Resubmit commit r211533

"Fix PR20056: Implement pseudo LDR <reg>, =<literal/label> for AArch64"
Missed files are added in this commit.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211605 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 95 insertions, 1 deletions

diff --git a/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp b/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
index 5d363a00dc..c4d840d90b 100644
--- a/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
+++ b/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
@@ -43,6 +43,11 @@ private:
   MCSubtargetInfo &STI;
   MCAsmParser &Parser;
 
+  AArch64TargetStreamer &getTargetStreamer() {
+    MCTargetStreamer &TS = *getParser().getStreamer().getTargetStreamer();
+    return static_cast<AArch64TargetStreamer &>(TS);
+  }
+
   MCAsmParser &getParser() const { return Parser; }
   MCAsmLexer &getLexer() const { return Parser.getLexer(); }
 
@@ -67,6 +72,7 @@ private:
   bool parseDirectiveTLSDescCall(SMLoc L);
 
   bool parseDirectiveLOH(StringRef LOH, SMLoc L);
+  bool parseDirectiveLtorg(SMLoc L);
 
   bool validateInstruction(MCInst &Inst, SmallVectorImpl<SMLoc> &Loc);
   bool MatchAndEmitInstruction(SMLoc IDLoc, unsigned &Opcode,
@@ -105,6 +111,8 @@ public:
                  const MCTargetOptions &Options)
       : MCTargetAsmParser(), STI(_STI), Parser(_Parser) {
     MCAsmParserExtension::Initialize(_Parser);
+    if (Parser.getStreamer().getTargetStreamer() == nullptr)
+      new AArch64TargetStreamer(Parser.getStreamer());
 
     // Initialize the set of available features.
     setAvailableFeatures(ComputeAvailableFeatures(STI.getFeatureBits()));
@@ -3004,6 +3012,43 @@ bool AArch64AsmParser::parseOperand(OperandVector &Operands, bool isCondCode,
     Operands.push_back(AArch64Operand::CreateImm(ImmVal, S, E, getContext()));
     return false;
   }
+  case AsmToken::Equal: {
+    SMLoc Loc = Parser.getTok().getLoc();
+    if (Mnemonic != "ldr") // only parse for ldr pseudo (e.g. ldr r0, =val)
+      return Error(Loc, "unexpected token in operand");
+    Parser.Lex(); // Eat '='
+    const MCExpr *SubExprVal;
+    if (getParser().parseExpression(SubExprVal))
+      return true;
+
+    MCContext& Ctx = getContext();
+    E = SMLoc::getFromPointer(Loc.getPointer() - 1);
+    // If the op is an imm and can be fit into a mov, then replace ldr with mov.
+    if (isa<MCConstantExpr>(SubExprVal) && Operands.size() >= 2 &&
+        static_cast<AArch64Operand &>(*Operands[1]).isReg()) {
+      bool IsXReg =  AArch64MCRegisterClasses[AArch64::GPR64allRegClassID].contains(
+            Operands[1]->getReg());
+      uint64_t Imm = (cast<MCConstantExpr>(SubExprVal))->getValue();
+      uint32_t ShiftAmt = 0, MaxShiftAmt = IsXReg ? 48 : 16;
+      while(Imm > 0xFFFF && countTrailingZeros(Imm) >= 16) {
+        ShiftAmt += 16;
+        Imm >>= 16;
+      }
+      if (ShiftAmt <= MaxShiftAmt && Imm <= 0xFFFF) {
+          Operands[0] = AArch64Operand::CreateToken("movz", false, Loc, Ctx);
+          Operands.push_back(AArch64Operand::CreateImm(
+                     MCConstantExpr::Create(Imm, Ctx), S, E, Ctx));
+        if (ShiftAmt)
+          Operands.push_back(AArch64Operand::CreateShiftExtend(AArch64_AM::LSL,
+                     ShiftAmt, true, S, E, Ctx));
+        return false;
+      }
+    }
+    // If it is a label or an imm that cannot fit in a movz, put it into CP.
+    const MCExpr *CPLoc = getTargetStreamer().addConstantPoolEntry(SubExprVal);
+    Operands.push_back(AArch64Operand::CreateImm(CPLoc, S, E, Ctx));
+    return false;
+  }
   }
 }
 
@@ -3810,7 +3855,8 @@ bool AArch64AsmParser::ParseDirective(AsmToken DirectiveID) {
     return parseDirectiveWord(8, Loc);
   if (IDVal == ".tlsdesccall")
     return parseDirectiveTLSDescCall(Loc);
-
+  if (IDVal == ".ltorg" || IDVal == ".pool")
+    return parseDirectiveLtorg(Loc);
   return parseDirectiveLOH(IDVal, Loc);
 }
 
@@ -3911,6 +3957,13 @@ bool AArch64AsmParser::parseDirectiveLOH(StringRef IDVal, SMLoc Loc) {
   return false;
 }
 
+/// parseDirectiveLtorg
+///  ::= .ltorg | .pool
+bool AArch64AsmParser::parseDirectiveLtorg(SMLoc L) {
+  getTargetStreamer().emitCurrentConstantPool();
+  return false;
+}
+
 bool
 AArch64AsmParser::classifySymbolRef(const MCExpr *Expr,
                                     AArch64MCExpr::VariantKind &ELFRefKind,
diff --git a/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp b/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp
new file mode 100644
index 0000000000..f9aeb35b64
--- /dev/null
+++ b/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp
@@ -0,0 +1,40 @@
+//===- AArch64TargetStreamer.cpp - AArch64TargetStreamer class --*- C++ -*---------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the AArch64TargetStreamer class.
+//
+//===----------------------------------------------------------------------===//
+#include "llvm/ADT/MapVector.h"
+#include "llvm/MC/ConstantPools.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCStreamer.h"
+
+using namespace llvm;
+
+//
+// AArch64TargetStreamer Implemenation
+//
+AArch64TargetStreamer::AArch64TargetStreamer(MCStreamer &S)
+    : MCTargetStreamer(S), ConstantPools(new AssemblerConstantPools()) {}
+
+AArch64TargetStreamer::~AArch64TargetStreamer() {}
+
+// The constant pool handling is shared by all AArch64TargetStreamer
+// implementations.
+const MCExpr *AArch64TargetStreamer::addConstantPoolEntry(const MCExpr *Expr) {
+  return ConstantPools->addEntry(Streamer, Expr);
+}
+
+void AArch64TargetStreamer::emitCurrentConstantPool() {
+  ConstantPools->emitForCurrentSection(Streamer);
+}
+
+// finish() - write out any non-empty assembler constant pools.
+void AArch64TargetStreamer::finish() { ConstantPools->emitAll(Streamer); }
diff --git a/lib/Target/AArch64/MCTargetDesc/CMakeLists.txt b/lib/Target/AArch64/MCTargetDesc/CMakeLists.txt
index 7d5bced17a..6d8be5e63f 100644
--- a/lib/Target/AArch64/MCTargetDesc/CMakeLists.txt
+++ b/lib/Target/AArch64/MCTargetDesc/CMakeLists.txt
@@ -7,6 +7,7 @@ add_llvm_library(LLVMAArch64Desc
   AArch64MCExpr.cpp
   AArch64MCTargetDesc.cpp
   AArch64MachObjectWriter.cpp
+  AArch64TargetStreamer.cpp
 )
 add_dependencies(LLVMAArch64Desc AArch64CommonTableGen)