[RISC-V][Mach-O] Print immediate operands in hexadecimal format.

llvm/lib/Target/RISCV/MCTargetDesc/RISCVInstPrinter.cpp

@@ -96,7 +96,7 @@ void RISCVInstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
   }
 
   if (MO.isImm()) {
-    markup(O, Markup::Immediate) << formatImm(MO.getImm());
+    printImm(MI, OpNo, STI, O);
     return;
   }
 
@@ -337,6 +337,22 @@ void RISCVInstPrinter::printVMaskReg(const MCInst *MI, unsigned OpNo,
   O << ".t";
 }
 
+void RISCVInstPrinter::printImm(const MCInst *MI, unsigned OpNo,
+                                const MCSubtargetInfo &STI, raw_ostream &O) {
+  const MCOperand &Op = MI->getOperand(OpNo);
+  const unsigned Opcode = MI->getOpcode();
+  uint64_t Imm = Op.getImm();
+  if (STI.getTargetTriple().isOSBinFormatMachO() &&
+      (Opcode == RISCV::ANDI || Opcode == RISCV::ORI || Opcode == RISCV::XORI ||
+       Opcode == RISCV::C_ANDI || Opcode == RISCV::AUIPC ||
+       Opcode == RISCV::LUI)) {
+    if (!STI.hasFeature(RISCV::Feature64Bit))
+      Imm &= 0xffffffff;
+    markup(O, Markup::Immediate) << formatHex(Imm);
+  } else
+    markup(O, Markup::Immediate) << formatImm(Imm);
+}
+
 const char *RISCVInstPrinter::getRegisterName(MCRegister Reg) {
   // When PrintAliases is enabled, and EmitX8AsFP is enabled, x8 will be printed
   // as fp instead of s0. Note that these similar registers are not replaced:

llvm/lib/Target/RISCV/MCTargetDesc/RISCVInstPrinter.h

@@ -52,6 +52,8 @@ class RISCVInstPrinter : public MCInstPrinter {
                        const MCSubtargetInfo &STI, raw_ostream &O);
   void printVMaskReg(const MCInst *MI, unsigned OpNo,
                      const MCSubtargetInfo &STI, raw_ostream &O);
+  void printImm(const MCInst *MI, unsigned OpNo, const MCSubtargetInfo &STI,
+                raw_ostream &O);
   void printRegList(const MCInst *MI, unsigned OpNo, const MCSubtargetInfo &STI,
                     raw_ostream &O);
   void printStackAdj(const MCInst *MI, unsigned OpNo,

llvm/test/MC/RISCV/hex-imm-macho.s

@@ -0,0 +1,16 @@
+// RUN: llvm-mc -triple riscv32-apple-unknown-macho -mattr=+c --riscv-no-aliases %s | FileCheck %s
+
+// CHECK: andi a0, a0, 0x190
+// CHECK: ori a0, a0, 0x400
+// CHECK: xori a0, a0, 0xfffffff4
+andi a0, a0, 400
+ori a0, a0, 1024
+xori a0, a0, -12
+
+// CHECK: c.andi s0, 0x1f
+c.andi s0, 31
+
+// CHECK: auipc a0, 0x3e8
+// CHECK: lui a0, 0x2710
+auipc a0, 1000
+lui a0, 10000