Imported Upstream version 5.18.0.167

Former-commit-id: 289509151e0fee68a1b591a20c9f109c3c789d3a

external/llvm/lib/Target/PowerPC/PPCQPXLoadSplat.cpp

@@ -1,166 +0,0 @@
-//===----- PPCQPXLoadSplat.cpp - QPX Load Splat Simplification ------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// The QPX vector registers overlay the scalar floating-point registers, and
-// any scalar floating-point loads splat their value across all vector lanes.
-// Thus, if we have a scalar load followed by a splat, we can remove the splat
-// (i.e. replace the load with a load-and-splat pseudo instruction).
-//
-// This pass must run after anything that might do store-to-load forwarding.
-//
-//===----------------------------------------------------------------------===//
-
-#include "PPC.h"
-#include "PPCInstrBuilder.h"
-#include "PPCInstrInfo.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/CodeGen/MachineFunctionPass.h"
-#include "llvm/CodeGen/TargetSubtargetInfo.h"
-#include "llvm/Support/MathExtras.h"
-#include "llvm/Target/TargetMachine.h"
-using namespace llvm;
-
-#define DEBUG_TYPE "ppc-qpx-load-splat"
-
-STATISTIC(NumSimplified, "Number of QPX load splats simplified");
-
-namespace llvm {
-  void initializePPCQPXLoadSplatPass(PassRegistry&);
-}
-
-namespace {
-  struct PPCQPXLoadSplat : public MachineFunctionPass {
-    static char ID;
-    PPCQPXLoadSplat() : MachineFunctionPass(ID) {
-      initializePPCQPXLoadSplatPass(*PassRegistry::getPassRegistry());
-    }
-
-    bool runOnMachineFunction(MachineFunction &Fn) override;
-
-    StringRef getPassName() const override {
-      return "PowerPC QPX Load Splat Simplification";
-    }
-  };
-  char PPCQPXLoadSplat::ID = 0;
-}
-
-INITIALIZE_PASS(PPCQPXLoadSplat, "ppc-qpx-load-splat",
-                "PowerPC QPX Load Splat Simplification",
-                false, false)
-
-FunctionPass *llvm::createPPCQPXLoadSplatPass() {
-  return new PPCQPXLoadSplat();
-}
-
-bool PPCQPXLoadSplat::runOnMachineFunction(MachineFunction &MF) {
-  if (skipFunction(MF.getFunction()))
-    return false;
-
-  bool MadeChange = false;
-  const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo();
-
-  for (auto MFI = MF.begin(), MFIE = MF.end(); MFI != MFIE; ++MFI) {
-    MachineBasicBlock *MBB = &*MFI;
-    SmallVector<MachineInstr *, 4> Splats;
-
-    for (auto MBBI = MBB->rbegin(); MBBI != MBB->rend(); ++MBBI) {
-      MachineInstr *MI = &*MBBI;
-
-      if (MI->hasUnmodeledSideEffects() || MI->isCall()) {
-        Splats.clear();
-        continue;
-      }
-
-      // We're looking for a sequence like this:
-      // %f0 = LFD 0, killed %x3, implicit-def %qf0; mem:LD8[%a](tbaa=!2)
-      // %qf1 = QVESPLATI killed %qf0, 0, implicit %rm
-
-      for (auto SI = Splats.begin(); SI != Splats.end();) {
-        MachineInstr *SMI = *SI;
-        unsigned SplatReg = SMI->getOperand(0).getReg();
-        unsigned SrcReg = SMI->getOperand(1).getReg();
-
-        if (MI->modifiesRegister(SrcReg, TRI)) {
-          switch (MI->getOpcode()) {
-          default:
-            SI = Splats.erase(SI);
-            continue;
-          case PPC::LFS:
-          case PPC::LFD:
-          case PPC::LFSU:
-          case PPC::LFDU:
-          case PPC::LFSUX:
-          case PPC::LFDUX:
-          case PPC::LFSX:
-          case PPC::LFDX:
-          case PPC::LFIWAX:
-          case PPC::LFIWZX:
-            if (SplatReg != SrcReg) {
-              // We need to change the load to define the scalar subregister of
-              // the QPX splat source register.
-              unsigned SubRegIndex =
-                TRI->getSubRegIndex(SrcReg, MI->getOperand(0).getReg());
-              unsigned SplatSubReg = TRI->getSubReg(SplatReg, SubRegIndex);
-
-              // Substitute both the explicit defined register, and also the
-              // implicit def of the containing QPX register.
-              MI->getOperand(0).setReg(SplatSubReg);
-              MI->substituteRegister(SrcReg, SplatReg, 0, *TRI);
-            }
-
-            SI = Splats.erase(SI);
-
-            // If SMI is directly after MI, then MBBI's base iterator is
-            // pointing at SMI.  Adjust MBBI around the call to erase SMI to
-            // avoid invalidating MBBI.
-            ++MBBI;
-            SMI->eraseFromParent();
-            --MBBI;
-
-            ++NumSimplified;
-            MadeChange = true;
-            continue;
-          }
-        }
-
-        // If this instruction defines the splat register, then we cannot move
-        // the previous definition above it. If it reads from the splat
-        // register, then it must already be alive from some previous
-        // definition, and if the splat register is different from the source
-        // register, then this definition must not be the load for which we're
-        // searching.
-        if (MI->modifiesRegister(SplatReg, TRI) ||
-            (SrcReg != SplatReg &&
-             MI->readsRegister(SplatReg, TRI))) {
-          SI = Splats.erase(SI);
-          continue;
-        }
-
-        ++SI;
-      }
-
-      if (MI->getOpcode() != PPC::QVESPLATI &&
-          MI->getOpcode() != PPC::QVESPLATIs &&
-          MI->getOpcode() != PPC::QVESPLATIb)
-        continue;
-      if (MI->getOperand(2).getImm() != 0)
-        continue;
-
-      // If there are other uses of the scalar value after this, replacing
-      // those uses might be non-trivial.
-      if (!MI->getOperand(1).isKill())
-        continue;
-
-      Splats.push_back(MI);
-    }
-  }
-
-  return MadeChange;
-}