[RISCV] Add Support of RISCV Zibimm Experimental Extension

BoyaoWang430 · BoyaoWang430 · commit fa402abe0736 · 2025-02-17T18:51:11.000+08:00
diff --git a/clang/test/Driver/print-supported-extensions-riscv.c b/clang/test/Driver/print-supported-extensions-riscv.c
@@ -183,6 +183,7 @@
 // CHECK-EMPTY:
 // CHECK-NEXT: Experimental extensions
 // CHECK-NEXT:     p                    0.14      'P' ('Base P' (Packed SIMD))
+// CHECK-NEXT:     zibimm               0.1       'Zibimm' (Branch with Immediate)
 // CHECK-NEXT:     zicfilp              1.0       'Zicfilp' (Landing pad)
 // CHECK-NEXT:     zicfiss              1.0       'Zicfiss' (Shadow stack)
 // CHECK-NEXT:     zalasr               0.1       'Zalasr' (Load-Acquire and Store-Release Instructions)
diff --git a/clang/test/Preprocessor/riscv-target-features.c b/clang/test/Preprocessor/riscv-target-features.c
@@ -118,6 +118,7 @@
 // CHECK-NOT: __riscv_zfinx {{.*$}}
 // CHECK-NOT: __riscv_zhinx {{.*$}}
 // CHECK-NOT: __riscv_zhinxmin {{.*$}}
+// CHECK-NOT: __riscv_zibimm {{.*$}}
 // CHECK-NOT: __riscv_zic64b {{.*$}}
 // CHECK-NOT: __riscv_zicbom {{.*$}}
 // CHECK-NOT: __riscv_zicbop {{.*$}}
@@ -998,6 +999,14 @@
 // RUN:   -o - | FileCheck --check-prefix=CHECK-ZHINXMIN-EXT %s
 // CHECK-ZHINXMIN-EXT: __riscv_zhinxmin 1000000{{$}}
 
+// RUN: %clang --target=riscv32 -menable-experimental-extensions \
+// RUN:   -march=rv32i_zibimm0p1 -E -dM %s \
+// RUN:   -o - | FileCheck --check-prefix=CHECK-ZIBIMM-EXT %s
+// RUN: %clang --target=riscv64 -menable-experimental-extensions \
+// RUN:   -march=rv64i_zibimm0p1 -E -dM %s \
+// RUN:   -o - | FileCheck --check-prefix=CHECK-ZIBIMM-EXT %s
+// CHECK-ZIBIMM-EXT: __riscv_zibimm
+
 // RUN: %clang --target=riscv32-unknown-linux-gnu \
 // RUN:   -march=rv32izic64b -E -dM %s \
 // RUN:   -o - | FileCheck --check-prefix=CHECK-ZIC64B-EXT %s
diff --git a/llvm/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp b/llvm/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp
@@ -735,6 +735,17 @@ struct RISCVOperand final : public MCParsedAsmOperand {
            VK == RISCVMCExpr::VK_RISCV_None;
   }
 
+  bool isUImm5Zibimm() const {
+    if (!isImm())
+      return false;
+    int64_t Imm;
+    RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
+    bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
+    Imm = fixImmediateForRV32(Imm, isRV64Imm());
+    return IsConstantImm && ((isUInt<5>(Imm) && Imm != 0) || Imm == -1) &&
+           VK == RISCVMCExpr::VK_RISCV_None;
+  }
+
   bool isUImm5GT3() const {
     if (!isImm())
       return false;
@@ -1550,6 +1561,10 @@ bool RISCVAsmParser::matchAndEmitInstruction(SMLoc IDLoc, unsigned &Opcode,
     return generateImmOutOfRangeError(Operands, ErrorInfo, 0, (1 << 5) - 1);
   case Match_InvalidUImm5NonZero:
     return generateImmOutOfRangeError(Operands, ErrorInfo, 1, (1 << 5) - 1);
+  case Match_InvalidUImm5Zibimm:
+    return generateImmOutOfRangeError(
+        Operands, ErrorInfo, -1, (1 << 5) - 1,
+        "immediate must be non-zero in the range");
   case Match_InvalidUImm5GT3:
     return generateImmOutOfRangeError(Operands, ErrorInfo, 4, (1 << 5) - 1);
   case Match_InvalidUImm6:
diff --git a/llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp b/llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp
@@ -350,6 +350,18 @@ static DecodeStatus decodeUImmNonZeroOperand(MCInst &Inst, uint32_t Imm,
   return decodeUImmOperand<N>(Inst, Imm, Address, Decoder);
 }
 
+template <unsigned N>
+static DecodeStatus decodeUImmZibimmOperand(MCInst &Inst, uint32_t Imm,
+                                            int64_t Address,
+                                            const MCDisassembler *Decoder) {
+  assert(isUInt<N>(Imm) && "Invalid immediate");
+  if (Imm)
+    Inst.addOperand(MCOperand::createImm(Imm));
+  else
+    Inst.addOperand(MCOperand::createImm(-1));
+  return MCDisassembler::Success;
+}
+
 static DecodeStatus
 decodeUImmLog2XLenNonZeroOperand(MCInst &Inst, uint32_t Imm, int64_t Address,
                                  const MCDisassembler *Decoder) {
diff --git a/llvm/lib/Target/RISCV/GISel/RISCVInstructionSelector.cpp b/llvm/lib/Target/RISCV/GISel/RISCVInstructionSelector.cpp
@@ -789,7 +789,7 @@ bool RISCVInstructionSelector::select(MachineInstr &MI) {
     RISCVCC::CondCode CC;
     getOperandsForBranch(MI.getOperand(0).getReg(), CC, LHS, RHS, *MRI);
 
-    auto Bcc = MIB.buildInstr(RISCVCC::getBrCond(CC), {}, {LHS, RHS})
+    auto Bcc = MIB.buildInstr(RISCVCC::getBrCond(STI, CC), {}, {LHS, RHS})
                    .addMBB(MI.getOperand(1).getMBB());
     MI.eraseFromParent();
     return constrainSelectedInstRegOperands(*Bcc, TII, TRI, RBI);
diff --git a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVBaseInfo.h b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVBaseInfo.h
@@ -302,6 +302,7 @@ enum OperandType : unsigned {
   OPERAND_UIMM4,
   OPERAND_UIMM5,
   OPERAND_UIMM5_NONZERO,
+  OPERAND_UIMM5_ZIBIMM,
   OPERAND_UIMM5_GT3,
   OPERAND_UIMM5_LSB0,
   OPERAND_UIMM6,
diff --git a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVMCCodeEmitter.cpp b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVMCCodeEmitter.cpp
@@ -84,6 +84,10 @@ class RISCVMCCodeEmitter : public MCCodeEmitter {
                              SmallVectorImpl<MCFixup> &Fixups,
                              const MCSubtargetInfo &STI) const;
 
+  uint64_t getImmOpValueZibimm(const MCInst &MI, unsigned OpNo,
+                               SmallVectorImpl<MCFixup> &Fixups,
+                               const MCSubtargetInfo &STI) const;
+
   uint64_t getImmOpValue(const MCInst &MI, unsigned OpNo,
                          SmallVectorImpl<MCFixup> &Fixups,
                          const MCSubtargetInfo &STI) const;
@@ -400,6 +404,22 @@ RISCVMCCodeEmitter::getImmOpValueAsr1(const MCInst &MI, unsigned OpNo,
   return getImmOpValue(MI, OpNo, Fixups, STI);
 }
 
+uint64_t
+RISCVMCCodeEmitter::getImmOpValueZibimm(const MCInst &MI, unsigned OpNo,
+                                        SmallVectorImpl<MCFixup> &Fixups,
+                                        const MCSubtargetInfo &STI) const {
+  const MCOperand &MO = MI.getOperand(OpNo);
+
+  if (MO.isImm()) {
+    uint64_t Res = MO.getImm();
+    if (Res >= 1 && Res <= 31)
+      return Res;
+    if (Res == (uint64_t)-1)
+      return 0;
+  }
+  return getImmOpValue(MI, OpNo, Fixups, STI);
+}
+
 uint64_t RISCVMCCodeEmitter::getImmOpValue(const MCInst &MI, unsigned OpNo,
                                            SmallVectorImpl<MCFixup> &Fixups,
                                            const MCSubtargetInfo &STI) const {
diff --git a/llvm/lib/Target/RISCV/RISCVFeatures.td b/llvm/lib/Target/RISCV/RISCVFeatures.td
@@ -77,6 +77,12 @@ def FeatureStdExtI
 def FeatureStdExtE
     : RISCVExtension<2, 0, "Embedded Instruction Set with 16 GPRs">;
 
+def FeatureStdExtZibimm
+    : RISCVExperimentalExtension<0, 1, "'Zibimm' (Branch with Immediate)">;
+def HasStdExtZibimm : Predicate<"Subtarget->hasStdExtZibimm()">,
+                      AssemblerPredicate<(all_of FeatureStdExtZibimm),
+                                         "'Zibimm' (Branch with Immediate)">;
+
 def FeatureStdExtZic64b
     : RISCVExtension<1, 0, "Cache Block Size Is 64 Bytes">;
 
diff --git a/llvm/lib/Target/RISCV/RISCVInstrFormats.td b/llvm/lib/Target/RISCV/RISCVInstrFormats.td
@@ -489,6 +489,22 @@ class RVInstB<bits<3> funct3, RISCVOpcode opcode, dag outs, dag ins,
   let Inst{6-0} = opcode.Value;
 }
 
+class RVInstBIMM<bits<3> funct3, RISCVOpcode opcode, dag outs, dag ins,
+                 string opcodestr, string argstr>
+    : RVInst<outs, ins, opcodestr, argstr, [], InstFormatB> {
+  bits<12> imm12;
+  bits<5> cimm;
+  bits<5> rs1;
+  let Inst{31} = imm12{11};
+  let Inst{30-25} = imm12{9-4};
+  let Inst{24-20} = cimm;
+  let Inst{19-15} = rs1;
+  let Inst{14-12} = funct3;
+  let Inst{11-8} = imm12{3-0};
+  let Inst{7} = imm12{10};
+  let Inst{6-0} = opcode.Value;
+}
+
 class RVInstU<RISCVOpcode opcode, dag outs, dag ins, string opcodestr,
               string argstr>
     : RVInst<outs, ins, opcodestr, argstr, [], InstFormatU> {
diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp b/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
@@ -923,6 +923,10 @@ static RISCVCC::CondCode getCondFromBranchOpc(unsigned Opc) {
     return RISCVCC::COND_EQ;
   case RISCV::CV_BNEIMM:
     return RISCVCC::COND_NE;
+  case RISCV::BEQI:
+    return RISCVCC::COND_EQ;
+  case RISCV::BNEI:
+    return RISCVCC::COND_NE;
   case RISCV::BEQ:
     return RISCVCC::COND_EQ;
   case RISCV::BNE:
@@ -953,14 +957,21 @@ static void parseCondBranch(MachineInstr &LastInst, MachineBasicBlock *&Target,
   Cond.push_back(LastInst.getOperand(1));
 }
 
-unsigned RISCVCC::getBrCond(RISCVCC::CondCode CC, bool Imm) {
+unsigned RISCVCC::getBrCond(const RISCVSubtarget &STI, RISCVCC::CondCode CC,
+                            bool Imm) {
   switch (CC) {
   default:
     llvm_unreachable("Unknown condition code!");
   case RISCVCC::COND_EQ:
-    return Imm ? RISCV::CV_BEQIMM : RISCV::BEQ;
+    return Imm ? (STI.hasStdExtZibimm()
+                      ? RISCV::BEQI
+                      : (STI.hasVendorXCVbi() ? RISCV::CV_BEQIMM : RISCV::BEQ))
+               : RISCV::BEQ;
   case RISCVCC::COND_NE:
-    return Imm ? RISCV::CV_BNEIMM : RISCV::BNE;
+    return Imm ? (STI.hasStdExtZibimm()
+                      ? RISCV::BNEI
+                      : (STI.hasVendorXCVbi() ? RISCV::CV_BNEIMM : RISCV::BNE))
+               : RISCV::BNE;
   case RISCVCC::COND_LT:
     return RISCV::BLT;
   case RISCVCC::COND_GE:
@@ -974,7 +985,7 @@ unsigned RISCVCC::getBrCond(RISCVCC::CondCode CC, bool Imm) {
 
 const MCInstrDesc &RISCVInstrInfo::getBrCond(RISCVCC::CondCode CC,
                                              bool Imm) const {
-  return get(RISCVCC::getBrCond(CC, Imm));
+  return get(RISCVCC::getBrCond(STI, CC, Imm));
 }
 
 RISCVCC::CondCode RISCVCC::getOppositeBranchCondition(RISCVCC::CondCode CC) {
@@ -1350,6 +1361,8 @@ bool RISCVInstrInfo::isBranchOffsetInRange(unsigned BranchOp,
   case RISCV::BGE:
   case RISCV::BLTU:
   case RISCV::BGEU:
+  case RISCV::BEQI:
+  case RISCV::BNEI:
   case RISCV::CV_BEQIMM:
   case RISCV::CV_BNEIMM:
     return isIntN(13, BrOffset);
@@ -2490,6 +2503,9 @@ bool RISCVInstrInfo::verifyInstruction(const MachineInstr &MI,
         case RISCVOp::OPERAND_UIMM2_LSB0:
           Ok = isShiftedUInt<1, 1>(Imm);
           break;
+        case RISCVOp::OPERAND_UIMM5_ZIBIMM:
+          Ok = (isUInt<5>(Imm) && Imm != 0) || Imm == -1;
+          break;
         case RISCVOp::OPERAND_UIMM5_LSB0:
           Ok = isShiftedUInt<4, 1>(Imm);
           break;
diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfo.h b/llvm/lib/Target/RISCV/RISCVInstrInfo.h
@@ -45,7 +45,7 @@ enum CondCode {
 };
 
 CondCode getOppositeBranchCondition(CondCode);
-unsigned getBrCond(CondCode CC, bool Imm = false);
+unsigned getBrCond(const RISCVSubtarget &STI, CondCode CC, bool Imm = false);
 
 } // end of namespace RISCVCC
 
diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfo.td b/llvm/lib/Target/RISCV/RISCVInstrInfo.td
@@ -2135,6 +2135,7 @@ include "RISCVInstrInfoZimop.td"
 include "RISCVInstrInfoZicbo.td"
 include "RISCVInstrInfoZicond.td"
 include "RISCVInstrInfoZicfiss.td"
+include "RISCVInstrInfoZibimm.td"
 
 //===----------------------------------------------------------------------===//
 // Vendor extensions
diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfoZibimm.td b/llvm/lib/Target/RISCV/RISCVInstrInfoZibimm.td
@@ -0,0 +1,48 @@
+//===-- RISCVInstrInfoZvabd.td - 'Zvabd' instructions ------*- tablegen -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+/// This file describes the RISC-V instructions for 'Zibimm' (branch with imm).
+///
+//===----------------------------------------------------------------------===//
+// A 5-bit unsigned immediate representing 1-31 and -1. 00000 represents -1.
+def uimm5_zibimm : RISCVOp, ImmLeaf<XLenVT, [{
+    return (Imm != 0 && isUInt<5>(Imm)) || Imm == -1;
+}]> {
+  let ParserMatchClass = UImmAsmOperand<5, "Zibimm">;
+  let EncoderMethod = "getImmOpValueZibimm";
+  let DecoderMethod = "decodeUImmZibimmOperand<5>";
+  let MCOperandPredicate = [{
+    int64_t Imm;
+    if (!MCOp.evaluateAsConstantImm(Imm))
+      return false;
+    return (Imm >= 1 && Imm <= 31) || Imm == -1;
+  }];
+  let OperandType = "OPERAND_UIMM5_ZIBIMM";
+}
+let hasSideEffects = 0, mayLoad = 0, mayStore = 0 in
+class Branch_imm<bits<3> funct3, string opcodestr>
+    : RVInstBIMM<funct3, OPC_BRANCH, (outs),
+              (ins GPR:$rs1, uimm5_zibimm:$cimm, simm13_lsb0:$imm12),
+              opcodestr, "$rs1, $cimm, $imm12">,
+      Sched<[WriteJmp, ReadJmp]> {
+  let isBranch = 1;
+  let isTerminator = 1;
+}
+let Predicates = [HasStdExtZibimm] in {
+def BEQI  : Branch_imm<0b010, "beqi">;
+def BNEI  : Branch_imm<0b011, "bnei">;
+} // Predicates = [HasStdExtZibimm]
+
+let Predicates = [HasStdExtZibimm] in {
+multiclass BccImmPat<CondCode Cond, Branch_imm Inst> {
+  def : Pat<(riscv_brcc (XLenVT GPR:$rs1), uimm5_zibimm:$cimm, Cond, bb:$imm12),
+            (Inst GPR:$rs1, uimm5_zibimm:$cimm, simm13_lsb0:$imm12)>;
+}
+defm : BccImmPat<SETEQ, BEQI>;
+defm : BccImmPat<SETNE, BNEI>;
+}// Predicates = [HasStdExtZibimm]
diff --git a/llvm/test/CodeGen/RISCV/attributes.ll b/llvm/test/CodeGen/RISCV/attributes.ll
@@ -151,6 +151,7 @@
 ; RUN: llc -mtriple=riscv32 -mattr=+supm %s -o - | FileCheck --check-prefix=RV32SUPM %s
 ; RUN: llc -mtriple=riscv32 -mattr=+experimental-smctr  %s -o - | FileCheck --check-prefix=RV32SMCTR %s
 ; RUN: llc -mtriple=riscv32 -mattr=+experimental-ssctr  %s -o - | FileCheck --check-prefix=RV32SSCTR %s
+; RUN: llc -mtriple=riscv32 -mattr=+experimental-zibimm %s -o - | FileCheck --check-prefix=RV32ZIBIMM %s
 
 ; RUN: llc -mtriple=riscv64 %s -o - | FileCheck %s
 ; RUN: llc -mtriple=riscv64 -mattr=+m %s -o - | FileCheck --check-prefixes=CHECK,RV64M %s
@@ -301,6 +302,7 @@
 ; RUN: llc -mtriple=riscv64 -mattr=+experimental-ssctr  %s -o - | FileCheck --check-prefix=RV64SSCTR %s
 ; RUN: llc -mtriple=riscv64 -mattr=+experimental-sdext  %s -o - | FileCheck --check-prefix=RV64SDEXT %s
 ; RUN: llc -mtriple=riscv64 -mattr=+experimental-sdtrig  %s -o - | FileCheck --check-prefix=RV64SDTRIG %s
+; RUN: llc -mtriple=riscv64 -mattr=+experimental-zibimm %s -o - | FileCheck --check-prefix=RV64ZIBIMM %s
 
 ; Tests for profile features.
 ; RUN: llc -mtriple=riscv32 -mattr=+rvi20u32 %s -o - | FileCheck --check-prefix=RVI20U32 %s
@@ -467,6 +469,7 @@
 ; RV32SUPM: .attribute 5, "rv32i2p1_supm1p0"
 ; RV32SMCTR: .attribute 5, "rv32i2p1_smctr1p0_sscsrind1p0"
 ; RV32SSCTR: .attribute 5, "rv32i2p1_sscsrind1p0_ssctr1p0"
+; RV32ZIBIMM: .attribute 5, "rv32i2p1_zibimm0p1"
 
 ; RV64M: .attribute 5, "rv64i2p1_m2p0_zmmul1p0"
 ; RV64ZMMUL: .attribute 5, "rv64i2p1_zmmul1p0"
@@ -615,6 +618,7 @@
 ; RV64SSCTR: .attribute 5, "rv64i2p1_sscsrind1p0_ssctr1p0"
 ; RV64SDEXT: .attribute 5, "rv64i2p1_sdext1p0"
 ; RV64SDTRIG: .attribute 5, "rv64i2p1_sdtrig1p0"
+; RV64ZIBIMM: .attribute 5, "rv64i2p1_zibimm0p1"
 
 ; RVI20U32: .attribute 5, "rv32i2p1"
 ; RVI20U64: .attribute 5, "rv64i2p1"
diff --git a/llvm/test/CodeGen/RISCV/zibimm.ll b/llvm/test/CodeGen/RISCV/zibimm.ll
diff --git a/llvm/test/MC/RISCV/zibimm-invalid.s b/llvm/test/MC/RISCV/zibimm-invalid.s
diff --git a/llvm/test/MC/RISCV/zibimm-valid.s b/llvm/test/MC/RISCV/zibimm-valid.s
diff --git a/llvm/unittests/TargetParser/RISCVISAInfoTest.cpp b/llvm/unittests/TargetParser/RISCVISAInfoTest.cpp
