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[JITLink][LoongArch] Add R_LARCH_{B16,B21} relocations support (llvm#121096)
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‎llvm/include/llvm/ExecutionEngine/JITLink/loongarch.h

Lines changed: 75 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -41,6 +41,50 @@ enum EdgeKind_loongarch : Edge::Kind {
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///
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Pointer32,
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/// A 16-bit PC-relative branch.
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///
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/// Represents a PC-relative branch to a target within +/-128Kb. The target
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/// must be 4-byte aligned.
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///
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/// Fixup expression:
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/// Fixup <- (Target - Fixup + Addend) >> 2 : int16
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///
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/// Notes:
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/// The '16' in the name refers to the number operand bits and follows the
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/// naming convention used by the corresponding ELF relocations. Since the low
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/// two bits must be zero (because of the 4-byte alignment of the target) the
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/// operand is effectively a signed 18-bit number.
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///
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/// Errors:
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/// - The result of the unshifted part of the fixup expression must be
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/// 4-byte aligned otherwise an alignment error will be returned.
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/// - The result of the fixup expression must fit into an int16 otherwise an
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/// out-of-range error will be returned.
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///
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Branch16PCRel,
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/// A 21-bit PC-relative branch.
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///
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/// Represents a PC-relative branch to a target within +/-4Mb. The Target must
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/// be 4-byte aligned.
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///
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/// Fixup expression:
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/// Fixup <- (Target - Fixup + Addend) >> 2 : int21
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///
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/// Notes:
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/// The '21' in the name refers to the number operand bits and follows the
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/// naming convention used by the corresponding ELF relocations. Since the low
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/// two bits must be zero (because of the 4-byte alignment of the target) the
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/// operand is effectively a signed 23-bit number.
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///
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/// Errors:
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/// - The result of the unshifted part of the fixup expression must be
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/// 4-byte aligned otherwise an alignment error will be returned.
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/// - The result of the fixup expression must fit into an int21 otherwise an
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/// out-of-range error will be returned.
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///
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Branch21PCRel,
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/// A 26-bit PC-relative branch.
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///
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/// Represents a PC-relative call or branch to a target within +/-128Mb. The
@@ -213,6 +257,37 @@ inline Error applyFixup(LinkGraph &G, Block &B, const Edge &E) {
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*(ulittle32_t *)FixupPtr = Value;
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break;
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}
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case Branch16PCRel: {
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int64_t Value = TargetAddress - FixupAddress + Addend;
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if (!isInt<18>(Value))
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return makeTargetOutOfRangeError(G, B, E);
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if (!isShiftedInt<16, 2>(Value))
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return makeAlignmentError(orc::ExecutorAddr(FixupAddress), Value, 4, E);
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uint32_t RawInstr = *(little32_t *)FixupPtr;
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uint32_t Imm = static_cast<uint32_t>(Value >> 2);
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uint32_t Imm15_0 = extractBits(Imm, /*Hi=*/15, /*Lo=*/0) << 10;
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*(little32_t *)FixupPtr = RawInstr | Imm15_0;
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break;
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}
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case Branch21PCRel: {
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int64_t Value = TargetAddress - FixupAddress + Addend;
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if (!isInt<23>(Value))
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return makeTargetOutOfRangeError(G, B, E);
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if (!isShiftedInt<21, 2>(Value))
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return makeAlignmentError(orc::ExecutorAddr(FixupAddress), Value, 4, E);
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uint32_t RawInstr = *(little32_t *)FixupPtr;
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uint32_t Imm = static_cast<uint32_t>(Value >> 2);
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uint32_t Imm15_0 = extractBits(Imm, /*Hi=*/15, /*Lo=*/0) << 10;
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uint32_t Imm20_16 = extractBits(Imm, /*Hi=*/20, /*Lo=*/16);
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*(little32_t *)FixupPtr = RawInstr | Imm15_0 | Imm20_16;
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break;
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}
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case Branch26PCRel: {
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int64_t Value = TargetAddress - FixupAddress + Addend;
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‎llvm/lib/ExecutionEngine/JITLink/ELF_loongarch.cpp

Lines changed: 4 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -58,6 +58,10 @@ class ELFLinkGraphBuilder_loongarch : public ELFLinkGraphBuilder<ELFT> {
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return Pointer32;
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case ELF::R_LARCH_32_PCREL:
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return Delta32;
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case ELF::R_LARCH_B16:
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return Branch16PCRel;
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case ELF::R_LARCH_B21:
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return Branch21PCRel;
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case ELF::R_LARCH_B26:
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return Branch26PCRel;
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case ELF::R_LARCH_PCALA_HI20:

‎llvm/lib/ExecutionEngine/JITLink/loongarch.cpp

Lines changed: 2 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -44,6 +44,8 @@ const char *getEdgeKindName(Edge::Kind K) {
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KIND_NAME_CASE(Delta32)
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KIND_NAME_CASE(NegDelta32)
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KIND_NAME_CASE(Delta64)
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KIND_NAME_CASE(Branch16PCRel)
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KIND_NAME_CASE(Branch21PCRel)
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KIND_NAME_CASE(Branch26PCRel)
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KIND_NAME_CASE(Page20)
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KIND_NAME_CASE(PageOffset12)

‎llvm/test/ExecutionEngine/JITLink/LoongArch/ELF_loongarch32_relocations.s

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Original file line numberDiff line numberDiff line change
@@ -103,6 +103,30 @@ test_gotoffset12_external:
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ld.w $a0, $a0, %got_pc_lo12(external_data)
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.size test_gotoffset12_external, .-test_gotoffset12_external
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## Check R_LARCH_B16 relocation for compare and branch instructions.
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# jitlink-check: decode_operand(test_br16, 2)[17:0] = \
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# jitlink-check: (test_br16_target - test_br16)[17:0]
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.globl test_br16, test_br16_target
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.p2align 2
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test_br16:
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beq $t1, $t2, %b16(test_br16_target)
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.skip (1 << 16)
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test_br16_target:
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.size test_br16, .-test_br16
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## Check R_LARCH_B21 relocation for compare and branch instructions.
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# jitlink-check: decode_operand(test_br21, 1)[22:0] = \
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# jitlink-check: (test_br21_target - test_br21)[22:0]
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.globl test_br21, test_br21_target
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.p2align 2
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test_br21:
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beqz $t1, %b21(test_br21_target)
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.skip (1 << 21)
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test_br21_target:
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.size test_br21, .-test_br21
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.globl named_data
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.p2align 4

‎llvm/test/ExecutionEngine/JITLink/LoongArch/ELF_loongarch64_relocations.s

Lines changed: 25 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -116,7 +116,6 @@ test_gotoffset12_external:
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ld.d $a0, $a0, %got_pc_lo12(external_data)
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.size test_gotoffset12_external, .-test_gotoffset12_external
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## Check R_LARCH_CALL36 relocation of a local function call.
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# jitlink-check: decode_operand(local_func_call36, 1)[19:0] = \
@@ -130,6 +129,31 @@ local_func_call36:
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jirl $ra, $ra, 0
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.size local_func_call36, .-local_func_call36
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## Check R_LARCH_B16 relocation for compare and branch instructions.
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# jitlink-check: decode_operand(test_br16, 2)[17:0] = \
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# jitlink-check: (test_br16_target - test_br16)[17:0]
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.globl test_br16, test_br16_target
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.p2align 2
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test_br16:
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beq $t1, $t2, %b16(test_br16_target)
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.skip (1 << 16)
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test_br16_target:
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.size test_br16, .-test_br16
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## Check R_LARCH_B21 relocation for compare and branch instructions.
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# jitlink-check: decode_operand(test_br21, 1)[22:0] = \
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# jitlink-check: (test_br21_target - test_br21)[22:0]
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.globl test_br21, test_br21_target
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.p2align 2
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test_br21:
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beqz $t1, %b21(test_br21_target)
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.skip (1 << 21)
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test_br21_target:
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.size test_br21, .-test_br21
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.globl named_data
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.p2align 4
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.type named_data,@object

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