[JITLink] Add RISCV label subtraction and addition relocations

[StephenFan]

Summary

This patch add RISCV label subtraction and addition relocations in JITLink

[StephenFan]

Fix typo

[StephenFan]

clang-format

[StephenFan]

clang-format

[lhames]

I think this will need an update for the JITTargetAddress -> ExecutorAddr switch in 118e953b18f, but otherwise LGTM. Thanks Stephen!

llvm/include/llvm/ExecutionEngine/JITLink/riscv.h

90

Typo: Targat should be Target.

[StephenFan]

Rebase and fix typo

llvm/include/llvm/ExecutionEngine/JITLink/riscv.h

enum EdgeKind_riscv : Edge::Kind {
   /// Fixup expression:
   ///   Fixup <- (GOT - Fixup + Addend) >> 12
   R_RISCV_GOT_HI20,
 
   /// PC relative call by PLT
   ///
   /// Fixup expression:
   ///   Fixup <- (Target - Fixup + Addend)
-  R_RISCV_CALL_PLT
+  R_RISCV_CALL_PLT,
 
+  /// 64 bits label addition
+  ///
+  /// Fixup expression:
+  ///   Fixup <- (Targat - *{8}Fixup + Addend)
+  R_RISCV_ADD64,
+
+  /// 32 bits label addition
+  ///
+  /// Fixup expression:
+  ///   Fixup <- (Target - *{4}Fixup + Addend)
+  R_RISCV_ADD32,
+
+  /// 16 bits label addition
+  ///
+  /// Fixup expression
+  ///   Fixup <- (Target - *{2}Fixup + Addend)
+  R_RISCV_ADD16,
+
+  /// 8 bits label addition
+  ///
+  /// Fixup expression
+  ///   Fixup <- (Target - *{1}Fixup + Addend)
+  R_RISCV_ADD8,
+
+  /// 64 bits label subtraction
+  ///
+  /// Fixup expression
+  ///   Fixup <- (Target - *{8}Fixup - Addend)
+  R_RISCV_SUB64,
+
+  /// 32 bits label subtraction
+  ///
+  /// Fixup expression
+  ///   Fixup <- (Target - *{4}Fixup - Addend)
+  R_RISCV_SUB32,
+
+  /// 16 bits label subtraction
+  ///
+  /// Fixup expression
+  ///   Fixup <- (Target - *{2}Fixup - Addend)
+  R_RISCV_SUB16,
+
+  /// 8 bits label subtraction
+  ///
+  /// Fixup expression
+  ///   Fixup <- (Target - *{1}Fixup - Addend)
+  R_RISCV_SUB8
 };
 
 /// Returns a string name for the given riscv edge. For debugging purposes
 /// only
 const char *getEdgeKindName(Edge::Kind K);
 } // namespace riscv
 } // namespace jitlink
 } // namespace llvm
 
 #endif

llvm/lib/ExecutionEngine/JITLink/ELF_riscv.cpp

 #include "ELFLinkGraphBuilder.h"
 #include "JITLinkGeneric.h"
 #include "PerGraphGOTAndPLTStubsBuilder.h"
 #include "llvm/BinaryFormat/ELF.h"
 #include "llvm/ExecutionEngine/JITLink/JITLink.h"
 #include "llvm/ExecutionEngine/JITLink/riscv.h"
 #include "llvm/Object/ELF.h"
 #include "llvm/Object/ELFObjectFile.h"
+#include "llvm/Support/Endian.h"
 
 #define DEBUG_TYPE "jitlink"
 using namespace llvm;
 using namespace llvm::jitlink;
 using namespace llvm::jitlink::riscv;
 
 namespace {
 
case R_RISCV_PCREL_LO12_S: {
       int64_t Lo = Value & 0xFFF;
       uint32_t Imm31_25 = extractBits(Lo, 5, 7) << 25;
       uint32_t Imm11_7 = extractBits(Lo, 0, 5) << 7;
       uint32_t RawInstr = *(little32_t *)FixupPtr;
 
       *(little32_t *)FixupPtr = (RawInstr & 0x1FFF07F) | Imm31_25 | Imm11_7;
       break;
     }
+    case R_RISCV_ADD64: {
+      int64_t Value = E.getTarget().getAddress() +
+                      support::endian::read64le(
+                          reinterpret_cast<const void *>(FixupAddress)) +
+                      E.getAddend();
+      *(little64_t *)FixupPtr = static_cast<uint64_t>(Value);
+      break;
+    }
+    case R_RISCV_ADD32: {
+      int64_t Value = E.getTarget().getAddress() +
+                      support::endian::read32le(
+                          reinterpret_cast<const void *>(FixupAddress)) +
+                      E.getAddend();
+      *(little32_t *)FixupPtr = static_cast<uint32_t>(Value);
+      break;
+    }
+    case R_RISCV_ADD16: {
+      int64_t Value = E.getTarget().getAddress() +
+                      support::endian::read16le(
+                          reinterpret_cast<const void *>(FixupAddress)) +
+                      E.getAddend();
+      *(little16_t *)FixupPtr = static_cast<uint32_t>(Value);
+      break;
+    }
+    case R_RISCV_ADD8: {
+      int64_t Value = E.getTarget().getAddress() +
+                      *(reinterpret_cast<const uint8_t *>(FixupAddress)) +
+                      E.getAddend();
+      *FixupPtr = static_cast<uint8_t>(Value);
+      break;
+    }
+    case R_RISCV_SUB64: {
+      int64_t Value = support::endian::read64le(
+                          reinterpret_cast<const void *>(FixupAddress)) -
+                      E.getTarget().getAddress() - E.getAddend();
+      *(little64_t *)FixupPtr = static_cast<uint64_t>(Value);
+      break;
+    }
+    case R_RISCV_SUB32: {
+      int64_t Value = support::endian::read32le(
+                          reinterpret_cast<const void *>(FixupAddress)) -
+                      E.getTarget().getAddress() - E.getAddend();
+      *(little32_t *)FixupPtr = static_cast<uint32_t>(Value);
+      break;
+    }
+    case R_RISCV_SUB16: {
+      int64_t Value = support::endian::read16le(
+                          reinterpret_cast<const void *>(FixupAddress)) -
+                      E.getTarget().getAddress() - E.getAddend();
+      *(little16_t *)FixupPtr = static_cast<uint32_t>(Value);
+      break;
+    }
+    case R_RISCV_SUB8: {
+      int64_t Value = *(reinterpret_cast<const uint8_t *>(FixupAddress)) -
+                      E.getTarget().getAddress() - E.getAddend();
+      *FixupPtr = static_cast<uint8_t>(Value);
+      break;
+    }
     }
     return Error::success();
   }
 };
 
 template <typename ELFT>
 class ELFLinkGraphBuilder_riscv : public ELFLinkGraphBuilder<ELFT> {
 private:
getRelocationKind(const uint32_t Type) {
     case ELF::R_RISCV_PCREL_LO12_I:
       return EdgeKind_riscv::R_RISCV_PCREL_LO12_I;
     case ELF::R_RISCV_PCREL_LO12_S:
       return EdgeKind_riscv::R_RISCV_PCREL_LO12_S;
     case ELF::R_RISCV_GOT_HI20:
       return EdgeKind_riscv::R_RISCV_GOT_HI20;
     case ELF::R_RISCV_CALL_PLT:
       return EdgeKind_riscv::R_RISCV_CALL_PLT;
+    case ELF::R_RISCV_ADD64:
+      return EdgeKind_riscv::R_RISCV_ADD64;
+    case ELF::R_RISCV_ADD32:
+      return EdgeKind_riscv::R_RISCV_ADD32;
+    case ELF::R_RISCV_ADD16:
+      return EdgeKind_riscv::R_RISCV_ADD16;
+    case ELF::R_RISCV_ADD8:
+      return EdgeKind_riscv::R_RISCV_ADD8;
+    case ELF::R_RISCV_SUB64:
+      return EdgeKind_riscv::R_RISCV_SUB64;
+    case ELF::R_RISCV_SUB32:
+      return EdgeKind_riscv::R_RISCV_SUB32;
+    case ELF::R_RISCV_SUB16:
+      return EdgeKind_riscv::R_RISCV_SUB16;
+    case ELF::R_RISCV_SUB8:
+      return EdgeKind_riscv::R_RISCV_SUB8;
     }
 
     return make_error<JITLinkError>("Unsupported riscv relocation:" +
                                     formatv("{0:d}", Type));
   }
 
   Error addRelocations() override {
     LLVM_DEBUG(dbgs() << "Processing relocations:\n");

llvm/lib/ExecutionEngine/JITLink/riscv.cpp

const char *getEdgeKindName(Edge::Kind K) {
   case R_RISCV_PCREL_HI20:
     return "R_RISCV_PCREL_HI20";
   case R_RISCV_PCREL_LO12_I:
     return "R_RISCV_PCREL_LO12_I";
   case R_RISCV_PCREL_LO12_S:
     return "R_RISCV_PCREL_LO12_S";
   case R_RISCV_CALL:
     return "R_RISCV_CALL";
+  case R_RISCV_ADD64:
+    return "R_RISCV_ADD64";
+  case R_RISCV_ADD32:
+    return "R_RISCV_ADD32";
+  case R_RISCV_ADD16:
+    return "R_RISCV_ADD16";
+  case R_RISCV_ADD8:
+    return "R_RISCV_ADD8";
+  case R_RISCV_SUB64:
+    return "R_RISCV_SUB64";
+  case R_RISCV_SUB32:
+    return "R_RISCV_SUB32";
+  case R_RISCV_SUB16:
+    return "R_RISCV_SUB16";
+  case R_RISCV_SUB8:
+    return "R_RISCV_SUB8";
   }
   return getGenericEdgeKindName(K);
 }
 } // namespace riscv
 } // namespace jitlink
 } // namespace llvm

llvm/test/ExecutionEngine/JITLink/RISCV/riscv_reloc_add.s

+# RUN: rm -rf %t && mkdir -p %t
+# RUN: llvm-mc -triple=riscv64 -filetype=obj -o %t/riscv64_reloc_add.o %s
+# RUN: llvm-mc -triple=riscv32 -filetype=obj -o %t/riscv32_reloc_add.o %s
+# RUN: llvm-jitlink -noexec -check %s %t/riscv64_reloc_add.o
+# RUN: llvm-jitlink -noexec -check %s %t/riscv32_reloc_add.o
+
+# jitlink-check: *{8}(named_data) = 0x8
+# jitlink-check: *{4}(named_data+8) = 0x8
+# jitlink-check: *{2}(named_data+12) = 0x8
+# jitlink-check: *{1}(named_data+14) = 0x8
+
+.global main
+main:
+.L0:
+# Referencing named_data symbol to avoid the following .rodata section be skipped.
+# This instruction will be expand to two instructions (auipc + ld).
+  lw a0, named_data
+.L1:
+
+.section ".rodata","",@progbits
+.type named_data,@object
+named_data:
+.dword .L1 - .L0
+.word .L1 - .L0
+.half .L1 - .L0
+.byte .L1 - .L0
+.size named_data, 15