diff options
Diffstat (limited to 'txr.1')
| -rw-r--r-- | txr.1 | 29 |
1 files changed, 23 insertions, 6 deletions
@@ -81293,12 +81293,29 @@ a structure can be read or written at the misaligned offsets depends on whether the individual members support it. If they are integer or floating-point types, or aggregates thereof, the usage is supported in a machine-independent manner. -Alignment interacts with bitfields. If a bitfield's type has an alignment -different from the previous member (whether that member is a bitfield or not), -then the bitfield is placed into a new cell, which is aligned according to -the alignment of its own type. The alignment of bitfields, other than -zero width bitfields, contributes to the determination of the most -strictly aligned member of the structure. +Alignment interacts with the allocation of bitfields in special ways. If +.meta width +is greater than 1, or regardless of +.meta width +if the operator is +.codn align , +the type is marked with a Boolean attribute indicating that it has +altered alignment. Then, when a bitfield is based on a type which has altered +alignment, then that bitfield isn't packed together with the previous +field, even if the allocation rules otherwise call for it. Due to the +alignment request, the byte offset is first adjusted according to the requested +alignment and the bit offset is reset to zero. The bit field is then allocated +at the new alignment. This requirement applies even if the requested alignment +is 1, which is possible via a combination of both +.code pack +and +.codn align , +both specified with a +.meta width +of 1. If the requested alignment for the type of a bitfield is 1, and +the previous member is a bitfield which has left a byte partially filled, +then the new bitfield starts on a fresh byte, even if it would otherwise +be packed with the previous bitfield. When .meta type |