[llvm] [ADT] Modernize Bitset (NFC) (PR #162430)

[Kazu Hirata via llvm-commits]

https://github.com/kazutakahirata updated https://github.com/llvm/llvm-project/pull/162430

>From e0ba22227da4b942709a1dc3e0e4736c2e145ce5 Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Tue, 7 Oct 2025 07:19:57 -0700
Subject: [PATCH 1/2] [ADT] Modernize Bitset (NFC)

This patch modernizes BitWord and BITWORD_SIZE with "using" and
"static constexpr", respectively.
---
 llvm/include/llvm/ADT/Bitset.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/llvm/include/llvm/ADT/Bitset.h b/llvm/include/llvm/ADT/Bitset.h
index ecb6b149f0494..d9f750ff55185 100644
--- a/llvm/include/llvm/ADT/Bitset.h
+++ b/llvm/include/llvm/ADT/Bitset.h
@@ -28,9 +28,9 @@ namespace llvm {
 /// initialization.
 template <unsigned NumBits>
 class Bitset {
-  typedef uintptr_t BitWord;
+  using BitWord = uintptr_t;
 
-  enum { BITWORD_SIZE = (unsigned)sizeof(BitWord) * CHAR_BIT };
+  static constexpr unsigned BITWORD_SIZE = sizeof(BitWord) * CHAR_BIT;
 
   static_assert(BITWORD_SIZE == 64 || BITWORD_SIZE == 32,
                 "Unsupported word size");

>From ac429a0cda148838ffff9dcb3f6da496919442bc Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Wed, 8 Oct 2025 06:49:08 -0700
Subject: [PATCH 2/2] Address a comment.

---
 llvm/include/llvm/ADT/Bitset.h | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/llvm/include/llvm/ADT/Bitset.h b/llvm/include/llvm/ADT/Bitset.h
index d9f750ff55185..b1e539e39aff7 100644
--- a/llvm/include/llvm/ADT/Bitset.h
+++ b/llvm/include/llvm/ADT/Bitset.h
@@ -30,13 +30,13 @@ template <unsigned NumBits>
 class Bitset {
   using BitWord = uintptr_t;
 
-  static constexpr unsigned BITWORD_SIZE = sizeof(BitWord) * CHAR_BIT;
+  static constexpr unsigned BitwordBits = sizeof(BitWord) * CHAR_BIT;
 
-  static_assert(BITWORD_SIZE == 64 || BITWORD_SIZE == 32,
+  static_assert(BitwordBits == 64 || BitwordBits == 32,
                 "Unsupported word size");
 
   static constexpr unsigned NumWords =
-      (NumBits + BITWORD_SIZE - 1) / BITWORD_SIZE;
+      (NumBits + BitwordBits - 1) / BitwordBits;
 
 protected:
   using StorageType = std::array<BitWord, NumWords>;
@@ -60,23 +60,23 @@ class Bitset {
   }
 
   constexpr Bitset &set(unsigned I) {
-    Bits[I / BITWORD_SIZE] |= BitWord(1) << (I % BITWORD_SIZE);
+    Bits[I / BitwordBits] |= BitWord(1) << (I % BitwordBits);
     return *this;
   }
 
   constexpr Bitset &reset(unsigned I) {
-    Bits[I / BITWORD_SIZE] &= ~(BitWord(1) << (I % BITWORD_SIZE));
+    Bits[I / BitwordBits] &= ~(BitWord(1) << (I % BitwordBits));
     return *this;
   }
 
   constexpr Bitset &flip(unsigned I) {
-    Bits[I / BITWORD_SIZE] ^= BitWord(1) << (I % BITWORD_SIZE);
+    Bits[I / BitwordBits] ^= BitWord(1) << (I % BitwordBits);
     return *this;
   }
 
   constexpr bool operator[](unsigned I) const {
-    BitWord Mask = BitWord(1) << (I % BITWORD_SIZE);
-    return (Bits[I / BITWORD_SIZE] & Mask) != 0;
+    BitWord Mask = BitWord(1) << (I % BitwordBits);
+    return (Bits[I / BitwordBits] & Mask) != 0;
   }
 
   constexpr bool test(unsigned I) const { return (*this)[I]; }