[JITLink][RISCV] Support R_RISCV_SET* and R_RISCV_32_PCREL relocations

This patch supports R_RISCV_SET* and R_RISCV_32_PCREL relocations in JITLink.

Reviewed By: StephenFan

Differential Revision: https://reviews.llvm.org/D117082

Author: fourdim

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

@@ -137,7 +137,37 @@ enum EdgeKind_riscv : Edge::Kind {
   ///
   /// Fixup expression
   ///   Fixup <- (Target - *{1}Fixup - Addend)
-  R_RISCV_SUB8
+  R_RISCV_SUB8,
+
+  /// Local label assignment
+  ///
+  /// Fixup expression:
+  ///   Fixup <- (Target + Addend)
+  R_RISCV_SET6,
+
+  /// Local label assignment
+  ///
+  /// Fixup expression:
+  ///   Fixup <- (Target + Addend)
+  R_RISCV_SET8,
+
+  /// Local label assignment
+  ///
+  /// Fixup expression:
+  ///   Fixup <- (Target + Addend)
+  R_RISCV_SET16,
+
+  /// Local label assignment
+  ///
+  /// Fixup expression:
+  ///   Fixup <- (Target + Addend)
+  R_RISCV_SET32,
+
+  /// Local label assignment
+  ///
+  /// Fixup expression:
+  ///   Fixup <- (Target - Fixup + Addend)
+  R_RISCV_32_PCREL,
 };
 
 /// Returns a string name for the given riscv edge. For debugging purposes

llvm/lib/ExecutionEngine/JITLink/ELF_riscv.cpp

@@ -359,6 +359,39 @@ class ELFJITLinker_riscv : public JITLinker<ELFJITLinker_riscv> {
       *FixupPtr = static_cast<uint8_t>(Value);
       break;
     }
+    case R_RISCV_SET6: {
+      int64_t Value = (E.getTarget().getAddress() + E.getAddend()).getValue();
+      uint32_t RawData = *(little32_t *)FixupPtr;
+      int64_t Word6 = Value & 0x3f;
+      *(little32_t *)FixupPtr = (RawData & 0xffffffc0) | Word6;
+      break;
+    }
+    case R_RISCV_SET8: {
+      int64_t Value = (E.getTarget().getAddress() + E.getAddend()).getValue();
+      uint32_t RawData = *(little32_t *)FixupPtr;
+      int64_t Word8 = Value & 0xff;
+      *(little32_t *)FixupPtr = (RawData & 0xffffff00) | Word8;
+      break;
+    }
+    case R_RISCV_SET16: {
+      int64_t Value = (E.getTarget().getAddress() + E.getAddend()).getValue();
+      uint32_t RawData = *(little32_t *)FixupPtr;
+      int64_t Word16 = Value & 0xffff;
+      *(little32_t *)FixupPtr = (RawData & 0xffff0000) | Word16;
+      break;
+    }
+    case R_RISCV_SET32: {
+      int64_t Value = (E.getTarget().getAddress() + E.getAddend()).getValue();
+      int64_t Word32 = Value & 0xffffffff;
+      *(little32_t *)FixupPtr = Word32;
+      break;
+    }
+    case R_RISCV_32_PCREL: {
+      int64_t Value = E.getTarget().getAddress() + E.getAddend() - FixupAddress;
+      int64_t Word32 = Value & 0xffffffff;
+      *(little32_t *)FixupPtr = Word32;
+      break;
+    }
     }
     return Error::success();
   }
@@ -409,6 +442,16 @@ class ELFLinkGraphBuilder_riscv : public ELFLinkGraphBuilder<ELFT> {
       return EdgeKind_riscv::R_RISCV_SUB16;
     case ELF::R_RISCV_SUB8:
       return EdgeKind_riscv::R_RISCV_SUB8;
+    case ELF::R_RISCV_SET6:
+      return EdgeKind_riscv::R_RISCV_SET6;
+    case ELF::R_RISCV_SET8:
+      return EdgeKind_riscv::R_RISCV_SET8;
+    case ELF::R_RISCV_SET16:
+      return EdgeKind_riscv::R_RISCV_SET16;
+    case ELF::R_RISCV_SET32:
+      return EdgeKind_riscv::R_RISCV_SET32;
+    case ELF::R_RISCV_32_PCREL:
+      return EdgeKind_riscv::R_RISCV_32_PCREL;
     }
 
     return make_error<JITLinkError>("Unsupported riscv relocation:" +

llvm/lib/ExecutionEngine/JITLink/riscv.cpp

@@ -54,6 +54,16 @@ const char *getEdgeKindName(Edge::Kind K) {
     return "R_RISCV_SUB16";
   case R_RISCV_SUB8:
     return "R_RISCV_SUB8";
+  case R_RISCV_SET6:
+    return "R_RISCV_SET6";
+  case R_RISCV_SET8:
+    return "R_RISCV_SET8";
+  case R_RISCV_SET16:
+    return "R_RISCV_SET16";
+  case R_RISCV_SET32:
+    return "R_RISCV_SET32";
+  case R_RISCV_32_PCREL:
+    return "R_RISCV_32_PCREL";
   }
   return getGenericEdgeKindName(K);
 }

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

@@ -0,0 +1,19 @@
+# RUN: rm -rf %t && mkdir -p %t
+# RUN: llvm-mc -triple=riscv64 -filetype=obj -o %t/riscv64_pc_relative.o %s
+# RUN: llvm-mc -triple=riscv32 -filetype=obj -o %t/riscv32_pc_relative.o %s
+# RUN: llvm-jitlink -noexec -check %s %t/riscv64_pc_relative.o
+# RUN: llvm-jitlink -noexec -check %s %t/riscv32_pc_relative.o
+
+# jitlink-check: *{4}(foo) = 0x4
+
+.global main
+main:
+  lw a0, foo
+
+.section ".text","",@progbits
+.type foo,@function
+foo:
+  nop
+  nop
+  .reloc foo, R_RISCV_32_PCREL, foo+4
+  .size foo, 8

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

@@ -0,0 +1,31 @@
+# RUN: rm -rf %t && mkdir -p %t
+# RUN: llvm-mc -triple=riscv64 -filetype=obj -o %t/riscv64_reloc_set.o %s
+# RUN: llvm-mc -triple=riscv32 -filetype=obj -o %t/riscv32_reloc_set.o %s
+# RUN: llvm-jitlink -noexec \
+# RUN:  -slab-allocate 100Kb -slab-address 0xfff0f0f0 -slab-page-size 4096 \
+# RUN:  -check %s %t/riscv64_reloc_set.o
+# RUN: llvm-jitlink -noexec \
+# RUN:  -slab-allocate 100Kb -slab-address 0xfff0f0f0 -slab-page-size 4096 \
+# RUN:  -check %s %t/riscv32_reloc_set.o
+
+# jitlink-check: *{4}(foo) = foo
+# jitlink-check: *{2}(foo+4) = foo[15:0]
+# jitlink-check: *{1}(foo+6) = foo[7:0]
+# jitlink-check: *{1}(foo+7) = foo[5:0]
+
+.global main
+main:
+  lw a0, foo
+
+.section ".rodata","",@progbits
+.type foo,@object
+foo:
+  .reloc foo, R_RISCV_SET32, foo
+  .reloc foo+4, R_RISCV_SET16, foo
+  .reloc foo+6, R_RISCV_SET8, foo
+  .reloc foo+7, R_RISCV_SET6, foo
+  .word 0
+  .half 0
+  .byte 0
+  .byte 0
+  .size foo, 8