[Support] Use standard power-of-two checks

3 files changed, 5 insertions, 8 deletions

diff --git a/backend/utils/TableGen/Common/CodeGenInstruction.cpp b/backend/utils/TableGen/Common/CodeGenInstruction.cpp
index a34f5ab..e7f5ddc 100644
--- a/backend/utils/TableGen/Common/CodeGenInstruction.cpp
+++ b/backend/utils/TableGen/Common/CodeGenInstruction.cpp
@@ -4,6 +4,7 @@
 
 #include <algorithm>
 #include <array>
+#include <bit>
 #include <cstdint>
 #include <limits>
 #include <ranges>
@@ -218,7 +219,7 @@ pipelineStageEnumerator(std::string_view Value) noexcept {
     const bool IsUnsigned = Predicate.Kind == "unsigned";
     if (Predicate.ID == 0 || !isIdentifier(Predicate.Symbol) || Predicate.Name.empty() ||
         (!IsSigned && !IsUnsigned) || Predicate.Bits == 0 || Predicate.Bits > 63 ||
-        !isPowerOfTwo(Predicate.Alignment) || !IDs.insert(Predicate.ID).second ||
+        !std::has_single_bit(Predicate.Alignment) || !IDs.insert(Predicate.ID).second ||
         !Symbols.insert(Predicate.Symbol).second || !Names.insert(Predicate.Name).second) {
       fail(Predicate.Range,
            "immediate predicates require nonzero unique IDs, symbols, names, a signed or "
diff --git a/backend/utils/TableGen/Common/CodeGenTarget.cpp b/backend/utils/TableGen/Common/CodeGenTarget.cpp
index d4c9795..478457c 100644
--- a/backend/utils/TableGen/Common/CodeGenTarget.cpp
+++ b/backend/utils/TableGen/Common/CodeGenTarget.cpp
@@ -6,6 +6,7 @@
 #include "rcc/TableGen/Parser.h"
 
 #include <algorithm>
+#include <bit>
 #include <cstddef>
 #include <ranges>
 #include <string>
@@ -15,10 +16,6 @@
 
 namespace rcc::targetgen {
 
-[[nodiscard]] bool isPowerOfTwo(std::uint64_t Value) noexcept {
-  return Value != 0 && (Value & (Value - 1U)) == 0;
-}
-
 CodeGenTarget::CodeGenTarget(const DescriptionAST &Input, std::string SourceName)
     : Input(Input), SourceName(std::move(SourceName)) {}
 
@@ -105,8 +102,8 @@ void CodeGenTarget::fail(TextRange Range, std::string Message) {
         IntegerClass == ClassBySymbol.end() || FloatingClass == ClassBySymbol.end() ||
         PreservedMask == Result.RegisterMasks.end() || Convention.StackAlignmentBytes == 0 ||
         Convention.StackArgumentAlignmentBytes == 0 ||
-        !isPowerOfTwo(Convention.StackAlignmentBytes) ||
-        !isPowerOfTwo(Convention.StackArgumentAlignmentBytes) ||
+        !std::has_single_bit(Convention.StackAlignmentBytes) ||
+        !std::has_single_bit(Convention.StackArgumentAlignmentBytes) ||
         Convention.StackAlignmentBytes % Convention.StackArgumentAlignmentBytes != 0 ||
         Convention.ShadowSpaceBytes % Convention.StackArgumentAlignmentBytes != 0 ||
         !IDs.insert(Convention.ID).second || !Symbols.insert(Convention.Symbol).second ||
diff --git a/backend/utils/TableGen/Common/CodeGenTarget.h b/backend/utils/TableGen/Common/CodeGenTarget.h
index 2ab6db1..a2aed7c 100644
--- a/backend/utils/TableGen/Common/CodeGenTarget.h
+++ b/backend/utils/TableGen/Common/CodeGenTarget.h
@@ -426,7 +426,6 @@ instructionFlagEnumerator(std::string_view Value) noexcept;
 pseudoOwnerEnumerator(std::string_view Value) noexcept;
 [[nodiscard]] std::optional<std::string_view>
 pipelineStageEnumerator(std::string_view Value) noexcept;
-[[nodiscard]] bool isPowerOfTwo(std::uint64_t Value) noexcept;
 
 class CodeGenTarget final {
 public: