Make quadruple precision in stdlib_specialfunctions_gamma.f90 optional

[osada-yum]

This pull request addresses systems that do not support real128 (see issue #964).
In stdlib_specialfunctions_gamma.f90, I added fypp directives to choose whether to include quadruple precision code.

• --with_qp: Quadruple precision is enabled.
• No --with_qp: All qp references (and related _cdp / _rdp procedures) are removed.

How it works

• I added #:if WITH_QP ... #:endif blocks in fypp, and replaced references to real128 with a new variable.
• When --with_qp is passed to fypp_deployment.py, the code for qp remains.
• When --with_qp is omitted, the code for qp is excluded.

diffs old and new src/temp/stdlib_specialfunctions_gamma.f90

With --with-qp

• Very few changes: iso_fortran_env, only : qp => real128 is replaced by use stdlib_kinds, only : ... qp, so quadruple precision still works essentially as before.

 $ python3 config/fypp_deployment.py --with_qp

@@ -1,7 +1,6 @@
 module stdlib_specialfunctions_gamma
-    use iso_fortran_env, only : qp => real128
     use ieee_arithmetic, only: ieee_value, ieee_quiet_nan
-    use stdlib_kinds, only :  sp, dp, int8, int16, int32, int64
+    use stdlib_kinds, only :  sp, dp, qp, int8, int16, int32, int64
     use stdlib_error, only : error_stop

     implicit none

Without --with_qp

• No qp references are generated, and any _cdp / _rdp procedures are removed.

 $ python3 config/fypp_deployment.py

(...) denotes abbreviation.

@@ -1,7 +1,6 @@
 module stdlib_specialfunctions_gamma
-    use iso_fortran_env, only : qp => real128
     use ieee_arithmetic, only: ieee_value, ieee_quiet_nan
-    use stdlib_kinds, only :  sp, dp, int8, int16, int32, int64
+    use stdlib_kinds, only :  sp, dp, qp, int8, int16, int32, int64
     use stdlib_error, only : error_stop

     implicit none
@@ -14,7 +13,6 @@

     real(sp), parameter :: tol_sp = epsilon(1.0_sp)
     real(dp), parameter :: tol_dp = epsilon(1.0_dp)
-    real(qp), parameter :: tol_qp = epsilon(1.0_qp)



@@ -33,7 +31,6 @@
         module procedure gamma_iint32
         module procedure gamma_iint64
         module procedure gamma_csp
-        module procedure gamma_cdp
     end interface gamma


@@ -46,7 +43,6 @@
         module procedure l_gamma_iint32
         module procedure l_gamma_iint64
         module procedure l_gamma_csp
-        module procedure l_gamma_cdp
     end interface log_gamma


@@ -75,7 +71,6 @@
         module procedure ingamma_low_iint64dp

         module procedure ingamma_low_rsp
-        module procedure ingamma_low_rdp
     end interface lower_incomplete_gamma


@@ -93,7 +88,6 @@
         module procedure l_ingamma_low_iint64dp

         module procedure l_ingamma_low_rsp
-        module procedure l_ingamma_low_rdp
     end interface log_lower_incomplete_gamma


@@ -111,7 +105,6 @@
         module procedure ingamma_up_iint64dp

         module procedure ingamma_up_rsp
-        module procedure ingamma_up_rdp
     end interface upper_incomplete_gamma


@@ -129,7 +122,6 @@
         module procedure l_ingamma_up_iint64dp

         module procedure l_ingamma_up_rsp
-        module procedure l_ingamma_up_rdp
     end interface log_upper_incomplete_gamma


@@ -147,7 +139,6 @@
         module procedure regamma_p_iint64dp

         module procedure regamma_p_rsp
-        module procedure regamma_p_rdp
     end interface regularized_gamma_p


@@ -165,7 +156,6 @@
         module procedure regamma_q_iint64dp

         module procedure regamma_q_rsp
-        module procedure regamma_q_rdp
     end interface regularized_gamma_q


@@ -175,7 +165,6 @@
     ! Internal use only
     !
         module procedure gpx_rsp         !for real p and x
-        module procedure gpx_rdp         !for real p and x

         module procedure gpx_iint8sp   !for integer p and real x
         module procedure gpx_iint8dp   !for integer p and real x
@@ -375,90 +364,6 @@
     end function gamma_csp


-    impure elemental function gamma_cdp(z) result(res)
(...)
-    end function gamma_cdp
-
-



@@ -962,102 +867,6 @@
         res = cmplx(sum, kind = sp)
     end function l_gamma_csp

-    impure elemental function l_gamma_cdp(z) result (res)
(...)
-    end function l_gamma_cdp
-



@@ -1298,122 +1107,6 @@
     end function gpx_rsp


-    impure elemental function gpx_rdp(p, x) result(res)
(...)
-    end function gpx_rdp
-
-


     impure elemental function gpx_iint8sp(p, x) result(res)
@@ -2514,37 +2207,6 @@
         end if
     end function ingamma_low_rsp

-    impure elemental function ingamma_low_rdp(p, x) result(res)
(...)
-    end function ingamma_low_rdp
-



@@ -2853,36 +2515,6 @@
         end if
     end function l_ingamma_low_rsp

-    impure elemental function l_ingamma_low_rdp(p, x) result(res)
(...)
-    end function l_ingamma_low_rdp
-



@@ -3130,38 +2762,6 @@
         end if
     end function ingamma_up_rsp

-    impure elemental function ingamma_up_rdp(p, x) result(res)
(...)
-    end function ingamma_up_rdp
-



@@ -3487,37 +3087,6 @@
         end if
     end function l_ingamma_up_rsp

-    impure elemental function l_ingamma_up_rdp(p, x) result(res)
(...)
-    end function l_ingamma_up_rdp
-



@@ -3827,35 +3396,6 @@
         end if
     end function regamma_p_rsp

-    impure elemental function regamma_p_rdp(p, x) result(res)
(...)
-    end function regamma_p_rdp
-



@@ -4131,35 +3671,6 @@
         end if
     end function regamma_q_rsp

-    impure elemental function regamma_q_rdp(p, x) result(res)
(...)
-    end function regamma_q_rdp
-

example/specialfunctions_gamma/example_gamma.f90 and example/specialfunctions_gamma/example_log_gamma.f90

• Change: Remove functions referencing deleted kinds (those requiring quad precision).

Summary

• Fix: Make qp optional to avoid build failures on systems without quadmath.
• Fix: Update two example files by removing references to non-existent (deleted) kinds.

[perazz]

I will close this PR: closed by #969