diff options
Diffstat (limited to 'lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp')
-rw-r--r-- | lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp | 74 |
1 files changed, 51 insertions, 23 deletions
diff --git a/lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp b/lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp index b696069..02cd12b 100644 --- a/lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp +++ b/lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp @@ -11,7 +11,6 @@ // //===----------------------------------------------------------------------===// -#define DEBUG_TYPE "asm-printer" #include "ByteStreamer.h" #include "llvm/CodeGen/AsmPrinter.h" #include "llvm/ADT/SmallBitVector.h" @@ -30,6 +29,8 @@ #include "llvm/Target/TargetRegisterInfo.h" using namespace llvm; +#define DEBUG_TYPE "asm-printer" + //===----------------------------------------------------------------------===// // Dwarf Emission Helper Routines //===----------------------------------------------------------------------===// @@ -216,30 +217,48 @@ static void emitDwarfRegOpIndirect(ByteStreamer &Streamer, int Reg, int Offset, /// Emit a dwarf register operation for describing /// - a small value occupying only part of a register or /// - a small register representing only part of a value. -static void emitDwarfOpPiece(ByteStreamer &Streamer, unsigned Size, - unsigned Offset) { - assert(Size > 0); - if (Offset > 0) { +static void emitDwarfOpPiece(ByteStreamer &Streamer, unsigned SizeInBits, + unsigned OffsetInBits) { + assert(SizeInBits > 0 && "zero-sized piece"); + unsigned SizeOfByte = 8; + if (OffsetInBits > 0 || SizeInBits % SizeOfByte) { Streamer.EmitInt8(dwarf::DW_OP_bit_piece, "DW_OP_bit_piece"); - Streamer.EmitULEB128(Size, Twine(Size)); - Streamer.EmitULEB128(Offset, Twine(Offset)); + Streamer.EmitULEB128(SizeInBits, Twine(SizeInBits)); + Streamer.EmitULEB128(OffsetInBits, Twine(OffsetInBits)); } else { Streamer.EmitInt8(dwarf::DW_OP_piece, "DW_OP_piece"); - unsigned ByteSize = Size / 8; // Assuming 8 bits per byte. + unsigned ByteSize = SizeInBits / SizeOfByte; Streamer.EmitULEB128(ByteSize, Twine(ByteSize)); } } -/// Some targets do not provide a DWARF register number for every -/// register. This function attempts to emit a dwarf register by -/// emitting a piece of a super-register or by piecing together -/// multiple subregisters that alias the register. -static void EmitDwarfRegOpPiece(ByteStreamer &Streamer, const AsmPrinter &AP, - const MachineLocation &MLoc) { - assert(!MLoc.isIndirect()); - const TargetRegisterInfo *TRI = AP.TM.getRegisterInfo(); +/// Emit a shift-right dwarf expression. +static void emitDwarfOpShr(ByteStreamer &Streamer, + unsigned ShiftBy) { + Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu"); + Streamer.EmitULEB128(ShiftBy); + Streamer.EmitInt8(dwarf::DW_OP_shr, "DW_OP_shr"); +} + +// Some targets do not provide a DWARF register number for every +// register. This function attempts to emit a DWARF register by +// emitting a piece of a super-register or by piecing together +// multiple subregisters that alias the register. +void AsmPrinter::EmitDwarfRegOpPiece(ByteStreamer &Streamer, + const MachineLocation &MLoc, + unsigned PieceSizeInBits, + unsigned PieceOffsetInBits) const { + assert(MLoc.isReg() && "MLoc must be a register"); + const TargetRegisterInfo *TRI = TM.getRegisterInfo(); int Reg = TRI->getDwarfRegNum(MLoc.getReg(), false); + // If this is a valid register number, emit it. + if (Reg >= 0) { + emitDwarfRegOp(Streamer, Reg); + emitDwarfOpPiece(Streamer, PieceSizeInBits, PieceOffsetInBits); + return; + } + // Walk up the super-register chain until we find a valid number. // For example, EAX on x86_64 is a 32-bit piece of RAX with offset 0. for (MCSuperRegIterator SR(MLoc.getReg(), TRI); SR.isValid(); ++SR) { @@ -248,9 +267,19 @@ static void EmitDwarfRegOpPiece(ByteStreamer &Streamer, const AsmPrinter &AP, unsigned Idx = TRI->getSubRegIndex(*SR, MLoc.getReg()); unsigned Size = TRI->getSubRegIdxSize(Idx); unsigned Offset = TRI->getSubRegIdxOffset(Idx); - AP.OutStreamer.AddComment("super-register"); + OutStreamer.AddComment("super-register"); emitDwarfRegOp(Streamer, Reg); - emitDwarfOpPiece(Streamer, Size, Offset); + if (PieceOffsetInBits == Offset) { + emitDwarfOpPiece(Streamer, Size, Offset); + } else { + // If this is part of a variable in a sub-register at a + // non-zero offset, we need to manually shift the value into + // place, since the DW_OP_piece describes the part of the + // variable, not the position of the subregister. + emitDwarfOpPiece(Streamer, Size, PieceOffsetInBits); + if (Offset) + emitDwarfOpShr(Streamer, Offset); + } return; } } @@ -260,7 +289,7 @@ static void EmitDwarfRegOpPiece(ByteStreamer &Streamer, const AsmPrinter &AP, // // Keep track of the current position so we can emit the more // efficient DW_OP_piece. - unsigned CurPos = 0; + unsigned CurPos = PieceOffsetInBits; // The size of the register in bits, assuming 8 bits per byte. unsigned RegSize = TRI->getMinimalPhysRegClass(MLoc.getReg())->getSize() * 8; // Keep track of the bits in the register we already emitted, so we @@ -281,7 +310,7 @@ static void EmitDwarfRegOpPiece(ByteStreamer &Streamer, const AsmPrinter &AP, // If this sub-register has a DWARF number and we haven't covered // its range, emit a DWARF piece for it. if (Reg >= 0 && Intersection.any()) { - AP.OutStreamer.AddComment("sub-register"); + OutStreamer.AddComment("sub-register"); emitDwarfRegOp(Streamer, Reg); emitDwarfOpPiece(Streamer, Size, Offset == CurPos ? 0 : Offset); CurPos = Offset + Size; @@ -291,7 +320,7 @@ static void EmitDwarfRegOpPiece(ByteStreamer &Streamer, const AsmPrinter &AP, } } - if (CurPos == 0) { + if (CurPos == PieceOffsetInBits) { // FIXME: We have no reasonable way of handling errors in here. Streamer.EmitInt8(dwarf::DW_OP_nop, "nop (could not find a dwarf register number)"); @@ -317,8 +346,7 @@ void AsmPrinter::EmitDwarfRegOp(ByteStreamer &Streamer, } // Attempt to find a valid super- or sub-register. - if (!Indirect && !MLoc.isIndirect()) - return EmitDwarfRegOpPiece(Streamer, *this, MLoc); + return EmitDwarfRegOpPiece(Streamer, MLoc); } if (MLoc.isIndirect()) |