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Commit 785abfd3 by Fritz Reese Committed by Steven G. Kargl
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dec_union_4.f90: Fix endian issue. 

2016-05-14  Fritz Reese  <fritzoreese@gmail.com>

	* gfortran.dg/dec_union_4.f90: Fix endian issue.

2016-05-14  Fritz Reese  <fritzoreese@gmail.com>

	* gfortran.texi: Update example of DEC UNION extension.

From-SVN: r236242
parent e75eb64f
Showing with 63 additions and 61 deletions
gcc/fortran/ChangeLog
2016-05-14 Fritz Reese <fritzoreese@gmail.com>
* gfortran.texi: Update example of DEC UNION extension.
2016-05-14 Fritz Reese <fritzoreese@gmail.com>
PR fortran/71047
* expr.c (gfc_default_initializer): Avoid extra component refs in
constructors for derived types and classes.
......
gcc/fortran/gfortran.texi
......@@ -2281,28 +2281,25 @@ Here is a small example:
structure /myunion/
union
map
integer(2) w, x, y, z
character(2) w0, w1, w2
end map
map
integer(4) wx, yz
character(6) long
end map
end union
end structure
record /myunion/ rec
! After these assignments...
rec.wx = z'0DEDBEEF'
rec.y = z'0BAD'
rec.z = z'0FAD'
! After this assignment...
rec.long = 'hello!'
! The following is true:
! rec.w === z'0DED'
! rec.x === z'BEEF'
! rec.yz === z'0BAD0FAD'
! rec.w0 === 'he'
! rec.w1 === 'll'
! rec.w2 === 'o!'
@end smallexample
The two maps share memory, and the size of the union is ultimately six bytes
(subject to alignment):
The two maps share memory, and the size of the union is ultimately six bytes:
@example
0 1 2 3 4 5 6 Byte offset
......@@ -2313,65 +2310,61 @@ The two maps share memory, and the size of the union is ultimately six bytes
^ W0 ^ W1 ^ W2 ^
\-------/ \-------/ \-------/
^ LONG ^ unused ^
\-----------------/ \-------/
^ LONG ^
\---------------------------/
@end example
Following is an example mirroring the layout of an Intel x86_64 register:
@example
structure /reg/
union ! rax
union ! U0 ! rax
map
integer*8 rx ! rax
character(16) rx
end map
map
integer*4 rh ! rah
union ! eax
character(8) rh ! rah
union ! U1
map
integer*4 rl ! ral
character(8) rl ! ral
end map
map
integer*4 ex ! eax
character(8) ex ! eax
end map
map
integer*2 eh ! eah
union ! ax
character(4) eh ! eah
union ! U2
map
integer*2 el ! eal
character(4) el ! eal
end map
map
integer*2 x ! ax
character(4) x ! ax
end map
map
integer*1 h ! ah
integer*1 l ! al
character(2) h ! ah
character(2) l ! al
end map
end union ! ax
end union
end map
end union ! eax
end union
end map
end union ! rax
end union
end structure
record /reg/ a
! After this assignment...
a.rx = z'AABBCCCCFFFFFFFF'
a.rx = 'AAAAAAAA.BBB.C.D'
! The following is true:
!
! a.rx == z'AABBCCCCFFFFFFFF'
! a.rh == z'FFFFFFFF'
! a.rl == z'AABBCCCC'
!
! a.ex == z'AABBCCCC'
! a.eh == z'CCCC'
! a.el == z'AABB'
!
! a.x == z'AABB'
! a.h == z'BB'
! a.l == z'AA'
a.rx === 'AAAAAAAA.BBB.C.D'
a.rh === 'AAAAAAAA'
a.rl === '.BBB.C.D'
a.ex === '.BBB.C.D'
a.eh === '.BBB'
a.el === '.C.D'
a.x === '.C.D'
a.h === '.C'
a.l === '.D'
@end example
......
gcc/testsuite/ChangeLog
2016-05-14 Fritz Reese <fritzoreese@gmail.com>
* gfortran.dg/dec_union_4.f90: Fix endian issue.
2016-05-14 Fritz Reese <fritzoreese@gmail.com>
PR fortran/71047
* gfortran.dg/pr71047.f08: New test.
......
gcc/testsuite/gfortran.dg/dec_union_4.f90
......@@ -14,29 +14,29 @@ end subroutine
structure /s4/
union ! U0 ! rax
map
integer(8) rx
character(16) rx
end map
map
integer(4) rh ! rah
character(8) rh ! rah
union ! U1
map
integer(4) rl ! ral
character(8) rl ! ral
end map
map
integer(4) ex ! eax
character(8) ex ! eax
end map
map
integer(2) eh ! eah
character(4) eh ! eah
union ! U2
map
integer(2) el ! eal
character(4) el ! eal
end map
map
integer(2) x ! ax
character(4) x ! ax
end map
map
integer(1) h ! ah
integer(1) l ! al
character(2) h ! ah
character(2) l ! al
end map
end union
end map
......@@ -48,15 +48,16 @@ record /s4/ r4
! Nested unions
r4.rx = z'7A7B7CCC7FFFFFFF'
if ( r4.rx .ne. z'7A7B7CCC7FFFFFFF' ) call aborts ("rax")
if ( r4.rh .ne. z'7FFFFFFF' ) call aborts ("rah")
if ( r4.rl .ne. z'7A7B7CCC' ) call aborts ("ral")
if ( r4.ex .ne. z'7A7B7CCC' ) call aborts ("eax")
if ( r4.eh .ne. z'7CCC' ) call aborts ("eah")
if ( r4.el .ne. z'7A7B' ) call aborts ("eal")
if ( r4.x .ne. z'7A7B' ) call aborts ("ax")
if ( r4.h .ne. z'7B' ) call aborts ("ah")
if ( r4.l .ne. z'7A' ) call aborts ("al")
r4.rx = 'AAAAAAAA.BBB.C.D'
if ( r4.rx .ne. 'AAAAAAAA.BBB.C.D' ) call aborts ("rax")
if ( r4.rh .ne. 'AAAAAAAA' ) call aborts ("rah")
if ( r4.rl .ne. '.BBB.C.D' ) call aborts ("ral")
if ( r4.ex .ne. '.BBB.C.D' ) call aborts ("eax")
if ( r4.eh .ne. '.BBB' ) call aborts ("eah")
if ( r4.el .ne. '.C.D' ) call aborts ("eal")
if ( r4.x .ne. '.C.D' ) call aborts ("ax")
if ( r4.h .ne. '.C' ) call aborts ("ah")
if ( r4.l .ne. '.D' ) call aborts ("al")
end
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