[PowerPC][Future] Add pld and pstd to future CPU

Add the prefixed instructions pld and pstd to future CPU. These are load and
store instructions that require new operand types that are 34 bits. This patch
adds the two instructions as well as the operand types required.

Note that this patch also makes a minor change to tablegen to account for the
fact that some instructions are going to require shifts greater than 31 bits
for the new 34 bit instructions.

Differential Revision: https://reviews.llvm.org/D72574

1 files changed, 29 insertions, 0 deletions

diff --git a/llvm/lib/Target/PowerPC/Disassembler/PPCDisassembler.cpp b/llvm/lib/Target/PowerPC/Disassembler/PPCDisassembler.cpp
index 872fe4b..49c2790 100644
--- a/llvm/lib/Target/PowerPC/Disassembler/PPCDisassembler.cpp
+++ b/llvm/lib/Target/PowerPC/Disassembler/PPCDisassembler.cpp
@@ -270,6 +270,35 @@ static DecodeStatus decodeMemRIX16Operands(MCInst &Inst, uint64_t Imm,
   return MCDisassembler::Success;
 }
 
+static DecodeStatus decodeMemRI34PCRelOperands(MCInst &Inst, uint64_t Imm,
+                                               int64_t Address,
+                                               const void *Decoder) {
+  // Decode the memri34_pcrel field (imm, reg), which has the low 34-bits as the
+  // displacement, and the next 5 bits as an immediate 0.
+  uint64_t Base = Imm >> 34;
+  uint64_t Disp = Imm & 0x3FFFFFFFFUL;
+
+  assert(Base < 32 && "Invalid base register");
+
+  Inst.addOperand(MCOperand::createImm(SignExtend64<34>(Disp)));
+  return decodeImmZeroOperand(Inst, Base, Address, Decoder);
+}
+
+static DecodeStatus decodeMemRI34Operands(MCInst &Inst, uint64_t Imm,
+                                          int64_t Address,
+                                          const void *Decoder) {
+  // Decode the memri34 field (imm, reg), which has the low 34-bits as the
+  // displacement, and the next 5 bits as the register #.
+  uint64_t Base = Imm >> 34;
+  uint64_t Disp = Imm & 0x3FFFFFFFFUL;
+
+  assert(Base < 32 && "Invalid base register");
+
+  Inst.addOperand(MCOperand::createImm(SignExtend64<34>(Disp)));
+  Inst.addOperand(MCOperand::createReg(RRegsNoR0[Base]));
+  return MCDisassembler::Success;
+}
+
 static DecodeStatus decodeSPE8Operands(MCInst &Inst, uint64_t Imm,
                                          int64_t Address, const void *Decoder) {
   // Decode the spe8disp field (imm, reg), which has the low 5-bits as the