[JITLink][RISCV] fix the R_RISCV_BRANCH relocation's behavior

[fourdim]

Summary

This patch fixes the R_RISCV_BRANCH relocation as the original one will miss one bit when calculating the fixup value.
Moreover, clang format.

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

enum EdgeKind_riscv : Edge::Kind {
 
   /// A plain 64-bit pointer value relocation
   ///
   /// Fixup expression:
   ///   Fixup <- Target + Addend : uint32
   ///
   R_RISCV_64,
 
-  /// Low 12 bits of PC-relative branch pointer value relocation
+  /// 12 bits of PC-relative branch pointer value relocation
   ///
   /// Fixup expression:
-  ///   Fixup <- (Target - Fixup + Addend) & 0xFFF
+  ///   Fixup <- (Target - Fixup + Addend)
   ///
   R_RISCV_BRANCH,
 
   /// High 20 bits of 32-bit pointer value relocation
   ///
   /// Fixup expression
   ///   Fixup <- (Target + Addend + 0x800) >> 12
   R_RISCV_HI20,

llvm/lib/ExecutionEngine/JITLink/ELF_riscv.cpp

case R_RISCV_64: {
       break;
     }
     case R_RISCV_BRANCH: {
       int64_t Value = E.getTarget().getAddress() + E.getAddend() - FixupAddress;
       Error AlignmentIssue = checkAlignment(FixupAddress, Value, 2, E);
       if (AlignmentIssue) {
         return AlignmentIssue;
       }
-      int64_t Lo = Value & 0xFFF;
-      uint32_t Imm31_25 = extractBits(Lo, 5, 6) << 25 | extractBits(Lo, 12, 1)
-                                                            << 31;
-      uint32_t Imm11_7 = extractBits(Lo, 1, 4) << 8 | extractBits(Lo, 11, 1)
-                                                          << 7;
+      uint32_t Imm31_25 =
+          extractBits(Value, 5, 6) << 25 | extractBits(Value, 12, 1) << 31;
+      uint32_t Imm11_7 =
+          extractBits(Value, 1, 4) << 8 | extractBits(Value, 11, 1) << 7;
       uint32_t RawInstr = *(little32_t *)FixupPtr;
       *(little32_t *)FixupPtr = (RawInstr & 0x1FFF07F) | Imm31_25 | Imm11_7;
       break;
     }
     case R_RISCV_HI20: {
       int64_t Value = (E.getTarget().getAddress() + E.getAddend()).getValue();
       int64_t Hi = Value + 0x800;
       if (LLVM_UNLIKELY(!isInRangeForImmS32(Hi)))
Error applyFixup(LinkGraph &G, Block &B, const Edge &E) const {
     }
     case R_RISCV_PCREL_LO12_I: {
       // FIXME: We assume that R_RISCV_PCREL_HI20 is present in object code and
       // pairs with current relocation R_RISCV_PCREL_LO12_I. So here may need a
       // check.
       auto RelHI20 = getRISCVPCRelHi20(E);
       if (!RelHI20)
         return RelHI20.takeError();
-      int64_t Value = RelHI20->getTarget().getAddress() +
-                      RelHI20->getAddend() - E.getTarget().getAddress();
+      int64_t Value = RelHI20->getTarget().getAddress() + RelHI20->getAddend() -
+                      E.getTarget().getAddress();
       int64_t Lo = Value & 0xFFF;
       uint32_t RawInstr = *(little32_t *)FixupPtr;
       *(little32_t *)FixupPtr =
           (RawInstr & 0xFFFFF) | (static_cast<uint32_t>(Lo & 0xFFF) << 20);
       break;
     }
     case R_RISCV_PCREL_LO12_S: {
       // FIXME: We assume that R_RISCV_PCREL_HI20 is present in object code and
       // pairs with current relocation R_RISCV_PCREL_LO12_S. So here may need a
       // check.
       auto RelHI20 = getRISCVPCRelHi20(E);
-      int64_t Value = RelHI20->getTarget().getAddress() +
-                      RelHI20->getAddend() - E.getTarget().getAddress();
+      int64_t Value = RelHI20->getTarget().getAddress() + RelHI20->getAddend() -
+                      E.getTarget().getAddress();
       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;
     }
createLinkGraphFromELFObject_riscv(MemoryBufferRef ObjectBuffer) {
   });
 
   auto ELFObj = object::ObjectFile::createELFObjectFile(ObjectBuffer);
   if (!ELFObj)
     return ELFObj.takeError();
 
   if ((*ELFObj)->getArch() == Triple::riscv64) {
     auto &ELFObjFile = cast<object::ELFObjectFile<object::ELF64LE>>(**ELFObj);
-    return ELFLinkGraphBuilder_riscv<object::ELF64LE>(
-               (*ELFObj)->getFileName(), ELFObjFile.getELFFile(),
+    return ELFLinkGraphBuilder_riscv<object::ELF64LE>((*ELFObj)->getFileName(),
+                                                      ELFObjFile.getELFFile(),
                                                       (*ELFObj)->makeTriple())
         .buildGraph();
   } else {
     assert((*ELFObj)->getArch() == Triple::riscv32 &&
            "Invalid triple for RISCV ELF object file");
     auto &ELFObjFile = cast<object::ELFObjectFile<object::ELF32LE>>(**ELFObj);
-    return ELFLinkGraphBuilder_riscv<object::ELF32LE>(
-               (*ELFObj)->getFileName(), ELFObjFile.getELFFile(),
+    return ELFLinkGraphBuilder_riscv<object::ELF32LE>((*ELFObj)->getFileName(),
+                                                      ELFObjFile.getELFFile(),
                                                       (*ELFObj)->makeTriple())
         .buildGraph();
   }
 }
 
 void link_ELF_riscv(std::unique_ptr<LinkGraph> G,
                     std::unique_ptr<JITLinkContext> Ctx) {
   PassConfiguration Config;
   const Triple &TT = G->getTargetTriple();