vendor/llvm/llvm-trunk-r321017

1 files changed, 99 insertions, 0 deletions

diff --git a/lib/Target/RISCV/MCTargetDesc/RISCVMCExpr.cpp b/lib/Target/RISCV/MCTargetDesc/RISCVMCExpr.cpp
new file mode 100644
index 0000000000000..b36236ea155f3
--- /dev/null
+++ b/lib/Target/RISCV/MCTargetDesc/RISCVMCExpr.cpp
@@ -0,0 +1,99 @@
+//===-- RISCVMCExpr.cpp - RISCV specific MC expression classes ------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the implementation of the assembly expression modifiers
+// accepted by the RISCV architecture (e.g. ":lo12:", ":gottprel_g1:", ...).
+//
+//===----------------------------------------------------------------------===//
+
+#include "RISCVMCExpr.h"
+#include "llvm/MC/MCAssembler.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCStreamer.h"
+#include "llvm/MC/MCSymbolELF.h"
+#include "llvm/MC/MCValue.h"
+#include "llvm/Object/ELF.h"
+#include "llvm/Support/ErrorHandling.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "riscvmcexpr"
+
+const RISCVMCExpr *RISCVMCExpr::create(const MCExpr *Expr, VariantKind Kind,
+                                       MCContext &Ctx) {
+  return new (Ctx) RISCVMCExpr(Expr, Kind);
+}
+
+void RISCVMCExpr::printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const {
+  bool HasVariant = getKind() != VK_RISCV_None;
+  if (HasVariant)
+    OS << '%' << getVariantKindName(getKind()) << '(';
+  Expr->print(OS, MAI);
+  if (HasVariant)
+    OS << ')';
+}
+
+bool RISCVMCExpr::evaluateAsRelocatableImpl(MCValue &Res,
+                                            const MCAsmLayout *Layout,
+                                            const MCFixup *Fixup) const {
+  return getSubExpr()->evaluateAsRelocatable(Res, Layout, Fixup);
+}
+
+void RISCVMCExpr::visitUsedExpr(MCStreamer &Streamer) const {
+  Streamer.visitUsedExpr(*getSubExpr());
+}
+
+RISCVMCExpr::VariantKind RISCVMCExpr::getVariantKindForName(StringRef name) {
+  return StringSwitch<RISCVMCExpr::VariantKind>(name)
+      .Case("lo", VK_RISCV_LO)
+      .Case("hi", VK_RISCV_HI)
+      .Case("pcrel_hi", VK_RISCV_PCREL_HI)
+      .Default(VK_RISCV_Invalid);
+}
+
+StringRef RISCVMCExpr::getVariantKindName(VariantKind Kind) {
+  switch (Kind) {
+  default:
+    llvm_unreachable("Invalid ELF symbol kind");
+  case VK_RISCV_LO:
+    return "lo";
+  case VK_RISCV_HI:
+    return "hi";
+  case VK_RISCV_PCREL_HI:
+    return "pcrel_hi";
+  }
+}
+
+bool RISCVMCExpr::evaluateAsConstant(int64_t &Res) const {
+  MCValue Value;
+
+  if (Kind == VK_RISCV_PCREL_HI)
+    return false;
+
+  if (!getSubExpr()->evaluateAsRelocatable(Value, nullptr, nullptr))
+    return false;
+
+  if (!Value.isAbsolute())
+    return false;
+
+  Res = evaluateAsInt64(Value.getConstant());
+  return true;
+}
+
+int64_t RISCVMCExpr::evaluateAsInt64(int64_t Value) const {
+  switch (Kind) {
+  default:
+    llvm_unreachable("Invalid kind");
+  case VK_RISCV_LO:
+    return SignExtend64<12>(Value);
+  case VK_RISCV_HI:
+    // Add 1 if bit 11 is 1, to compensate for low 12 bits being negative.
+    return ((Value + 0x800) >> 12) & 0xfffff;
+  }
+}