Commit Graph

10 Commits

Author SHA1 Message Date
Matthias Braun
0e3f9cfb8b Revert "AArch64: Fix emergency spillslot being out of reach for large callframes"
Revert for now as the testcase is hitting a pre-existing verifier error
that manifest as a failure when expensive checks are enabled (or
-verify-machineinstrs) is used.

This reverts commit r322200.

llvm-svn: 322231
2018-01-10 22:36:28 +00:00
Matthias Braun
63ad6b7f05 AArch64: Fix emergency spillslot being out of reach for large callframes
Large callframes (calls with several hundreds or thousands or
parameters) could lead to situations in which the emergency spillslot is
out of range to be addressed relative to the stack pointer.
This commit forces the use of a frame pointer in the presence of large
callframes.

This commit does several things:
- Compute max callframe size at the end of instruction selection.
- Add mirFileLoaded target callback. Use it to compute the max callframe size
  after loading a .mir file when the size wasn't specified in the file.
- Let TargetFrameLowering::hasFP() return true if there exists a
  callframe > 255 bytes.
- Always place the emergency spillslot close to FP if we have a frame
  pointer.
- Note that `useFPForScavengingIndex()` would previously return false
  when a base pointer was available leading to the emergency spillslot
  getting allocated late (that's the whole effect of this callback).
  Which made no sense to me so I took this case out: Even though the
  emergency spillslot is technically not referenced by FP in this case
  we still want it allocated early.

Differential Revision: https://reviews.llvm.org/D40876

llvm-svn: 322200
2018-01-10 18:16:24 +00:00
David Blaikie
e01dc73ad2 Fix a bunch more layering of CodeGen headers that are in Target
All these headers already depend on CodeGen headers so moving them into
CodeGen fixes the layering (since CodeGen depends on Target, not the
other way around).

llvm-svn: 318490
2017-11-17 01:07:10 +00:00
David Blaikie
45b647d5eb Target/TargetInstrInfo.h -> CodeGen/TargetInstrInfo.h to match layering
This header includes CodeGen headers, and is not, itself, included by
any Target headers, so move it into CodeGen to match the layering of its
implementation.

llvm-svn: 317647
2017-11-08 01:01:31 +00:00
Marina Yatsina
b5c80eef49 Add logic to greedy reg alloc to avoid bad eviction chains
This fixes bugzilla 26810
https://bugs.llvm.org/show_bug.cgi?id=26810

This is intended to prevent sequences like:
movl %ebp, 8(%esp) # 4-byte Spill
movl %ecx, %ebp
movl %ebx, %ecx
movl %edi, %ebx
movl %edx, %edi
cltd
idivl %esi
movl %edi, %edx
movl %ebx, %edi
movl %ecx, %ebx
movl %ebp, %ecx
movl 16(%esp), %ebp # 4 - byte Reload

Such sequences are created in 2 scenarios:

Scenario #1:
vreg0 is evicted from physreg0 by vreg1
Evictee vreg0 is intended for region splitting with split candidate physreg0 (the reg vreg0 was evicted from)
Region splitting creates a local interval because of interference with the evictor vreg1 (normally region spliiting creates 2 interval, the "by reg" and "by stack" intervals. Local interval created when interference occurs.)
one of the split intervals ends up evicting vreg2 from physreg1
Evictee vreg2 is intended for region splitting with split candidate physreg1
one of the split intervals ends up evicting vreg3 from physreg2 etc.. until someone spills

Scenario #2
vreg0 is evicted from physreg0 by vreg1
vreg2 is evicted from physreg2 by vreg3 etc
Evictee vreg0 is intended for region splitting with split candidate physreg1
Region splitting creates a local interval because of interference with the evictor vreg1
one of the split intervals ends up evicting back original evictor vreg1 from physreg0 (the reg vreg0 was evicted from)
Another evictee vreg2 is intended for region splitting with split candidate physreg1
one of the split intervals ends up evicting vreg3 from physreg2 etc.. until someone spills

As compile time was a concern, I've added a flag to control weather we do cost calculations for local intervals we expect to be created (it's on by default for X86 target, off for the rest).

Differential Revision: https://reviews.llvm.org/D35816

Change-Id: Id9411ff7bbb845463d289ba2ae97737a1ee7cc39
llvm-svn: 316295
2017-10-22 17:59:38 +00:00
Andrew V. Tischenko
3fc6c47540 Support itineraries in TargetSubtargetInfo::getSchedInfoStr - Now if the given instr does not have sched model then we try to calculate the latecy/throughput with help of itineraries.
Differential Revision https://reviews.llvm.org/D35997

llvm-svn: 309666
2017-08-01 09:15:43 +00:00
Eugene Zelenko
027b1deacd [Target] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 305757
2017-06-19 22:43:19 +00:00
Chandler Carruth
eb66b33867 Sort the remaining #include lines in include/... and lib/....
I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.

I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.

This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.

Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).

llvm-svn: 304787
2017-06-06 11:49:48 +00:00
Andrew V. Tischenko
b1cf1f0925 This patch closes PR#32216: Better testing of schedule model instruction latencies/throughputs.
The details are here: https://reviews.llvm.org/D30941

llvm-svn: 300311
2017-04-14 07:44:23 +00:00
Matthias Braun
882a081504 TargetSubtargetInfo: Move implementation to lib/CodeGen; NFC
TargetSubtargetInfo is filled with CodeGen specific interfaces nowadays
(getInstrInfo(), getFrameLowering(), getSelectionDAGInfo()) most of the
tuning flags like enablePostRAScheduler(), getAntiDepBreakMode(),
enableRALocalReassignment(), ... also do not seem to be universal enough
to make sense outside of CodeGen.

Differential Revision: https://reviews.llvm.org/D26948

llvm-svn: 287708
2016-11-22 22:09:03 +00:00