Commit graph

438 commits

Author SHA1 Message Date
Akash Bagdia
e7e17f92db power: Add voltage domains to the clock domains
This patch adds the notion of voltage domains, and groups clock
domains that operate under the same voltage (i.e. power supply) into
domains. Each clock domain is required to be associated with a voltage
domain, and the latter requires the voltage to be explicitly set.

A voltage domain is an independently controllable voltage supply being
provided to section of the design. Thus, if you wish to perform
dynamic voltage scaling on a CPU, its clock domain should be
associated with a separate voltage domain.

The current implementation of the voltage domain does not take into
consideration cases where there are derived voltage domains running at
ratio of native voltage domains, as with the case where there can be
on-chip buck/boost (charge pumps) voltage regulation logic.

The regression and configuration scripts are updated with a generic
voltage domain for the system, and one for the CPUs.
2013-08-19 03:52:28 -04:00
Andreas Hansson
204df3b928 sim: Make MaxTick in Python match the one in C++
This patch aligns the MaxTick in Python with the one in C++. Thus,
both reflect the maximum value that an unsigned 64-bit integer can
have.
2013-07-18 08:29:08 -04:00
Andreas Hansson
a0e551869c config: Remove Clock parameter multiplication
This patch removes the multiplication operator support for Clock
parameters as this functionality is now achieved by creating derived
clock domains.

Nate, this one is for you.
2013-06-27 05:49:50 -04:00
Andreas Sandberg
63dae28703 base: Make the Python module loader PEP302 compliant
The custom Python loader didn't comply with PEP302 for two reasons:

 * Previously, we would overwrite old modules on name
   conflicts. PEP302 explicitly states that: "If there is an existing
   module object named 'fullname' in sys.modules, the loader must use
   that existing module".

 * The "__package__" attribute wasn't set. PEP302: "The __package__
   attribute must be set."

This changeset addresses both of these issues.
2013-06-03 13:51:03 +02:00
Andreas Hansson
319443d42d scons: Add warning for missing declarations
This patch enables warnings for missing declarations. To avoid issues
with SWIG-generated code, the warning is only applied to non-SWIG
code.
2013-02-19 05:56:07 -05:00
Andreas Hansson
5c7ebee434 x86: Move APIC clock divider to Python
This patch moves the 16x APIC clock divider to the Python code to
avoid the post-instantiation modifications to the clock. The x86 APIC
was the only object setting the clock after creation time and this
required some custom functionality and configuration. With this patch,
the clock multiplier is moved to the Python code and the objects are
instantiated with the appropriate clock.
2013-02-19 05:56:06 -05:00
Sascha Bischoff
2f3b322280 base: Add warn() and inform() to m5.utils for use from python
This patch adds two fuctions to m5.util, warn and inform, which mirror those
found in the C++ side of gem5. These are added in addition to the already
existing m5.util.panic and m5.util.fatal which already mirror the C++
functionality. This ensures that warning and information messages generated
by python are in the same format as those generated by C++.

Occurrences of
    print "Warning: %s..." % name
have been replaced with
    warn("%s...", name)
2013-02-15 17:40:10 -05:00
Andreas Sandberg
b904bd5437 sim: Add a system-global option to bypass caches
Virtualized CPUs and the fastmem mode of the atomic CPU require direct
access to physical memory. We currently require caches to be disabled
when using them to prevent chaos. This is not ideal when switching
between hardware virutalized CPUs and other CPU models as it would
require a configuration change on each switch. This changeset
introduces a new version of the atomic memory mode,
'atomic_noncaching', where memory accesses are inserted into the
memory system as atomic accesses, but bypass caches.

To make memory mode tests cleaner, the following methods are added to
the System class:

 * isAtomicMode() -- True if the memory mode is 'atomic' or 'direct'.
 * isTimingMode() -- True if the memory mode is 'timing'.
 * bypassCaches() -- True if caches should be bypassed.

The old getMemoryMode() and setMemoryMode() methods should never be
used from the C++ world anymore.
2013-02-15 17:40:09 -05:00
Andreas Sandberg
e5dca84c3f config: Move CPU handover logic to m5.switchCpus()
CPU switching consists of the following steps:
 1. Drain the system
 2. Switch out old CPUs (cpu.switchOut())
 3. Change the system timing mode to the mode the new CPUs require
 4. Flush caches if switching to hardware virtualization
 5. Inform new CPUs of the handover (cpu.takeOverFrom())
 6. Resume the system

m5.switchCpus() previously only did step 2 & 5. Since information
about the new processors' memory system requirements is now exposed,
do all of the steps above.

This patch adds automatic memory system switching and flush (if
needed) to switchCpus(). Additionally, it adds optional draining to
switchCpus(). This has the following implications:

* changeToTiming and changeToAtomic are no longer needed, so they have
  been removed.

* changeMemoryMode is only used internally, so it is has been renamed
  to be private.

* switchCpus requires a reference to the system containing the CPUs as
  its first parameter.

WARNING: This changeset breaks compatibility with existing
configuration scripts since it changes the signature of
m5.switchCpus().
2013-02-15 17:40:08 -05:00
Andreas Sandberg
d4eca0591d base: Add support for newer versions of IPython
IPython is used for the interactive gem5 shell if it exists. IPython
made API changes in version 0.11. This patch adds support for IPython
version 0.11 and above.

--HG--
extra : rebase_source : 5388d0919adb58d97f49a1a637db48cba61283a3
2013-02-10 13:23:58 +01:00
Andreas Sandberg
10f1f8c6a4 base: Fix broken IPython argument handling
Prior to this changeset, we used to clear sys.argv before entering the
IPython shell. This caused some versions of IPython to crash because
they assume argv[0] to exist. The correct way of overriding the
arguments passed to IPython is to set the argv keyword argument when
initializing the shell.
2013-02-10 13:23:56 +01:00
Sascha Bischoff
8a767885d6 stats: Fix swig wrapping for Tick in stats
Tick was not correctly wrapped for the stats system, and therefore it was not
possible to configure the stats dumping from the python scripts without
defining Ticks as long long. This patch fixes the wrapping of Tick by copying
the typemap of uint64_t to Tick.
2013-01-07 16:56:36 -05:00
Andreas Sandberg
a7e0cbeb36 cpu: Introduce sanity checks when switching between CPUs
This patch introduces the following sanity checks when switching
between CPUs:

 * Check that the set of new and old CPUs do not overlap. Having an
   overlap between the set of new CPUs and the set of old CPUs is
   currently not supported. Doing such a switch used to result in the
   following assertion error:
     BaseCPU::takeOverFrom(BaseCPU*): \
       Assertion `!new_itb_port->isConnected()' failed.

 * Check that all new CPUs are in the switched out state.

 * Check that all old CPUs are in the switched in state.
2013-01-07 13:05:44 -05:00
Andreas Hansson
01c5598373 mem: Add interleaving bits to the address ranges
This patch adds support for interleaving bits for the address
ranges. What was previously just a start and end address, now has an
additional three fields, for the high bit, and number of bits to use
for interleaving, and a match value to compare against. If the number
of interleaving bits is set to zero it is effectively disabled.

A number of convenience functions are added to the range to enquire
about the interleaving, its granularity and the number of stripes it
is part of.
2013-01-07 13:05:38 -05:00
Andreas Hansson
e6c57786a4 config: Traverse lists when visiting children in all proxy
This patch makes the all proxy traverse any potential list that is
encountered in the object hierarchy instead of only looking at
children that are SimObjects. An example of where this is useful is
when creating a multi-channel memory system as a list of controllers,
whilst ensuring that the memories are still visible in the system.
2013-01-07 13:05:38 -05:00
Nilay Vaish
2d6470936c sim: have a curTick per eventq
This patch adds a _curTick variable to an eventq. This variable is updated
whenever an event is serviced in function serviceOne(), or all events upto
a particular time are processed in function serviceEvents(). This change
helps when there are eventqs that do not make use of curTick for scheduling
events.
2012-11-16 10:27:47 -06:00
Andreas Sandberg
050f24c796 sim: Add drain methods to request additional cleanup operations
This patch adds the following two methods to the Drainable base class:

memWriteback() - Write back all dirty cache lines to memory using
functional accesses.

memInvalidate() - Invalidate memory system buffers. Dirty data
won't be written back.

Specifying calling memWriteback() after draining will allow us to
checkpoint systems with caches. memInvalidate() can be used to drop
memory system buffers in preparation for switching to an accelerated
CPU model that bypasses the gem5 memory system (e.g., hardware
virtualized CPUs).

Note: This patch only adds the methods to Drainable, the code for
flushing the TLB and the cache is committed separately.
2012-11-02 11:32:02 -05:00
Andreas Sandberg
aae6134b54 sim: Add SWIG interface for Serializable
This changeset adds a SWIG interface for the Serializable class, which
fixes a warning when compiling the SWIG interface for the event
queue. Currently, the only method exported is the name() method.
2012-11-02 11:32:02 -05:00
Andreas Sandberg
dc01535c7e python: Rename doDrain()->drain() and make it do the right thing
There is no point in exporting the old drain() method in
Simulate.py. It should only be used internally by doDrain(). This
patch moves the old drain() method into doDrain() and renames
doDrain() to drain().
2012-11-02 11:32:02 -05:00
Andreas Sandberg
196397fea4 sim: Reuse the code to change memory mode.
changeToAtomic and changeToTiming both do essentially the same thing,
they check the type of their input argument, drain the system, and
switch to the desired memory mode. This patch moves all of that code
to a separate method (changeMemoryMode) and calls that from both
changeToAtomic and changeToTiming.
2012-11-02 11:32:02 -05:00
Andreas Sandberg
b81a977e6a sim: Move the draining interface into a separate base class
This patch moves the draining interface from SimObject to a separate
class that can be used by any object needing draining. However,
objects not visible to the Python code (i.e., objects not deriving
from SimObject) still depend on their parents informing them when to
drain. This patch also gets rid of the CountedDrainEvent (which isn't
really an event) and replaces it with a DrainManager.
2012-11-02 11:32:01 -05:00
Andreas Sandberg
c0ab52799c sim: Include object header files in SWIG interfaces
When casting objects in the generated SWIG interfaces, SWIG uses
classical C-style casts ( (Foo *)bar; ). In some cases, this can
degenerate into the equivalent of a reinterpret_cast (mainly if only a
forward declaration of the type is available). This usually works for
most compilers, but it is known to break if multiple inheritance is
used anywhere in the object hierarchy.

This patch introduces the cxx_header attribute to Python SimObject
definitions, which should be used to specify a header to include in
the SWIG interface. The header should include the declaration of the
wrapped object. We currently don't enforce header the use of the
header attribute, but a warning will be generated for objects that do
not use it.
2012-11-02 11:32:01 -05:00
Andreas Sandberg
7e25052fee Partly revert [4f54b0f229b5] and move draining to m5.changeToTiming
Changeset 4f54b0f229b5 removed the call to doDrain in changeToTiming
based on the assumption that the system does not need draining when
running in atomic mode. This is a false assumption since at least the
System class requires the system to be drained before it allows
switching of memory modes. This patch reverts that part of the
changeset.
2012-11-02 11:32:00 -05:00
Andreas Hansson
2a740aa096 Port: Add protocol-agnostic ports in the port hierarchy
This patch adds an additional level of ports in the inheritance
hierarchy, separating out the protocol-specific and protocl-agnostic
parts. All the functionality related to the binding of ports is now
confined to use BaseMaster/BaseSlavePorts, and all the
protocol-specific parts stay in the Master/SlavePort. In the future it
will be possible to add other protocol-specific implementations.

The functions used in the binding of ports, i.e. getMaster/SlavePort
now use the base classes, and the index parameter is updated to use
the PortID typedef with the symbolic InvalidPortID as the default.
2012-10-15 08:12:35 -04:00
Andreas Hansson
8cc503f1dd Param: Fix proxy traversal to support chained proxies
This patch modifies how proxies are traversed and unproxied to allow
chained proxies. The issue that is solved manifested itself when a
proxy during its evaluation ended up being hitting another proxy, and
the second one got evaluated using the object that was originally used
for the first proxy.

For a more tangible example, see the following patch on making the
default clock being inherited from the parent. In this patch, the CPU
clock is a proxy Parent.clock, which is overridden in the system to be
an actual value. This all works fine, but the AlphaLinuxSystem has a
boot_cpu_frequency parameter that is Self.cpu[0].clock.frequency. When
the latter is evaluated, it all happens relative to the current object
of the proxy, i.e. the system. Thus the cpu.clock is evaluated as
Parent.clock, but using the system rather than the cpu as the object
to enquire.
2012-10-15 08:07:06 -04:00
Sascha Bischoff
74ab69c7ea Statistics: Add a function to configure periodic stats dumping
This patch adds a function, periodicStatDump(long long period), which will dump
and reset the statistics every period. This function is designed to be called
from the python configuration scripts. This allows the periodic stats dumping to
be configured more easilly at run time.

The period is currently specified as a long long as there are issues passing
Tick into the C++ from the python as they have conflicting definitions. If the
period is less than curTick, the first occurance occurs at curTick. If the
period is set to 0, then the event is descheduled and the stats are not
periodically dumped.

Due to issues when resumung from a checkpoint, the StatDump event must be moved
forward such that it occues AFTER the current tick. As the function is called
from the python, the event is scheduled before the system resumes from the
checkpoint. Therefore, the event is moved using the updateEvents() function.
This is called from simulate.py once the system has resumed from the checkpoint.

NOTE: It should be noted that this is a fairly temporary patch which re-adds the
capability to extract temporal information  from the communication monitors. It
should not be used at the same time as anything that relies on dumping the
statistics based on in simulation events i.e. a context switch.
2012-09-25 11:49:41 -05:00
Andreas Sandberg
6598241f2c sim: Move CPU-specific methods from SimObject to the BaseCPU class 2012-09-25 11:49:40 -05:00
Andreas Sandberg
5f32eceeda sim: Remove SimObject::setMemoryMode
Remove SimObject::setMemoryMode from the main SimObject class since it
is only valid for the System class. In addition to removing the method
from the C++ sources, this patch also removes getMemoryMode and
changeTiming from SimObject.py and updates the simulation code to call
the (get|set)MemoryMode method on the System object instead.
2012-09-25 11:49:40 -05:00
Andreas Hansson
ffb6aec603 AddrRange: Transition from Range<T> to AddrRange
This patch takes the final plunge and transitions from the templated
Range class to the more specific AddrRange. In doing so it changes the
obvious Range<Addr> to AddrRange, and also bumps the range_map to be
AddrRangeMap.

In addition to the obvious changes, including the removal of redundant
includes, this patch also does some house keeping in preparing for the
introduction of address interleaving support in the ranges. The Range
class is also stripped of all the functionality that is never used.

--HG--
rename : src/base/range.hh => src/base/addr_range.hh
rename : src/base/range_map.hh => src/base/addr_range_map.hh
2012-09-19 06:15:44 -04:00
Andreas Hansson
fccbf8bb45 AddrRange: Simplify AddrRange params Python hierarchy
This patch simplifies the Range object hierarchy in preparation for an
address range class that also allows striping (e.g. selecting a few
bits as matching in addition to the range).

To extend the AddrRange class to an AddrRegion, the first step is to
simplify the hierarchy such that we can make it as lean as possible
before adding the new functionality. The only class using Range and
MetaRange is AddrRange, and the three classes are now collapsed into
one.
2012-09-19 06:15:41 -04:00
Joel Hestness
234fa4cf7e Standard Switch: Drain the system before switching CPUs
When switching from an atomic CPU to any of the timing CPUs, a drain is
unnecessary since no events are scheduled in atomic mode. However, when
trying to switch CPUs starting with a timing CPU, there may be events
scheduled. This change ensures that all events are drained from the system
by calling m5.drain before switching CPUs.
2012-09-12 21:41:37 -05:00
Andreas Sandberg
2f397f314b sim: Remove the unused SimObject::regFormulas method
Simulation objects normally register derived statistics, presumably
what regFormulas originally was meant for, in regStats(). This patch
removes regRegformulas since there is no need to have a separate
method call to register formulas.
2012-09-07 14:20:53 -05:00
Andreas Hansson
287ea1a081 Param: Transition to Cycles for relevant parameters
This patch is a first step to using Cycles as a parameter type. The
main affected modules are the CPUs and the Ruby caches. There are
definitely plenty more places that are affected, but this patch serves
as a starting point to making the transition.

An important part of this patch is to actually enable parameters to be
specified as Param.Cycles which involves some changes to params.py.
2012-09-07 12:34:38 -04:00
Andreas Hansson
0cacf7e817 Clock: Add a Cycles wrapper class and use where applicable
This patch addresses the comments and feedback on the preceding patch
that reworks the clocks and now more clearly shows where cycles
(relative cycle counts) are used to express time.

Instead of bumping the existing patch I chose to make this a separate
patch, merely to try and focus the discussion around a smaller set of
changes. The two patches will be pushed together though.

This changes done as part of this patch are mostly following directly
from the introduction of the wrapper class, and change enough code to
make things compile and run again. There are definitely more places
where int/uint/Tick is still used to represent cycles, and it will
take some time to chase them all down. Similarly, a lot of parameters
should be changed from Param.Tick and Param.Unsigned to
Param.Cycles.

In addition, the use of curTick is questionable as there should not be
an absolute cycle. Potential solutions can be built on top of this
patch. There is a similar situation in the o3 CPU where
lastRunningCycle is currently counting in Cycles, and is still an
absolute time. More discussion to be had in other words.

An additional change that would be appropriate in the future is to
perform a similar wrapping of Tick and probably also introduce a
Ticks class along with suitable operators for all these classes.
2012-08-28 14:30:33 -04:00
Brad Beckmann
11b725c19d ruby: changes how Topologies are created
Instead of just passing a list of controllers to the makeTopology function
in src/mem/ruby/network/topologies/<Topo>.py we pass in a function pointer
which knows how to make the topology, possibly with some extra state set
in the configs/ruby/<protocol>.py file. Thus, we can move all of the files
from network/topologies to configs/topologies. A new class BaseTopology
is added which all topologies in configs/topologies must inheirit from and
follow its API.

--HG--
rename : src/mem/ruby/network/topologies/Crossbar.py => configs/topologies/Crossbar.py
rename : src/mem/ruby/network/topologies/Mesh.py => configs/topologies/Mesh.py
rename : src/mem/ruby/network/topologies/MeshDirCorners.py => configs/topologies/MeshDirCorners.py
rename : src/mem/ruby/network/topologies/Pt2Pt.py => configs/topologies/Pt2Pt.py
rename : src/mem/ruby/network/topologies/Torus.py => configs/topologies/Torus.py
2012-07-10 22:51:53 -07:00
Ali Saidi
1b370431d0 sim: Remove FastAlloc
While FastAlloc provides a small performance increase (~1.5%) over regular malloc it isn't thread safe.
After removing FastAlloc and using tcmalloc I've seen a performance increase of 12% over libc malloc
when running twolf for ARM.
2012-06-05 01:23:08 -04:00
Mitchell Hayenga
8294d49bb6 stats: Provide a mechanism to get a callback when stats are dumped.
This mechanism is useful for dumping output that is correlated with stats
dumping, but isn't tracked by the gem5 statistics.
2012-06-05 01:23:08 -04:00
Andreas Hansson
01906f957a Config: Use the attribute naming and include ports in JSON
This patch changes the organisation of the JSON output slightly to
make it easier to traverse and use the files. Most importantly, the
hierarchical dictionaries now use keys that correspond to the
attribute names also in the case of VectorParams (used to be
e.f. "cpu0 cpu1"). It also adds the name and the path to each
SimObject directory entry. Before this patch, to get cpu0, you would
have to query dict['system']['cpu0 cpu1'][0] and this could be a dict
with 'cpu0' : { cpu parameters }. Now you use dict['system']['cpu'][0]
and get { cpu parameters } (where one is "name" : "cpu0").

Additionally this patch includes more verbose information about the
ports, specifying their role, and using a JSON array rather than a
concatenated string for the peer.
2012-05-23 09:16:39 -04:00
Andreas Hansson
31b4ac5cec Config: Exit with fatal if a port is already connected
This patch turns the existing warning into a fatal, as there should
never be any cases where a (non-vector) port is assigned to and then
later connected to something else. If this behaviour is allowed, as it
used to be, there are cases where the wrong number of C++ ports are
created when instantiating objects with VectorPorts (obviously that
could be fixed, but the better approach is to simply not allow it).
2012-05-23 09:01:56 -04:00
Uri Wiener
29a5e6ff35 DOT: improved dot-based system visualization
Revised system visualization to reflect structure and memory hierarchy.
Improved visualization: less congested and cluttered; more colorful.
Nodes reflect components; directed edges reflect dirctional relation, from
a master port to a slave port. Requires pydot.
2012-05-10 18:04:27 -05:00
Uri Wiener
cb1b63ea61 DOT: fixed broken code for visualizing configuration using dot
Fixed broken code which visualizes the system configuration by generating a
tree from each component's children, starting from root.
Requires DOT (hence pydot).
2012-05-10 18:04:27 -05:00
Ali Saidi
413ba1fdaf stats: track if the stats have been enabled and prevent requesting master id
Track the point in the initialization where statistics have been registered.
After this point registering new masterIds can no longer work as some
SimObjects may have sized stats vectors based on the previous value. If someone
tries to register a masterId after this point the simulator executes fatal().
2012-05-10 18:04:26 -05:00
Andreas Hansson
b9bc530ad2 Regression: Add ANSI colours to highlight test status
This patch adds a very basic pretty-printing of the test status
(passed or failed) to highlight failing tests even more: green for
passed, and red for failed. The printing only uses ANSI it the target
output is a tty and supports ANSI colours. Hence, any regression
scripts that are outputting to files or sending e-mails etc should
still be fine.
2012-04-14 05:44:27 -04:00
Brad Beckmann
f12961bf25 python: added __nonzero__ function to SimObject Bool params 2012-04-06 13:47:07 -07:00
Andreas Hansson
aab2001ab7 Python: Make the All proxy traverse SimObject children as well
This patch changes the behaviour of the All proxy parameter to not
only consider the direct children, but also do a pre-order depth-first
traversal of the object tree and append all results from the
children.

This is used in a later patch to find all the memories in the system,
independent of where they are located in the hierarchy.
2012-04-05 10:44:35 -04:00
William Wang
f9d403a7b9 MEM: Introduce the master/slave port sub-classes in C++
This patch introduces the notion of a master and slave port in the C++
code, thus bringing the previous classification from the Python
classes into the corresponding simulation objects and memory objects.

The patch enables us to classify behaviours into the two bins and add
assumptions and enfore compliance, also simplifying the two
interfaces. As a starting point, isSnooping is confined to a master
port, and getAddrRanges to slave ports. More of these specilisations
are to come in later patches.

The getPort function is not getMasterPort and getSlavePort, and
returns a port reference rather than a pointer as NULL would never be
a valid return value. The default implementation of these two
functions is placed in MemObject, and calls fatal.

The one drawback with this specific patch is that it requires some
code duplication, e.g. QueuedPort becomes QueuedMasterPort and
QueuedSlavePort, and BusPort becomes BusMasterPort and BusSlavePort
(avoiding multiple inheritance). With the later introduction of the
port interfaces, moving the functionality outside the port itself, a
lot of the duplicated code will disappear again.
2012-03-30 09:40:11 -04:00
Andreas Hansson
12742835bc Python: Fix a conditional expression that requires Python 2.5
This patch changes a conditional expression to a conventional if/else
block, which does not require Python >= 2.5.
2012-03-21 19:02:03 -04:00
Andreas Hansson
72538294fb gcc: Clean-up of non-C++0x compliant code, first steps
This patch cleans up a number of minor issues aiming to get closer to
compliance with the C++0x standard as interpreted by gcc and clang
(compile with std=c++0x and -pedantic-errors). In particular, the
patch cleans up enums where the last item was succeded by a comma,
namespaces closed by a curcly brace followed by a semi-colon, and the
use of the GNU-extension typeof (replaced by templated functions). It
does not address variable-length arrays, zero-size arrays, anonymous
structs, range expressions in switch statements, and the use of long
long. The generated CPU code also has a large number of issues that
remain to be fixed, mainly related to overflows in implicit constant
conversion (due to shifts).
2012-03-19 06:36:09 -04:00
Andreas Hansson
a444a6f8d6 scripts: Fix to ensure that port connection count is always set
This patch ensures that the port connection count is set to zero in those
cases when the port is not connected.
2012-03-19 06:34:02 -04:00
Andreas Hansson
88abdc0fad SWIG: Ensure ptrdiff_t is a known type in gcc >= 4.6.1
This patch fixes a compilation error that occurs with gcc >= 4.6.1,
caused by swig not including cstddef and not using the std:: namespace
prefix for ptrdiff_t. There is an old patch,
http://reviews.m5sim.org/r/913/ that no longer applies cleanly and
this might be re-iterating the same issue.

We work around the problem by always enforcing the inclusion of
cstddef in all swig interface declarations, and also by explicitly
using std::ptrdiff_t.
2012-02-29 04:26:58 -05:00