R600/SI: cleanup literal handling v3

Seems to be allot simpler, and also paves the
way for further improvements.

v2: rebased on master, use 0 in BUFFER_LOAD_FORMAT_XYZW,
    use VGPR0 in dummy EXP, avoid compiler warning, break
    after encoding the first literal.
v3: correctly use V_ADD_F32_e64

This is a candidate for the stable branch.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Tom Stellard <thomas.stellard@amd.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175354 91177308-0d34-0410-b5e6-96231b3b80d8

10 files changed, 176 insertions, 195 deletions

diff --git a/lib/Target/R600/AMDGPU.h b/lib/Target/R600/AMDGPU.h
index bac01a3f42..ba8791870d 100644
--- a/lib/Target/R600/AMDGPU.h
+++ b/lib/Target/R600/AMDGPU.h
@@ -30,7 +30,6 @@ FunctionPass *createSIAnnotateControlFlowPass();
 FunctionPass *createSIAssignInterpRegsPass(TargetMachine &tm);
 FunctionPass *createSILowerControlFlowPass(TargetMachine &tm);
 FunctionPass *createSICodeEmitterPass(formatted_raw_ostream &OS);
-FunctionPass *createSILowerLiteralConstantsPass(TargetMachine &tm);
 FunctionPass *createSIInsertWaits(TargetMachine &tm);
 
 // Passes common to R600 and SI
diff --git a/lib/Target/R600/AMDGPUAsmPrinter.cpp b/lib/Target/R600/AMDGPUAsmPrinter.cpp
index 89d13072b3..c30dbe430d 100644
--- a/lib/Target/R600/AMDGPUAsmPrinter.cpp
+++ b/lib/Target/R600/AMDGPUAsmPrinter.cpp
@@ -91,8 +91,6 @@ void AMDGPUAsmPrinter::EmitProgramInfo(MachineFunction &MF) {
         switch (reg) {
         default: break;
         case AMDGPU::EXEC:
-        case AMDGPU::SI_LITERAL_CONSTANT:
-        case AMDGPU::SREG_LIT_0:
         case AMDGPU::M0:
           continue;
         }
diff --git a/lib/Target/R600/AMDGPUTargetMachine.cpp b/lib/Target/R600/AMDGPUTargetMachine.cpp
index 821e86476f..e2f00be41e 100644
--- a/lib/Target/R600/AMDGPUTargetMachine.cpp
+++ b/lib/Target/R600/AMDGPUTargetMachine.cpp
@@ -145,7 +145,6 @@ bool AMDGPUPassConfig::addPreEmitPass() {
     addPass(&FinalizeMachineBundlesID);
     addPass(createR600LowerConstCopy(*TM));
   } else {
-    addPass(createSILowerLiteralConstantsPass(*TM));
     addPass(createSILowerControlFlowPass(*TM));
   }
 
diff --git a/lib/Target/R600/MCTargetDesc/SIMCCodeEmitter.cpp b/lib/Target/R600/MCTargetDesc/SIMCCodeEmitter.cpp
index fbdf77e8dc..0d9f3d8140 100644
--- a/lib/Target/R600/MCTargetDesc/SIMCCodeEmitter.cpp
+++ b/lib/Target/R600/MCTargetDesc/SIMCCodeEmitter.cpp
@@ -27,6 +27,13 @@
 using namespace llvm;
 
 namespace {
+
+/// \brief Helper type used in encoding
+typedef union {
+  int32_t I;
+  float F;
+} IntFloatUnion;
+
 class SIMCCodeEmitter : public  AMDGPUMCCodeEmitter {
   SIMCCodeEmitter(const SIMCCodeEmitter &); // DO NOT IMPLEMENT
   void operator=(const SIMCCodeEmitter &); // DO NOT IMPLEMENT
@@ -35,6 +42,15 @@ class SIMCCodeEmitter : public  AMDGPUMCCodeEmitter {
   const MCSubtargetInfo &STI;
   MCContext &Ctx;
 
+  /// \brief Encode a sequence of registers with the correct alignment.
+  unsigned GPRAlign(const MCInst &MI, unsigned OpNo, unsigned shift) const;
+
+  /// \brief Can this operand also contain immediate values?
+  bool isSrcOperand(const MCInstrDesc &Desc, unsigned OpNo) const;
+
+  /// \brief Encode an fp or int literal
+  uint32_t getLitEncoding(const MCOperand &MO) const;
+
 public:
   SIMCCodeEmitter(const MCInstrInfo &mcii, const MCRegisterInfo &mri,
                   const MCSubtargetInfo &sti, MCContext &ctx)
@@ -50,11 +66,6 @@ public:
   virtual uint64_t getMachineOpValue(const MCInst &MI, const MCOperand &MO,
                                      SmallVectorImpl<MCFixup> &Fixups) const;
 
-public:
-
-  /// \brief Encode a sequence of registers with the correct alignment.
-  unsigned GPRAlign(const MCInst &MI, unsigned OpNo, unsigned shift) const;
-
   /// \brief Encoding for when 2 consecutive registers are used
   virtual unsigned GPR2AlignEncode(const MCInst &MI, unsigned OpNo,
                                    SmallVectorImpl<MCFixup> &Fixup) const;
@@ -73,39 +84,131 @@ MCCodeEmitter *llvm::createSIMCCodeEmitter(const MCInstrInfo &MCII,
   return new SIMCCodeEmitter(MCII, MRI, STI, Ctx);
 }
 
+bool SIMCCodeEmitter::isSrcOperand(const MCInstrDesc &Desc,
+                                   unsigned OpNo) const {
+
+  unsigned RegClass = Desc.OpInfo[OpNo].RegClass;
+  return (AMDGPU::SSrc_32RegClassID == RegClass) ||
+         (AMDGPU::SSrc_64RegClassID == RegClass) ||
+         (AMDGPU::VSrc_32RegClassID == RegClass) ||
+         (AMDGPU::VSrc_64RegClassID == RegClass);
+}
+
+uint32_t SIMCCodeEmitter::getLitEncoding(const MCOperand &MO) const {
+
+  IntFloatUnion Imm;
+  if (MO.isImm())
+    Imm.I = MO.getImm();
+  else if (MO.isFPImm())
+    Imm.F = MO.getFPImm();
+  else
+    return ~0;
+
+  if (Imm.I >= 0 && Imm.I <= 64)
+    return 128 + Imm.I;
+
+  if (Imm.I >= -16 && Imm.I <= -1)
+    return 192 + abs(Imm.I);
+
+  if (Imm.F == 0.5f)
+    return 240;
+
+  if (Imm.F == -0.5f)
+    return 241;
+
+  if (Imm.F == 1.0f)
+    return 242;
+
+  if (Imm.F == -1.0f)
+    return 243;
+
+  if (Imm.F == 2.0f)
+    return 244;
+
+  if (Imm.F == -2.0f)
+    return 245;
+
+  if (Imm.F == 4.0f)
+    return 246;
+
+  if (Imm.F == 4.0f)
+    return 247;
+
+  return 255;
+}
+
 void SIMCCodeEmitter::EncodeInstruction(const MCInst &MI, raw_ostream &OS,
                                        SmallVectorImpl<MCFixup> &Fixups) const {
+
   uint64_t Encoding = getBinaryCodeForInstr(MI, Fixups);
-  unsigned bytes = MCII.get(MI.getOpcode()).getSize();
+  const MCInstrDesc &Desc = MCII.get(MI.getOpcode());
+  unsigned bytes = Desc.getSize();
+
   for (unsigned i = 0; i < bytes; i++) {
     OS.write((uint8_t) ((Encoding >> (8 * i)) & 0xff));
   }
+
+  if (bytes > 4)
+    return;
+
+  // Check for additional literals in SRC0/1/2 (Op 1/2/3)
+  for (unsigned i = 0, e = MI.getNumOperands(); i < e; ++i) {
+
+    // Check if this operand should be encoded as [SV]Src
+    if (!isSrcOperand(Desc, i))
+      continue;
+
+    // Is this operand a literal immediate?
+    const MCOperand &Op = MI.getOperand(i);
+    if (getLitEncoding(Op) != 255)
+      continue;
+
+    // Yes! Encode it
+    IntFloatUnion Imm;
+    if (Op.isImm())
+      Imm.I = Op.getImm();
+    else
+      Imm.F = Op.getFPImm();
+
+    for (unsigned j = 0; j < 4; j++) {
+      OS.write((uint8_t) ((Imm.I >> (8 * j)) & 0xff));
+    }
+
+    // Only one literal value allowed
+    break;
+  }
 }
 
 uint64_t SIMCCodeEmitter::getMachineOpValue(const MCInst &MI,
                                             const MCOperand &MO,
                                        SmallVectorImpl<MCFixup> &Fixups) const {
-  if (MO.isReg()) {
+  if (MO.isReg())
     return MRI.getEncodingValue(MO.getReg());
-  } else if (MO.isImm()) {
-    return MO.getImm();
-  } else if (MO.isFPImm()) {
-    // XXX: Not all instructions can use inline literals
-    // XXX: We should make sure this is a 32-bit constant
-    union {
-      float F;
-      uint32_t I;
-    } Imm;
-    Imm.F = MO.getFPImm();
-    return Imm.I;
-  } else if (MO.isExpr()) {
+
+  if (MO.isExpr()) {
     const MCExpr *Expr = MO.getExpr();
     MCFixupKind Kind = MCFixupKind(FK_PCRel_4);
     Fixups.push_back(MCFixup::Create(0, Expr, Kind, MI.getLoc()));
     return 0;
-  } else{
-    llvm_unreachable("Encoding of this operand type is not supported yet.");
   }
+
+  // Figure out the operand number, needed for isSrcOperand check
+  unsigned OpNo = 0;
+  for (unsigned e = MI.getNumOperands(); OpNo < e; ++OpNo) {
+    if (&MO == &MI.getOperand(OpNo))
+      break;
+  }
+
+  const MCInstrDesc &Desc = MCII.get(MI.getOpcode());
+  if (isSrcOperand(Desc, OpNo)) {
+    uint32_t Enc = getLitEncoding(MO);
+    if (Enc != ~0U && (Enc != 255 || Desc.getSize() == 4))
+      return Enc;
+
+  } else if (MO.isImm())
+    return MO.getImm();
+
+  llvm_unreachable("Encoding of this operand type is not supported yet.");
   return 0;
 }
 
@@ -118,6 +221,7 @@ unsigned SIMCCodeEmitter::GPRAlign(const MCInst &MI, unsigned OpNo,
   unsigned regCode = MRI.getEncodingValue(MI.getOperand(OpNo).getReg());
   return (regCode & 0xff) >> shift;
 }
+
 unsigned SIMCCodeEmitter::GPR2AlignEncode(const MCInst &MI,
                                           unsigned OpNo ,
                                         SmallVectorImpl<MCFixup> &Fixup) const {
diff --git a/lib/Target/R600/SIISelLowering.cpp b/lib/Target/R600/SIISelLowering.cpp
index 3919b97786..9a8ce803fd 100644
--- a/lib/Target/R600/SIISelLowering.cpp
+++ b/lib/Target/R600/SIISelLowering.cpp
@@ -77,8 +77,8 @@ MachineBasicBlock * SITargetLowering::EmitInstrWithCustomInserter(
     BuildMI(*BB, I, BB->findDebugLoc(I), TII->get(AMDGPU::V_ADD_F32_e64))
            .addOperand(MI->getOperand(0))
            .addOperand(MI->getOperand(1))
-           .addReg(AMDGPU::SREG_LIT_0)
-           .addReg(AMDGPU::SREG_LIT_0)
+           .addImm(0x80) // SRC1
+           .addImm(0x80) // SRC2
            .addImm(0) // ABS
            .addImm(1) // CLAMP
            .addImm(0) // OMOD
@@ -90,8 +90,8 @@ MachineBasicBlock * SITargetLowering::EmitInstrWithCustomInserter(
     BuildMI(*BB, I, BB->findDebugLoc(I), TII->get(AMDGPU::V_ADD_F32_e64))
                  .addOperand(MI->getOperand(0))
                  .addOperand(MI->getOperand(1))
-                 .addReg(AMDGPU::SREG_LIT_0)
-                 .addReg(AMDGPU::SREG_LIT_0)
+                 .addImm(0x80) // SRC1
+                 .addImm(0x80) // SRC2
                  .addImm(1) // ABS
                  .addImm(0) // CLAMP
                  .addImm(0) // OMOD
@@ -103,8 +103,8 @@ MachineBasicBlock * SITargetLowering::EmitInstrWithCustomInserter(
     BuildMI(*BB, I, BB->findDebugLoc(I), TII->get(AMDGPU::V_ADD_F32_e64))
                  .addOperand(MI->getOperand(0))
                  .addOperand(MI->getOperand(1))
-                 .addReg(AMDGPU::SREG_LIT_0)
-                 .addReg(AMDGPU::SREG_LIT_0)
+                 .addImm(0x80) // SRC1
+                 .addImm(0x80) // SRC2
                  .addImm(0) // ABS
                  .addImm(0) // CLAMP
                  .addImm(0) // OMOD
@@ -176,7 +176,7 @@ void SITargetLowering::LowerSI_V_CNDLT(MachineInstr *MI, MachineBasicBlock &BB,
   BuildMI(BB, I, BB.findDebugLoc(I),
           TII->get(AMDGPU::V_CMP_GT_F32_e32),
           VCC)
-          .addReg(AMDGPU::SREG_LIT_0)
+          .addImm(0)
           .addOperand(MI->getOperand(1));
 
   BuildMI(BB, I, BB.findDebugLoc(I), TII->get(AMDGPU::V_CNDMASK_B32_e32))
diff --git a/lib/Target/R600/SIInstrInfo.cpp b/lib/Target/R600/SIInstrInfo.cpp
index f6d00f5eda..4dfd26e97d 100644
--- a/lib/Target/R600/SIInstrInfo.cpp
+++ b/lib/Target/R600/SIInstrInfo.cpp
@@ -68,7 +68,7 @@ SIInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
 
 MachineInstr * SIInstrInfo::getMovImmInstr(MachineFunction *MF, unsigned DstReg,
                                            int64_t Imm) const {
-  MachineInstr * MI = MF->CreateMachineInstr(get(AMDGPU::V_MOV_IMM_I32), DebugLoc());
+  MachineInstr * MI = MF->CreateMachineInstr(get(AMDGPU::V_MOV_B32_e32), DebugLoc());
   MachineInstrBuilder MIB(*MF, MI);
   MIB.addReg(DstReg, RegState::Define);
   MIB.addImm(Imm);
@@ -84,9 +84,6 @@ bool SIInstrInfo::isMov(unsigned Opcode) const {
   case AMDGPU::S_MOV_B64:
   case AMDGPU::V_MOV_B32_e32:
   case AMDGPU::V_MOV_B32_e64:
-  case AMDGPU::V_MOV_IMM_F32:
-  case AMDGPU::V_MOV_IMM_I32:
-  case AMDGPU::S_MOV_IMM_I32:
     return true;
   }
 }
diff --git a/lib/Target/R600/SIInstructions.td b/lib/Target/R600/SIInstructions.td
index 16c9c0188c..613fe137e3 100644
--- a/lib/Target/R600/SIInstructions.td
+++ b/lib/Target/R600/SIInstructions.td
@@ -1018,45 +1018,6 @@ def S_BFE_I64 : SOP2_64 <0x0000002a, "S_BFE_I64", []>;
 //def S_CBRANCH_G_FORK : SOP2_ <0x0000002b, "S_CBRANCH_G_FORK", []>;
 def S_ABSDIFF_I32 : SOP2_32 <0x0000002c, "S_ABSDIFF_I32", []>;
 
-class V_MOV_IMM <ValueType type, Operand immType, SDNode immNode> : InstSI <
-  (outs VReg_32:$dst),
-  (ins immType:$src0),
-  "V_MOV_IMM",
-   [(set VReg_32:$dst, (type immNode:$src0))]
->;
-
-let isCodeGenOnly = 1, isPseudo = 1 in {
-
-def V_MOV_IMM_I32 : V_MOV_IMM<i32, i32imm, imm>;
-def V_MOV_IMM_F32 : V_MOV_IMM<f32, f32imm, fpimm>;
-
-def S_MOV_IMM_I32 : InstSI <
-  (outs SReg_32:$dst),
-  (ins i32imm:$src0),
-  "S_MOV_IMM_I32",
-  [(set SReg_32:$dst, (imm:$src0))]
->;
-
-} // End isCodeGenOnly, isPseudo = 1
-
-// i64 immediates aren't supported in hardware, split it into two 32bit values
-def : Pat <
-  (i64 imm:$imm),
-  (INSERT_SUBREG (INSERT_SUBREG (i64 (IMPLICIT_DEF)),
-    (S_MOV_IMM_I32 (LO32 imm:$imm)), sub0),
-    (S_MOV_IMM_I32 (HI32 imm:$imm)), sub1)
->;
-
-class SI_LOAD_LITERAL<Operand ImmType> :
-    Enc32 <(outs), (ins ImmType:$imm), "LOAD_LITERAL $imm", []> {
-
-  bits<32> imm;
-  let Inst{31-0} = imm;
-}
-
-def SI_LOAD_LITERAL_I32 : SI_LOAD_LITERAL<i32imm>;
-def SI_LOAD_LITERAL_F32 : SI_LOAD_LITERAL<f32imm>;
-
 let isCodeGenOnly = 1, isPseudo = 1 in {
 
 def SET_M0 : InstSI <
@@ -1173,7 +1134,7 @@ def SI_KILL : InstSI <
 
 def : Pat <
   (int_AMDGPU_kilp),
-  (SI_KILL (V_MOV_IMM_I32 0xbf800000))
+  (SI_KILL (V_MOV_B32_e32 0xbf800000))
 >;
 
 /* int_SI_vs_load_input */
@@ -1182,7 +1143,7 @@ def : Pat<
                         VReg_32:$buf_idx_vgpr),
   (BUFFER_LOAD_FORMAT_XYZW imm:$attr_offset, 0, 1, 0, 0, 0,
                            VReg_32:$buf_idx_vgpr, SReg_128:$tlst,
-                           0, 0, (i32 SREG_LIT_0))
+                           0, 0, 0)
 >;
 
 /* int_SI_export */
@@ -1319,6 +1280,38 @@ def : Pat <
   (COPY_TO_REGCLASS SReg_64:$vcc, VCCReg)
 >;
 
+/********** ================== **********/
+/********** Immediate Patterns **********/
+/********** ================== **********/
+
+def : Pat <
+  (i32 imm:$imm),
+  (V_MOV_B32_e32 imm:$imm)
+>;
+
+def : Pat <
+  (f32 fpimm:$imm),
+  (V_MOV_B32_e32 fpimm:$imm)
+>;
+
+def : Pat <
+  (i32 imm:$imm),
+  (S_MOV_B32 imm:$imm)
+>;
+
+def : Pat <
+  (f32 fpimm:$imm),
+  (S_MOV_B32 fpimm:$imm)
+>;
+
+// i64 immediates aren't supported in hardware, split it into two 32bit values
+def : Pat <
+  (i64 imm:$imm),
+  (INSERT_SUBREG (INSERT_SUBREG (i64 (IMPLICIT_DEF)),
+    (S_MOV_B32 (i32 (LO32 imm:$imm))), sub0),
+    (S_MOV_B32 (i32 (HI32 imm:$imm))), sub1)
+>;
+
 /********** ===================== **********/
 /********** Interpolation Paterns **********/
 /********** ===================== **********/
@@ -1397,12 +1390,12 @@ def : Pat<
 
 def : Pat <
   (fcos VSrc_32:$src0),
-  (V_COS_F32_e32 (V_MUL_F32_e32 VSrc_32:$src0, (V_MOV_IMM_I32 CONST.TWO_PI_INV)))
+  (V_COS_F32_e32 (V_MUL_F32_e32 VSrc_32:$src0, (V_MOV_B32_e32 CONST.TWO_PI_INV)))
 >;
 
 def : Pat <
   (fsin VSrc_32:$src0),
-  (V_SIN_F32_e32 (V_MUL_F32_e32 VSrc_32:$src0, (V_MOV_IMM_I32 CONST.TWO_PI_INV)))
+  (V_SIN_F32_e32 (V_MUL_F32_e32 VSrc_32:$src0, (V_MOV_B32_e32 CONST.TWO_PI_INV)))
 >;
 
 def : Pat <
@@ -1448,7 +1441,7 @@ multiclass SMRD_Pattern <SMRD Instr_IMM, SMRD Instr_SGPR, ValueType vt> {
   // 2. Offset loaded in an 32bit SGPR
   def : Pat <
     (constant_load (SIadd64bit32bit SReg_64:$sbase, imm:$offset)),
-    (vt (Instr_SGPR SReg_64:$sbase, (S_MOV_IMM_I32 imm:$offset)))
+    (vt (Instr_SGPR SReg_64:$sbase, (S_MOV_B32 imm:$offset)))
   >;
 
   // 3. No offset at all
diff --git a/lib/Target/R600/SILowerControlFlow.cpp b/lib/Target/R600/SILowerControlFlow.cpp
index 1b0dbcc45f..b215aa22db 100644
--- a/lib/Target/R600/SILowerControlFlow.cpp
+++ b/lib/Target/R600/SILowerControlFlow.cpp
@@ -158,10 +158,10 @@ void SILowerControlFlowPass::SkipIfDead(MachineInstr &MI) {
           .addImm(0)
           .addImm(1)
           .addImm(1)
-          .addReg(AMDGPU::SREG_LIT_0)
-          .addReg(AMDGPU::SREG_LIT_0)
-          .addReg(AMDGPU::SREG_LIT_0)
-          .addReg(AMDGPU::SREG_LIT_0);
+          .addReg(AMDGPU::VGPR0)
+          .addReg(AMDGPU::VGPR0)
+          .addReg(AMDGPU::VGPR0)
+          .addReg(AMDGPU::VGPR0);
 
   // ... and terminate wavefront
   BuildMI(MBB, Insert, DL, TII->get(AMDGPU::S_ENDPGM));
@@ -296,7 +296,7 @@ void SILowerControlFlowPass::Kill(MachineInstr &MI) {
 
   // Clear this pixel from the exec mask if the operand is negative
   BuildMI(MBB, &MI, DL, TII->get(AMDGPU::V_CMPX_LE_F32_e32), AMDGPU::VCC)
-          .addReg(AMDGPU::SREG_LIT_0)
+          .addImm(0)
           .addOperand(MI.getOperand(0));
 
   MI.eraseFromParent();
diff --git a/lib/Target/R600/SILowerLiteralConstants.cpp b/lib/Target/R600/SILowerLiteralConstants.cpp
deleted file mode 100644
index 6f5fd36396..0000000000
--- a/lib/Target/R600/SILowerLiteralConstants.cpp
+++ /dev/null
@@ -1,107 +0,0 @@
-//===-- SILowerLiteralConstants.cpp - Lower intrs using literal constants--===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-/// \file
-/// \brief This pass performs the following transformation on instructions with
-/// literal constants:
-///
-/// %VGPR0 = V_MOV_IMM_I32 1
-///
-/// becomes:
-///
-/// BUNDLE
-///   * %VGPR = V_MOV_B32_32 SI_LITERAL_CONSTANT
-///   * SI_LOAD_LITERAL 1
-///
-/// The resulting sequence matches exactly how the hardware handles immediate
-/// operands, so this transformation greatly simplifies the code generator.
-///
-/// Only the *_MOV_IMM_* support immediate operands at the moment, but when
-/// support for immediate operands is added to other instructions, they
-/// will be lowered here as well.
-//===----------------------------------------------------------------------===//
-
-#include "AMDGPU.h"
-#include "llvm/CodeGen/MachineFunction.h"
-#include "llvm/CodeGen/MachineFunctionPass.h"
-#include "llvm/CodeGen/MachineInstrBuilder.h"
-#include "llvm/CodeGen/MachineInstrBundle.h"
-
-using namespace llvm;
-
-namespace {
-
-class SILowerLiteralConstantsPass : public MachineFunctionPass {
-
-private:
-  static char ID;
-  const TargetInstrInfo *TII;
-
-public:
-  SILowerLiteralConstantsPass(TargetMachine &tm) :
-    MachineFunctionPass(ID), TII(tm.getInstrInfo()) { }
-
-  virtual bool runOnMachineFunction(MachineFunction &MF);
-
-  const char *getPassName() const {
-    return "SI Lower literal constants pass";
-  }
-};
-
-} // End anonymous namespace
-
-char SILowerLiteralConstantsPass::ID = 0;
-
-FunctionPass *llvm::createSILowerLiteralConstantsPass(TargetMachine &tm) {
-  return new SILowerLiteralConstantsPass(tm);
-}
-
-bool SILowerLiteralConstantsPass::runOnMachineFunction(MachineFunction &MF) {
-  for (MachineFunction::iterator BB = MF.begin(), BB_E = MF.end();
-                                                  BB != BB_E; ++BB) {
-    MachineBasicBlock &MBB = *BB;
-    for (MachineBasicBlock::iterator I = MBB.begin(), Next = llvm::next(I);
-                               I != MBB.end(); I = Next) {
-      Next = llvm::next(I);
-      MachineInstr &MI = *I;
-      switch (MI.getOpcode()) {
-      default: break;
-      case AMDGPU::S_MOV_IMM_I32:
-      case AMDGPU::V_MOV_IMM_F32:
-      case AMDGPU::V_MOV_IMM_I32: {
-          unsigned MovOpcode;
-          unsigned LoadLiteralOpcode;
-          MachineOperand LiteralOp = MI.getOperand(1);
-          if (AMDGPU::VReg_32RegClass.contains(MI.getOperand(0).getReg())) {
-            MovOpcode = AMDGPU::V_MOV_B32_e32;
-          } else {
-            MovOpcode = AMDGPU::S_MOV_B32;
-          }
-          if (LiteralOp.isImm()) {
-            LoadLiteralOpcode = AMDGPU::SI_LOAD_LITERAL_I32;
-          } else {
-            LoadLiteralOpcode = AMDGPU::SI_LOAD_LITERAL_F32;
-          }
-          MIBundleBuilder Bundle(MBB, I);
-          Bundle
-            .append(BuildMI(MF, MBB.findDebugLoc(I), TII->get(MovOpcode),
-                            MI.getOperand(0).getReg())
-                    .addReg(AMDGPU::SI_LITERAL_CONSTANT))
-            .append(BuildMI(MF, MBB.findDebugLoc(I),
-                            TII->get(LoadLiteralOpcode))
-                    .addOperand(MI.getOperand(1)));
-          llvm::finalizeBundle(MBB, Bundle.begin());
-          MI.eraseFromParent();
-          break;
-        }
-      }
-    }
-  }
-  return false;
-}
diff --git a/lib/Target/R600/SIRegisterInfo.td b/lib/Target/R600/SIRegisterInfo.td
index 150c92ee55..7f1fec086d 100644
--- a/lib/Target/R600/SIRegisterInfo.td
+++ b/lib/Target/R600/SIRegisterInfo.td
@@ -22,8 +22,6 @@ def EXEC_LO : SIReg <"EXEC LO", 126>;
 def EXEC_HI : SIReg <"EXEC HI", 127>;
 def EXEC : SI_64<"EXEC", [EXEC_LO, EXEC_HI], 126>;
 def SCC : SIReg<"SCC", 253>;
-def SREG_LIT_0 : SIReg <"S LIT 0", 128>;
-def SI_LITERAL_CONSTANT : SIReg<"LITERAL CONSTANT", 255>;
 def M0 : SIReg <"M0", 124>;
 
 //Interpolation registers
@@ -136,7 +134,7 @@ def VGPR_512 : RegisterTuples<[sub0, sub1, sub2, sub3, sub4, sub5, sub6, sub7,
 
 // Register class for all scalar registers (SGPRs + Special Registers)
 def SReg_32 : RegisterClass<"AMDGPU", [f32, i32], 32,
-    (add SGPR_32,  SREG_LIT_0, M0, EXEC_LO, EXEC_HI)
+    (add SGPR_32, M0, EXEC_LO, EXEC_HI)
 >;
 
 def SReg_64 : RegisterClass<"AMDGPU", [i64], 64, (add SGPR_64, VCC, EXEC)>;