[RISCV] Support assembling TLS LA pseudo instructions

This patch adds the pseudo instructions la.tls.ie and la.tls.gd, used in
the initial-exec and global-dynamic TLS models respectively when
addressing a global. The pseudo instructions are expanded in the
assembly parser.

llvm-svn: 361499

2 files changed, 53 insertions, 0 deletions

diff --git a/llvm/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp b/llvm/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp
index a1d0854e202..bac43187ca7 100644
--- a/llvm/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp
+++ b/llvm/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp
@@ -93,6 +93,14 @@ class RISCVAsmParser : public MCTargetAsmParser {
   // Helper to emit pseudo instruction "la" used in GOT/PC-rel addressing.
   void emitLoadAddress(MCInst &Inst, SMLoc IDLoc, MCStreamer &Out);
 
+  // Helper to emit pseudo instruction "la.tls.ie" used in initial-exec TLS
+  // addressing.
+  void emitLoadTLSIEAddress(MCInst &Inst, SMLoc IDLoc, MCStreamer &Out);
+
+  // Helper to emit pseudo instruction "la.tls.gd" used in global-dynamic TLS
+  // addressing.
+  void emitLoadTLSGDAddress(MCInst &Inst, SMLoc IDLoc, MCStreamer &Out);
+
   // Helper to emit pseudo load/store instruction with a symbol.
   void emitLoadStoreSymbol(MCInst &Inst, unsigned Opcode, SMLoc IDLoc,
                            MCStreamer &Out, bool HasTmpReg);
@@ -1590,6 +1598,35 @@ void RISCVAsmParser::emitLoadAddress(MCInst &Inst, SMLoc IDLoc,
   emitAuipcInstPair(DestReg, DestReg, Symbol, VKHi, SecondOpcode, IDLoc, Out);
 }
 
+void RISCVAsmParser::emitLoadTLSIEAddress(MCInst &Inst, SMLoc IDLoc,
+                                          MCStreamer &Out) {
+  // The load TLS IE address pseudo-instruction "la.tls.ie" is used in
+  // initial-exec TLS model addressing of global symbols:
+  //   la.tls.ie rdest, symbol
+  // expands to
+  //   TmpLabel: AUIPC rdest, %tls_ie_pcrel_hi(symbol)
+  //             Lx rdest, %pcrel_lo(TmpLabel)(rdest)
+  MCOperand DestReg = Inst.getOperand(0);
+  const MCExpr *Symbol = Inst.getOperand(1).getExpr();
+  unsigned SecondOpcode = isRV64() ? RISCV::LD : RISCV::LW;
+  emitAuipcInstPair(DestReg, DestReg, Symbol, RISCVMCExpr::VK_RISCV_TLS_GOT_HI,
+                    SecondOpcode, IDLoc, Out);
+}
+
+void RISCVAsmParser::emitLoadTLSGDAddress(MCInst &Inst, SMLoc IDLoc,
+                                          MCStreamer &Out) {
+  // The load TLS GD address pseudo-instruction "la.tls.gd" is used in
+  // global-dynamic TLS model addressing of global symbols:
+  //   la.tls.gd rdest, symbol
+  // expands to
+  //   TmpLabel: AUIPC rdest, %tls_gd_pcrel_hi(symbol)
+  //             ADDI rdest, rdest, %pcrel_lo(TmpLabel)
+  MCOperand DestReg = Inst.getOperand(0);
+  const MCExpr *Symbol = Inst.getOperand(1).getExpr();
+  emitAuipcInstPair(DestReg, DestReg, Symbol, RISCVMCExpr::VK_RISCV_TLS_GD_HI,
+                    RISCV::ADDI, IDLoc, Out);
+}
+
 void RISCVAsmParser::emitLoadStoreSymbol(MCInst &Inst, unsigned Opcode,
                                          SMLoc IDLoc, MCStreamer &Out,
                                          bool HasTmpReg) {
@@ -1657,6 +1694,12 @@ bool RISCVAsmParser::processInstruction(MCInst &Inst, SMLoc IDLoc,
   case RISCV::PseudoLA:
     emitLoadAddress(Inst, IDLoc, Out);
     return false;
+  case RISCV::PseudoLA_TLS_IE:
+    emitLoadTLSIEAddress(Inst, IDLoc, Out);
+    return false;
+  case RISCV::PseudoLA_TLS_GD:
+    emitLoadTLSGDAddress(Inst, IDLoc, Out);
+    return false;
   case RISCV::PseudoLB:
     emitLoadStoreSymbol(Inst, RISCV::LB, IDLoc, Out, /*HasTmpReg=*/false);
     return false;
diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfo.td b/llvm/lib/Target/RISCV/RISCVInstrInfo.td
index 99002386281..d7bcc21f3b4 100644
--- a/llvm/lib/Target/RISCV/RISCVInstrInfo.td
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfo.td
@@ -926,6 +926,16 @@ let hasSideEffects = 0, mayLoad = 1, mayStore = 0, isCodeGenOnly = 0,
 def PseudoLA : Pseudo<(outs GPR:$dst), (ins bare_symbol:$src), [],
                       "la", "$dst, $src">;
 
+let hasSideEffects = 0, mayLoad = 1, mayStore = 0, isCodeGenOnly = 0,
+    isAsmParserOnly = 1 in
+def PseudoLA_TLS_IE : Pseudo<(outs GPR:$dst), (ins bare_symbol:$src), [],
+                             "la.tls.ie", "$dst, $src">;
+
+let hasSideEffects = 0, mayLoad = 1, mayStore = 0, isCodeGenOnly = 0,
+    isAsmParserOnly = 1 in
+def PseudoLA_TLS_GD : Pseudo<(outs GPR:$dst), (ins bare_symbol:$src), [],
+                             "la.tls.gd", "$dst, $src">;
+
 /// Loads
 
 multiclass LdPat<PatFrag LoadOp, RVInst Inst> {