Commit Graph

15 Commits

Author SHA1 Message Date
Sander de Smalen f28e1128d9 Relanding r368987 [AArch64] Change location of frame-record within callee-save area.
Changes:
There was a condition for `!NeedsFrameRecord` missing in the assert. The
assert in question has changed to:

+    assert((!RPI.isPaired() || !NeedsFrameRecord || RPI.Reg2 != AArch64::FP ||
+            RPI.Reg1 == AArch64::LR) &&
+           "FrameRecord must be allocated together with LR");

This addresses PR43016.

llvm-svn: 369122
2019-08-16 15:42:28 +00:00
Nico Weber ee96499a42 Revert r368987, it caused PR43016.
llvm-svn: 369080
2019-08-16 02:21:21 +00:00
Sander de Smalen 643adb5576 [AArch64] Change location of frame-record within callee-save area.
This patch changes the location of the frame-record (FP, LR) to the 
bottom of the callee-saved area. According to the AAPCS the location of
the frame-record within the stackframe is unspecified (section 5.2.3 The 
Frame Pointer), so the compiler should be free to choose a different
location.

The reason for changing the location of the frame-record is to prepare
the frame for allocating an SVE area below the callee-saves. This way the 
compiler can use the VL-scaled addressing modes to directly access SVE 
objects from the frame-pointer.

            :                :   
        | stack |        | stack |
        |  args |        |  args |
        +-------+        +-------+
        |  x30  |        |  x19  |
        |  x29  |        |  x20  |
  FP -> |- - - -|        |  x21  |
        |  x19  |   ==>  |  x22  |
        |  x20  |        |- - - -|
        |  x21  |        |  x30  |
        |  x22  |        |  x29  |
        +-------+        +-------+ <- FP
        |///////|        |///////|         // realignment gap 
        |- - - -|        |- - - -|
        |spills/|        |spills/|
        | locals|        | locals|
  SP -> +-------+        +-------+ <- SP

Things to point out:
- The algorithm to find a paired register should be prevented from
  accidentally pairing some callee-saved register with LR that is not 
  FP, since they should always be paired together when the frame
  has a frame-record.
- For Darwin platforms the location of the frame-record is unchanged,
  since the unwind encoding does not allow for encoding this position
  dynamically and other tools currently depend on the former layout. 

Reviewers: efriedma, rovka, rengolin, thegameg, greened, t.p.northover

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D65653

llvm-svn: 368987
2019-08-15 10:34:16 +00:00
Francis Visoiu Mistrih f2c22050e8 [AArch64] Use FP to access the emergency spill slot
In the presence of variable-sized stack objects, we always picked the
base pointer when resolving frame indices if it was available.

This makes us hit an assert where we can't reach the emergency spill
slot if it's too far away from the base pointer. Since on AArch64 we
decide to place the emergency spill slot at the top of the frame, it
makes more sense to use FP to access it.

The changes here don't affect only emergency spill slots but all the
frame indices. The goal here is to try to choose between FP, BP and SP
so that we minimize the offset and avoid scavenging, or worse, asserting
when trying to access a slot allocated by the scavenger.

Previously discussed here: https://reviews.llvm.org/D40876.

Differential Revision: https://reviews.llvm.org/D45358

llvm-svn: 329691
2018-04-10 11:29:40 +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
Simon Pilgrim fc4d4b251d [AARCH64] Enable AARCH64 lit tests on windows dev machines
As discussed on PR27654, this patch fixes the triples of a lot of aarch64 tests and enables lit tests on windows

This will hopefully help stop cases where windows developers break the aarch64 target

Differential Revision: https://reviews.llvm.org/D22191

llvm-svn: 275973
2016-07-19 13:35:11 +00:00
Jun Bum Lim 6755c3bc5f [AArch64] Promote loads from stored
This is a recommit of r256004 which was reverted in r256160. The issue was the
incorrect promotion for half and byte loads transformed into mov instructions.
This fix will replace half and byte type loads only with bit field extracts.

Original commit message:

This change promotes load instructions which directly read from stored by
replacing them with mov instructions. If the store is wider than the load,
the load will be replaced with a bitfield extract.
For example :
  STRWui %W1, %X0, 1
  %W0 = LDRHHui %X0, 3
becomes
  STRWui %W1, %X0, 1
  %W0 = UBFMWri %W1, 16, 31

llvm-svn: 256249
2015-12-22 16:36:16 +00:00
Jun Bum Lim 4bb171c8da Revert "[AArch64] Promote loads from stores"
This reverts commit r256004 due to a failure in cortex-a53.

llvm-svn: 256160
2015-12-21 15:36:49 +00:00
Jun Bum Lim 3509d64c24 [AArch64] Promote loads from stores
This change promotes load instructions which directly read from stores by
replacing them with mov instructions. If the store is wider than the load,
the load will be replaced with a bitfield extract.
For example :
  STRWui %W1, %X0, 1
  %W0 = LDRHHui %X0, 3
becomes
  STRWui %W1, %X0, 1
  %W0 = UBFMWri %W1, 16, 31

llvm-svn: 256004
2015-12-18 18:08:30 +00:00
David Blaikie a79ac14fa6 [opaque pointer type] Add textual IR support for explicit type parameter to load instruction
Essentially the same as the GEP change in r230786.

A similar migration script can be used to update test cases, though a few more
test case improvements/changes were required this time around: (r229269-r229278)

import fileinput
import sys
import re

pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)")

for line in sys.stdin:
  sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line))

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7649

llvm-svn: 230794
2015-02-27 21:17:42 +00:00
Tim Northover 3b0846e8f7 AArch64/ARM64: move ARM64 into AArch64's place
This commit starts with a "git mv ARM64 AArch64" and continues out
from there, renaming the C++ classes, intrinsics, and other
target-local objects for consistency.

"ARM64" test directories are also moved, and tests that began their
life in ARM64 use an arm64 triple, those from AArch64 use an aarch64
triple. Both should be equivalent though.

This finishes the AArch64 merge, and everyone should feel free to
continue committing as normal now.

llvm-svn: 209577
2014-05-24 12:50:23 +00:00