86::FP0+Op1);
+ DebugLoc dl = MI->getDebugLoc();
+
+ unsigned TOS = getStackEntry(0);
+
+ // One of our operands must be on the top of the stack. If neither is yet, we
+ // need to move one.
+ if (Op0 != TOS && Op1 != TOS) { // No operand at TOS?
+ // We can choose to move either operand to the top of the stack. If one of
+ // the operands is killed by this instruction, we want that one so that we
+ // can update right on top of the old version.
+ if (KillsOp0) {
+ moveToTop(Op0, I); // Move dead operand to TOS.
+ TOS = Op0;
+ } else if (KillsOp1) {
+ moveToTop(Op1, I);
+ TOS = Op1;
+ } else {
+ // All of the operands are live after this instruction executes, so we
+ // cannot update on top of any operand. Because of this, we must
+ // duplicate one of the stack elements to the top. It doesn't matter
+ // which one we pick.
+ //
+ duplicateToTop(Op0, Dest, I);
+ Op0 = TOS = Dest;
+ KillsOp0 = true;
+ }
+ } else if (!KillsOp0 && !KillsOp1) {
+ // If we DO have one of our operands at the top of the stack, but we don't
+ // have a dead operand, we must duplicate one of the operands to a new slot
+ // on the stack.
+ duplicateToTop(Op0, Dest, I);
+ Op0 = TOS = Dest;
+ KillsOp0 = true;
+ }
+
+ // Now we know that one of our operands is on the top of the stack, and at
+ // least one of our operands is killed by this instruction.
+ assert((TOS == Op0 || TOS == Op1) && (KillsOp0 || KillsOp1) &&
+ "Stack conditions not set up right!");
+
+ // We decide which form to use based on what is on the top of the stack, and
+ // which operand is killed by this instruction.
+ const TableEntry *InstTable;
+ bool isForward = TOS == Op0;
+ bool updateST0 = (TOS == Op0 && !KillsOp1) || (TOS == Op1 && !KillsOp0);
+ if (updateST0) {
+ if (isForward)
+ InstTable = ForwardST0Table;
+ else
+ InstTable = ReverseST0Table;
+ } else {
+ if (isForward)
+ InstTable = ForwardSTiTable;
+ else
+ InstTable = ReverseSTiTable;
+ }
+
+ int Opcode = Lookup(InstTable, array_lengthof(ForwardST0Table),
+ MI->getOpcode());
+ assert(Opcode != -1 && "Unknown TwoArgFP pseudo instruction!");
+
+ // NotTOS - The register which is not on the top of stack...
+ unsigned NotTOS = (TOS == Op0) ? Op1 : Op0;
+
+ // Replace the old instruction with a new instruction
+ MBB->remove(I++);
+ I = BuildMI(*MBB, I, dl, TII->get(Opcode)).addReg(getSTReg(NotTOS));
+
+ // If both operands are killed, pop one off of the stack in addition to
+ // overwriting the other one.
+ if (KillsOp0 && KillsOp1 && Op0 != Op1) {
+ assert(!updateST0 && "Should have updated other operand!");
+ popStackAfter(I); // Pop the top of stack
+ }
+
+ // Update stack information so that we know the destination register is now on
+ // the stack.
+ unsigned UpdatedSlot = getSlot(updateST0 ? TOS : NotTOS);
+ assert(UpdatedSlot < StackTop && Dest < 7);
+ Stack[UpdatedSlot] = Dest;
+ RegMap[Dest] = UpdatedSlot;
+ MBB->getParent()->DeleteMachineInstr(MI); // Remove the old instruction
+}
+
+/// handleCompareFP - Handle FUCOM and FUCOMI instructions, which have two FP
+/// register arguments and no explicit destinations.
+///
+void FPS::handleCompareFP(MachineBasicBlock::iterator &I) {
+ ASSERT_SORTED(ForwardST0Table); ASSERT_SORTED(ReverseST0Table);
+ ASSERT_SORTED(ForwardSTiTable); ASSERT_SORTED(ReverseSTiTable);
+ MachineInstr *MI = I;
+
+ unsigned NumOperands = MI->getDesc().getNumOperands();
+ assert(NumOperands == 2 && "Illegal FUCOM* instruction!");
+ unsigned Op0 = getFPReg(MI->getOperand(NumOperands-2));
+ unsigned Op1 = getFPReg(MI->getOperand(NumOperands-1));
+ bool KillsOp0 = MI->killsRegister(X86::FP0+Op0);
+ bool KillsOp1 = MI->killsRegister(X86::FP0+Op1);
+
+ // Make sure the first operand is on the top of stack, the other one can be
+ // anywhere.
+ moveToTop(Op0, I);
+
+ // Change from the pseudo instruction to the concrete instruction.
+ MI->getOperand(0).setReg(getSTReg(Op1));
+ MI->RemoveOperand(1);
+ MI->setDesc(TII->get(getConcreteOpcode(MI->getOpcode())));
+
+ // If any of the operands are killed by this instruction, free them.
+ if (KillsOp0) freeStackSlotAfter(I, Op0);
+ if (KillsOp1 && Op0 != Op1) freeStackSlotAfter(I, Op1);
+}
+
+/// handleCondMovFP - Handle two address conditional move instructions. These
+/// instructions move a st(i) register to st(0) iff a condition is true. These
+/// instructions require that the first operand is at the top of the stack, but
+/// otherwise don't modify the stack at all.
+void FPS::handleCondMovFP(MachineBasicBlock::iterator &I) {
+ MachineInstr *MI = I;
+
+ unsigned Op0 = getFPReg(MI->getOperand(0));
+ unsigned Op1 = getFPReg(MI->getOperand(2));
+ bool KillsOp1 = MI->killsRegister(X86::FP0+Op1);
+
+ // The first operand *must* be on the top of the stack.
+ moveToTop(Op0, I);
+
+ // Change the second operand to the stack register that the operand is in.
+ // Change from the pseudo instruction to the concrete instruction.
+ MI->RemoveOperand(0);
+ MI->RemoveOperand(1);
+ MI->getOperand(0).setReg(getSTReg(Op1));
+ MI->setDesc(TII->get(getConcreteOpcode(MI->getOpcode())));
+
+ // If we kill the second operand, make sure to pop it from the stack.
+ if (Op0 != Op1 && KillsOp1) {
+ // Get this value off of the register stack.
+ freeStackSlotAfter(I, Op1);
+ }
+}
+
+
+/// handleSpecialFP - Handle special instructions which behave unlike other
+/// floating point instructions. This is primarily intended for use by pseudo
+/// instructions.
+///
+void FPS::handleSpecialFP(MachineBasicBlock::iterator &I) {
+ MachineInstr *MI = I;
+ switch (MI->getOpcode()) {
+ default: llvm_unreachable("Unknown SpecialFP instruction!");
+ case TargetOpcode::COPY: {
+ // We handle three kinds of copies: FP <- FP, FP <- ST, and ST <- FP.
+ const MachineOperand &MO1 = MI->getOperand(1);
+ const MachineOperand &MO0 = MI->getOperand(0);
+ unsigned DstST = MO0.getReg() - X86::ST0;
+ unsigned SrcST = MO1.getReg() - X86::ST0;
+ bool KillsSrc = MI->killsRegister(MO1.getReg());
+
+ // ST = COPY FP. Set up a pending ST register.
+ if (DstST < 8) {
+ unsigned SrcFP = getFPReg(MO1);
+ assert(isLive(SrcFP) && "Cannot copy dead register");
+ assert(!MO0.isDead() && "Cannot copy to dead ST register");
+
+ // Unallocated STs are marked as the nonexistent FP255.
+ while (NumPendingSTs <= DstST)
+ PendingST[NumPendingSTs++] = NumFPRegs;
+
+ // STi could still be live from a previous inline asm.
+ if (isScratchReg(PendingST[DstST])) {
+ DEBUG(dbgs() << "Clobbering old ST in FP" << unsigned(PendingST[DstST])
+ << '\n');
+ freeStackSlotBefore(MI, PendingST[DstST]);
+ }
+
+ // When the source is killed, allocate a scratch FP register.
+ if (KillsSrc) {
+ duplicatePendingSTBeforeKill(SrcFP, I);
+ unsigned Slot = getSlot(SrcFP);
+ unsigned SR = getScratchReg();
+ PendingST[DstST] = SR;
+ Stack[Slot] = SR;
+ RegMap[SR] = Slot;
+ } else
+ PendingST[DstST] = SrcFP;
+ break;
+ }
+
+ // FP = COPY ST. Extract fixed stack value.
+ // Any instruction defining ST registers must have assigned them to a
+ // scratch register.
+ if (SrcST < 8) {
+ unsigned DstFP = getFPReg(MO0);
+ assert(!isLive(DstFP) && "Cannot copy ST to live FP register");
+ assert(NumPendingSTs > SrcST && "Cannot copy from dead ST register");
+ unsigned SrcFP = PendingST[SrcST];
+ assert(isScratchReg(SrcFP) && "Expected ST in a scratch register");
+ assert(isLive(SrcFP) && "Scratch holding ST is dead");
+
+ // DstFP steals the stack slot from SrcFP.
+ unsigned Slot = getSlot(SrcFP);
+ Stack[Slot] = DstFP;
+ RegMap[DstFP] = Slot;
+
+ // Always treat the ST as killed.
+ PendingST[SrcST] = NumFPRegs;
+ while (NumPendingSTs && PendingST[NumPendingSTs - 1] == NumFPRegs)
+ --NumPendingSTs;
+ break;
+ }
+
+ // FP <- FP copy.
+ unsigned DstFP = getFPReg(MO0);
+ unsigned SrcFP = getFPReg(MO1);
+ assert(isLive(SrcFP) && "Cannot copy dead register");
+ if (KillsSrc) {
+ // If the input operand is killed, we can just change the owner of the
+ // incoming stack slot into the result.
+ unsigned Slot = getSlot(SrcFP);
+ Stack[Slot] = DstFP;
+ RegMap[DstFP] = Slot;
+ } else {
+ // For COPY we just duplicate the specified value to a new stack slot.
+ // This could be made better, but would require substantial changes.
+ duplicateToTop(SrcFP, DstFP, I);
+ }
+ break;
+ }
+
+ case TargetOpcode::IMPLICIT_DEF: {
+ // All FP registers must be explicitly defined, so load a 0 instead.
+ unsigned Reg = MI->getOperand(0).getReg() - X86::FP0;
+ DEBUG(dbgs() << "Emitting LD_F0 for implicit FP" << Reg << '\n');
+ BuildMI(*MBB, I, MI->getDebugLoc(), TII->get(X86::LD_F0));
+ pushReg(Reg);
+ break;
+ }
+
+ case X86::FpPOP_RETVAL: {
+ // The FpPOP_RETVAL instruction is used after calls that return a value on
+ // the floating point stack. We cannot model this with ST defs since CALL
+ // instructions have fixed clobber lists. This instruction is interpreted
+ // to mean that there is one more live register on the stack than we
+ // thought.
+ //
+ // This means that StackTop does not match the hardware stack between a
+ // call and the FpPOP_RETVAL instructions. We do tolerate FP instructions
+ // between CALL and FpPOP_RETVAL as long as they don't overflow the
+ // hardware stack.
+ unsigned DstFP = getFPReg(MI->getOperand(0));
+
+ // Move existing stack elements up to reflect reality.
+ assert(StackTop < 8 && "Stack overflowed before FpPOP_RETVAL");
+ if (StackTop) {
+ std::copy_backward(Stack, Stack + StackTop, Stack + StackTop + 1);
+ for (unsigned i = 0; i != NumFPRegs; ++i)
+ ++RegMap[i];
+ }
+ ++StackTop;
+
+ // DstFP is the new bottom of the stack.
+ Stack[0] = DstFP;
+ RegMap[DstFP] = 0;
+
+ // DstFP will be killed by processBasicBlock if this was a dead def.
+ break;
+ }
+
+ case TargetOpcode::INLINEASM: {
+ // The inline asm MachineInstr currently only *uses* FP registers for the
+ // 'f' constraint. These should be turned into the current ST(x) register
+ // in the machine instr.
+ //
+ // There are special rules for x87 inline assembly. The compiler must know
+ // exactly how many registers are popped and pushed implicitly by the asm.
+ // Otherwise it is not possible to restore the stack state after the inline
+ // asm.
+ //
+ // There are 3 kinds of input operands:
+ //
+ // 1. Popped inputs. These must appear at the stack top in ST0-STn. A
+ // popped input operand must be in a fixed stack slot, and it is either
+ // tied to an output operand, or in the clobber list. The MI has ST use
+ // and def operands for these inputs.
+ //
+ // 2. Fixed inputs. These inputs appear in fixed stack slots, but are
+ // preserved by the inline asm. The fixed stack slots must be STn-STm
+ // following the popped inputs. A fixed input operand cannot be tied to
+ // an output or appear in the clobber list. The MI has ST use operands
+ // and no defs for these inputs.
+ //
+ // 3. Preserved inputs. These inputs use the "f" constraint which is
+ // represented as an FP register. The inline asm won't change these
+ // stack slots.
+ //
+ // Outputs must be in ST registers, FP outputs are not allowed. Clobbered
+ // registers do not count as output operands. The inline asm changes the
+ // stack as if it popped all the popped inputs and then pushed all the
+ // output operands.
+
+ // Scan the assembly for ST registers used, defined and clobbered. We can
+ // only tell clobbers from defs by looking at the asm descriptor.
+ unsigned STUses = 0, STDefs = 0, STClobbers = 0, STDeadDefs = 0;
+ unsigned NumOps = 0;
+ for (unsigned i = InlineAsm::MIOp_FirstOperand, e = MI->getNumOperands();
+ i != e && MI->getOperand(i).isImm(); i += 1 + NumOps) {
+ unsigned Flags = MI->getOperand(i).getImm();
+ NumOps = InlineAsm::getNumOperandRegisters(Flags);
+ if (NumOps != 1)
+ continue;
+ const MachineOperand &MO = MI->getOperand(i + 1);
+ if (!MO.isReg())
+ continue;
+ unsigned STReg = MO.getReg() - X86::ST0;
+ if (STReg >= 8)
+ continue;
+
+ switch (InlineAsm::getKind(Flags)) {
+ case InlineAsm::Kind_RegUse:
+ STUses |= (1u << STReg);
+ break;
+ case InlineAsm::Kind_RegDef:
+ case InlineAsm::Kind_RegDefEarlyClobber:
+ STDefs |= (1u << STReg);
+ if (MO.isDead())
+ STDeadDefs |= (1u << STReg);
+ break;
+ case InlineAsm::Kind_Clobber:
+ STClobbers |= (1u << STReg);
+ break;
+ default:
+ break;
+ }
+ }
+
+ if (STUses && !isMask_32(STUses))
+ MI->emitError("fixed input regs must be last on the x87 stack");
+ unsigned NumSTUses = CountTrailingOnes_32(STUses);
+
+ // Defs must be contiguous from the stack top. ST0-STn.
+ if (STDefs && !isMask_32(STDefs)) {
+ MI->emitError("output regs must be last on the x87 stack");
+ STDefs = NextPowerOf2(STDefs) - 1;
+ }
+ unsigned NumSTDefs = CountTrailingOnes_32(STDefs);
+
+ // So must the clobbered stack slots. ST0-STm, m >= n.
+ if (STClobbers && !isMask_32(STDefs | STClobbers))
+ MI->emitError("clobbers must be last on the x87 stack");
+
+ // Popped inputs are the ones that are also clobbered or defined.
+ unsigned STPopped = STUses & (STDefs | STClobbers);
+ if (STPopped && !isMask_32(STPopped))
+ MI->emitError("implicitly popped regs must be last on the x87 stack");
+ unsigned NumSTPopped = CountTrailingOnes_32(STPopped);
+
+ DEBUG(dbgs() << "Asm uses " << NumSTUses << " fixed regs, pops "
+ << NumSTPopped << ", and defines " << NumSTDefs << " regs.\n");
+
+ // Scan the instruction for FP uses corresponding to "f" constraints.
+ // Collect FP registers to kill afer the instruction.
+ // Always kill all the scratch regs.
+ unsigned FPKills = ((1u << NumFPRegs) - 1) & ~0xff;
+ unsigned FPUsed = 0;
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ MachineOperand &Op = MI->getOperand(i);
+ if (!Op.isReg() || Op.getReg() < X86::FP0 || Op.getReg() > X86::FP6)
+ continue;
+ if (!Op.isUse())
+ MI->emitError("illegal \"f\" output constraint");
+ unsigned FPReg = getFPReg(Op);
+ FPUsed |= 1U << FPReg;
+
+ // If we kill this operand, make sure to pop it from the stack after the
+ // asm. We just remember it for now, and pop them all off at the end in
+ // a batch.
+ if (Op.isKill())
+ FPKills |= 1U << FPReg;
+ }
+
+ // The popped inputs will be killed by the instruction, so duplicate them
+ // if the FP register needs to be live after the instruction, or if it is
+ // used in the instruction itself. We effectively treat the popped inputs
+ // as early clobbers.
+ for (unsigned i = 0; i < NumSTPopped; ++i) {
+ if ((FPKills & ~FPUsed) & (1u << PendingST[i]))
+ continue;
+ unsigned SR = getScratchReg();
+ duplicateToTop(PendingST[i], SR, I);
+ DEBUG(dbgs() << "Duplicating ST" << i << " in FP"
+ << unsigned(PendingST[i]) << " to avoid clobbering it.\n");
+ PendingST[i] = SR;
+ }
+
+ // Make sure we have a unique live register for every fixed use. Some of
+ // them could be undef uses, and we need to emit LD_F0 instructions.
+ for (unsigned i = 0; i < NumSTUses; ++i) {
+ if (i < NumPendingSTs && PendingST[i] < NumFPRegs) {
+ // Check for shared assignments.
+ for (unsigned j = 0; j < i; ++j) {
+ if (PendingST[j] != PendingST[i])
+ continue;
+ // STi and STj are inn the same register, create a copy.
+ unsigned SR = getScratchReg();
+ duplicateToTop(PendingST[i], SR, I);
+ DEBUG(dbgs() << "Duplicating ST" << i << " in FP"
+ << unsigned(PendingST[i])
+ << " to avoid collision with ST" << j << '\n');
+ PendingST[i] = SR;
+ }
+ continue;
+ }
+ unsigned SR = getScratchReg();
+ DEBUG(dbgs() << "Emitting LD_F0 for ST" << i << " in FP" << SR << '\n');
+ BuildMI(*MBB, I, MI->getDebugLoc(), TII->get(X86::LD_F0));
+ pushReg(SR);
+ PendingST[i] = SR;
+ if (NumPendingSTs == i)
+ ++NumPendingSTs;
+ }
+ assert(NumPendingSTs >= NumSTUses && "Fixed registers should be assigned");
+
+ // Now we can rearrange the live registers to match what was requested.
+ shuffleStackTop(PendingST, NumPendingSTs, I);
+ DEBUG({dbgs() << "Before asm: "; dumpStack();});
+
+ // With the stack layout fixed, rewrite the FP registers.
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ MachineOperand &Op = MI->getOperand(i);
+ if (!Op.isReg() || Op.getReg() < X86::FP0 || Op.getReg() > X86::FP6)
+ continue;
+ unsigned FPReg = getFPReg(Op);
+ Op.setReg(getSTReg(FPReg));
+ }
+
+ // Simulate the inline asm popping its inputs and pushing its outputs.
+ StackTop -= NumSTPopped;
+
+ // Hold the fixed output registers in scratch FP registers. They will be
+ // transferred to real FP registers by copies.
+ NumPendingSTs = 0;
+ for (unsigned i = 0; i < NumSTDefs; ++i) {
+ unsigned SR = getScratchReg();
+ pushReg(SR);
+ FPKills &= ~(1u << SR);
+ }
+ for (unsigned i = 0; i < NumSTDefs; ++i)
+ PendingST[NumPendingSTs++] = getStackEntry(i);
+ DEBUG({dbgs() << "After asm: "; dumpStack();});
+
+ // If any of the ST defs were dead, pop them immediately. Our caller only
+ // handles dead FP defs.
+ MachineBasicBlock::iterator InsertPt = MI;
+ for (unsigned i = 0; STDefs & (1u << i); ++i) {
+ if (!(STDeadDefs & (1u << i)))
+ continue;
+ freeStackSlotAfter(InsertPt, PendingST[i]);
+ PendingST[i] = NumFPRegs;
+ }
+ while (NumPendingSTs && PendingST[NumPendingSTs - 1] == NumFPRegs)
+ --NumPendingSTs;
+
+ // If this asm kills any FP registers (is the last use of them) we must
+ // explicitly emit pop instructions for them. Do this now after the asm has
+ // executed so that the ST(x) numbers are not off (which would happen if we
+ // did this inline with operand rewriting).
+ //
+ // Note: this might be a non-optimal pop sequence. We might be able to do
+ // better by trying to pop in stack order or something.
+ while (FPKills) {
+ unsigned FPReg = CountTrailingZeros_32(FPKills);
+ if (isLive(FPReg))
+ freeStackSlotAfter(InsertPt, FPReg);
+ FPKills &= ~(1U << FPReg);
+ }
+ // Don't delete the inline asm!
+ return;
+ }
+
+ case X86::WIN_FTOL_32:
+ case X86::WIN_FTOL_64: {
+ // Push the operand into ST0.
+ MachineOperand &Op = MI->getOperand(0);
+ assert(Op.isUse() && Op.isReg() &&
+ Op.getReg() >= X86::FP0 && Op.getReg() <= X86::FP6);
+ unsigned FPReg = getFPReg(Op);
+ if (Op.isKill())
+ moveToTop(FPReg, I);
+ else
+ duplicateToTop(FPReg, FPReg, I);
+
+ // Emit the call. This will pop the operand.
+ BuildMI(*MBB, I, MI->getDebugLoc(), TII->get(X86::CALLpcrel32))
+ .addExternalSymbol("_ftol2")
+ .addReg(X86::ST0, RegState::ImplicitKill)
+ .addReg(X86::EAX, RegState::Define | RegState::Implicit)
+ .addReg(X86::EDX, RegState::Define | RegState::Implicit)
+ .addReg(X86::EFLAGS, RegState::Define | RegState::Implicit);
+ --StackTop;
+
+ break;
+ }
+
+ case X86::RET:
+ case X86::RETI:
+ // If RET has an FP register use operand, pass the first one in ST(0) and
+ // the second one in ST(1).
+
+ // Find the register operands.
+ unsigned FirstFPRegOp = ~0U, SecondFPRegOp = ~0U;
+ unsigned LiveMask = 0;
+
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ MachineOperand &Op = MI->getOperand(i);
+ if (!Op.isReg() || Op.getReg() < X86::FP0 || Op.getReg() > X86::FP6)
+ continue;
+ // FP Register uses must be kills unless there are two uses of the same
+ // register, in which case only one will be a kill.
+ assert(Op.isUse() &&
+ (Op.isKill() || // Marked kill.
+ getFPReg(Op) == FirstFPRegOp || // Second instance.
+ MI->killsRegister(Op.getReg())) && // Later use is marked kill.
+ "Ret only defs operands, and values aren't live beyond it");
+
+ if (FirstFPRegOp == ~0U)
+ FirstFPRegOp = getFPReg(Op);
+ else {
+ assert(SecondFPRegOp == ~0U && "More than two fp operands!");
+ SecondFPRegOp = getFPReg(Op);
+ }
+ LiveMask |= (1 << getFPReg(Op));
+
+ // Remove the operand so that later passes don't see it.
+ MI->RemoveOperand(i);
+ --i, --e;
+ }
+
+ // We may have been carrying spurious live-ins, so make sure only the returned
+ // registers are left live.
+ adjustLiveRegs(LiveMask, MI);
+ if (!LiveMask) return; // Quick check to see if any are possible.
+
+ // There are only four possibilities here:
+ // 1) we are returning a single FP value. In this case, it has to be in
+ // ST(0) already, so just declare success by removing the value from the
+ // FP Stack.
+ if (SecondFPRegOp == ~0U) {
+ // Assert that the top of stack contains the right FP register.
+ assert(StackTop == 1 && FirstFPRegOp == getStackEntry(0) &&
+ "Top of stack not the right register for RET!");
+
+ // Ok, everything is good, mark the value as not being on the stack
+ // anymore so that our assertion about the stack being empty at end of
+ // block doesn't fire.
+ StackTop = 0;
+ return;
+ }
+
+ // Otherwise, we are returning two values:
+ // 2) If returning the same value for both, we only have one thing in the FP
+ // stack. Consider: RET FP1, FP1
+ if (StackTop == 1) {
+ assert(FirstFPRegOp == SecondFPRegOp && FirstFPRegOp == getStackEntry(0)&&
+ "Stack misconfiguration for RET!");
+
+ // Duplicate the TOS so that we return it twice. Just pick some other FPx
+ // register to hold it.
+ unsigned NewReg = getScratchReg();
+ duplicateToTop(FirstFPRegOp, NewReg, MI);
+ FirstFPRegOp = NewReg;
+ }
+
+ /// Okay we know we have two different FPx operands now:
+ assert(StackTop == 2 && "Must have two values live!");
+
+ /// 3) If SecondFPRegOp is currently in ST(0) and FirstFPRegOp is currently
+ /// in ST(1). In this case, emit an fxch.
+ if (getStackEntry(0) == SecondFPRegOp) {
+ assert(getStackEntry(1) == FirstFPRegOp && "Unknown regs live");
+ moveToTop(FirstFPRegOp, MI);
+ }
+
+ /// 4) Finally, FirstFPRegOp must be in ST(0) and SecondFPRegOp must be in
+ /// ST(1). Just remove both from our understanding of the stack and return.
+ assert(getStackEntry(0) == FirstFPRegOp && "Unknown regs live");
+ assert(getStackEntry(1) == SecondFPRegOp && "Unknown regs live");
+ StackTop = 0;
+ return;
+ }
+
+ I = MBB->erase(I); // Remove the pseudo instruction
+
+ // We want to leave I pointing to the previous instruction, but what if we
+ // just erased the first instruction?
+ if (I == MBB->begin()) {
+ DEBUG(dbgs() << "Inserting dummy KILL\n");
+ I = BuildMI(*MBB, I, DebugLoc(), TII->get(TargetOpcode::KILL));
+ } else
+ --I;
+}
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