[CIR] Add CIRGenFunction::getTypeSizeInBits and use it for size computation (#1874)

Author: wizardengineer

clang/lib/CIR/CodeGen/CIRGenBuiltinX86.cpp

@@ -1053,18 +1053,7 @@ mlir::Value CIRGenFunction::emitX86BuiltinExpr(unsigned BuiltinID,
     unsigned numElts = vecTy.getSize();
     auto eltTy = vecTy.getElementType();
 
-    assert(isSized(eltTy) && "Element type must be a sized type");
-
-    unsigned eltBitWidth =
-        llvm::TypeSwitch<mlir::Type, unsigned>(eltTy)
-            .Case<cir::IntType>([](auto intTy) { return intTy.getWidth(); })
-            .Case<cir::SingleType>([](auto) { return 32; })
-            .Case<cir::DoubleType>([](auto) { return 64; })
-            .Default([](auto) {
-              llvm_unreachable("NYI: Unsupported type");
-              return 0;
-            });
-
+    unsigned eltBitWidth = getTypeSizeInBits(eltTy).getFixedValue();
     unsigned vecBitWidth = numElts * eltBitWidth;
     unsigned numLanes = vecBitWidth / 128;
     unsigned numLaneElts = numElts / numLanes;

clang/lib/CIR/CodeGen/CIRGenFunction.h

@@ -1842,6 +1842,13 @@ class CIRGenFunction : public CIRGenTypeCache {
   mlir::Value emitBuiltinObjectSize(const Expr *E, unsigned Type,
                                     cir::IntType ResType, mlir::Value EmittedE,
                                     bool IsDynamic);
+
+  /// Get size of type in bits using SizedTypeInterface
+  llvm::TypeSize getTypeSizeInBits(mlir::Type Ty) const {
+    assert(cir::isSized(Ty) && "Type must implement SizedTypeInterface");
+    return CGM.getDataLayout().getTypeSizeInBits(Ty);
+  }
+
   template <uint32_t N>
   [[maybe_unused]] RValue
   emitBuiltinWithOneOverloadedType(const CallExpr *E, llvm::StringRef Name) {