[CodeGen] Add machine IR value semantics

Add strongly typed machine indices, lane masks, instruction flags, fixed-point branch probabilities, and preserved-register masks.

Model immutable machine memory operands with explicit base identity, size, alignment, address space, alias information, and validated atomic operation and ordering rules. Cover normal, boundary, and invalid combinations in standalone tests.

1 files changed, 29 insertions, 0 deletions

diff --git a/backend/lib/CodeGen/MachineIRTypes.cpp b/backend/lib/CodeGen/MachineIRTypes.cpp
new file mode 100644
index 0000000..7f97e98
--- /dev/null
+++ b/backend/lib/CodeGen/MachineIRTypes.cpp
@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "rcc/CodeGen/MachineIRTypes.h"
+
+namespace rcc {
+
+Expected<BranchProbability> BranchProbability::fromFraction(std::uint32_t Numerator,
+                                                            std::uint32_t Denominator) {
+  if (Denominator == 0) {
+    return makeUnexpected(ErrorCode::InvalidArgument,
+                          "branch probability denominator must be nonzero");
+  }
+  if (Numerator > Denominator) {
+    return makeUnexpected(ErrorCode::InvalidArgument,
+                          "branch probability numerator cannot exceed its denominator");
+  }
+
+  const std::uint64_t ScaledNumerator = static_cast<std::uint64_t>(Numerator) * MaxRawValue;
+  const std::uint64_t Rounded =
+      (ScaledNumerator + static_cast<std::uint64_t>(Denominator / 2)) / Denominator;
+  return BranchProbability(static_cast<std::uint32_t>(Rounded));
+}
+
+MachineInstrFlags::MachineInstrFlags(std::initializer_list<MachineInstrFlag> Flags) noexcept {
+  for (const MachineInstrFlag Flag : Flags)
+    set(Flag);
+}
+
+} // namespace rcc