ARM: do not generate BLX instructions on Cortex-M CPUs.
[oota-llvm.git] / lib / Target / ARM / MCTargetDesc / ARMWinCOFFObjectWriter.cpp
1 //===-- ARMWinCOFFObjectWriter.cpp - ARM Windows COFF Object Writer -- C++ -==//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 #include "MCTargetDesc/ARMFixupKinds.h"
11 #include "llvm/MC/MCFixup.h"
12 #include "llvm/MC/MCValue.h"
13 #include "llvm/MC/MCWinCOFFObjectWriter.h"
14 #include "llvm/Support/COFF.h"
15 #include "llvm/Support/Debug.h"
16
17 using namespace llvm;
18
19 namespace {
20 class ARMWinCOFFObjectWriter : public MCWinCOFFObjectTargetWriter {
21 public:
22   ARMWinCOFFObjectWriter(bool Is64Bit)
23     : MCWinCOFFObjectTargetWriter(COFF::IMAGE_FILE_MACHINE_ARMNT) {
24     assert(!Is64Bit && "AArch64 support not yet implemented");
25   }
26   virtual ~ARMWinCOFFObjectWriter() { }
27
28   unsigned getRelocType(const MCValue &Target, const MCFixup &Fixup,
29                         bool IsCrossSection) const override;
30
31   bool recordRelocation(const MCFixup &) const override;
32 };
33
34 unsigned ARMWinCOFFObjectWriter::getRelocType(const MCValue &Target,
35                                               const MCFixup &Fixup,
36                                               bool IsCrossSection) const {
37   assert(getMachine() == COFF::IMAGE_FILE_MACHINE_ARMNT &&
38          "AArch64 support not yet implemented");
39
40   MCSymbolRefExpr::VariantKind Modifier =
41     Target.isAbsolute() ? MCSymbolRefExpr::VK_None : Target.getSymA()->getKind();
42
43   switch (static_cast<unsigned>(Fixup.getKind())) {
44   default: llvm_unreachable("unsupported relocation type");
45   case FK_Data_4:
46     switch (Modifier) {
47     case MCSymbolRefExpr::VK_COFF_IMGREL32:
48       return COFF::IMAGE_REL_ARM_ADDR32NB;
49     case MCSymbolRefExpr::VK_SECREL:
50       return COFF::IMAGE_REL_ARM_SECREL;
51     default:
52       return COFF::IMAGE_REL_ARM_ADDR32;
53     }
54   case FK_SecRel_2:
55     return COFF::IMAGE_REL_ARM_SECTION;
56   case FK_SecRel_4:
57     return COFF::IMAGE_REL_ARM_SECREL;
58   case ARM::fixup_t2_condbranch:
59     return COFF::IMAGE_REL_ARM_BRANCH20T;
60   case ARM::fixup_t2_uncondbranch:
61     return COFF::IMAGE_REL_ARM_BRANCH24T;
62   case ARM::fixup_arm_thumb_bl:
63   case ARM::fixup_arm_thumb_blx:
64     return COFF::IMAGE_REL_ARM_BLX23T;
65   case ARM::fixup_t2_movw_lo16:
66   case ARM::fixup_t2_movt_hi16:
67     return COFF::IMAGE_REL_ARM_MOV32T;
68   }
69 }
70
71 bool ARMWinCOFFObjectWriter::recordRelocation(const MCFixup &Fixup) const {
72   return static_cast<unsigned>(Fixup.getKind()) != ARM::fixup_t2_movt_hi16;
73 }
74 }
75
76 namespace llvm {
77 MCObjectWriter *createARMWinCOFFObjectWriter(raw_ostream &OS, bool Is64Bit) {
78   MCWinCOFFObjectTargetWriter *MOTW = new ARMWinCOFFObjectWriter(Is64Bit);
79   return createWinCOFFObjectWriter(MOTW, OS);
80 }
81 }
82