[CIR] Add MLIR lowering for f16, bf16, and f128 (#1264)

Author: Lancern

clang/lib/CIR/Lowering/ThroughMLIR/LowerCIRToMLIR.cpp

@@ -1401,6 +1401,15 @@ static mlir::TypeConverter prepareTypeConverter() {
   converter.addConversion([&](cir::LongDoubleType type) -> mlir::Type {
     return converter.convertType(type.getUnderlying());
   });
+  converter.addConversion([&](cir::FP128Type type) -> mlir::Type {
+    return mlir::FloatType::getF128(type.getContext());
+  });
+  converter.addConversion([&](cir::FP16Type type) -> mlir::Type {
+    return mlir::FloatType::getF16(type.getContext());
+  });
+  converter.addConversion([&](cir::BF16Type type) -> mlir::Type {
+    return mlir::FloatType::getBF16(type.getContext());
+  });
   converter.addConversion([&](cir::ArrayType type) -> mlir::Type {
     SmallVector<int64_t> shape;
     mlir::Type curType = type;

clang/test/CIR/Lowering/ThroughMLIR/float.cir

@@ -0,0 +1,23 @@
+// RUN: cir-opt %s -cir-to-mlir -o %t.mlir
+// RUN: FileCheck %s --input-file %t.mlir
+
+module {
+  cir.func @foo() {
+    %0 = cir.const #cir.fp<1.0> : !cir.float
+    %1 = cir.const #cir.fp<1.0> : !cir.double
+    %2 = cir.const #cir.fp<1.0> : !cir.long_double<!cir.f80>
+    %3 = cir.const #cir.fp<1.0> : !cir.f128
+    %4 = cir.const #cir.fp<1.0> : !cir.f16
+    %5 = cir.const #cir.fp<1.0> : !cir.bf16
+    cir.return
+  }
+
+  // CHECK-LABEL: @foo
+  //      CHECK:   %{{.+}} = arith.constant 1.000000e+00 : f32
+  // CHECK-NEXT:   %{{.+}} = arith.constant 1.000000e+00 : f64
+  // CHECK-NEXT:   %{{.+}} = arith.constant 1.000000e+00 : f80
+  // CHECK-NEXT:   %{{.+}} = arith.constant 1.000000e+00 : f128
+  // CHECK-NEXT:   %{{.+}} = arith.constant 1.000000e+00 : f16
+  // CHECK-NEXT:   %{{.+}} = arith.constant 1.000000e+00 : bf16
+  //      CHECK: }
+}