[CodeGen][NFCI] Don't re-implement parts of ASTContext::getIntWidth

[jrtc27]

ASTContext::getIntWidth returns 1 if isBooleanType(), and falls back on
getTypeSize in the default case, which itself just returns the Width
from getTypeInfo's returned struct, so can be used in all cases here,
not just for _BitInt types.

[llvmbot]

@llvm/pr-subscribers-clang

@llvm/pr-subscribers-clang-codegen

Author: Jessica Clarke (jrtc27)

Changes

ASTContext::getIntWidth returns 1 if isBooleanType(), and falls back on
getTypeSize in the default case, which itself just returns the Width
from getTypeInfo's returned struct, so can be used in all cases here,
not just for _BitInt types.

---

Full diff: https://github.com/llvm/llvm-project/pull/101765.diff

1 Files Affected:

• (modified) clang/lib/CodeGen/CGBuiltin.cpp (+1-3)

diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 3221989e14351..a0140b81925d1 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -756,9 +756,7 @@ static WidthAndSignedness
 getIntegerWidthAndSignedness(const clang::ASTContext &context,
                              const clang::QualType Type) {
   assert(Type->isIntegerType() && "Given type is not an integer.");
-  unsigned Width = Type->isBooleanType()  ? 1
-                   : Type->isBitIntType() ? context.getIntWidth(Type)
-                                          : context.getTypeInfo(Type).Width;
+  unsigned Width = context.getIntWidth(Type);
   bool Signed = Type->isSignedIntegerType();
   return {Width, Signed};
 }

[jrtc27]

For the avoidance of doubt, I would appreciate a review from a core Clang developer, given Alex also comes from a CHERI LLVM background.

[arichardson]

I just had another look at ASTContext::getIntWidth() and the logic there results in the same value being returned, so this should be a NFC change.

unsigned ASTContext::getIntWidth(QualType T) const {
  if (const auto *ET = T->getAs<EnumType>())
    T = ET->getDecl()->getIntegerType();
  if (T->isBooleanType())
    return 1;
  if (const auto *EIT = T->getAs<BitIntType>())
    return EIT->getNumBits();
  // For builtin types, just use the standard type sizing method
  return (unsigned)getTypeSize(T);
}

[mizvekov]

Yeah, looks NFC to me as well.

LGTM