[flang] Implement ieee_is_normal

[DavidTruby]

Summary

This patch adds an implementation of ieee_is_normal using a call
to llvm.is.fpclass.

Depends on D144649

[kiranchandramohan]

flang/lib/Optimizer/Builder/IntrinsicCall.cpp

3614

Did you miss the zero checks (i.e bits 5 and 6)?

`The result has the value true if IEEE_CLASS (X) has one of the values IEEE_NEGATIVE_-
NORMAL, IEEE_NEGATIVE_ZERO, IEEE_POSITIVE_ZERO or IEEE_POSITIVE_NORMAL; otherwise,
the result has the value false.`

3614

Also is there another way to say the bit positions without having to eye-ball?

flang/test/Lower/Intrinsics/ieee_is_normal.f90

3

kind=2,3 (half precision, bfloat) are also supported.

[DavidTruby]

Add checks for negative and positive zero
Add tests for f16 and bf16

[kiranchandramohan]

LGTM.

flang/lib/Evaluate/fold-logical.cpp

if (name == "all") {
     using DefaultReal = Type<TypeCategory::Real, 4>;
     return FoldElementalIntrinsic<T, DefaultReal>(context, std::move(funcRef),
         ScalarFunc<T, DefaultReal>([](const Scalar<DefaultReal> &x) {
           return Scalar<T>{x.IsNegative()};
         }));
   } else if (name == "__builtin_ieee_is_normal") {
     auto restorer{context.messages().DiscardMessages()};
     using DefaultReal = Type<TypeCategory::Real, 4>;
+    if (args[0] && args[0]->UnwrapExpr() &&
+        IsActuallyConstant(*args[0]->UnwrapExpr())) {
       return FoldElementalIntrinsic<T, DefaultReal>(context, std::move(funcRef),
           ScalarFunc<T, DefaultReal>([](const Scalar<DefaultReal> &x) {
             return Scalar<T>{x.IsNormal()};
           }));
+    }
   } else if (name == "is_contiguous") {
     if (args.at(0)) {
       if (auto *expr{args[0]->UnwrapExpr()}) {
         if (auto contiguous{IsContiguous(*expr, context)}) {
           return Expr<T>{*contiguous};
         }
       }
     }

flang/lib/Optimizer/Builder/IntrinsicCall.cpp

struct IntrinsicLibrary {
   mlir::Value genIand(mlir::Type, llvm::ArrayRef<mlir::Value>);
   fir::ExtendedValue genIany(mlir::Type, llvm::ArrayRef<fir::ExtendedValue>);
   mlir::Value genIbclr(mlir::Type, llvm::ArrayRef<mlir::Value>);
   mlir::Value genIbits(mlir::Type, llvm::ArrayRef<mlir::Value>);
   mlir::Value genIbset(mlir::Type, llvm::ArrayRef<mlir::Value>);
   fir::ExtendedValue genIchar(mlir::Type, llvm::ArrayRef<fir::ExtendedValue>);
   fir::ExtendedValue genFindloc(mlir::Type, llvm::ArrayRef<fir::ExtendedValue>);
   mlir::Value genIeeeIsFinite(mlir::Type, llvm::ArrayRef<mlir::Value>);
+  mlir::Value genIeeeIsNormal(mlir::Type, llvm::ArrayRef<mlir::Value>);
   template <mlir::arith::CmpIPredicate pred>
   fir::ExtendedValue genIeeeTypeCompare(mlir::Type,
                                         llvm::ArrayRef<fir::ExtendedValue>);
   mlir::Value genIeor(mlir::Type, llvm::ArrayRef<mlir::Value>);
   fir::ExtendedValue genIndex(mlir::Type, llvm::ArrayRef<fir::ExtendedValue>);
   mlir::Value genIor(mlir::Type, llvm::ArrayRef<mlir::Value>);
   fir::ExtendedValue genIparity(mlir::Type, llvm::ArrayRef<fir::ExtendedValue>);
   fir::ExtendedValue genIsContiguous(mlir::Type,
                                      llvm::ArrayRef<fir::ExtendedValue>);
   mlir::Value genIsNan(mlir::Type, llvm::ArrayRef<mlir::Value>);
+  mlir::Value genIsFPClass(mlir::Type, llvm::ArrayRef<mlir::Value>,
+                           int fpclass);
   mlir::Value genIshft(mlir::Type, llvm::ArrayRef<mlir::Value>);
   mlir::Value genIshftc(mlir::Type, llvm::ArrayRef<mlir::Value>);
   fir::ExtendedValue genLbound(mlir::Type, llvm::ArrayRef<fir::ExtendedValue>);
   mlir::Value genLeadz(mlir::Type, llvm::ArrayRef<mlir::Value>);
   fir::ExtendedValue genLen(mlir::Type, llvm::ArrayRef<fir::ExtendedValue>);
   fir::ExtendedValue genLenTrim(mlir::Type, llvm::ArrayRef<fir::ExtendedValue>);
   fir::ExtendedValue genLoc(mlir::Type, llvm::ArrayRef<fir::ExtendedValue>);
   template <typename Shift>
static constexpr IntrinsicHandler handlers[]{
     {"ibclr", &I::genIbclr},
     {"ibits", &I::genIbits},
     {"ibset", &I::genIbset},
     {"ichar", &I::genIchar},
     {"ieee_class_eq", &I::genIeeeTypeCompare<mlir::arith::CmpIPredicate::eq>},
     {"ieee_class_ne", &I::genIeeeTypeCompare<mlir::arith::CmpIPredicate::ne>},
     {"ieee_is_finite", &I::genIeeeIsFinite},
     {"ieee_is_nan", &I::genIsNan},
+    {"ieee_is_normal", &I::genIeeeIsNormal},
     {"ieee_round_eq", &I::genIeeeTypeCompare<mlir::arith::CmpIPredicate::eq>},
     {"ieee_round_ne", &I::genIeeeTypeCompare<mlir::arith::CmpIPredicate::ne>},
     {"ieor", &I::genIeor},
     {"index",
      &I::genIndex,
      {{{"string", asAddr},
        {"substring", asAddr},
        {"back", asValue, handleDynamicOptional},
mlir::Value exponent = genIbits(
       intType, {intVal, significand,
                 builder.createIntegerConstant(loc, intType, exponentBits)});
   return builder.createConvert(
       loc, resultType,
       builder.create<mlir::arith::CmpIOp>(loc, mlir::arith::CmpIPredicate::ne,
                                           exponent, maxExponent));
 }
 
+mlir::Value
+IntrinsicLibrary::genIeeeIsNormal(mlir::Type resultType,
+                                  llvm::ArrayRef<mlir::Value> args) {
+  // Check if is positive or negative normal
+  return genIsFPClass(resultType, args, 0b100001000);
+}
+
 // IEOR
 mlir::Value IntrinsicLibrary::genIeor(mlir::Type resultType,
                                       llvm::ArrayRef<mlir::Value> args) {
   assert(args.size() == 2);
   return builder.create<mlir::arith::XOrIOp>(loc, args[0], args[1]);
 }
 
 // INDEX
if (const auto *boxValue = args[0].getBoxOf<fir::BoxValue>())
     if (boxValue->hasAssumedRank())
       TODO(loc, "intrinsic: is_contiguous with assumed rank argument");
 
   return builder.createConvert(
       loc, resultType,
       fir::runtime::genIsContiguous(builder, loc, fir::getBase(args[0])));
 }
 
-mlir::Value IntrinsicLibrary::genIsNan(mlir::Type resultType,
-                                       llvm::ArrayRef<mlir::Value> args) {
+mlir::Value IntrinsicLibrary::genIsFPClass(mlir::Type resultType,
+                                           llvm::ArrayRef<mlir::Value> args,
+                                           int fpclass) {
   assert(args.size() == 1);
   mlir::MLIRContext *context = builder.getContext();
   mlir::IntegerType i1ty = mlir::IntegerType::get(context, 1);
   mlir::IntegerType i32ty = mlir::IntegerType::get(context, 32);
-  // The last two bits indicate we are checking for signalling or quiet nan.
-  mlir::Value nan = builder.createIntegerConstant(loc, i32ty, 0b11);
 
-  mlir::Value isnan =
-      builder.create<mlir::LLVM::IsFPClass>(loc, i1ty, args[0], nan);
-  return builder.createConvert(loc, resultType, isnan);
+  mlir::Value test = builder.createIntegerConstant(loc, i32ty, fpclass);
+  mlir::Value isfpclass =
+      builder.create<mlir::LLVM::IsFPClass>(loc, i1ty, args[0], test);
+  return builder.createConvert(loc, resultType, isfpclass);
+}
+
+mlir::Value IntrinsicLibrary::genIsNan(mlir::Type resultType,
+                                       llvm::ArrayRef<mlir::Value> args) {
+  // Check is signaling or quiet nan
+  return genIsFPClass(resultType, args, 0b11);
 }
 
 // ISHFT
 mlir::Value IntrinsicLibrary::genIshft(mlir::Type resultType,
                                        llvm::ArrayRef<mlir::Value> args) {
   // A conformant ISHFT(I,SHIFT) call satisfies:
   //     abs(SHIFT) <= BIT_SIZE(I)
   // Return:  abs(SHIFT) >= BIT_SIZE(I)

flang/test/Lower/Intrinsics/ieee_is_normal.f90

+! RUN: bbc -emit-fir %s -o - | FileCheck %s
+! RUN: flang-new -fc1 -emit-fir %s -o - | FileCheck %s
+
+! CHECK-LABEL: ieee_is_normal_f32
+subroutine ieee_is_normal_f32(r)
+  use ieee_arithmetic
+  real :: r
+  i = ieee_is_normal(r)
+  ! CHECK: %[[test:.*]] = arith.constant 264 : i32
+  ! CHECK: %[[l:.*]] = "llvm.intr.is.fpclass"(%{{.*}}, %[[test]]) : (f32, i32) -> i1
+  ! CHECK: fir.convert %[[l]] : (i1) -> !fir.logical<4>
+end subroutine ieee_is_normal_f32
+
+! CHECK-LABEL: ieee_is_normal_f64
+subroutine ieee_is_normal_f64(r)
+  use ieee_arithmetic
+  real(KIND=8) :: r
+  i = ieee_is_normal(r)
+  ! CHECK: %[[test:.*]] = arith.constant 264 : i32
+  ! CHECK: %[[l:.*]] = "llvm.intr.is.fpclass"(%{{.*}}, %[[test]]) : (f64, i32) -> i1
+  ! CHECK: fir.convert %[[l]] : (i1) -> !fir.logical<4>
+end subroutine ieee_is_normal_f64
+
+! CHECK-LABEL: ieee_is_normal_f80
+subroutine ieee_is_normal_f80(r)
+  use ieee_arithmetic
+  real(KIND=10) :: r
+  i = ieee_is_normal(r)
+  ! CHECK: %[[test:.*]] = arith.constant 264 : i32
+  ! CHECK: %[[l:.*]] = "llvm.intr.is.fpclass"(%{{.*}}, %[[test]]) : (f80, i32) -> i1
+  ! CHECK: fir.convert %[[l]] : (i1) -> !fir.logical<4>
+end subroutine ieee_is_normal_f80
+
+! CHECK-LABEL: ieee_is_normal_f128
+subroutine ieee_is_normal_f128(r)
+  use ieee_arithmetic
+  real(KIND=16) :: r
+  i = ieee_is_normal(r)
+  ! CHECK: %[[test:.*]] = arith.constant 264 : i32
+  ! CHECK: %[[l:.*]] = "llvm.intr.is.fpclass"(%{{.*}}, %[[test]]) : (f128, i32) -> i1
+  ! CHECK: fir.convert %[[l]] : (i1) -> !fir.logical<4>
+end subroutine ieee_is_normal_f128