XL Fortran Enterprise Edition for AIX : User's Guide - IBM

! Data values between r8 and x16 are preserved.
! Data values between i8 and b are preserved.
! x16 = (1.123456789123456789q0,2.123456789123456789q0)
! ! promotion occurred
! x8 = upper 8 bytes of r8(1) ! padding occurred
! r8(1) = real(x16) ! promotion occurred
! r8(2) = imag(x16) ! promotion occurred
! i8(1) = upper 8 bytes of real(x16) ! padding occurred
! i8(2) = upper 8 bytes of imag(x16) ! padding occurred
! b(1:8)= i8(1) ! padding occurred
! b(9:16)= i8(2) ! padding occurred
end
0 4 8 16 32
64
COMPLEX (16 ) (padded)
COMPLEX (8) (promoted)
COMPLEX (4) (promoted)
REAL (16) (padded)
REAL (8) (promoted)
REAL (4) (promoted)
INTEGER (8) (padded)
INTEGER (4) (padded)
CHARACTER (16)
Figure 12. Storage Relationships with -qautodbl=dblpad
In the figure above, the dashed lines represent the padding.
@process autodbl(dblpad)
block data
complex(4) x8 /(1.123456789e0,2.123456789e0)/
real(16) r16(2) /1.123q0,2.123q0/
integer(8) i8(2) /1000,2000/
character*5 c(2) /"abcde","12345"/
common /named/ x8,r16,i8,c
end
subroutine s()
complex(8) x8
real(16) r16(4)
integer(8) i8(4)
character*5 c(2)
common /named/ x8,r16,i8,c
! x8 = (1.123456789d0,2.123456789d0) ! promotion occurred
! r16(1) = 1.123q0 ! padding occurred
! r16(3) = 2.123q0 ! padding occurred
! i8(1) = 1000 ! padding occurred
! i8(3) = 2000 ! padding occurred
! c(1) = "abcde" ! no padding occurred
! c(2) = "12345" ! no padding occurred
end subroutine s
418 XL Fortran Enterprise Edition for AIX : User’s Guide