Commit Graph

14 Commits

Author SHA1 Message Date
Amara Emerson 854d10d10b [AArch64][GlobalISel] Enable GlobalISel at -O0 by default
Tests updated to explicitly use fast-isel at -O0 instead of implicitly.

This change also allows an explicit -fast-isel option to override an
implicitly enabled global-isel. Otherwise -fast-isel would have no effect at -O0.

Differential Revision: https://reviews.llvm.org/D41362

llvm-svn: 321655
2018-01-02 16:30:47 +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
Arnold Schwaighofer ae9312c487 ISel: Fix FastISel of swifterror values
The code assumed that we process instructions in basic block order.  FastISel
processes instructions in reverse basic block order. We need to pre-assign
virtual registers before selecting otherwise we get def-use relationships wrong.

This only affects code with swifterror registers.

rdar://32659327

llvm-svn: 305484
2017-06-15 17:34:42 +00:00
Arnold Schwaighofer 8f3df731dc swiftcc: Don't emit tail calls from callers with swifterror parameters
Backends don't support this yet. They would have to move to the swifterror
register before the tail call to make sure it is live-in to the call.

rdar://30495920

llvm-svn: 294982
2017-02-13 19:58:28 +00:00
Arnold Schwaighofer 26f016f143 SwiftCC: swifterror register cannot be as the base register
Functions that have a dynamic alloca require a base register which is defined to
be X19 on AArch64 and r6 on ARM.  We have defined the swifterror register to be
the same register. Use a different callee save register for swifterror instead:

 X21 on AArch64
 R8 on ARM

rdar://30433803

llvm-svn: 294551
2017-02-09 01:52:17 +00:00
Arnold Schwaighofer 7f4b31c057 More swift calling convention tests
llvm-svn: 285417
2016-10-28 17:21:05 +00:00
Arnold Schwaighofer 3f25658143 swifterror: Don't compute swifterror vregs during instruction selection
The code used llvm basic block predecessors to decided where to insert phi
nodes. Instruction selection can and will liberally insert new machine basic
block predecessors. There is not a guaranteed one-to-one mapping from pred.
llvm basic blocks and machine basic blocks.

Therefore the current approach does not work as it assumes we can mark
predecessor machine basic block as needing a copy, and needs to know the set of
all predecessor machine basic blocks to decide when to insert phis.

Instead of computing the swifterror vregs as we select instructions, propagate
them at the end of instruction selection when the MBB CFG is complete.

When an instruction needs a swifterror vreg and we don't know the value yet,
generate a new vreg and remember this "upward exposed" use, and reconcile this
at the end of instruction selection.

This will only happen if the target supports promoting swifterror parameters to
registers and the swifterror attribute is used.

rdar://28300923

llvm-svn: 283617
2016-10-07 22:06:55 +00:00
Arnold Schwaighofer de2490d0dc Disable tail calls if there is an swifterror argument
ISel does not handle them correctly yet i.e we crash trying to emit tail call
code.

radar://28407842

llvm-svn: 282088
2016-09-21 16:53:36 +00:00
Manman Ren 2aa7f23272 swifterror: fix up a testing case.
llvm-svn: 266000
2016-04-11 21:45:33 +00:00
Manman Ren 5751814eda Swift Calling Convention: swifterror target support.
Differential Revision: http://reviews.llvm.org/D18716

llvm-svn: 265997
2016-04-11 21:08:06 +00:00