Commit Graph

14 Commits

Author SHA1 Message Date
Bruno Cardoso Lopes
4cb31436bd Move ELFCodeEmiter stuff to new files
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72785 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-03 17:47:27 +00:00
Oscar Fuentes
030019f113 CMake: Added missing source file to lib/CodeGen/CMakeLists.txt.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72775 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-03 15:29:09 +00:00
Duncan Sands
b0f1e1780c Add a new codegen pass that normalizes dwarf exception handling
code in preparation for code generation.  The main thing it does
is handle the case when eh.exception calls (and, in a future
patch, eh.selector calls) are far away from landing pads.  Right
now in practice you only find eh.exception calls close to landing
pads: either in a landing pad (the common case) or in a landing
pad successor, due to loop passes shifting them about.  However
future exception handling improvements will result in calls far
from landing pads:
(1) Inlining of rewinds.  Consider the following case:
In function @f:
...
  invoke @g to label %normal unwind label %unwinds
...
unwinds:
  %ex = call i8* @llvm.eh.exception()
...

In function @g:
...
  invoke @something to label %continue unwind label %handler
...
handler:
  %ex = call i8* @llvm.eh.exception()
... perform cleanups ...
  "rethrow exception"

Now inline @g into @f.  Currently this is turned into:
In function @f:
...
  invoke @something to label %continue unwind label %handler
...
handler:
  %ex = call i8* @llvm.eh.exception()
... perform cleanups ...
  invoke "rethrow exception" to label %normal unwind label %unwinds
unwinds:
  %ex = call i8* @llvm.eh.exception()
...

However we would like to simplify invoke of "rethrow exception" into
a branch to the %unwinds label.  Then %unwinds is no longer a landing
pad, and the eh.exception call there is then far away from any landing
pads.

(2) Using the unwind instruction for cleanups.
It would be nice to have codegen handle the following case:
  invoke @something to label %continue unwind label %run_cleanups
...
handler:
... perform cleanups ...
  unwind

This requires turning "unwind" into a library call, which
necessarily takes a pointer to the exception as an argument
(this patch also does this unwind lowering).  But that means
you are using eh.exception again far from a landing pad.

(3) Bugpoint simplifications.  When bugpoint is simplifying
exception handling code it often generates eh.exception calls
far from a landing pad, which then causes codegen to assert.
Bugpoint then latches on to this assertion and loses sight
of the original problem.

Note that it is currently rare for this pass to actually do
anything.  And in fact it normally shouldn't do anything at
all given the code coming out of llvm-gcc!  But it does fire
a few times in the testsuite.  As far as I can see this is
almost always due to the LoopStrengthReduce codegen pass
introducing pointless loop preheader blocks which are landing
pads and only contain a branch to another block.  This other
block contains an eh.exception call.  So probably by tweaking
LoopStrengthReduce a bit this can be avoided.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72276 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-22 20:36:31 +00:00
Mike Stump
1d4c738603 Fix cmake builds.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72078 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-19 00:18:14 +00:00
Jakob Stoklund Olesen
48872e0d84 Pass to verify generated machine code.
The following is checked:

* Operand counts: All explicit operands must be present.

* Register classes: All physical and virtual register operands must be
  compatible with the register class required by the instruction descriptor.

* Register live intervals: Registers must be defined only once, and must be
  defined before use.

The machine code verifier is enabled with the command-line option
'-verify-machineinstrs', or by defining the environment variable
LLVM_VERIFY_MACHINEINSTRS to the name of a file that will receive all the
verifier errors.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71918 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-16 00:33:53 +00:00
Chris Lattner
9422e01a63 add ShrinkWrapping.cpp
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71645 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-13 06:27:38 +00:00
Evan Cheng
bbf1db7213 Rename "loop aligner" pass to "code placement optimization" pass.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71150 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-07 05:42:24 +00:00
Oscar Fuentes
5dcf50bd03 CMake: Updated lib/CodeGen/CMakeLists.txt.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71085 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-06 14:56:40 +00:00
Gabor Greif
c40d4f85dd update
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66733 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-11 22:52:25 +00:00
Dan Gohman
343f0c0467 Experimental post-pass scheduling support. Post-pass scheduling
is currently off by default, and can be enabled with
-disable-post-RA-scheduler=false.

This doesn't have a significant impact on most code yet because it doesn't
yet do anything to address anti-dependencies and it doesn't attempt to
disambiguate memory references. Also, several popular targets
don't have pipeline descriptions yet.

The majority of the changes here are splitting the SelectionDAG-specific
code out of ScheduleDAG, so that ScheduleDAG can be moved to
libLLVMCodeGen.a. The interface between ScheduleDAG-using code and
the rest of the scheduling code is somewhat rough and will evolve.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59676 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-19 23:18:57 +00:00
Oscar Fuentes
5c42fd8af1 CMake: Updated list of source files.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58676 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-04 03:24:04 +00:00
Oscar Fuentes
7334b15210 CMake: updated lib/CodeGen/CMakeLists.txt
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57869 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-21 02:37:50 +00:00
Oscar Fuentes
80533040bc CMake: Reflected changes on source file structure. New plugin support
for llvmc2 incomplete.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57076 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-04 21:18:50 +00:00
Oscar Fuentes
3d01fc7de8 Initial support for the CMake build system.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56419 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-22 01:08:49 +00:00