From b69c7b76f1def0ff2fcb791c48f1b5620990d008 Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Wed, 12 May 2010 05:16:34 +0000
Subject: [PATCH] Add support for movi32 of global values to the new (MC) asm
 printer.

llvm-svn: 103576
---
 llvm/include/llvm/MC/MCExpr.h                 |  4 ++-
 llvm/lib/MC/MCExpr.cpp                        | 10 ++++++-
 .../Target/ARM/AsmPrinter/ARMAsmPrinter.cpp   | 27 ++++++++++++++++---
 .../Target/ARM/AsmPrinter/ARMInstPrinter.cpp  |  3 ++-
 4 files changed, 37 insertions(+), 7 deletions(-)

diff --git a/llvm/include/llvm/MC/MCExpr.h b/llvm/include/llvm/MC/MCExpr.h
index bd0684df67e9..bb8f2bb13500 100644
--- a/llvm/include/llvm/MC/MCExpr.h
+++ b/llvm/include/llvm/MC/MCExpr.h
@@ -134,7 +134,9 @@ public:
     VK_NTPOFF,
     VK_PLT,
     VK_TLSGD,
-    VK_TPOFF
+    VK_TPOFF,
+    VK_ARM_HI16, // The R_ARM_MOVT_ABS relocation (:upper16: in the asm file)
+    VK_ARM_LO16 // The R_ARM_MOVW_ABS_NC relocation (:lower16: in the asm file)
   };
 
 private:
diff --git a/llvm/lib/MC/MCExpr.cpp b/llvm/lib/MC/MCExpr.cpp
index 3d4bbbaaf513..068ca8122685 100644
--- a/llvm/lib/MC/MCExpr.cpp
+++ b/llvm/lib/MC/MCExpr.cpp
@@ -39,6 +39,10 @@ void MCExpr::print(raw_ostream &OS) const {
     const MCSymbolRefExpr &SRE = cast<MCSymbolRefExpr>(*this);
     const MCSymbol &Sym = SRE.getSymbol();
 
+    if (SRE.getKind() == MCSymbolRefExpr::VK_ARM_HI16 ||
+	SRE.getKind() == MCSymbolRefExpr::VK_ARM_LO16)
+      OS << MCSymbolRefExpr::getVariantKindName(SRE.getKind());
+
     // Parenthesize names that start with $ so that they don't look like
     // absolute names.
     if (Sym.getName()[0] == '$')
@@ -46,7 +50,9 @@ void MCExpr::print(raw_ostream &OS) const {
     else
       OS << Sym;
 
-    if (SRE.getKind() != MCSymbolRefExpr::VK_None)
+    if (SRE.getKind() != MCSymbolRefExpr::VK_None &&
+	SRE.getKind() != MCSymbolRefExpr::VK_ARM_HI16 &&
+	SRE.getKind() != MCSymbolRefExpr::VK_ARM_LO16)
       OS << '@' << MCSymbolRefExpr::getVariantKindName(SRE.getKind());
 
     return;
@@ -169,6 +175,8 @@ StringRef MCSymbolRefExpr::getVariantKindName(VariantKind Kind) {
   case VK_PLT: return "PLT";
   case VK_TLSGD: return "TLSGD";
   case VK_TPOFF: return "TPOFF";
+  case VK_ARM_HI16: return ":upper16:";
+  case VK_ARM_LO16: return ":lower16:";
   }
 }
 
diff --git a/llvm/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp b/llvm/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp
index 80a9d2d714e6..321c9148992e 100644
--- a/llvm/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp
+++ b/llvm/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp
@@ -1375,13 +1375,32 @@ void ARMAsmPrinter::printInstructionThroughMCStreamer(const MachineInstr *MI) {
   case ARM::MOVi32imm: { // FIXME: Remove asmstring from td file.
     // This is a hack that lowers as a two instruction sequence.
     unsigned DstReg = MI->getOperand(0).getReg();
-    unsigned ImmVal = (unsigned)MI->getOperand(1).getImm();
-    
+    const MachineOperand &MO = MI->getOperand(1);
+    MCOperand V1, V2;
+    if (MO.isImm()) {
+      unsigned ImmVal = (unsigned)MI->getOperand(1).getImm();
+      V1 = MCOperand::CreateImm(ImmVal & 65535);
+      V2 = MCOperand::CreateImm(ImmVal >> 16);
+    } else if (MO.isGlobal()) {
+      MCSymbol *Symbol = MCInstLowering.GetGlobalAddressSymbol(MO);
+      const MCSymbolRefExpr *SymRef1 =
+	MCSymbolRefExpr::Create(Symbol,
+				MCSymbolRefExpr::VK_ARM_LO16, OutContext);
+      const MCSymbolRefExpr *SymRef2 =
+	MCSymbolRefExpr::Create(Symbol,
+				MCSymbolRefExpr::VK_ARM_HI16, OutContext);
+      V1 = MCOperand::CreateExpr(SymRef1);
+      V2 = MCOperand::CreateExpr(SymRef2);
+    } else {
+      MI->dump();
+      llvm_unreachable("cannot handle this operand");
+    }
+
     {
       MCInst TmpInst;
       TmpInst.setOpcode(ARM::MOVi16);
       TmpInst.addOperand(MCOperand::CreateReg(DstReg));         // dstreg
-      TmpInst.addOperand(MCOperand::CreateImm(ImmVal & 65535)); // lower16(imm)
+      TmpInst.addOperand(V1); // lower16(imm)
       
       // Predicate.
       TmpInst.addOperand(MCOperand::CreateImm(MI->getOperand(2).getImm()));
@@ -1395,7 +1414,7 @@ void ARMAsmPrinter::printInstructionThroughMCStreamer(const MachineInstr *MI) {
       TmpInst.setOpcode(ARM::MOVTi16);
       TmpInst.addOperand(MCOperand::CreateReg(DstReg));         // dstreg
       TmpInst.addOperand(MCOperand::CreateReg(DstReg));         // srcreg
-      TmpInst.addOperand(MCOperand::CreateImm(ImmVal >> 16));   // upper16(imm)
+      TmpInst.addOperand(V2);   // upper16(imm)
       
       // Predicate.
       TmpInst.addOperand(MCOperand::CreateImm(MI->getOperand(2).getImm()));
diff --git a/llvm/lib/Target/ARM/AsmPrinter/ARMInstPrinter.cpp b/llvm/lib/Target/ARM/AsmPrinter/ARMInstPrinter.cpp
index ac6331f931fc..7b49466a9b0c 100644
--- a/llvm/lib/Target/ARM/AsmPrinter/ARMInstPrinter.cpp
+++ b/llvm/lib/Target/ARM/AsmPrinter/ARMInstPrinter.cpp
@@ -217,7 +217,8 @@ void ARMInstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
            ((Modifier == 0 || Modifier[0] == 0) && "No modifiers supported"));
     O << '#' << Op.getImm();
   } else {
-    assert((Modifier == 0 || Modifier[0] == 0) && "No modifiers supported");
+    if (Modifier && Modifier[0] != 0 && strcmp(Modifier, "call") != 0)
+      llvm_unreachable("Unsupported modifier");
     assert(Op.isExpr() && "unknown operand kind in printOperand");
     O << *Op.getExpr();
   }