Commit Graph

17 Commits

Author SHA1 Message Date
Petar Jovanovic e2bfcd6394 Correct dwarf unwind information in function epilogue
This patch aims to provide correct dwarf unwind information in function
epilogue for X86.
It consists of two parts. The first part inserts CFI instructions that set
appropriate cfa offset and cfa register in emitEpilogue() in
X86FrameLowering. This part is X86 specific.

The second part is platform independent and ensures that:

* CFI instructions do not affect code generation (they are not counted as
  instructions when tail duplicating or tail merging)
* Unwind information remains correct when a function is modified by
  different passes. This is done in a late pass by analyzing information
  about cfa offset and cfa register in BBs and inserting additional CFI
  directives where necessary.

Added CFIInstrInserter pass:

* analyzes each basic block to determine cfa offset and register are valid
  at its entry and exit
* verifies that outgoing cfa offset and register of predecessor blocks match
  incoming values of their successors
* inserts additional CFI directives at basic block beginning to correct the
  rule for calculating CFA

Having CFI instructions in function epilogue can cause incorrect CFA
calculation rule for some basic blocks. This can happen if, due to basic
block reordering, or the existence of multiple epilogue blocks, some of the
blocks have wrong cfa offset and register values set by the epilogue block
above them.
CFIInstrInserter is currently run only on X86, but can be used by any target
that implements support for adding CFI instructions in epilogue.

Patch by Violeta Vukobrat.

Differential Revision: https://reviews.llvm.org/D42848

llvm-svn: 330706
2018-04-24 10:32:08 +00:00
Amaury Sechet fb10aff542 Regenerate test result for stateppint-vector.ll. NFC.
llvm-svn: 323594
2018-01-27 17:16:26 +00:00
Nirav Dave d839749ae8 [DAG] Improve Aliasing of operations to static alloca
Re-recommiting after landing DAG extension-crash fix.

Recommiting after adding check to avoid miscomputing alias information
on addresses of the same base but different subindices.

Memory accesses offset from frame indices may alias, e.g., we
may merge write from function arguments passed on the stack when they
are contiguous. As a result, when checking aliasing, we consider the
underlying frame index's offset from the stack pointer.

Static allocs are realized as stack objects in SelectionDAG, but its
offset is not set until post-DAG causing DAGCombiner's alias check to
consider access to static allocas to frequently alias. Modify isAlias
to consider access between static allocas and access from other frame
objects to be considered aliasing.

Many test changes are included here. Most are fixes for tests which
indirectly relied on our aliasing ability and needed to be modified to
preserve their original intent.

The remaining tests have minor improvements due to relaxed
ordering. The exception is CodeGen/X86/2011-10-19-widen_vselect.ll
which has a minor degradation dispite though the pre-legalized DAG is
improved.

Reviewers: rnk, mkuper, jonpa, hfinkel, uweigand

Reviewed By: rnk

Subscribers: sdardis, nemanjai, javed.absar, llvm-commits

Differential Revision: https://reviews.llvm.org/D33345

llvm-svn: 308350
2017-07-18 20:06:24 +00:00
Chandler Carruth a15e080b05 Revert r308025 due to uncovering a crash in SelectionDAG. This is filed
with a minimal test case in http://llvm.org/PR33833.

Original commit message:
  Improve Aliasing of operations to static alloca

llvm-svn: 308271
2017-07-18 07:53:47 +00:00
Nirav Dave a8f63af9d1 Improve Aliasing of operations to static alloca
Recommiting after adding check to avoid miscomputing alias information
on addresses of the same base but different subindices.

Memory accesses offset from frame indices may alias, e.g., we
may merge write from function arguments passed on the stack when they
are contiguous. As a result, when checking aliasing, we consider the
underlying frame index's offset from the stack pointer.

Static allocs are realized as stack objects in SelectionDAG, but its
offset is not set until post-DAG causing DAGCombiner's alias check to
consider access to static allocas to frequently alias. Modify isAlias
to consider access between static allocas and access from other frame
objects to be considered aliasing.

Many test changes are included here. Most are fixes for tests which
indirectly relied on our aliasing ability and needed to be modified to
preserve their original intent.

The remaining tests have minor improvements due to relaxed
ordering. The exception is CodeGen/X86/2011-10-19-widen_vselect.ll
which has a minor degradation dispite though the pre-legalized DAG is
improved.

Reviewers: rnk, mkuper, jonpa, hfinkel, uweigand

Reviewed By: rnk

Subscribers: sdardis, nemanjai, javed.absar, llvm-commits

Differential Revision: https://reviews.llvm.org/D33345

llvm-svn: 308025
2017-07-14 13:56:21 +00:00
Matthias Braun b38736706e Revert "[DAG] Improve Aliasing of operations to static alloca"
Reverting as it breaks tramp3d-v4 in the llvm test-suite. I added some
comments to https://reviews.llvm.org/D33345 about it.

This reverts commit r307546.

llvm-svn: 307589
2017-07-10 20:51:30 +00:00
Nirav Dave 163e1ad9dc [DAG] Improve Aliasing of operations to static alloca
Memory accesses offset from frame indices may alias, e.g., we
may merge write from function arguments passed on the stack when they
are contiguous. As a result, when checking aliasing, we consider the
underlying frame index's offset from the stack pointer.

Static allocs are realized as stack objects in SelectionDAG, but its
offset is not set until post-DAG causing DAGCombiner's alias check to
consider access to static allocas to frequently alias. Modify isAlias
to consider access between static allocas and access from other frame
objects to be considered aliasing.

Many test changes are included here. Most are fixes for tests which
indirectly relied on our aliasing ability and needed to be modified to
preserve their original intent.

The remaining tests have minor improvements due to relaxed
ordering. The exception is CodeGen/X86/2011-10-19-widen_vselect.ll
which has a minor degradation dispite though the pre-legalized DAG is
improved.

Reviewers: rnk, mkuper, jonpa, hfinkel, uweigand

Reviewed By: rnk

Subscribers: sdardis, nemanjai, javed.absar, llvm-commits

Differential Revision: https://reviews.llvm.org/D33345

llvm-svn: 307546
2017-07-10 15:39:41 +00:00
Philip Reames 94cc4a29ed Add placeholder for more extensive verification of psuedo ops
This initial patch doesn't actually do much useful. It's just to show where the new code goes. Once this is in, I'll extend the verification logic to check more useful properties.

For those curious, the more complicated version of this patch already found one very suspicious thing.

Differential Revision: https://reviews.llvm.org/D33819

llvm-svn: 304564
2017-06-02 16:36:37 +00:00
Sanjoy Das ba0daee6b2 [StackMaps] Increase the size of the "location size" field
Summary:
In some cases LLVM (especially the SLP vectorizer) will create vectors
that are 256 bytes (or larger).  Given that this is intentional[0] is
likely to get more common, this patch updates the StackMap binary
format to deal with the spill locations for said vectors.

This change also bumps the stack map version from 2 to 3.

[0]: https://reviews.llvm.org/D32533#738350

Reviewers: reames, kavon, skatkov, javed.absar

Subscribers: mcrosier, nemanjai, llvm-commits

Differential Revision: https://reviews.llvm.org/D32629

llvm-svn: 301615
2017-04-28 04:48:42 +00:00
Ayman Musa d9fb157845 [X86][SSE2] Fix asm string for movq (Move Quadword) instruction.
Replace "mov{d|q}" with "movq".

Differential Revision: https://reviews.llvm.org/D32220

llvm-svn: 301386
2017-04-26 07:08:44 +00:00
Matthias Braun 39c3c89cdc MCStreamer: Use "cfi" for CFI related temp labels.
Choosing a "cfi" name makes the intend a bit clearer in an assembly dump
and more importantly the assembly dumps are slightly more stable as the
numbers don't move around anymore when unrelated code calls
createTempSymbol() more or less often.
As they are temp labels the name doesn't influence the generated object
code.

Differential Revision: https://reviews.llvm.org/D27244

llvm-svn: 288290
2016-11-30 23:48:26 +00:00
Elena Demikhovsky 39a0020f2d Fixed -mcpu flag
"core-avx" does not exist; I changed to "nehalem"

llvm-svn: 263932
2016-03-21 11:06:20 +00:00
Zia Ansari 30a02384f7 Implemented stack symbol table ordering/packing optimization to improve data locality and code size from SP/FP offset encoding.
Differential Revision: http://reviews.llvm.org/D15393

llvm-svn: 260917
2016-02-15 23:44:13 +00:00
NAKAMURA Takumi 7e887bd80d llvm/test/CodeGen/X86/statepoint-vector.ll REQUIRES asserts due to a debug option.
llvm-svn: 257031
2016-01-07 05:40:37 +00:00
Philip Reames cffc628ca1 One more attempt at stablizing a test on all platforms.
llvm-svn: 257026
2016-01-07 04:20:52 +00:00
Philip Reames afdbcc6a84 [Statepoints] Add test cases around vectors and stablize test
Unlike my comment in 257022 said, it turns out we do handle constant vectors in the statepoint lowering, but only because SelectionDAG doesn't actually produce constants for them.  Add a couple of tests which show this working.

Also, add a triple to the same test file to hopefully fix a failing bot.

It turns out we do han

llvm-svn: 257025
2016-01-07 04:15:31 +00:00
Philip Reames 3e2cf5320c [Statepoints] Initial support for relocating vectors of pointers
Currently, we try to split vectors of pointers back into their component pointer elements during rewrite-statepoints-for-gc. This is less than ideal since presumably the vectorizer chose to vectorize for a reason. :) It's also been a source of bugs - in particular, the relocation logic as currently implemented was recently discovered to be wrong.

The alternate approach is to allow gc.relocates of vector-of-pointer type and update the backend to handle them. That's what this patch tries to do. This won't actually enable vector-of-pointers in practice - there are some RS4GC changes needed - but the lowering is standalone and testable so it makes sense to separate.

Note that there are some known cases around vector constants which this patch does not handle. Once this is in, I'll send another patch with individual fixes and test cases. 

Differential Revision: http://reviews.llvm.org/D15632

llvm-svn: 257022
2016-01-07 03:32:11 +00:00