[mips][mips64r6] Add compact branch instructions

Differential Revision: http://reviews.llvm.org/D3691


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208974 91177308-0d34-0410-b5e6-96231b3b80d8

6 files changed, 236 insertions, 10 deletions

diff --git a/lib/Target/Mips/Disassembler/MipsDisassembler.cpp b/lib/Target/Mips/Disassembler/MipsDisassembler.cpp
index 958712602b..21abe6c585 100644
--- a/lib/Target/Mips/Disassembler/MipsDisassembler.cpp
+++ b/lib/Target/Mips/Disassembler/MipsDisassembler.cpp
@@ -205,6 +205,16 @@ static DecodeStatus DecodeJumpTarget(MCInst &Inst,
                                      uint64_t Address,
                                      const void *Decoder);
 
+static DecodeStatus DecodeBranchTarget21(MCInst &Inst,
+                                         unsigned Offset,
+                                         uint64_t Address,
+                                         const void *Decoder);
+
+static DecodeStatus DecodeBranchTarget26(MCInst &Inst,
+                                         unsigned Offset,
+                                         uint64_t Address,
+                                         const void *Decoder);
+
 // DecodeBranchTargetMM - Decode microMIPS branch offset, which is
 // shifted left by 1 bit.
 static DecodeStatus DecodeBranchTargetMM(MCInst &Inst,
@@ -856,6 +866,26 @@ static DecodeStatus DecodeJumpTarget(MCInst &Inst,
   return MCDisassembler::Success;
 }
 
+static DecodeStatus DecodeBranchTarget21(MCInst &Inst,
+                                         unsigned Offset,
+                                         uint64_t Address,
+                                         const void *Decoder) {
+  int32_t BranchOffset = SignExtend32<21>(Offset) << 2;
+
+  Inst.addOperand(MCOperand::CreateImm(BranchOffset));
+  return MCDisassembler::Success;
+}
+
+static DecodeStatus DecodeBranchTarget26(MCInst &Inst,
+                                         unsigned Offset,
+                                         uint64_t Address,
+                                         const void *Decoder) {
+  int32_t BranchOffset = SignExtend32<26>(Offset) << 2;
+
+  Inst.addOperand(MCOperand::CreateImm(BranchOffset));
+  return MCDisassembler::Success;
+}
+
 static DecodeStatus DecodeBranchTargetMM(MCInst &Inst,
                                          unsigned Offset,
                                          uint64_t Address,
diff --git a/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp b/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp
index 538a0cda9b..fc516188c3 100644
--- a/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp
+++ b/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp
@@ -242,6 +242,46 @@ getBranchTargetOpValueMM(const MCInst &MI, unsigned OpNo,
   return 0;
 }
 
+/// getBranchTarget21OpValue - Return binary encoding of the branch
+/// target operand. If the machine operand requires relocation,
+/// record the relocation and return zero.
+unsigned MipsMCCodeEmitter::
+getBranchTarget21OpValue(const MCInst &MI, unsigned OpNo,
+                         SmallVectorImpl<MCFixup> &Fixups,
+                         const MCSubtargetInfo &STI) const {
+
+  const MCOperand &MO = MI.getOperand(OpNo);
+
+  // If the destination is an immediate, divide by 4.
+  if (MO.isImm()) return MO.getImm() >> 2;
+
+  assert(MO.isExpr() &&
+         "getBranchTarget21OpValue expects only expressions or immediates");
+
+  // TODO: Push 21 PC fixup.
+  return 0;
+}
+
+/// getBranchTarget26OpValue - Return binary encoding of the branch
+/// target operand. If the machine operand requires relocation,
+/// record the relocation and return zero.
+unsigned MipsMCCodeEmitter::
+getBranchTarget26OpValue(const MCInst &MI, unsigned OpNo,
+                         SmallVectorImpl<MCFixup> &Fixups,
+                         const MCSubtargetInfo &STI) const {
+
+  const MCOperand &MO = MI.getOperand(OpNo);
+
+  // If the destination is an immediate, divide by 4.
+  if (MO.isImm()) return MO.getImm() >> 2;
+
+  assert(MO.isExpr() &&
+         "getBranchTarget26OpValue expects only expressions or immediates");
+
+  // TODO: Push 26 PC fixup.
+  return 0;
+}
+
 /// getJumpTargetOpValue - Return binary encoding of the jump
 /// target operand. If the machine operand requires relocation,
 /// record the relocation and return zero.
diff --git a/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.h b/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.h
index 735b0e43bb..e99146e801 100644
--- a/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.h
+++ b/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.h
@@ -88,6 +88,20 @@ public:
                                     SmallVectorImpl<MCFixup> &Fixups,
                                     const MCSubtargetInfo &STI) const;
 
+  // getBranchTarget21OpValue - Return binary encoding of the branch
+  // offset operand. If the machine operand requires relocation,
+  // record the relocation and return zero.
+  unsigned getBranchTarget21OpValue(const MCInst &MI, unsigned OpNo,
+                                   SmallVectorImpl<MCFixup> &Fixups,
+                                   const MCSubtargetInfo &STI) const;
+
+  // getBranchTarget26OpValue - Return binary encoding of the branch
+  // offset operand. If the machine operand requires relocation,
+  // record the relocation and return zero.
+  unsigned getBranchTarget26OpValue(const MCInst &MI, unsigned OpNo,
+                                    SmallVectorImpl<MCFixup> &Fixups,
+                                    const MCSubtargetInfo &STI) const;
+
   // getMachineOpValue - Return binary encoding of operand. If the machin
   // operand requires relocation, record the relocation and return zero.
   unsigned getMachineOpValue(const MCInst &MI, const MCOperand &MO,
diff --git a/lib/Target/Mips/Mips32r6InstrFormats.td b/lib/Target/Mips/Mips32r6InstrFormats.td
index 4d49ca1812..0f78eea18c 100644
--- a/lib/Target/Mips/Mips32r6InstrFormats.td
+++ b/lib/Target/Mips/Mips32r6InstrFormats.td
@@ -191,6 +191,42 @@ class SPECIAL_3R_FM<bits<5> mulop, bits<6> funct> : MipsR6Inst {
   let Inst{5-0}   = funct;
 }
 
+class CMP_BRANCH_OFF16_FM<bits<6> funct> : MipsR6Inst {
+  bits<5> rs;
+  bits<5> rt;
+  bits<16> offset;
+
+  bits<32> Inst;
+
+  let Inst{31-26} = funct;
+  let Inst{25-21} = rs;
+  let Inst{20-16} = rt;
+  let Inst{15-0} = offset;
+}
+
+class CMP_BRANCH_RT_OFF16_FM<bits<6> funct> : CMP_BRANCH_OFF16_FM<funct> {
+  let Inst{25-21} = 0b00000;
+}
+
+class CMP_BRANCH_OFF21_FM<bits<6> funct> : MipsR6Inst {
+  bits<5> rs;
+  bits<21> offset;
+
+  bits<32> Inst;
+
+  let Inst{31-26} = funct;
+  let Inst{25-21} = rs;
+  let Inst{20-0} = offset;
+}
+
+class BRANCH_OFF26_FM<bits<6> funct> : MipsR6Inst {
+  bits<32> Inst;
+  bits<26> offset;
+
+  let Inst{31-26} = funct;
+  let Inst{25-0} = offset;
+}
+
 class SPECIAL3_ALIGN_FM<OPCODE6 Operation> : MipsR6Inst {
   bits<5> rd;
   bits<5> rs;
diff --git a/lib/Target/Mips/Mips32r6InstrInfo.td b/lib/Target/Mips/Mips32r6InstrInfo.td
index 9c57ed6c7a..f37fd30461 100644
--- a/lib/Target/Mips/Mips32r6InstrInfo.td
+++ b/lib/Target/Mips/Mips32r6InstrInfo.td
@@ -52,6 +52,20 @@ include "Mips32r6InstrFormats.td"
 // Removed: teqi, tgei, tgeiu, tlti, tltiu, tnei
 // Rencoded: [ls][wd]c2
 
+def brtarget21 : Operand<OtherVT> {
+  let EncoderMethod = "getBranchTarget21OpValue";
+  let OperandType = "OPERAND_PCREL";
+  let DecoderMethod = "DecodeBranchTarget21";
+  let ParserMatchClass = MipsJumpTargetAsmOperand;
+}
+
+def brtarget26 : Operand<OtherVT> {
+  let EncoderMethod = "getBranchTarget26OpValue";
+  let OperandType = "OPERAND_PCREL";
+  let DecoderMethod = "DecodeBranchTarget26";
+  let ParserMatchClass = MipsJumpTargetAsmOperand;
+}
+
 //===----------------------------------------------------------------------===//
 //
 // Instruction Encodings
@@ -63,6 +77,21 @@ class ALIGN_ENC  : SPECIAL3_ALIGN_FM<OPCODE6_ALIGN>;
 class ALUIPC_ENC : PCREL16_FM<OPCODE5_ALUIPC>;
 class AUI_ENC    : AUI_FM;
 class AUIPC_ENC  : PCREL16_FM<OPCODE5_AUIPC>;
+
+class BALC_ENC  : BRANCH_OFF26_FM<0b111010>;
+class BC_ENC    : BRANCH_OFF26_FM<0b110010>;
+class BEQC_ENC  : CMP_BRANCH_OFF16_FM<0b001000>;
+class BNEC_ENC  : CMP_BRANCH_OFF16_FM<0b011000>;
+
+class BLTZC_ENC : CMP_BRANCH_OFF16_FM<0b010111>;
+class BGEZC_ENC : CMP_BRANCH_OFF16_FM<0b010110>;
+
+class BLEZC_ENC : CMP_BRANCH_RT_OFF16_FM<0b010110>;
+class BGTZC_ENC : CMP_BRANCH_RT_OFF16_FM<0b010111>;
+
+class BEQZC_ENC : CMP_BRANCH_OFF21_FM<0b110110>;
+class BNEZC_ENC : CMP_BRANCH_OFF21_FM<0b111110>;
+
 class BITSWAP_ENC : SPECIAL3_2R_FM<OPCODE6_BITSWAP>;
 class DIV_ENC    : SPECIAL_3R_FM<0b00010, 0b011010>;
 class DIVU_ENC   : SPECIAL_3R_FM<0b00010, 0b011011>;
@@ -215,6 +244,66 @@ class AUI_DESC_BASE<string instr_asm, RegisterOperand GPROpnd> {
 
 class AUI_DESC : AUI_DESC_BASE<"aui", GPR32Opnd>;
 
+class BRANCH_DESC_BASE {
+  bit isBranch = 1;
+  bit isTerminator = 1;
+  bit hasDelaySlot = 0;
+}
+
+class BC_DESC_BASE<string instr_asm, DAGOperand opnd> : BRANCH_DESC_BASE {
+  dag InOperandList = (ins opnd:$offset);
+  dag OutOperandList = (outs);
+  string AsmString = !strconcat(instr_asm, "\t$offset");
+  bit isBarrier = 1;
+}
+
+class CMP_BC_DESC_BASE<string instr_asm, DAGOperand opnd,
+                       RegisterOperand GPROpnd> : BRANCH_DESC_BASE {
+  dag InOperandList = (ins GPROpnd:$rs, GPROpnd:$rt, opnd:$offset);
+  dag OutOperandList = (outs);
+  string AsmString = !strconcat(instr_asm, "\t$rs, $rt, $offset");
+  list<Register> Defs = [AT];
+}
+
+class CMP_CBR_EQNE_Z_DESC_BASE<string instr_asm, DAGOperand opnd,
+                               RegisterOperand GPROpnd> : BRANCH_DESC_BASE {
+  dag InOperandList = (ins GPROpnd:$rs, opnd:$offset);
+  dag OutOperandList = (outs);
+  string AsmString = !strconcat(instr_asm, "\t$rs, $offset");
+  list<Register> Defs = [AT];
+}
+
+class CMP_CBR_RT_Z_DESC_BASE<string instr_asm, DAGOperand opnd,
+                             RegisterOperand GPROpnd> : BRANCH_DESC_BASE {
+  dag InOperandList = (ins GPROpnd:$rs, GPROpnd:$rt, opnd:$offset);
+  dag OutOperandList = (outs);
+  string AsmString = !strconcat(instr_asm, "\t$rt, $offset");
+  list<Register> Defs = [AT];
+}
+
+class BALC_DESC : BC_DESC_BASE<"balc", brtarget26> {
+  bit isCall = 1;
+  list<Register> Defs = [RA];
+}
+
+class BC_DESC : BC_DESC_BASE<"bc", brtarget26>;
+class BEQC_DESC : CMP_BC_DESC_BASE<"beqc", brtarget, GPR32Opnd>;
+class BNEC_DESC : CMP_BC_DESC_BASE<"bnec", brtarget, GPR32Opnd>;
+
+class BLTZC_DESC : CMP_CBR_RT_Z_DESC_BASE<"bltzc", brtarget, GPR32Opnd> {
+  string Constraints = "$rs = $rt";
+}
+
+class BGEZC_DESC : CMP_CBR_RT_Z_DESC_BASE<"bgezc", brtarget, GPR32Opnd> {
+  string Constraints = "$rs = $rt";
+}
+
+class BLEZC_DESC : CMP_CBR_RT_Z_DESC_BASE<"blezc", brtarget, GPR32Opnd>;
+class BGTZC_DESC : CMP_CBR_RT_Z_DESC_BASE<"bgtzc", brtarget, GPR32Opnd>;
+
+class BEQZC_DESC : CMP_CBR_EQNE_Z_DESC_BASE<"beqzc", brtarget21, GPR32Opnd>;
+class BNEZC_DESC : CMP_CBR_EQNE_Z_DESC_BASE<"bnezc", brtarget21, GPR32Opnd>;
+
 class BITSWAP_DESC_BASE<string instr_asm, RegisterOperand GPROpnd> {
   dag OutOperandList = (outs GPROpnd:$rd);
   dag InOperandList = (ins GPROpnd:$rt);
@@ -316,31 +405,31 @@ def ALIGN : ALIGN_ENC, ALIGN_DESC, ISA_MIPS32R6;
 def ALUIPC : ALUIPC_ENC, ALUIPC_DESC, ISA_MIPS32R6;
 def AUI : AUI_ENC, AUI_DESC, ISA_MIPS32R6;
 def AUIPC : AUIPC_ENC, AUIPC_DESC, ISA_MIPS32R6;
-def BALC;
+def BALC : BALC_ENC, BALC_DESC, ISA_MIPS32R6;
 def BC1EQZ;
 def BC1NEZ;
 def BC2EQZ;
 def BC2NEZ;
-def BC;
-def BEQC;
+def BC : BC_ENC, BC_DESC, ISA_MIPS32R6;
+def BEQC : BEQC_ENC, BEQC_DESC, ISA_MIPS32R6;
 def BEQZALC;
-def BEQZC;
+def BEQZC : BEQZC_ENC, BEQZC_DESC, ISA_MIPS32R6;
 def BGEC;  // Also aliased to blec with operands swapped
 def BGEUC; // Also aliased to bleuc with operands swapped
 def BGEZALC;
-def BGEZC;
+def BGEZC : BGEZC_ENC, BGEZC_DESC, ISA_MIPS32R6;
 def BGTZALC;
-def BGTZC;
+def BGTZC : BGTZC_ENC, BGTZC_DESC, ISA_MIPS32R6;
 def BITSWAP : BITSWAP_ENC, BITSWAP_DESC, ISA_MIPS32R6;
 def BLEZALC;
-def BLEZC;
+def BLEZC : BLEZC_ENC, BLEZC_DESC, ISA_MIPS32R6;
 def BLTC; // Also aliased to bgtc with operands swapped
 def BLTUC; // Also aliased to bgtuc with operands swapped
 def BLTZALC;
-def BLTZC;
-def BNEC;
+def BLTZC : BLTZC_ENC, BLTZC_DESC, ISA_MIPS32R6;
+def BNEC : BNEC_ENC, BNEC_DESC, ISA_MIPS32R6;
 def BNEZALC;
-def BNEZC;
+def BNEZC : BNEZC_ENC, BNEZC_DESC, ISA_MIPS32R6;
 def BNVC;
 def BOVC;
 def CLASS_D : CLASS_D_ENC, CLASS_D_DESC, ISA_MIPS32R6;
diff --git a/lib/Target/Mips/MipsCodeEmitter.cpp b/lib/Target/Mips/MipsCodeEmitter.cpp
index d13a4661f3..ebbcd0cdb8 100644
--- a/lib/Target/Mips/MipsCodeEmitter.cpp
+++ b/lib/Target/Mips/MipsCodeEmitter.cpp
@@ -110,6 +110,11 @@ private:
   unsigned getBranchTargetOpValueMM(const MachineInstr &MI,
                                     unsigned OpNo) const;
 
+  unsigned getBranchTarget21OpValue(const MachineInstr &MI,
+                                    unsigned OpNo) const;
+  unsigned getBranchTarget26OpValue(const MachineInstr &MI,
+                                    unsigned OpNo) const;
+
   unsigned getBranchTargetOpValue(const MachineInstr &MI, unsigned OpNo) const;
   unsigned getMemEncoding(const MachineInstr &MI, unsigned OpNo) const;
   unsigned getMemEncodingMMImm12(const MachineInstr &MI, unsigned OpNo) const;
@@ -203,6 +208,18 @@ unsigned MipsCodeEmitter::getBranchTargetOpValueMM(const MachineInstr &MI,
   return 0;
 }
 
+unsigned MipsCodeEmitter::getBranchTarget21OpValue(const MachineInstr &MI,
+                                                   unsigned OpNo) const {
+  llvm_unreachable("Unimplemented function.");
+  return 0;
+}
+
+unsigned MipsCodeEmitter::getBranchTarget26OpValue(const MachineInstr &MI,
+                                                   unsigned OpNo) const {
+  llvm_unreachable("Unimplemented function.");
+  return 0;
+}
+
 unsigned MipsCodeEmitter::getBranchTargetOpValue(const MachineInstr &MI,
                                                  unsigned OpNo) const {
   MachineOperand MO = MI.getOperand(OpNo);