Unverified Commit 87081f1c authored by Eymen Ünay's avatar Eymen Ünay Committed by GitHub
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[JITLink][AArch32] Add support for ELF::R_ARM_THM_MOV{W_PREL_NC,T_PREL} (#70364) 

Support for ELF::R_ARM_THM_MOVW_PREL_NC and ELF::R_ARM_THM_MOVT_PREL
is added. Move instructions with PC-relative immediates can be handled
in Thumb mode with this addition.
parent 228ef85b

llvm/include/llvm/ExecutionEngine/JITLink/aarch32.h

+9 −1
Original line number Diff line number Diff line
@@ -89,7 +89,15 @@ enum EdgeKind_aarch32 : Edge::Kind { 
  /// Write immediate value to the top halfword of the destination register

  Thumb_MovtAbs,



  LastThumbRelocation = Thumb_MovtAbs,

  /// Write PC-relative immediate value to the lower halfword of the destination

  /// register

  Thumb_MovwPrelNC,



  /// Write PC-relative immediate value to the top halfword of the destination

  /// register

  Thumb_MovtPrel,



  LastThumbRelocation = Thumb_MovtPrel,

};



/// Flags enum for AArch32-specific symbol properties

llvm/lib/ExecutionEngine/JITLink/ELF_aarch32.cpp

+8 −0
Original line number Diff line number Diff line
@@ -53,6 +53,10 @@ Expected<aarch32::EdgeKind_aarch32> getJITLinkEdgeKind(uint32_t ELFType) { 
    return aarch32::Thumb_MovwAbsNC;

  case ELF::R_ARM_THM_MOVT_ABS:

    return aarch32::Thumb_MovtAbs;

  case ELF::R_ARM_THM_MOVW_PREL_NC:

    return aarch32::Thumb_MovwPrelNC;

  case ELF::R_ARM_THM_MOVT_PREL:

    return aarch32::Thumb_MovtPrel;

  }



  return make_error<JITLinkError>(
@@ -83,6 +87,10 @@ Expected<uint32_t> getELFRelocationType(Edge::Kind Kind) { 
    return ELF::R_ARM_THM_MOVW_ABS_NC;

  case aarch32::Thumb_MovtAbs:

    return ELF::R_ARM_THM_MOVT_ABS;

  case aarch32::Thumb_MovwPrelNC:

    return ELF::R_ARM_THM_MOVW_PREL_NC;

  case aarch32::Thumb_MovtPrel:

    return ELF::R_ARM_THM_MOVT_PREL;

  }



  return make_error<JITLinkError>(formatv("Invalid aarch32 edge {0:d}: ",

llvm/lib/ExecutionEngine/JITLink/aarch32.cpp

+18 −0
Original line number Diff line number Diff line
@@ -377,12 +377,14 @@ Expected<int64_t> readAddendThumb(LinkGraph &G, Block &B, const Edge &E, 
                  : decodeImmBT4BlT1BlxT2(R.Hi, R.Lo);



  case Thumb_MovwAbsNC:

  case Thumb_MovwPrelNC:

    if (!checkOpcode<Thumb_MovwAbsNC>(R))

      return makeUnexpectedOpcodeError(G, R, Kind);

    // Initial addend is interpreted as a signed value

    return SignExtend64<16>(decodeImmMovtT1MovwT3(R.Hi, R.Lo));



  case Thumb_MovtAbs:

  case Thumb_MovtPrel:

    if (!checkOpcode<Thumb_MovtAbs>(R))

      return makeUnexpectedOpcodeError(G, R, Kind);

    // Initial addend is interpreted as a signed value
@@ -610,6 +612,20 @@ Error applyFixupThumb(LinkGraph &G, Block &B, const Edge &E, 
    writeImmediate<Thumb_MovtAbs>(R, encodeImmMovtT1MovwT3(Value));

    return Error::success();

  }

  case Thumb_MovwPrelNC: {

    if (!checkOpcode<Thumb_MovwAbsNC>(R))

      return makeUnexpectedOpcodeError(G, R, Kind);

    uint16_t Value = ((TargetAddress + Addend - FixupAddress) & 0xffff);

    writeImmediate<Thumb_MovwAbsNC>(R, encodeImmMovtT1MovwT3(Value));

    return Error::success();

  }

  case Thumb_MovtPrel: {

    if (!checkOpcode<Thumb_MovtAbs>(R))

      return makeUnexpectedOpcodeError(G, R, Kind);

    uint16_t Value = (((TargetAddress + Addend - FixupAddress) >> 16) & 0xffff);

    writeImmediate<Thumb_MovtAbs>(R, encodeImmMovtT1MovwT3(Value));

    return Error::success();

  }



  default:

    return make_error<JITLinkError>(
@@ -659,6 +675,8 @@ const char *getEdgeKindName(Edge::Kind K) { 
    KIND_NAME_CASE(Thumb_Jump24)

    KIND_NAME_CASE(Thumb_MovwAbsNC)

    KIND_NAME_CASE(Thumb_MovtAbs)

    KIND_NAME_CASE(Thumb_MovwPrelNC)

    KIND_NAME_CASE(Thumb_MovtPrel)

  default:

    return getGenericEdgeKindName(K);

  }

llvm/test/ExecutionEngine/JITLink/AArch32/ELF_static_thumb_reloc.s

+30 −1
Original line number Diff line number Diff line
@@ -2,7 +2,8 @@ 
# RUN: llvm-objdump -r %t.o | FileCheck --check-prefix=CHECK-TYPE %s

# RUN: llvm-objdump --disassemble %t.o | FileCheck --check-prefix=CHECK-INSTR %s

# RUN: llvm-jitlink -noexec -slab-address 0x76ff0000 -slab-allocate 10Kb \

# RUN:              -slab-page-size 4096 -show-entry-es -check %s %t.o

# RUN:              -slab-page-size 4096 -abs external_func=0x76bbe880 \

# RUN:              -check %s %t.o





	.text
@@ -95,6 +96,34 @@ data_symbol: 


	.text



# CHECK-TYPE: {{[0-9a-f]+}} R_ARM_THM_MOVW_PREL_NC external_func

# CHECK-INSTR: 	00000014 <movw_prel>:

# CHECK-INSTR: 	      14: f240 0000     movw    r0, #0x0

# jitlink-check: decode_operand(movw_prel, 1) = \

# jitlink-check:              ((external_func - movw_prel)&0x0000ffff)

.globl	movw_prel

.type	movw_prel,%function

.p2align	1

.code	16

.thumb_func

movw_prel:

	movw r0, :lower16:external_func - .

	.size	movw_prel,	.-movw_prel



# CHECK-TYPE: {{[0-9a-f]+}} R_ARM_THM_MOVT_PREL external_func 

# CHECK-INSTR: 	00000018 <movt_prel>:

# CHECK-INSTR: 	      18: f2c0 0000    movt    r0, #0x0

# jitlink-check: decode_operand(movt_prel, 2) = \

# jitlink-check:               ((external_func - movt_prel)&0xffff0000>>16)

.globl	movt_prel

.type	movt_prel,%function

.p2align	1

.code	16

.thumb_func

movt_prel:

	movt r0, :upper16:external_func - .

	.size	movt_prel,	.-movt_prel



# Empty main function for jitlink to be happy

	.globl	main

	.type	main,%function