Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 246 insertions, 0 deletions

diff --git a/js/src/jit/x64/Assembler-x64.cpp b/js/src/jit/x64/Assembler-x64.cpp
new file mode 100644
index 0000000000..e00e34e830
--- /dev/null
+++ b/js/src/jit/x64/Assembler-x64.cpp
@@ -0,0 +1,246 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "jit/x64/Assembler-x64.h"
+
+#include "gc/Tracer.h"
+#include "util/Memory.h"
+
+using namespace js;
+using namespace js::jit;
+
+ABIArgGenerator::ABIArgGenerator()
+    :
+#if defined(XP_WIN)
+      regIndex_(0),
+      stackOffset_(ShadowStackSpace),
+#else
+      intRegIndex_(0),
+      floatRegIndex_(0),
+      stackOffset_(0),
+#endif
+      current_() {
+}
+
+ABIArg ABIArgGenerator::next(MIRType type) {
+#if defined(XP_WIN)
+  static_assert(NumIntArgRegs == NumFloatArgRegs);
+  if (regIndex_ == NumIntArgRegs) {
+    if (type == MIRType::Simd128) {
+      // On Win64, >64 bit args need to be passed by reference.  However, wasm
+      // doesn't allow passing SIMD values to JS, so the only way to reach this
+      // is wasm to wasm calls.  Ergo we can break the native ABI here and use
+      // the Wasm ABI instead.
+      stackOffset_ = AlignBytes(stackOffset_, SimdMemoryAlignment);
+      current_ = ABIArg(stackOffset_);
+      stackOffset_ += Simd128DataSize;
+    } else {
+      current_ = ABIArg(stackOffset_);
+      stackOffset_ += sizeof(uint64_t);
+    }
+    return current_;
+  }
+  switch (type) {
+    case MIRType::Int32:
+    case MIRType::Int64:
+    case MIRType::Pointer:
+    case MIRType::RefOrNull:
+    case MIRType::StackResults:
+      current_ = ABIArg(IntArgRegs[regIndex_++]);
+      break;
+    case MIRType::Float32:
+      current_ = ABIArg(FloatArgRegs[regIndex_++].asSingle());
+      break;
+    case MIRType::Double:
+      current_ = ABIArg(FloatArgRegs[regIndex_++]);
+      break;
+    case MIRType::Simd128:
+      // On Win64, >64 bit args need to be passed by reference, but wasm
+      // doesn't allow passing SIMD values to FFIs. The only way to reach
+      // here is asm to asm calls, so we can break the ABI here.
+      current_ = ABIArg(FloatArgRegs[regIndex_++].asSimd128());
+      break;
+    default:
+      MOZ_CRASH("Unexpected argument type");
+  }
+  return current_;
+#else
+  switch (type) {
+    case MIRType::Int32:
+    case MIRType::Int64:
+    case MIRType::Pointer:
+    case MIRType::RefOrNull:
+    case MIRType::StackResults:
+      if (intRegIndex_ == NumIntArgRegs) {
+        current_ = ABIArg(stackOffset_);
+        stackOffset_ += sizeof(uint64_t);
+        break;
+      }
+      current_ = ABIArg(IntArgRegs[intRegIndex_++]);
+      break;
+    case MIRType::Double:
+    case MIRType::Float32:
+      if (floatRegIndex_ == NumFloatArgRegs) {
+        current_ = ABIArg(stackOffset_);
+        stackOffset_ += sizeof(uint64_t);
+        break;
+      }
+      if (type == MIRType::Float32) {
+        current_ = ABIArg(FloatArgRegs[floatRegIndex_++].asSingle());
+      } else {
+        current_ = ABIArg(FloatArgRegs[floatRegIndex_++]);
+      }
+      break;
+    case MIRType::Simd128:
+      if (floatRegIndex_ == NumFloatArgRegs) {
+        stackOffset_ = AlignBytes(stackOffset_, SimdMemoryAlignment);
+        current_ = ABIArg(stackOffset_);
+        stackOffset_ += Simd128DataSize;
+        break;
+      }
+      current_ = ABIArg(FloatArgRegs[floatRegIndex_++].asSimd128());
+      break;
+    default:
+      MOZ_CRASH("Unexpected argument type");
+  }
+  return current_;
+#endif
+}
+
+void Assembler::addPendingJump(JmpSrc src, ImmPtr target,
+                               RelocationKind reloc) {
+  MOZ_ASSERT(target.value != nullptr);
+
+  // Emit reloc before modifying the jump table, since it computes a 0-based
+  // index. This jump is not patchable at runtime.
+  if (reloc == RelocationKind::JITCODE) {
+    jumpRelocations_.writeUnsigned(src.offset());
+  }
+
+  static_assert(MaxCodeBytesPerProcess <= uint64_t(2) * 1024 * 1024 * 1024,
+                "Code depends on using int32_t for cross-JitCode jump offsets");
+
+  MOZ_ASSERT_IF(reloc == RelocationKind::JITCODE,
+                AddressIsInExecutableMemory(target.value));
+
+  RelativePatch patch(src.offset(), target.value, reloc);
+  if (reloc == RelocationKind::JITCODE ||
+      AddressIsInExecutableMemory(target.value)) {
+    enoughMemory_ &= codeJumps_.append(patch);
+  } else {
+    enoughMemory_ &= extendedJumps_.append(patch);
+  }
+}
+
+void Assembler::finish() {
+  if (oom()) {
+    return;
+  }
+
+  AutoCreatedBy acb(*this, "Assembler::finish");
+
+  if (!extendedJumps_.length()) {
+    // Since we may be folowed by non-executable data, eagerly insert an
+    // undefined instruction byte to prevent processors from decoding
+    // gibberish into their pipelines. See Intel performance guides.
+    masm.ud2();
+    return;
+  }
+
+  // Emit the jump table.
+  masm.haltingAlign(SizeOfJumpTableEntry);
+  extendedJumpTable_ = masm.size();
+
+  // Zero the extended jumps table.
+  for (size_t i = 0; i < extendedJumps_.length(); i++) {
+#ifdef DEBUG
+    size_t oldSize = masm.size();
+#endif
+    MOZ_ASSERT(hasCreator());
+    masm.jmp_rip(2);
+    MOZ_ASSERT_IF(!masm.oom(), masm.size() - oldSize == 6);
+    // Following an indirect branch with ud2 hints to the hardware that
+    // there's no fall-through. This also aligns the 64-bit immediate.
+    masm.ud2();
+    MOZ_ASSERT_IF(!masm.oom(), masm.size() - oldSize == 8);
+    masm.immediate64(0);
+    MOZ_ASSERT_IF(!masm.oom(), masm.size() - oldSize == SizeOfExtendedJump);
+    MOZ_ASSERT_IF(!masm.oom(), masm.size() - oldSize == SizeOfJumpTableEntry);
+  }
+}
+
+void Assembler::executableCopy(uint8_t* buffer) {
+  AssemblerX86Shared::executableCopy(buffer);
+
+  for (RelativePatch& rp : codeJumps_) {
+    uint8_t* src = buffer + rp.offset;
+    MOZ_ASSERT(rp.target);
+
+    MOZ_RELEASE_ASSERT(X86Encoding::CanRelinkJump(src, rp.target));
+    X86Encoding::SetRel32(src, rp.target);
+  }
+
+  for (size_t i = 0; i < extendedJumps_.length(); i++) {
+    RelativePatch& rp = extendedJumps_[i];
+    uint8_t* src = buffer + rp.offset;
+    MOZ_ASSERT(rp.target);
+
+    if (X86Encoding::CanRelinkJump(src, rp.target)) {
+      X86Encoding::SetRel32(src, rp.target);
+    } else {
+      // An extended jump table must exist, and its offset must be in
+      // range.
+      MOZ_ASSERT(extendedJumpTable_);
+      MOZ_ASSERT((extendedJumpTable_ + i * SizeOfJumpTableEntry) <=
+                 size() - SizeOfJumpTableEntry);
+
+      // Patch the jump to go to the extended jump entry.
+      uint8_t* entry = buffer + extendedJumpTable_ + i * SizeOfJumpTableEntry;
+      X86Encoding::SetRel32(src, entry);
+
+      // Now patch the pointer, note that we need to align it to
+      // *after* the extended jump, i.e. after the 64-bit immedate.
+      X86Encoding::SetPointer(entry + SizeOfExtendedJump, rp.target);
+    }
+  }
+}
+
+class RelocationIterator {
+  CompactBufferReader reader_;
+  uint32_t offset_ = 0;
+
+ public:
+  explicit RelocationIterator(CompactBufferReader& reader) : reader_(reader) {}
+
+  bool read() {
+    if (!reader_.more()) {
+      return false;
+    }
+    offset_ = reader_.readUnsigned();
+    return true;
+  }
+
+  uint32_t offset() const { return offset_; }
+};
+
+JitCode* Assembler::CodeFromJump(JitCode* code, uint8_t* jump) {
+  uint8_t* target = (uint8_t*)X86Encoding::GetRel32Target(jump);
+
+  MOZ_ASSERT(!code->containsNativePC(target),
+             "Extended jump table not used for cross-JitCode jumps");
+
+  return JitCode::FromExecutable(target);
+}
+
+void Assembler::TraceJumpRelocations(JSTracer* trc, JitCode* code,
+                                     CompactBufferReader& reader) {
+  RelocationIterator iter(reader);
+  while (iter.read()) {
+    JitCode* child = CodeFromJump(code, code->raw() + iter.offset());
+    TraceManuallyBarrieredEdge(trc, &child, "rel32");
+    MOZ_ASSERT(child == CodeFromJump(code, code->raw() + iter.offset()));
+  }
+}