From mboxrd@z Thu Jan  1 00:00:00 1970
From: Toon Moene <toon@moene.indiv.nluug.nl>
To: nobody@gcc.gnu.org
Cc: gcc-prs@gcc.gnu.org
Subject: Re: fortran/4398: float c subroutine returns bad value to FORTRAN main
Date: Wed, 26 Sep 2001 12:36:00 -0000
Message-id: <20010926193600.23205.qmail@sourceware.cygnus.com>
X-SW-Source: 2001-09/msg00499.html
List-Id: <gcc-prs.sourceware.org>

The following reply was made to PR fortran/4398; it has been noted by GNATS.

From: Toon Moene <toon@moene.indiv.nluug.nl>
To: Sabba.Hillel@verizon.net
Cc: gcc-gnats@gcc.gnu.org
Subject: Re: fortran/4398: float c subroutine returns bad value to FORTRAN main
Date: Wed, 26 Sep 2001 21:18:42 +0200

 Sabba.Hillel@verizon.net wrote:
 
 > Solaris 5.6, 5.7, 5.8
 > compiled with g77-3.0.1 and gcc-3.0.1
 > used -fno-second-underscore
 
 > When compiling a FORTRAN main program calling a C subroutine which returns a floating point value,
 > the result printed from the FORTRAN main routin is incorrect.
 > When compiling using Solaris Workshop 6, f77, the result is correct.
 > When using double returns, the results are correct.
 > 
 > I am unable to connect the system with the gcc to the net so I am typing in the test program
 > 
 > test-gcc.f
 > 
 >       PROGRAM TEST_G77
 > 
 >       REAL*4 PRINT_A
 >       REAL*4 TEST_GCC
 >       REAL*4 S, V, T
 >       REAL*8 PRINT_DA
 >       REAL*8 TEST_DGCC
 >       REAL*8 DS, DV, DT
 > 
 >       S = TEST_GCC(T)
 >       WRITE (*, '(A, F16.5, 3X, Z16)') "S = ", S, S
 >       WRITE (*, '(A, F16.5, 3X, Z16)') "T = ", T, T
 >       V = PRINT_A(S)
 >       V = PRINT_A(T)
 > 
 >       DS = TEST_DGCC(DT)
 >       WRITE (*, '(A, F16.5, 3X, Z16)') "DS = ", DS, DS
 >       WRITE (*, '(A, F16.5, 3X, Z16)') "DT = ", DT, DT
 >       DV = PRINT_A(DS)
 >       DV = PRINT_A(DT)
 >       END
 
 Hmmm, exactly which values turn up wrong ?  You might want to study the
 warning messages g77 issues:
 
 testf.f: In program `test_g77':
 testf.f:13: warning:
          V = PRINT_A(S)
              1
 testf.f:19: (continued):
          DV = PRINT_A(DS)
               2
 Argument #1 of `print_a' is one precision at (2) but is some other
 precision at (1) [info -f g77 M GLOBALS]
 testf.f:13: warning:
          V = PRINT_A(S)
              1
 testf.f:20: (continued):
          DV = PRINT_A(DT)
               2
 Argument #1 of `print_a' is one precision at (2) but is some other
 precision at (1) [info -f g77 M GLOBALS]
 
 -- 
 Toon Moene - mailto:toon@moene.indiv.nluug.nl - phoneto: +31 346 214290
 Saturnushof 14, 3738 XG  Maartensdijk, The Netherlands
 Maintainer, GNU Fortran 77: http://gcc.gnu.org/onlinedocs/g77_news.html
 Join GNU Fortran 95: http://g95.sourceforge.net/ (under construction)