[flang] lower SPACING f16/bf16 to new runtime APIs (#107541)

Use APIs added in #106575

This is needed to fix HDF5 builds that are blocked by SPACING TODOs for
REAL(2) and currently needs manual hacks.

Author: jeanPerier

flang/lib/Optimizer/Builder/Runtime/Numeric.cpp

@@ -625,7 +625,11 @@ mlir::Value fir::runtime::genSpacing(fir::FirOpBuilder &builder,
                                      mlir::Location loc, mlir::Value x) {
   mlir::func::FuncOp func;
   mlir::Type fltTy = x.getType();
-
+  // TODO: for f16/bf16, there are better alternatives that do not require
+  // casting the argument (resp. result) to (resp. from) f32, but this requires
+  // knowing that the target runtime has been compiled with std::float16_t or
+  // std::bfloat16_t support, which is not an information available here for
+  // now.
   if (fltTy.isF32())
     func = fir::runtime::getRuntimeFunc<mkRTKey(Spacing4)>(loc, builder);
   else if (fltTy.isF64())
@@ -634,12 +638,17 @@ mlir::Value fir::runtime::genSpacing(fir::FirOpBuilder &builder,
     func = fir::runtime::getRuntimeFunc<ForcedSpacing10>(loc, builder);
   else if (fltTy.isF128())
     func = fir::runtime::getRuntimeFunc<ForcedSpacing16>(loc, builder);
+  else if (fltTy.isF16())
+    func = fir::runtime::getRuntimeFunc<mkRTKey(Spacing2By4)>(loc, builder);
+  else if (fltTy.isBF16())
+    func = fir::runtime::getRuntimeFunc<mkRTKey(Spacing3By4)>(loc, builder);
   else
     fir::intrinsicTypeTODO(builder, fltTy, loc, "SPACING");
 
   auto funcTy = func.getFunctionType();
   llvm::SmallVector<mlir::Value> args = {
       builder.createConvert(loc, funcTy.getInput(0), x)};
 
-  return builder.create<fir::CallOp>(loc, func, args).getResult(0);
+  mlir::Value res = builder.create<fir::CallOp>(loc, func, args).getResult(0);
+  return builder.createConvert(loc, fltTy, res);
 }

flang/test/Lower/Intrinsics/spacing.f90

@@ -1,20 +1,36 @@
-! RUN: bbc -emit-fir -hlfir=false %s -o - | FileCheck %s
-! RUN: %flang_fc1 -emit-fir -flang-deprecated-no-hlfir %s -o - | FileCheck %s
+! RUN: bbc -emit-fir %s -o - | FileCheck %s
+! RUN: %flang_fc1 -emit-fir %s -o - | FileCheck %s
 
 ! CHECK-LABEL: func @_QPspacing_test(
-! CHECK-SAME: %[[x:[^:]+]]: !fir.ref<f32>{{.*}}) -> f32
 real*4 function spacing_test(x)
   real*4 :: x
   spacing_test = spacing(x)
-! CHECK: %[[a1:.*]] = fir.load %[[x]] : !fir.ref<f32>
+! CHECK: %[[a1:.*]] = fir.load %{{.*}} : !fir.ref<f32>
 ! CHECK: %{{.*}} = fir.call @_FortranASpacing4(%[[a1]]) {{.*}}: (f32) -> f32
 end function
 
 ! CHECK-LABEL: func @_QPspacing_test2(
-! CHECK-SAME: %[[x:[^:]+]]: !fir.ref<f80>{{.*}}) -> f80
 real*10 function spacing_test2(x)
   real*10 :: x
   spacing_test2 = spacing(x)
-! CHECK: %[[a1:.*]] = fir.load %[[x]] : !fir.ref<f80>
+! CHECK: %[[a1:.*]] = fir.load %{{.*}} : !fir.ref<f80>
 ! CHECK: %{{.*}} = fir.call @_FortranASpacing10(%[[a1]]) {{.*}}: (f80) -> f80
 end function
+
+! CHECK-LABEL: test_real2
+subroutine test_real2(x, y)
+  real(2) :: x, y
+  y = spacing(x)
+! CHECK: %[[CAST_ARG:.*]] = fir.convert %{{.*}} : (f16) -> f32
+! CHECK: %[[RT_RES:.*]] = fir.call @_FortranASpacing2By4(%[[CAST_ARG]]){{.*}}: (f32) -> f32
+! CHECK: fir.convert %[[RT_RES]] : (f32) -> f16
+end subroutine
+
+! CHECK-LABEL: test_real3
+subroutine test_real3(x, y)
+  real(3) :: x, y
+  y = spacing(x)
+! CHECK: %[[CAST_ARG:.*]] = fir.convert %{{.*}} : (bf16) -> f32
+! CHECK: %[[RT_RES:.*]] = fir.call @_FortranASpacing3By4(%[[CAST_ARG]]){{.*}}: (f32) -> f32
+! CHECK: fir.convert %[[RT_RES]] : (f32) -> bf16
+end subroutine