[flang][cuda] Add interfaces for __expf and __exp10f (#153633)

Author: clementval

flang/module/cudadevice.f90

@@ -1741,6 +1741,20 @@ attributes(device,host) logical function on_device() bind(c)
     end function
   end interface
 
+  interface __expf
+    attributes(device) real function __expf(r) bind(c, name='__nv_expf')
+      !dir$ ignore_tkr (d) r
+      real, value :: r
+    end function
+  end interface
+
+  interface __exp10f
+    attributes(device) real function __exp10f(r) bind(c, name='__nv_exp10f')
+      !dir$ ignore_tkr (d) r
+      real, value :: r
+    end function
+  end interface
+
 contains
 
   attributes(device) subroutine syncthreads()

flang/test/Lower/CUDA/cuda-libdevice.cuf

@@ -89,3 +89,14 @@ end subroutine
 
 ! CHECK-LABEL: _QPtest_tanf
 ! CHECK: %{{.*}} = fir.call @__nv_tanf(%{{.*}}) proc_attrs<bind_c> fastmath<contract> : (f32) -> f32
+
+attributes(global) subroutine test_exp()
+  real :: res
+  real :: r
+  res = __expf(r)
+  res = __exp10f(r)
+end subroutine
+
+! CHECK-LABEL: _QPtest_exp
+! CHECK: %{{.*}} = fir.call @__nv_expf(%{{.*}}) proc_attrs<bind_c> fastmath<contract> : (f32) -> f32
+! CHECK: %{{.*}} = fir.call @__nv_exp10f(%{{.*}}) proc_attrs<bind_c> fastmath<contract> : (f32) -> f32