[llvm] r279199 - Revert "RegScavenging: Add scavengeRegisterBackwards()"
Matthias Braun via llvm-commits
llvm-commits at lists.llvm.org
Thu Aug 18 20:03:25 PDT 2016
Author: matze
Date: Thu Aug 18 22:03:24 2016
New Revision: 279199
URL: http://llvm.org/viewvc/llvm-project?rev=279199&view=rev
Log:
Revert "RegScavenging: Add scavengeRegisterBackwards()"
The ppc64 multistage bot fails on this.
This reverts commit r279124.
Also Revert "CodeGen: Add/Factor out LiveRegUnits class; NFCI" because it depends on the previous change
This reverts commit r279171.
Removed:
llvm/trunk/include/llvm/CodeGen/LiveRegUnits.h
llvm/trunk/lib/CodeGen/LiveRegUnits.cpp
Modified:
llvm/trunk/include/llvm/CodeGen/RegisterScavenging.h
llvm/trunk/lib/CodeGen/CMakeLists.txt
llvm/trunk/lib/CodeGen/PrologEpilogInserter.cpp
llvm/trunk/lib/CodeGen/RegisterScavenging.cpp
llvm/trunk/test/CodeGen/AMDGPU/captured-frame-index.ll
llvm/trunk/test/CodeGen/Mips/emergency-spill-slot-near-fp.ll
llvm/trunk/test/CodeGen/PowerPC/dyn-alloca-aligned.ll
llvm/trunk/test/CodeGen/Thumb/large-stack.ll
Removed: llvm/trunk/include/llvm/CodeGen/LiveRegUnits.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/LiveRegUnits.h?rev=279198&view=auto
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/LiveRegUnits.h (original)
+++ llvm/trunk/include/llvm/CodeGen/LiveRegUnits.h (removed)
@@ -1,116 +0,0 @@
-//===- llvm/CodeGen/LiveRegUnits.h - Register Unit Set ----------*- C++ -*-===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-/// \file
-/// A set of register units. It is intended for register liveness tracking.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef LLVM_CODEGEN_LIVEREGUNITS_H
-#define LLVM_CODEGEN_LIVEREGUNITS_H
-
-#include "llvm/ADT/BitVector.h"
-#include "llvm/Target/TargetRegisterInfo.h"
-
-namespace llvm {
-
-class MachineInstr;
-class MachineBasicBlock;
-
-/// A set of register units used to track register liveness.
-class LiveRegUnits {
- const TargetRegisterInfo *TRI;
- BitVector Units;
-
-public:
- /// Constructs a new empty LiveRegUnits set.
- LiveRegUnits() : TRI(nullptr) {}
-
- /// Constructs and initialize an empty LiveRegUnits set.
- LiveRegUnits(const TargetRegisterInfo &TRI) {
- init(TRI);
- }
-
- /// Initialize and clear the set.
- void init(const TargetRegisterInfo &TRI) {
- this->TRI = &TRI;
- Units.reset();
- Units.resize(TRI.getNumRegUnits());
- }
-
- /// Clears the set.
- void clear() { Units.reset(); }
-
- /// Returns true if the set is empty.
- bool empty() const { return Units.empty(); }
-
- /// Adds register units covered by physical register \p Reg.
- void addReg(unsigned Reg) {
- for (MCRegUnitIterator Unit(Reg, TRI); Unit.isValid(); ++Unit)
- Units.set(*Unit);
- }
-
- /// \brief Adds register units covered by physical register \p Reg that are
- /// part of the lanemask \p Mask.
- void addRegMasked(unsigned Reg, LaneBitmask Mask) {
- for (MCRegUnitMaskIterator Unit(Reg, TRI); Unit.isValid(); ++Unit) {
- LaneBitmask UnitMask = (*Unit).second;
- if (UnitMask == 0 || (UnitMask & Mask) != 0)
- Units.set((*Unit).first);
- }
- }
-
- /// Removes all register units covered by physical register \p Reg.
- void removeReg(unsigned Reg) {
- for (MCRegUnitIterator Unit(Reg, TRI); Unit.isValid(); ++Unit)
- Units.reset(*Unit);
- }
-
- /// Removes register units not preserved by the regmask \p RegMask.
- /// The regmask has the same format as the one in the RegMask machine operand.
- void removeRegsNotPreserved(const uint32_t *RegMask);
-
- /// Returns true if no part of physical register \p Reg is live.
- bool available(unsigned Reg) const {
- for (MCRegUnitIterator Unit(Reg, TRI); Unit.isValid(); ++Unit) {
- if (Units.test(*Unit))
- return false;
- }
- return true;
- }
-
- /// Updates liveness when stepping backwards over the instruction \p MI.
- void stepBackward(const MachineInstr &MI);
-
- /// Adds registers living out of block \p MBB.
- /// Live out registers are the union of the live-in registers of the successor
- /// blocks and pristine registers. Live out registers of the end block are the
- /// callee saved registers.
- void addLiveOuts(const MachineBasicBlock &MBB);
-
- /// Adds registers living into block \p MBB.
- void addLiveIns(const MachineBasicBlock &MBB);
-
- /// Adds all register units marked in the bitvector \p RegUnits.
- void addUnits(const BitVector &RegUnits) {
- Units |= RegUnits;
- }
- /// Removes all register units marked in the bitvector \p RegUnits.
- void removeUnits(const BitVector &RegUnits) {
- Units.reset(RegUnits);
- }
- /// Return the internal bitvector representation of the set.
- const BitVector &getBitVector() const {
- return Units;
- }
-};
-
-} // namespace llvm
-
-#endif
Modified: llvm/trunk/include/llvm/CodeGen/RegisterScavenging.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/RegisterScavenging.h?rev=279199&r1=279198&r2=279199&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/RegisterScavenging.h (original)
+++ llvm/trunk/include/llvm/CodeGen/RegisterScavenging.h Thu Aug 18 22:03:24 2016
@@ -19,7 +19,6 @@
#define LLVM_CODEGEN_REGISTERSCAVENGING_H
#include "llvm/ADT/BitVector.h"
-#include "llvm/CodeGen/LiveRegUnits.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
@@ -59,7 +58,10 @@ class RegScavenger {
/// A vector of information on scavenged registers.
SmallVector<ScavengedInfo, 2> Scavenged;
- LiveRegUnits LiveUnits;
+ /// The current state of each reg unit immediately before MBBI.
+ /// One bit per register unit. If bit is not set it means any
+ /// register containing that register unit is currently being used.
+ BitVector RegUnitsAvailable;
// These BitVectors are only used internally to forward(). They are members
// to avoid frequent reallocations.
@@ -155,24 +157,12 @@ public:
/// available and do the appropriate bookkeeping. SPAdj is the stack
/// adjustment due to call frame, it's passed along to eliminateFrameIndex().
/// Returns the scavenged register.
- /// This function performs worse if kill flags are incomplete, consider using
- /// scavengeRegisterBackwards() instead!
unsigned scavengeRegister(const TargetRegisterClass *RegClass,
MachineBasicBlock::iterator I, int SPAdj);
unsigned scavengeRegister(const TargetRegisterClass *RegClass, int SPAdj) {
return scavengeRegister(RegClass, MBBI, SPAdj);
}
- /// Make a register of the specific register class available from the current
- /// position backwards to the place before \p To. If \p RestoreAfter is true
- /// this includes the instruction following the current position.
- /// SPAdj is the stack adjustment due to call frame, it's passed along to
- /// eliminateFrameIndex().
- /// Returns the scavenged register.
- unsigned scavengeRegisterBackwards(const TargetRegisterClass &RC,
- MachineBasicBlock::iterator To,
- bool RestoreAfter, int SPAdj);
-
/// Tell the scavenger a register is used.
void setRegUsed(unsigned Reg, LaneBitmask LaneMask = ~0u);
private:
@@ -181,11 +171,11 @@ private:
/// setUsed / setUnused - Mark the state of one or a number of register units.
///
- void setUsed(const BitVector &RegUnits) {
- LiveUnits.addUnits(RegUnits);
+ void setUsed(BitVector &RegUnits) {
+ RegUnitsAvailable.reset(RegUnits);
}
- void setUnused(const BitVector &RegUnits) {
- LiveUnits.removeUnits(RegUnits);
+ void setUnused(BitVector &RegUnits) {
+ RegUnitsAvailable |= RegUnits;
}
/// Processes the current instruction and fill the KillRegUnits and
@@ -212,12 +202,6 @@ private:
/// Mark live-in registers of basic block as used.
void setLiveInsUsed(const MachineBasicBlock &MBB);
-
- /// Spill a register after position \p After and reload it before position
- /// \p UseMI.
- ScavengedInfo &spill(unsigned Reg, const TargetRegisterClass &RC, int SPAdj,
- MachineBasicBlock::iterator After,
- MachineBasicBlock::iterator &UseMI);
};
} // End llvm namespace
Modified: llvm/trunk/lib/CodeGen/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/CMakeLists.txt?rev=279199&r1=279198&r2=279199&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/CMakeLists.txt (original)
+++ llvm/trunk/lib/CodeGen/CMakeLists.txt Thu Aug 18 22:03:24 2016
@@ -44,7 +44,6 @@ add_llvm_library(LLVMCodeGen
LiveRangeCalc.cpp
LiveRangeEdit.cpp
LiveRegMatrix.cpp
- LiveRegUnits.cpp
LiveStackAnalysis.cpp
LiveVariables.cpp
LLVMTargetMachine.cpp
Removed: llvm/trunk/lib/CodeGen/LiveRegUnits.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/LiveRegUnits.cpp?rev=279198&view=auto
==============================================================================
--- llvm/trunk/lib/CodeGen/LiveRegUnits.cpp (original)
+++ llvm/trunk/lib/CodeGen/LiveRegUnits.cpp (removed)
@@ -1,97 +0,0 @@
-//===--- LiveRegUnits.cpp - Register Unit Set -----------------------------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-/// \file This file imlements the LiveRegUnits set.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/CodeGen/LiveRegUnits.h"
-#include "llvm/CodeGen/MachineFrameInfo.h"
-#include "llvm/CodeGen/MachineFunction.h"
-#include "llvm/CodeGen/MachineInstrBundle.h"
-using namespace llvm;
-
-void LiveRegUnits::removeRegsNotPreserved(const uint32_t *RegMask) {
- for (unsigned U = 0, E = TRI->getNumRegUnits(); U != E; ++U) {
- for (MCRegUnitRootIterator RootReg(U, TRI); RootReg.isValid(); ++RootReg) {
- if (MachineOperand::clobbersPhysReg(RegMask, *RootReg))
- Units.reset(U);
- }
- }
-}
-
-void LiveRegUnits::stepBackward(const MachineInstr &MI) {
- // Remove defined registers and regmask kills from the set.
- for (ConstMIBundleOperands O(MI); O.isValid(); ++O) {
- if (O->isReg()) {
- if (!O->isDef())
- continue;
- unsigned Reg = O->getReg();
- if (!TargetRegisterInfo::isPhysicalRegister(Reg))
- continue;
- removeReg(Reg);
- } else if (O->isRegMask())
- removeRegsNotPreserved(O->getRegMask());
- }
-
- // Add uses to the set.
- for (ConstMIBundleOperands O(MI); O.isValid(); ++O) {
- if (!O->isReg() || !O->readsReg())
- continue;
- unsigned Reg = O->getReg();
- if (!TargetRegisterInfo::isPhysicalRegister(Reg))
- continue;
- addReg(Reg);
- }
-}
-
-/// Add live-in registers of basic block \p MBB to \p LiveUnits.
-static void addLiveIns(LiveRegUnits &LiveUnits, const MachineBasicBlock &MBB) {
- for (const auto &LI : MBB.liveins())
- LiveUnits.addRegMasked(LI.PhysReg, LI.LaneMask);
-}
-
-static void addLiveOuts(LiveRegUnits &LiveUnits, const MachineBasicBlock &MBB) {
- // To get the live-outs we simply merge the live-ins of all successors.
- for (const MachineBasicBlock *Succ : MBB.successors())
- addLiveIns(LiveUnits, *Succ);
-}
-
-/// Add pristine registers to the given \p LiveUnits. This function removes
-/// actually saved callee save registers when \p InPrologueEpilogue is false.
-static void removeSavedRegs(LiveRegUnits &LiveUnits, const MachineFunction &MF,
- const MachineFrameInfo &MFI,
- const TargetRegisterInfo &TRI) {
- for (const CalleeSavedInfo &Info : MFI.getCalleeSavedInfo())
- LiveUnits.removeReg(Info.getReg());
-}
-
-void LiveRegUnits::addLiveOuts(const MachineBasicBlock &MBB) {
- const MachineFunction &MF = *MBB.getParent();
- const MachineFrameInfo &MFI = MF.getFrameInfo();
- if (MFI.isCalleeSavedInfoValid()) {
- for (const MCPhysReg *I = TRI->getCalleeSavedRegs(&MF); *I; ++I)
- addReg(*I);
- if (!MBB.isReturnBlock())
- removeSavedRegs(*this, MF, MFI, *TRI);
- }
- ::addLiveOuts(*this, MBB);
-}
-
-void LiveRegUnits::addLiveIns(const MachineBasicBlock &MBB) {
- const MachineFunction &MF = *MBB.getParent();
- const MachineFrameInfo &MFI = MF.getFrameInfo();
- if (MFI.isCalleeSavedInfoValid()) {
- for (const MCPhysReg *I = TRI->getCalleeSavedRegs(&MF); *I; ++I)
- addReg(*I);
- if (&MBB != &MF.front())
- removeSavedRegs(*this, MF, MFI, *TRI);
- }
- ::addLiveIns(*this, MBB);
-}
Modified: llvm/trunk/lib/CodeGen/PrologEpilogInserter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/PrologEpilogInserter.cpp?rev=279199&r1=279198&r2=279199&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/PrologEpilogInserter.cpp (original)
+++ llvm/trunk/lib/CodeGen/PrologEpilogInserter.cpp Thu Aug 18 22:03:24 2016
@@ -41,7 +41,6 @@
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/Target/TargetSubtargetInfo.h"
-#include <algorithm>
#include <climits>
using namespace llvm;
@@ -1146,55 +1145,6 @@ void PEI::replaceFrameIndices(MachineBas
}
}
-/// Allocate a register for the virtual register \p VReg. The last use of
-/// \p VReg is around the current position of the register scavenger \p RS.
-/// \p ReserveAfter controls whether the scavenged register needs to be reserved
-/// after the current instruction, otherwise it will only be reserved before the
-/// current instruction.
-static unsigned scavengeVReg(MachineRegisterInfo &MRI, RegScavenger &RS,
- unsigned VReg, bool ReserveAfter) {
-#ifndef NDEBUG
- // Verify that all definitions and uses are in the same basic block.
- const MachineBasicBlock *CommonMBB = nullptr;
- bool HadDef = false;
- for (MachineOperand &MO : MRI.reg_nodbg_operands(VReg)) {
- MachineBasicBlock *MBB = MO.getParent()->getParent();
- if (CommonMBB == nullptr)
- CommonMBB = MBB;
- assert(MBB == CommonMBB && "All defs+uses must be in the same basic block");
- if (MO.isDef())
- HadDef = true;
- }
- assert(HadDef && "Must have at least 1 Def");
-#endif
-
- // We should only have one definition of the register. However to accomodate
- // the requirements of two address code we also allow definitions in
- // subsequent instructions provided they also read the register. That way
- // we get a single contiguous lifetime.
- //
- // Definitions in MRI.def_begin() are unordered, search for the first.
- const TargetRegisterInfo &TRI = *MRI.getTargetRegisterInfo();
- MachineRegisterInfo::def_iterator FirstDef =
- std::find_if(MRI.def_begin(VReg), MRI.def_end(),
- [VReg, &TRI](const MachineOperand &MO) {
- return !MO.getParent()->readsRegister(VReg, &TRI);
- });
- assert(FirstDef != MRI.def_end() &&
- "Must have one definition that does not redefine vreg");
- MachineInstr &DefMI = *FirstDef->getParent();
-
- // The register scavenger will report a free register inserting an emergency
- // spill/reload if necessary.
- int SPAdj = 0;
- const TargetRegisterClass &RC = *MRI.getRegClass(VReg);
- unsigned SReg = RS.scavengeRegisterBackwards(RC, DefMI.getIterator(),
- ReserveAfter, SPAdj);
- MRI.replaceRegWith(VReg, SReg);
- ++NumScavengedRegs;
- return SReg;
-}
-
/// doScavengeFrameVirtualRegs - Replace all frame index virtual registers
/// with physical registers. Use the register scavenger to find an
/// appropriate register to use.
@@ -1206,51 +1156,78 @@ static void
doScavengeFrameVirtualRegs(MachineFunction &MF, RegScavenger *RS) {
// Run through the instructions and find any virtual registers.
MachineRegisterInfo &MRI = MF.getRegInfo();
- const TargetRegisterInfo &TRI = *MRI.getTargetRegisterInfo();
for (MachineBasicBlock &MBB : MF) {
- RS->enterBasicBlockEnd(MBB);
+ RS->enterBasicBlock(MBB);
- bool LastIterationHadVRegUses = false;
- for (MachineBasicBlock::iterator I = MBB.end(); I != MBB.begin(); ) {
- --I;
- // Move RegScavenger to the position between *I and *std::next(I).
- RS->backward(I);
-
- // Look for unassigned vregs in the uses of *std::next(I).
- if (LastIterationHadVRegUses) {
- MachineBasicBlock::iterator N = std::next(I);
- const MachineInstr &NMI = *N;
- for (const MachineOperand &MO : NMI.operands()) {
- if (!MO.isReg() || !MO.readsReg())
- continue;
- unsigned Reg = MO.getReg();
- if (TargetRegisterInfo::isVirtualRegister(Reg)) {
- unsigned SReg = scavengeVReg(MRI, *RS, Reg, true);
- N->addRegisterKilled(SReg, &TRI, false);
- RS->setRegUsed(SReg);
- }
- }
- }
+ int SPAdj = 0;
+
+ // The instruction stream may change in the loop, so check MBB.end()
+ // directly.
+ for (MachineBasicBlock::iterator I = MBB.begin(); I != MBB.end(); ) {
+ // We might end up here again with a NULL iterator if we scavenged a
+ // register for which we inserted spill code for definition by what was
+ // originally the first instruction in MBB.
+ if (I == MachineBasicBlock::iterator(nullptr))
+ I = MBB.begin();
- // Look for unassigned vregs in the defs of *I.
- LastIterationHadVRegUses = false;
const MachineInstr &MI = *I;
+ MachineBasicBlock::iterator J = std::next(I);
+ MachineBasicBlock::iterator P =
+ I == MBB.begin() ? MachineBasicBlock::iterator(nullptr)
+ : std::prev(I);
+
+ // RS should process this instruction before we might scavenge at this
+ // location. This is because we might be replacing a virtual register
+ // defined by this instruction, and if so, registers killed by this
+ // instruction are available, and defined registers are not.
+ RS->forward(I);
+
for (const MachineOperand &MO : MI.operands()) {
if (!MO.isReg())
continue;
unsigned Reg = MO.getReg();
if (!TargetRegisterInfo::isVirtualRegister(Reg))
continue;
- // We have to look at all operands anyway so we can precalculate here
- // whether there is a reading operand. This allows use to skip the use
- // step in the next iteration if there was none.
- if (MO.readsReg())
- LastIterationHadVRegUses = true;
- if (MO.isDef()) {
- unsigned SReg = scavengeVReg(MRI, *RS, Reg, false);
- I->addRegisterDead(SReg, &TRI, false);
- }
+
+ // When we first encounter a new virtual register, it
+ // must be a definition.
+ assert(MO.isDef() && "frame index virtual missing def!");
+ // Scavenge a new scratch register
+ const TargetRegisterClass *RC = MRI.getRegClass(Reg);
+ unsigned ScratchReg = RS->scavengeRegister(RC, J, SPAdj);
+
+ ++NumScavengedRegs;
+
+ // Replace this reference to the virtual register with the
+ // scratch register.
+ assert(ScratchReg && "Missing scratch register!");
+ MRI.replaceRegWith(Reg, ScratchReg);
+
+ // Because this instruction was processed by the RS before this
+ // register was allocated, make sure that the RS now records the
+ // register as being used.
+ RS->setRegUsed(ScratchReg);
}
+
+ // If the scavenger needed to use one of its spill slots, the
+ // spill code will have been inserted in between I and J. This is a
+ // problem because we need the spill code before I: Move I to just
+ // prior to J.
+ if (I != std::prev(J)) {
+ MBB.splice(J, &MBB, I);
+
+ // Before we move I, we need to prepare the RS to visit I again.
+ // Specifically, RS will assert if it sees uses of registers that
+ // it believes are undefined. Because we have already processed
+ // register kills in I, when it visits I again, it will believe that
+ // those registers are undefined. To avoid this situation, unprocess
+ // the instruction I.
+ assert(RS->getCurrentPosition() == I &&
+ "The register scavenger has an unexpected position");
+ I = P;
+ RS->unprocess(P);
+ } else
+ ++I;
}
}
}
Modified: llvm/trunk/lib/CodeGen/RegisterScavenging.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/RegisterScavenging.cpp?rev=279199&r1=279198&r2=279199&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/RegisterScavenging.cpp (original)
+++ llvm/trunk/lib/CodeGen/RegisterScavenging.cpp Thu Aug 18 22:03:24 2016
@@ -32,7 +32,11 @@ using namespace llvm;
#define DEBUG_TYPE "reg-scavenging"
void RegScavenger::setRegUsed(unsigned Reg, LaneBitmask LaneMask) {
- LiveUnits.addRegMasked(Reg, LaneMask);
+ for (MCRegUnitMaskIterator RUI(Reg, TRI); RUI.isValid(); ++RUI) {
+ LaneBitmask UnitMask = (*RUI).second;
+ if (UnitMask == 0 || (LaneMask & UnitMask) != 0)
+ RegUnitsAvailable.reset((*RUI).first);
+ }
}
void RegScavenger::init(MachineBasicBlock &MBB) {
@@ -40,7 +44,6 @@ void RegScavenger::init(MachineBasicBloc
TII = MF.getSubtarget().getInstrInfo();
TRI = MF.getSubtarget().getRegisterInfo();
MRI = &MF.getRegInfo();
- LiveUnits.init(*TRI);
assert((NumRegUnits == 0 || NumRegUnits == TRI->getNumRegUnits()) &&
"Target changed?");
@@ -53,6 +56,7 @@ void RegScavenger::init(MachineBasicBloc
// Self-initialize.
if (!this->MBB) {
NumRegUnits = TRI->getNumRegUnits();
+ RegUnitsAvailable.resize(NumRegUnits);
KillRegUnits.resize(NumRegUnits);
DefRegUnits.resize(NumRegUnits);
TmpRegUnits.resize(NumRegUnits);
@@ -65,17 +69,32 @@ void RegScavenger::init(MachineBasicBloc
I->Restore = nullptr;
}
+ // All register units start out unused.
+ RegUnitsAvailable.set();
+
+ // Pristine CSRs are not available.
+ BitVector PR = MF.getFrameInfo().getPristineRegs(MF);
+ for (int I = PR.find_first(); I>0; I = PR.find_next(I))
+ setRegUsed(I);
+
Tracking = false;
}
+void RegScavenger::setLiveInsUsed(const MachineBasicBlock &MBB) {
+ for (const auto &LI : MBB.liveins())
+ setRegUsed(LI.PhysReg, LI.LaneMask);
+}
+
void RegScavenger::enterBasicBlock(MachineBasicBlock &MBB) {
init(MBB);
- LiveUnits.addLiveIns(MBB);
+ setLiveInsUsed(MBB);
}
void RegScavenger::enterBasicBlockEnd(MachineBasicBlock &MBB) {
init(MBB);
- LiveUnits.addLiveOuts(MBB);
+ // Merge live-ins of successors to get live-outs.
+ for (const MachineBasicBlock *Succ : MBB.successors())
+ setLiveInsUsed(*Succ);
// Move internal iterator at the last instruction of the block.
if (MBB.begin() != MBB.end()) {
@@ -249,13 +268,34 @@ void RegScavenger::backward() {
assert(Tracking && "Must be tracking to determine kills and defs");
const MachineInstr &MI = *MBBI;
- LiveUnits.stepBackward(MI);
-
- // Expire scavenge spill frameindex uses.
- for (ScavengedInfo &I : Scavenged) {
- if (I.Restore == &MI) {
- I.Reg = 0;
- I.Restore = nullptr;
+ // Defined or clobbered registers are available now.
+ for (const MachineOperand &MO : MI.operands()) {
+ if (MO.isRegMask()) {
+ for (unsigned RU = 0, RUEnd = TRI->getNumRegUnits(); RU != RUEnd;
+ ++RU) {
+ for (MCRegUnitRootIterator RURI(RU, TRI); RURI.isValid(); ++RURI) {
+ if (MO.clobbersPhysReg(*RURI)) {
+ RegUnitsAvailable.set(RU);
+ break;
+ }
+ }
+ }
+ } else if (MO.isReg() && MO.isDef()) {
+ unsigned Reg = MO.getReg();
+ if (!Reg || TargetRegisterInfo::isVirtualRegister(Reg) ||
+ isReserved(Reg))
+ continue;
+ addRegUnits(RegUnitsAvailable, Reg);
+ }
+ }
+ // Mark read registers as unavailable.
+ for (const MachineOperand &MO : MI.uses()) {
+ if (MO.isReg() && MO.readsReg()) {
+ unsigned Reg = MO.getReg();
+ if (!Reg || TargetRegisterInfo::isVirtualRegister(Reg) ||
+ isReserved(Reg))
+ continue;
+ removeRegUnits(RegUnitsAvailable, Reg);
}
}
@@ -267,9 +307,12 @@ void RegScavenger::backward() {
}
bool RegScavenger::isRegUsed(unsigned Reg, bool includeReserved) const {
- if (isReserved(Reg))
- return includeReserved;
- return !LiveUnits.available(Reg);
+ if (includeReserved && isReserved(Reg))
+ return true;
+ for (MCRegUnitIterator RUI(Reg, TRI); RUI.isValid(); ++RUI)
+ if (!RegUnitsAvailable.test(*RUI))
+ return true;
+ return false;
}
unsigned RegScavenger::FindUnusedReg(const TargetRegisterClass *RC) const {
@@ -355,69 +398,6 @@ unsigned RegScavenger::findSurvivorReg(M
return Survivor;
}
-static std::pair<unsigned, MachineBasicBlock::iterator>
-findSurvivorBackwards(const TargetRegisterInfo &TRI,
- MachineBasicBlock::iterator From, MachineBasicBlock::iterator To,
- BitVector &Available, BitVector &Candidates) {
- bool FoundTo = false;
- unsigned Survivor = 0;
- MachineBasicBlock::iterator Pos;
- MachineBasicBlock &MBB = *From->getParent();
- unsigned InstrLimit = 25;
- unsigned InstrCountDown = InstrLimit;
- for (MachineBasicBlock::iterator I = From;; --I) {
- const MachineInstr &MI = *I;
-
- // Remove any candidates touched by instruction.
- bool FoundVReg = false;
- for (const MachineOperand &MO : MI.operands()) {
- if (MO.isRegMask()) {
- Candidates.clearBitsNotInMask(MO.getRegMask());
- continue;
- }
- if (!MO.isReg() || MO.isUndef() || MO.isDebug())
- continue;
- unsigned Reg = MO.getReg();
- if (TargetRegisterInfo::isVirtualRegister(Reg)) {
- FoundVReg = true;
- } else if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
- for (MCRegAliasIterator AI(Reg, &TRI, true); AI.isValid(); ++AI)
- Candidates.reset(*AI);
- }
- }
-
- if (I == To) {
- // If one of the available registers survived this long take it.
- Available &= Candidates;
- int Reg = Available.find_first();
- if (Reg != -1)
- return std::make_pair(Reg, MBB.end());
- // Otherwise we will continue up to InstrLimit instructions to find
- // the register which is not defined/used for the longest time.
- FoundTo = true;
- Pos = To;
- }
- if (FoundTo) {
- if (Survivor == 0 || !Candidates.test(Survivor)) {
- int Reg = Candidates.find_first();
- if (Reg == -1)
- break;
- Survivor = Reg;
- }
- if (--InstrCountDown == 0 || I == MBB.begin())
- break;
- if (FoundVReg) {
- // Keep searching when we find a vreg since the spilled register will
- // be usefull for this other vreg as well later.
- InstrCountDown = InstrLimit;
- Pos = I;
- }
- }
- }
-
- return std::make_pair(Survivor, Pos);
-}
-
static unsigned getFrameIndexOperandNum(MachineInstr &MI) {
unsigned i = 0;
while (!MI.getOperand(i).isFI()) {
@@ -427,16 +407,43 @@ static unsigned getFrameIndexOperandNum(
return i;
}
-RegScavenger::ScavengedInfo &
-RegScavenger::spill(unsigned Reg, const TargetRegisterClass &RC, int SPAdj,
- MachineBasicBlock::iterator Before,
- MachineBasicBlock::iterator &UseMI) {
+unsigned RegScavenger::scavengeRegister(const TargetRegisterClass *RC,
+ MachineBasicBlock::iterator I,
+ int SPAdj) {
+ MachineInstr &MI = *I;
+ const MachineFunction &MF = *MI.getParent()->getParent();
+ // Consider all allocatable registers in the register class initially
+ BitVector Candidates = TRI->getAllocatableSet(MF, RC);
+
+ // Exclude all the registers being used by the instruction.
+ for (const MachineOperand &MO : MI.operands()) {
+ if (MO.isReg() && MO.getReg() != 0 && !(MO.isUse() && MO.isUndef()) &&
+ !TargetRegisterInfo::isVirtualRegister(MO.getReg()))
+ Candidates.reset(MO.getReg());
+ }
+
+ // Try to find a register that's unused if there is one, as then we won't
+ // have to spill.
+ BitVector Available = getRegsAvailable(RC);
+ Available &= Candidates;
+ if (Available.any())
+ Candidates = Available;
+
+ // Find the register whose use is furthest away.
+ MachineBasicBlock::iterator UseMI;
+ unsigned SReg = findSurvivorReg(I, Candidates, 25, UseMI);
+
+ // If we found an unused register there is no reason to spill it.
+ if (!isRegUsed(SReg)) {
+ DEBUG(dbgs() << "Scavenged register: " << TRI->getName(SReg) << "\n");
+ return SReg;
+ }
+
// Find an available scavenging slot with size and alignment matching
// the requirements of the class RC.
- const MachineFunction &MF = *Before->getParent()->getParent();
const MachineFrameInfo &MFI = MF.getFrameInfo();
- unsigned NeedSize = RC.getSize();
- unsigned NeedAlign = RC.getAlignment();
+ unsigned NeedSize = RC->getSize();
+ unsigned NeedAlign = RC->getAlignment();
unsigned SI = Scavenged.size(), Diff = UINT_MAX;
int FIB = MFI.getObjectIndexBegin(), FIE = MFI.getObjectIndexEnd();
@@ -471,110 +478,42 @@ RegScavenger::spill(unsigned Reg, const
}
// Avoid infinite regress
- Scavenged[SI].Reg = Reg;
+ Scavenged[SI].Reg = SReg;
// If the target knows how to save/restore the register, let it do so;
// otherwise, use the emergency stack spill slot.
- if (!TRI->saveScavengerRegister(*MBB, Before, UseMI, &RC, Reg)) {
- // Spill the scavenged register before \p Before.
+ if (!TRI->saveScavengerRegister(*MBB, I, UseMI, RC, SReg)) {
+ // Spill the scavenged register before I.
int FI = Scavenged[SI].FrameIndex;
if (FI < FIB || FI >= FIE) {
std::string Msg = std::string("Error while trying to spill ") +
- TRI->getName(Reg) + " from class " + TRI->getRegClassName(&RC) +
+ TRI->getName(SReg) + " from class " + TRI->getRegClassName(RC) +
": Cannot scavenge register without an emergency spill slot!";
report_fatal_error(Msg.c_str());
}
- TII->storeRegToStackSlot(*MBB, Before, Reg, true, Scavenged[SI].FrameIndex,
- &RC, TRI);
- MachineBasicBlock::iterator II = std::prev(Before);
+ TII->storeRegToStackSlot(*MBB, I, SReg, true, Scavenged[SI].FrameIndex,
+ RC, TRI);
+ MachineBasicBlock::iterator II = std::prev(I);
unsigned FIOperandNum = getFrameIndexOperandNum(*II);
TRI->eliminateFrameIndex(II, SPAdj, FIOperandNum, this);
// Restore the scavenged register before its use (or first terminator).
- TII->loadRegFromStackSlot(*MBB, UseMI, Reg, Scavenged[SI].FrameIndex,
- &RC, TRI);
+ TII->loadRegFromStackSlot(*MBB, UseMI, SReg, Scavenged[SI].FrameIndex,
+ RC, TRI);
II = std::prev(UseMI);
FIOperandNum = getFrameIndexOperandNum(*II);
TRI->eliminateFrameIndex(II, SPAdj, FIOperandNum, this);
}
- return Scavenged[SI];
-}
-unsigned RegScavenger::scavengeRegister(const TargetRegisterClass *RC,
- MachineBasicBlock::iterator I,
- int SPAdj) {
- MachineInstr &MI = *I;
- const MachineFunction &MF = *MI.getParent()->getParent();
- // Consider all allocatable registers in the register class initially
- BitVector Candidates = TRI->getAllocatableSet(MF, RC);
+ Scavenged[SI].Restore = &*std::prev(UseMI);
- // Exclude all the registers being used by the instruction.
- for (const MachineOperand &MO : MI.operands()) {
- if (MO.isReg() && MO.getReg() != 0 && !(MO.isUse() && MO.isUndef()) &&
- !TargetRegisterInfo::isVirtualRegister(MO.getReg()))
- Candidates.reset(MO.getReg());
- }
-
- // Try to find a register that's unused if there is one, as then we won't
- // have to spill.
- BitVector Available = getRegsAvailable(RC);
- Available &= Candidates;
- if (Available.any())
- Candidates = Available;
-
- // Find the register whose use is furthest away.
- MachineBasicBlock::iterator UseMI;
- unsigned SReg = findSurvivorReg(I, Candidates, 25, UseMI);
-
- // If we found an unused register there is no reason to spill it.
- if (!isRegUsed(SReg)) {
- DEBUG(dbgs() << "Scavenged register: " << TRI->getName(SReg) << "\n");
- return SReg;
- }
-
- ScavengedInfo &Scavenged = spill(SReg, *RC, SPAdj, I, UseMI);
- Scavenged.Restore = &*std::prev(UseMI);
+ // Doing this here leads to infinite regress.
+ // Scavenged[SI].Reg = SReg;
DEBUG(dbgs() << "Scavenged register (with spill): " << TRI->getName(SReg) <<
"\n");
return SReg;
}
-
-unsigned RegScavenger::scavengeRegisterBackwards(const TargetRegisterClass &RC,
- MachineBasicBlock::iterator To,
- bool RestoreAfter, int SPAdj) {
- const MachineBasicBlock &MBB = *To->getParent();
- const MachineFunction &MF = *MBB.getParent();
- // Consider all allocatable registers in the register class initially
- BitVector Candidates = TRI->getAllocatableSet(MF, &RC);
-
- // Try to find a register that's unused if there is one, as then we won't
- // have to spill.
- BitVector Available = getRegsAvailable(&RC);
-
- // Find the register whose use is furthest away.
- MachineBasicBlock::iterator UseMI;
- std::pair<unsigned, MachineBasicBlock::iterator> P =
- findSurvivorBackwards(*TRI, MBBI, To, Available, Candidates);
- unsigned Reg = P.first;
- assert(Reg != 0 && "No register left to scavenge!");
- // Found an available register?
- if (!Available.test(Reg)) {
- MachineBasicBlock::iterator ReloadAfter =
- RestoreAfter ? std::next(MBBI) : MBBI;
- MachineBasicBlock::iterator ReloadBefore = std::next(ReloadAfter);
- DEBUG(dbgs() << "Reload before: " << *ReloadBefore << '\n');
- MachineBasicBlock::iterator SpillBefore = P.second;
- ScavengedInfo &Scavenged = spill(Reg, RC, SPAdj, SpillBefore, ReloadBefore);
- Scavenged.Restore = &*std::prev(SpillBefore);
- LiveUnits.removeReg(Reg);
- DEBUG(dbgs() << "Scavenged register with spill: " << PrintReg(Reg, TRI)
- << " until " << *SpillBefore);
- } else {
- DEBUG(dbgs() << "Scavenged free register: " << PrintReg(Reg, TRI) << '\n');
- }
- return Reg;
-}
Modified: llvm/trunk/test/CodeGen/AMDGPU/captured-frame-index.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AMDGPU/captured-frame-index.ll?rev=279199&r1=279198&r2=279199&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AMDGPU/captured-frame-index.ll (original)
+++ llvm/trunk/test/CodeGen/AMDGPU/captured-frame-index.ll Thu Aug 18 22:03:24 2016
@@ -140,8 +140,8 @@ define void @stored_fi_to_global_2_small
}
; GCN-LABEL: {{^}}stored_fi_to_global_huge_frame_offset:
-; GCN-DAG: s_add_i32 [[BASE_1_OFF_0:s[0-9]+]], 0, 0x3ffc
-; GCN-DAG: v_mov_b32_e32 [[BASE_0:v[0-9]+]], 0{{$}}
+; GCN: s_add_i32 [[BASE_1_OFF_0:s[0-9]+]], 0, 0x3ffc
+; GCN: v_mov_b32_e32 [[BASE_0:v[0-9]+]], 0{{$}}
; GCN: buffer_store_dword [[BASE_0]], v{{[0-9]+}}, s{{\[[0-9]+:[0-9]+\]}}, s{{[0-9]+}} offen
; GCN: v_mov_b32_e32 [[V_BASE_1_OFF_0:v[0-9]+]], [[BASE_1_OFF_0]]
Modified: llvm/trunk/test/CodeGen/Mips/emergency-spill-slot-near-fp.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/Mips/emergency-spill-slot-near-fp.ll?rev=279199&r1=279198&r2=279199&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/Mips/emergency-spill-slot-near-fp.ll (original)
+++ llvm/trunk/test/CodeGen/Mips/emergency-spill-slot-near-fp.ll Thu Aug 18 22:03:24 2016
@@ -1,62 +1,34 @@
-; RUN: llc -march=mipsel -O0 -relocation-model=pic < %s | FileCheck %s
; Check that register scavenging spill slot is close to $fp.
-target triple="mipsel--"
-
- at var = external global i32
- at ptrvar = external global i8*
-
-; CHECK-LABEL: func:
-define void @func() {
- %space = alloca i32, align 4
- %stackspace = alloca[16384 x i32], align 4
-
- ; ensure stackspace is not optimized out
- %stackspace_casted = bitcast [16384 x i32]* %stackspace to i8*
- store volatile i8* %stackspace_casted, i8** @ptrvar
-
- ; Load values to increase register pressure.
- %v0 = load volatile i32, i32* @var
- %v1 = load volatile i32, i32* @var
- %v2 = load volatile i32, i32* @var
- %v3 = load volatile i32, i32* @var
- %v4 = load volatile i32, i32* @var
- %v5 = load volatile i32, i32* @var
- %v6 = load volatile i32, i32* @var
- %v7 = load volatile i32, i32* @var
- %v8 = load volatile i32, i32* @var
- %v9 = load volatile i32, i32* @var
- %v10 = load volatile i32, i32* @var
- %v11 = load volatile i32, i32* @var
- %v12 = load volatile i32, i32* @var
- %v13 = load volatile i32, i32* @var
- %v14 = load volatile i32, i32* @var
- %v15 = load volatile i32, i32* @var
- %v16 = load volatile i32, i32* @var
-
- ; Computing a stack-relative values needs an additional register.
- ; We should get an emergency spill/reload for this.
- ; CHECK: sw ${{.*}}, 0($sp)
- ; CHECK: lw ${{.*}}, 0($sp)
- store volatile i32 %v0, i32* %space
+; RUN: llc -march=mipsel -O0 -relocation-model=pic < %s | FileCheck %s
- ; store values so they are used.
- store volatile i32 %v0, i32* @var
- store volatile i32 %v1, i32* @var
- store volatile i32 %v2, i32* @var
- store volatile i32 %v3, i32* @var
- store volatile i32 %v4, i32* @var
- store volatile i32 %v5, i32* @var
- store volatile i32 %v6, i32* @var
- store volatile i32 %v7, i32* @var
- store volatile i32 %v8, i32* @var
- store volatile i32 %v9, i32* @var
- store volatile i32 %v10, i32* @var
- store volatile i32 %v11, i32* @var
- store volatile i32 %v12, i32* @var
- store volatile i32 %v13, i32* @var
- store volatile i32 %v14, i32* @var
- store volatile i32 %v15, i32* @var
- store volatile i32 %v16, i32* @var
+; CHECK: sw ${{.*}}, 8($sp)
+; CHECK: lw ${{.*}}, 8($sp)
- ret void
+define i32 @main(i32 signext %argc, i8** %argv) #0 {
+entry:
+ %retval = alloca i32, align 4
+ %argc.addr = alloca i32, align 4
+ %argv.addr = alloca i8**, align 4
+ %v0 = alloca <16 x i8>, align 16
+ %.compoundliteral = alloca <16 x i8>, align 16
+ %v1 = alloca <16 x i8>, align 16
+ %.compoundliteral1 = alloca <16 x i8>, align 16
+ %unused_variable = alloca [16384 x i32], align 4
+ %result = alloca <16 x i8>, align 16
+ store i32 0, i32* %retval
+ store i32 %argc, i32* %argc.addr, align 4
+ store i8** %argv, i8*** %argv.addr, align 4
+ store <16 x i8> <i8 1, i8 2, i8 3, i8 4, i8 5, i8 6, i8 7, i8 8, i8 9, i8 10, i8 11, i8 12, i8 13, i8 14, i8 15, i8 16>, <16 x i8>* %.compoundliteral
+ %0 = load <16 x i8>, <16 x i8>* %.compoundliteral
+ store <16 x i8> %0, <16 x i8>* %v0, align 16
+ store <16 x i8> zeroinitializer, <16 x i8>* %.compoundliteral1
+ %1 = load <16 x i8>, <16 x i8>* %.compoundliteral1
+ store <16 x i8> %1, <16 x i8>* %v1, align 16
+ %2 = load <16 x i8>, <16 x i8>* %v0, align 16
+ %3 = load <16 x i8>, <16 x i8>* %v1, align 16
+ %mul = mul <16 x i8> %2, %3
+ store <16 x i8> %mul, <16 x i8>* %result, align 16
+ ret i32 0
}
+
+attributes #0 = { noinline "no-frame-pointer-elim"="true" }
Modified: llvm/trunk/test/CodeGen/PowerPC/dyn-alloca-aligned.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/PowerPC/dyn-alloca-aligned.ll?rev=279199&r1=279198&r2=279199&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/PowerPC/dyn-alloca-aligned.ll (original)
+++ llvm/trunk/test/CodeGen/PowerPC/dyn-alloca-aligned.ll Thu Aug 18 22:03:24 2016
@@ -25,8 +25,8 @@ entry:
; CHECK-DAG: li [[REG1:[0-9]+]], -128
; CHECK-DAG: neg [[REG2:[0-9]+]],
-; CHECK: and [[REG3:[0-9]+]], [[REG2]], [[REG1]]
-; CHECK: stdux {{[0-9]+}}, 1, [[REG3]]
+; CHECK: and [[REG1]], [[REG2]], [[REG1]]
+; CHECK: stdux {{[0-9]+}}, 1, [[REG1]]
; CHECK: blr
Modified: llvm/trunk/test/CodeGen/Thumb/large-stack.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/Thumb/large-stack.ll?rev=279199&r1=279198&r2=279199&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/Thumb/large-stack.ll (original)
+++ llvm/trunk/test/CodeGen/Thumb/large-stack.ll Thu Aug 18 22:03:24 2016
@@ -46,8 +46,8 @@ define i32 @test3() {
; CHECK-LABEL: test3:
; CHECK: ldr [[TEMP:r[0-7]]],
; CHECK: add sp, [[TEMP]]
-; CHECK: ldr [[TEMP2:r[0-7]]],
-; CHECK: add [[TEMP2]], sp
+; CHECK: ldr [[TEMP]],
+; CHECK: add [[TEMP]], sp
; EABI: ldr [[TEMP:r[0-7]]],
; EABI: add sp, [[TEMP]]
; IOS: subs r4, r7, #4
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