Commit Graph

334 Commits

Author SHA1 Message Date
Duncan P. N. Exon Smith 6307eb5518 CodeGen: TII: Take MachineInstr& in predicate API, NFC
Change TargetInstrInfo API to take `MachineInstr&` instead of
`MachineInstr*` in the functions related to predicated instructions
(I'll try to come back later and get some of the rest).  All of these
functions require non-null parameters already, so references are more
clear.  As a bonus, this happens to factor away a host of implicit
iterator => pointer conversions.

No functionality change intended.

llvm-svn: 261605
2016-02-23 02:46:52 +00:00
Junmo Park 7ceec0b82f [BranchFolding] Set correct mem refs (2nd try)
This is a recommit of r257253 which was reverted in r257270.
Previous testcase can make failure on some targets due to using opt with O3 option.

Original Summary:
Merge MBBICommon and MBBI's MMOs.

Differential Revision: http://reviews.llvm.org/D15990

llvm-svn: 257317
2016-01-11 07:15:38 +00:00
Michael Zolotukhin 0fc89c67cc Revert "[BranchFolding] Set correct mem refs"
This reverts commit 1ff11017d2669b933b29fcbb6451cfcda34ad693.

llvm-svn: 257270
2016-01-09 23:53:16 +00:00
Junmo Park e1582cec34 [BranchFolding] Set correct mem refs
Merge MBBICommon and MBBI's MMOs.

Differential Revision: http://reviews.llvm.org/D15990

llvm-svn: 257253
2016-01-09 07:30:13 +00:00
Philip Reames 5eb90a7835 Consolidate MemRefs handling from BranchFolding and correct latent bug
Move the logic from BranchFolding to use the shared infrastructure for merging MMOs introduced in 256909. This has the effect of making BranchFolding more capable.

In the process, fix a latent bug. The existing handling for merging didn't handle the case where one of the instructions being merged had overflowed and dropped MemRefs. This was a latent bug in the places the code was commoned from, but potentially reachable in BranchFolding.

Once this is in, we're left with a single place to consider implementing MMO unique-ing as proposed in http://reviews.llvm.org/D15230.

Differential Revision: http://reviews.llvm.org/D15913

llvm-svn: 256966
2016-01-06 19:33:12 +00:00
Philip Reames 4e66c84722 [MemOperands] Clarify code around dropping memory operands [NFC]
Clarify a comment about what it means to drop memory operands from an instruction.  While I'm adding change the name of the method slightly to make it a bit more clear what's going on when reading calling code.

llvm-svn: 256346
2015-12-23 19:16:04 +00:00
Rafael Espindola 71bd70cc30 Revert "[BranchFolding] Merge MMOs during tail merge"
This reverts commit r254694.

It broke bootstrap.

llvm-svn: 254700
2015-12-04 04:15:05 +00:00
Junmo Park c0731ca183 [BranchFolding] Merge MMOs during tail merge
Summary:
If we remove the MMOs from Load/Store instructions,
they are treated as volatile. This makes other optimization passes unhappy.
eg. Load/Store Optimization

So, it looks better to merge, not remove.

Reviewers: gberry, mcrosier

Subscribers: gberry, llvm-commits

Differential Revision: http://reviews.llvm.org/D14797

llvm-svn: 254694
2015-12-04 02:29:25 +00:00
Junmo Park 7cc13f2e58 (no commit message)
llvm-svn: 254686
2015-12-04 02:06:59 +00:00
Andrew Kaylor 9efb2332e2 [WinEH] Avoid infinite loop in BranchFolding for multiple single block funclets
Differential Revision: http://reviews.llvm.org/D14996

llvm-svn: 254629
2015-12-03 18:55:28 +00:00
Cong Hou d97c100dc4 Replace all weight-based interfaces in MBB with probability-based interfaces, and update all uses of old interfaces.
(This is the second attempt to submit this patch. The first caused two assertion
 failures and was reverted. See https://llvm.org/bugs/show_bug.cgi?id=25687)

The patch in http://reviews.llvm.org/D13745 is broken into four parts:

1. New interfaces without functional changes (http://reviews.llvm.org/D13908).
2. Use new interfaces in SelectionDAG, while in other passes treat probabilities
as weights (http://reviews.llvm.org/D14361).
3. Use new interfaces in all other passes.
4. Remove old interfaces.

This patch is 3+4 above. In this patch, MBB won't provide weight-based
interfaces any more, which are totally replaced by probability-based ones.
The interface addSuccessor() is redesigned so that the default probability is
unknown. We allow unknown probabilities but don't allow using it together
with known probabilities in successor list. That is to say, we either have a
list of successors with all known probabilities, or all unknown
probabilities. In the latter case, we assume each successor has 1/N
probability where N is the number of successors. An assertion checks if the
user is attempting to add a successor with the disallowed mixed use as stated
above. This can help us catch many misuses.

All uses of weight-based interfaces are now updated to use probability-based
ones.


Differential revision: http://reviews.llvm.org/D14973

llvm-svn: 254377
2015-12-01 05:29:22 +00:00
Hans Wennborg 1dbaf67537 Revert r254348: "Replace all weight-based interfaces in MBB with probability-based interfaces, and update all uses of old interfaces."
and the follow-up r254356: "Fix a bug in MachineBlockPlacement that may cause assertion failure during BranchProbability construction."

Asserts were firing in Chromium builds. See PR25687.

llvm-svn: 254366
2015-12-01 03:49:42 +00:00
Cong Hou fa1917c673 Replace all weight-based interfaces in MBB with probability-based interfaces, and update all uses of old interfaces.
The patch in http://reviews.llvm.org/D13745 is broken into four parts:

1. New interfaces without functional changes (http://reviews.llvm.org/D13908).
2. Use new interfaces in SelectionDAG, while in other passes treat probabilities
as weights (http://reviews.llvm.org/D14361).
3. Use new interfaces in all other passes.
4. Remove old interfaces.

This patch is 3+4 above. In this patch, MBB won't provide weight-based
interfaces any more, which are totally replaced by probability-based ones.
The interface addSuccessor() is redesigned so that the default probability is
unknown. We allow unknown probabilities but don't allow using it together
with known probabilities in successor list. That is to say, we either have a
list of successors with all known probabilities, or all unknown
probabilities. In the latter case, we assume each successor has 1/N
probability where N is the number of successors. An assertion checks if the
user is attempting to add a successor with the disallowed mixed use as stated
above. This can help us catch many misuses.

All uses of weight-based interfaces are now updated to use probability-based
ones.


Differential revision: http://reviews.llvm.org/D14973

llvm-svn: 254348
2015-12-01 00:02:51 +00:00
Reid Kleckner b9204a584c [WinEH] Don't forward branches across empty EH pad BBs
For really simple SEH catchpads, we tried to forward the invoke unwind
edge across the empty block.

llvm-svn: 252822
2015-11-11 23:09:31 +00:00
Rafael Espindola 84921b9860 Refactor: Simplify boolean conditional return statements in lib/CodeGen.
Patch by Richard.

llvm-svn: 251213
2015-10-24 23:11:13 +00:00
Duncan P. N. Exon Smith 980f8f2639 CodeGen: Remove implicit conversions from Analysis and BranchFolding
Remove a few more implicit ilist iterator conversions, this time from
Analysis.cpp and BranchFolding.cpp.

I added a few overloads for `remove()` and `erase()`, which quite
naturally take pointers as well as iterators as parameters.  This will
reduce the churn at least in the short term, but I don't really have a
problem with these existing for longer.

llvm-svn: 249867
2015-10-09 18:23:49 +00:00
David Majnemer 161935520d [WinEH] Permit branch folding in the face of funclets
Track which basic blocks belong to which funclets.  Permit branch
folding to fire but only if it can prove that doing so will not cause
code in one funclet to be reused in another.

llvm-svn: 249257
2015-10-04 02:22:52 +00:00
David Majnemer 4600c06434 [WinEH] Stop BranchFolding from merging across funclets
BranchFolding would merge two funclets together, this is not OK.
Disable this and strengthen the assertion in FuncletLayout.

llvm-svn: 249069
2015-10-01 21:04:13 +00:00
Reid Kleckner ed17079b52 [WinEH] Add and use hasEHPadSuccessor instead of getLandingPadSuccessor
getLandingPadSuccessor assumes that each invoke can have at most one EH
pad successor, but WinEH invokes can have more than one. Two out of
three callers of getLandingPadSuccessor don't use the returned
landingpad, so we can make them use this simple predicate instead.

Eventually we'll have to circle back and fix SplitKit.cpp so that
register allocation works. Baby steps.

llvm-svn: 247904
2015-09-17 17:19:40 +00:00
Craig Topper 5db36df4d0 Use range-based for loops. NFC
llvm-svn: 247772
2015-09-16 03:52:35 +00:00
Reid Kleckner 0e2882345d [WinEH] Add some support for code generating catchpad
We can now run 32-bit programs with empty catch bodies.  The next step
is to change PEI so that we get funclet prologues and epilogues.

llvm-svn: 246235
2015-08-27 23:27:47 +00:00
Sanjay Patel d967a878fa fix minsize detection: minsize attribute implies optimizing for size
llvm-svn: 244528
2015-08-10 23:07:26 +00:00
Sanjay Patel 924879ad2c wrap OptSize and MinSize attributes for easier and consistent access (NFCI)
Create wrapper methods in the Function class for the OptimizeForSize and MinSize
attributes. We want to hide the logic of "or'ing" them together when optimizing
just for size (-Os).

Currently, we are not consistent about this and rely on a front-end to always set
OptimizeForSize (-Os) if MinSize (-Oz) is on. Thus, there are 18 FIXME changes here
that should be added as follow-on patches with regression tests.

This patch is NFC-intended: it just replaces existing direct accesses of the attributes
by the equivalent wrapper call.

Differential Revision: http://reviews.llvm.org/D11734

llvm-svn: 243994
2015-08-04 15:49:57 +00:00
Jingyue Wu 3a04dc6e78 Roll forward r242871
r242871 missed one place that should be guarded with isPhysicalReg. This patch
fixes that.

llvm-svn: 243555
2015-07-29 18:59:09 +00:00
Jingyue Wu 7ec38530a5 Temporarily revert r242871
PR24299

llvm-svn: 243522
2015-07-29 15:26:11 +00:00
Jingyue Wu 20d73c6cc0 [BranchFolding] do not iterate the aliases of virtual registers
Summary:
MCRegAliasIterator only works for physical registers. So, do not run it
on virtual registers.

With this issue fixed, we can resurrect the BranchFolding pass in NVPTX
backend.

Reviewers: jholewinski, bkramer

Subscribers: henryhu, meheff, llvm-commits, jholewinski

Differential Revision: http://reviews.llvm.org/D11174

llvm-svn: 242871
2015-07-22 04:16:52 +00:00
Benjamin Kramer 8c57cfd51b [BranchFolding] Document why replacing HashMachineInstr with hash_code doesn't work
llvm-svn: 240415
2015-06-23 14:47:36 +00:00
Benjamin Kramer 6b568964ba [MachineBasicBlock] Add getFirstNonDebugInstr to complement getLastNonDebugInstr
Use it in CodeGen where applicable. No functionality change intended.

llvm-svn: 240414
2015-06-23 14:47:29 +00:00
Alexander Kornienko f00654e31b Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC)
Apparently, the style needs to be agreed upon first.

llvm-svn: 240390
2015-06-23 09:49:53 +00:00
NAKAMURA Takumi 34d3376afc Reformat.
llvm-svn: 240213
2015-06-20 06:22:04 +00:00
NAKAMURA Takumi 3746abba00 Revert r240040, "[BranchFolding] Replace custom MachineInstr with MachineInstrExpressionTrait"
It caused different emission between stage2 and stage3. Investigating.

llvm-svn: 240212
2015-06-20 06:21:48 +00:00
Alexander Kornienko 70bc5f1398 Fixed/added namespace ending comments using clang-tidy. NFC
The patch is generated using this command:

tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
  -checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
  llvm/lib/


Thanks to Eugene Kosov for the original patch!

llvm-svn: 240137
2015-06-19 15:57:42 +00:00
Benjamin Kramer 8985b32e76 [BranchFolding] Replace custom MachineInstr with MachineInstrExpressionTrait
While the hash functions are subtly different it shouldn't have an
impact. Instructions are checked with isIdenticalTo later.

llvm-svn: 240040
2015-06-18 20:00:03 +00:00
Matthias Braun 07066cca20 MachineInstr: Remove unused parameter.
llvm-svn: 237726
2015-05-19 21:22:20 +00:00
Pete Cooper 4d8d2ec3eb Don't rewrite jumps to empty BBs to landing pads.
In the test case here, the 'unreachable' BB was removed by BranchFolding because its empty.

It then rewrote the jump from 'entry' to jump to its fallthrough, which was a landing pad.

This results in 'entry' jumping to 2 different landing pads, which fails the machine verifier.

rdar://problem/20750162

llvm-svn: 236248
2015-04-30 18:58:23 +00:00
Benjamin Kramer 848c9facc8 BranchFolding: MergePotentialsElt has a total order, just call array_pod_sort.
No functionality change intended.

llvm-svn: 232217
2015-03-13 21:17:02 +00:00
Chad Rosier 99fb8d17ec Don't evaluate rend() on every iteration of the loop.
llvm-svn: 231837
2015-03-10 20:29:59 +00:00
Chad Rosier 3b67c8d0f7 [BranchFolding] Remove MMOs during tail merge to preserve dependencies.
When tail merging it may be necessary to remove MMOs from memory operations to
ensures later passes (e.g., MI sched) conservatively compute dependencies.
Currently, we only remove the MMO from the common tail if the MMO doesn't match
with the relative instruction in the non-common tail(s).

A more robust solution would be to add multiple MMOs from the duplicate MIs to
the new MI. Currently ScheduleDAGInstrs.cpp ignores all MMOs on instructions
with multiple MMOs, so this solution is equivalent for the time being.

No test case included as this is incredibly difficult to reproduce.

Patch was a collaborative effort between Ana Pazos and myself.
Phabricator: http://reviews.llvm.org/D7769

llvm-svn: 231799
2015-03-10 16:22:52 +00:00
Duncan P. N. Exon Smith 70eb9c5ae5 CodeGen: Canonicalize access to function attributes, NFC
Canonicalize access to function attributes to use the simpler API.

getAttributes().getAttribute(AttributeSet::FunctionIndex, Kind)
  => getFnAttribute(Kind)

getAttributes().hasAttribute(AttributeSet::FunctionIndex, Kind)
  => hasFnAttribute(Kind)

Also, add `Function::getFnStackAlignment()`, and canonicalize:

getAttributes().getStackAlignment(AttributeSet::FunctionIndex)
  => getFnStackAlignment()

llvm-svn: 229208
2015-02-14 01:44:41 +00:00
David Blaikie 70573dcd9f Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool>
This is to be consistent with StringSet and ultimately with the standard
library's associative container insert function.

This lead to updating SmallSet::insert to return pair<iterator, bool>,
and then to update SmallPtrSet::insert to return pair<iterator, bool>,
and then to update all the existing users of those functions...

llvm-svn: 222334
2014-11-19 07:49:26 +00:00
Eric Christopher 307c2cb26f Remove unnecessary TargetMachine.h includes.
llvm-svn: 219672
2014-10-14 07:22:08 +00:00
Akira Hatanaka bbd33f6766 [Branch probability] Recompute branch weights of tail-merged basic blocks.
BranchFolderPass was not correctly setting the basic block branch weights when
tail-merging created or merged blocks. This patch recomutes the weights of
tail-merged blocks using the following formula:

branch_weight(merged block to successor j) =
sum(block_frequency(bb) * branch_probability(bb -> j))

bb is a block that is in the set of merged blocks.

<rdar://problem/16256423>

llvm-svn: 215135
2014-08-07 19:30:13 +00:00
Eric Christopher fc6de428c8 Have MachineFunction cache a pointer to the subtarget to make lookups
shorter/easier and have the DAG use that to do the same lookup. This
can be used in the future for TargetMachine based caching lookups from
the MachineFunction easily.

Update the MIPS subtarget switching machinery to update this pointer
at the same time it runs.

llvm-svn: 214838
2014-08-05 02:39:49 +00:00
Pedro Artigas ec7cbd7d14 Changed the liveness tracking in the RegisterScavenger
to use register units instead of registers.

reviewed by Jakob Stoklund Olesen.

llvm-svn: 214798
2014-08-04 23:07:49 +00:00
Eric Christopher d913448b38 Remove the TargetMachine forwards for TargetSubtargetInfo based
information and update all callers. No functional change.

llvm-svn: 214781
2014-08-04 21:25:23 +00:00
Sasa Stankovic 56c12e679a Prevent hoisting the instruction whose def might be clobbered by the terminator.
llvm-svn: 210261
2014-06-05 13:42:48 +00:00
Chandler Carruth 1b9dde087e [Modules] Remove potential ODR violations by sinking the DEBUG_TYPE
define below all header includes in the lib/CodeGen/... tree. While the
current modules implementation doesn't check for this kind of ODR
violation yet, it is likely to grow support for it in the future. It
also removes one layer of macro pollution across all the included
headers.

Other sub-trees will follow.

llvm-svn: 206837
2014-04-22 02:02:50 +00:00
Craig Topper c0196b1b40 [C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr.
llvm-svn: 206142
2014-04-14 00:51:57 +00:00
Paul Robinson 7c99ec5b99 Disable each MachineFunctionPass for 'optnone' functions, unless that
pass normally runs at optimization level None, or is part of the
register allocation pipeline.

llvm-svn: 205228
2014-03-31 17:43:35 +00:00
Ekaterina Romanova b9aea9383a This is a fix for PR# 19051. I noticed code gen differences due to code motion when running tests with and without the debug info at O2. The problem is in branch folding. A loop wanted to skip the debug info, but actually it didn't do so.
llvm-svn: 204865
2014-03-26 22:15:28 +00:00
Craig Topper 4584cd54e3 [C++11] Add 'override' keyword to virtual methods that override their base class.
llvm-svn: 203220
2014-03-07 09:26:03 +00:00
Benjamin Kramer b6d0bd48bd [C++11] Replace llvm::next and llvm::prior with std::next and std::prev.
Remove the old functions.

llvm-svn: 202636
2014-03-02 12:27:27 +00:00
Vincent Lejeune 92b0a64906 Add a RequireStructuredCFG Field to TargetMachine.
llvm-svn: 196634
2013-12-07 01:49:19 +00:00
Andrew Trick 97a1d7c475 Fix tail merging to assign the (more) correct BasicBlock when splitting.
This makes it possible to write unit tests that are less susceptible
to minor code motion, particularly copy placement. block-placement.ll
covers this case with -pre-RA-sched=source which will soon be
default. One incorrectly named block is already fixed, but without
this fix, enabling new coalescing and scheduling would cause more
failures.

llvm-svn: 184680
2013-06-24 01:55:01 +00:00
Chad Rosier abdb1d69ab Simplify logic now that r182490 is in place. No functional change intended.
llvm-svn: 182531
2013-05-22 23:17:36 +00:00
Chandler Carruth 9fb823bbd4 Move all of the header files which are involved in modelling the LLVM IR
into their new header subdirectory: include/llvm/IR. This matches the
directory structure of lib, and begins to correct a long standing point
of file layout clutter in LLVM.

There are still more header files to move here, but I wanted to handle
them in separate commits to make tracking what files make sense at each
layer easier.

The only really questionable files here are the target intrinsic
tablegen files. But that's a battle I'd rather not fight today.

I've updated both CMake and Makefile build systems (I think, and my
tests think, but I may have missed something).

I've also re-sorted the includes throughout the project. I'll be
committing updates to Clang, DragonEgg, and Polly momentarily.

llvm-svn: 171366
2013-01-02 11:36:10 +00:00
Bill Wendling 698e84fc4f Remove the Function::getFnAttributes method in favor of using the AttributeSet
directly.

This is in preparation for removing the use of the 'Attribute' class as a
collection of attributes. That will shift to the AttributeSet class instead.

llvm-svn: 171253
2012-12-30 10:32:01 +00:00
Bill Wendling 3d7b0b8ac7 Rename the 'Attributes' class to 'Attribute'. It's going to represent a single attribute in the future.
llvm-svn: 170502
2012-12-19 07:18:57 +00:00
Chandler Carruth ed0881b2a6 Use the new script to sort the includes of every file under lib.
Sooooo many of these had incorrect or strange main module includes.
I have manually inspected all of these, and fixed the main module
include to be the nearest plausible thing I could find. If you own or
care about any of these source files, I encourage you to take some time
and check that these edits were sensible. I can't have broken anything
(I strictly added headers, and reordered them, never removed), but they
may not be the headers you'd really like to identify as containing the
API being implemented.

Many forward declarations and missing includes were added to a header
files to allow them to parse cleanly when included first. The main
module rule does in fact have its merits. =]

llvm-svn: 169131
2012-12-03 16:50:05 +00:00
Jakub Staszak 8262b885da Remove unneeded #include.
llvm-svn: 168670
2012-11-27 02:00:27 +00:00
Bill Wendling c9b22d735a Create enums for the different attributes.
We use the enums to query whether an Attributes object has that attribute. The
opaque layer is responsible for knowing where that specific attribute is stored.

llvm-svn: 165488
2012-10-09 07:45:08 +00:00
Craig Topper 2f6031c643 Fix indentation. Remove 'else' after return. No functional change.
llvm-svn: 165381
2012-10-07 20:31:05 +00:00
Bill Wendling 863bab689a Remove the `hasFnAttr' method from Function.
The hasFnAttr method has been replaced by querying the Attributes explicitly. No
intended functionality change.

llvm-svn: 164725
2012-09-26 21:48:26 +00:00
Benjamin Kramer f29db275b2 Reduce duplicated hash map lookups.
llvm-svn: 162362
2012-08-22 15:37:57 +00:00
Benjamin Kramer bde9176663 Fix typos found by http://github.com/lyda/misspell-check
llvm-svn: 157885
2012-06-02 10:20:22 +00:00
Jakob Stoklund Olesen 54038d796c Switch all register list clients to the new MC*Iterator interface.
No functional change intended.

Sorry for the churn. The iterator classes are supposed to help avoid
giant commits like this one in the future. The TableGen-produced
register lists are getting quite large, and it may be necessary to
change the table representation.

This makes it possible to do so without changing all clients (again).

llvm-svn: 157854
2012-06-01 23:28:30 +00:00
Jakob Stoklund Olesen 92a0083944 Switch some getAliasSet clients to MCRegAliasIterator.
MCRegAliasIterator can optionally visit the register itself, allowing
for simpler code.

llvm-svn: 157837
2012-06-01 20:36:54 +00:00
Bill Wendling e351e8c52d Forgot to reverse conditional.
llvm-svn: 157349
2012-05-23 22:12:50 +00:00
Bill Wendling 041793c452 Reduce indentation by early detection of 'continue'. No functionality change.
llvm-svn: 157348
2012-05-23 22:09:50 +00:00
Preston Gurd 9a0914753a This patch fixes a problem which arose when using the Post-RA scheduler
on X86 Atom. Some of our tests failed because the tail merging part of
the BranchFolding pass was creating new basic blocks which did not
contain live-in information. When the anti-dependency code in the Post-RA
scheduler ran, it would sometimes rename the register containing
the function return value because the fact that the return value was
live-in to the subsequent block had been lost. To fix this, it is necessary
to run the RegisterScavenging code in the BranchFolding pass.

This patch makes sure that the register scavenging code is invoked
in the X86 subtarget only when post-RA scheduling is being done.
Post RA scheduling in the X86 subtarget is only done for Atom.

This patch adds a new function to the TargetRegisterClass to control
whether or not live-ins should be preserved during branch folding.
This is necessary in order for the anti-dependency optimizations done
during the PostRASchedulerList pass to work properly when doing
Post-RA scheduling for the X86 in general and for the Intel Atom in particular.

The patch adds and invokes the new function trackLivenessAfterRegAlloc()
instead of using the existing requiresRegisterScavenging().
It changes BranchFolding.cpp to call trackLivenessAfterRegAlloc() instead of
requiresRegisterScavenging(). It changes the all the targets that
implemented requiresRegisterScavenging() to also implement
trackLivenessAfterRegAlloc().  

It adds an assertion in the Post RA scheduler to make sure that post RA
liveness information is available when it is needed.

It changes the X86 break-anti-dependencies test to use –mcpu=atom, in order
to avoid running into the added assertion.

Finally, this patch restores the use of anti-dependency checking
(which was turned off temporarily for the 3.1 release) for
Intel Atom in the Post RA scheduler.

Patch by Andy Zhang!

Thanks to Jakob and Anton for their reviews.

llvm-svn: 155395
2012-04-23 21:39:35 +00:00
Jakob Stoklund Olesen d1664a1571 Branch folding may invalidate liveness.
Branch folding can use a register scavenger to update liveness
information when required. Don't do that if liveness information is
already invalid.

llvm-svn: 153517
2012-03-27 17:06:09 +00:00
Bill Wendling 7c5dcb6ccf Where the BranchFolding pass removes a branch then adds another better branch,
the DebugLoc information can be maintained throughout by grabbing the DebugLoc
before the RemoveBranch and then passing the result to the InsertBranch.
Patch by Andrew Stanford-Jason!

llvm-svn: 152212
2012-03-07 08:49:42 +00:00
Craig Topper 4b02a29eba Convert more GenRegisterInfo tables from unsigned to uint16_t to reduce static data size.
llvm-svn: 152016
2012-03-05 05:37:41 +00:00
Craig Topper 1d32658877 Use uint16_t to store register overlaps to reduce static data.
llvm-svn: 152001
2012-03-04 10:43:23 +00:00
Chad Rosier 5dfe6dab25 Remove extra semi-colons.
llvm-svn: 151169
2012-02-22 17:25:00 +00:00
Jakob Stoklund Olesen e9e30d083c Handle register masks in branch folding.
Don't attempt to move instructions with regmask operands. They are most
likely calls anyway.

llvm-svn: 150634
2012-02-15 23:42:54 +00:00
Andrew Trick 58648e4e98 Move pass configuration out of pass constructors: BranchFolderPass
llvm-svn: 150095
2012-02-08 21:22:48 +00:00
Andrew Trick 9e761997d8 whitespace
llvm-svn: 150094
2012-02-08 21:22:43 +00:00
David Blaikie 46a9f016c5 More dead code removal (using -Wunreachable-code)
llvm-svn: 148578
2012-01-20 21:51:11 +00:00
Evan Cheng 5c03a6b8f5 When hoisting common code, watch out for uses which are marked "kill". If the
killed registers are needed below the insertion point, then unset the kill
marker.

Sorry I'm not able to find a reduced test case.

rdar://10660944

llvm-svn: 148043
2012-01-12 20:31:24 +00:00
Evan Cheng 6cc8d49885 Revert part of r147716. Looks like x87 instructions kill markers are all messed
up so branch folding pass can't use the scavenger. :-(  This doesn't breaks
anything currently. It just means targets which do not carefully update kill
markers cannot run post-ra scheduler (not new, it has always been the case).

We should fix this at some point since it's really hacky.

llvm-svn: 147719
2012-01-07 03:35:48 +00:00
Evan Cheng 00b1a3cd7e Added a late machine instruction copy propagation pass. This catches
opportunities that only present themselves after late optimizations
such as tail duplication .e.g.
## BB#1:
        movl    %eax, %ecx
        movl    %ecx, %eax
        ret

The register allocator also leaves some of them around (due to false
dep between copies from phi-elimination, etc.)

This required some changes in codegen passes. Post-ra scheduler and the
pseudo-instruction expansion passes have been moved after branch folding
and tail merging. They were before branch folding before because it did
not always update block livein's. That's fixed now. The pass change makes
independently since we want to properly schedule instructions after
branch folding / tail duplication.

rdar://10428165
rdar://10640363

llvm-svn: 147716
2012-01-07 03:02:36 +00:00
Evan Cheng 7fae11b231 - Add MachineInstrBundle.h and MachineInstrBundle.cpp. This includes a function
to finalize MI bundles (i.e. add BUNDLE instruction and computing register def
  and use lists of the BUNDLE instruction) and a pass to unpack bundles.
- Teach more of MachineBasic and MachineInstr methods to be bundle aware.
- Switch Thumb2 IT block to MI bundles and delete the hazard recognizer hack to
  prevent IT blocks from being broken apart.

llvm-svn: 146542
2011-12-14 02:11:42 +00:00
Evan Cheng 7f8e563a69 Add bundle aware API for querying instruction properties and switch the code
generator to it. For non-bundle instructions, these behave exactly the same
as the MC layer API.

For properties like mayLoad / mayStore, look into the bundle and if any of the
bundled instructions has the property it would return true.
For properties like isPredicable, only return true if *all* of the bundled
instructions have the property.
For properties like canFoldAsLoad, isCompare, conservatively return false for
bundles.

llvm-svn: 146026
2011-12-07 07:15:52 +00:00
Bill Wendling 9b9932229d Reapply r142920 with fix:
An MBB which branches to an EH landing pad shouldn't be considered for tail merging.

In SjLj EH, the jump to the landing pad is not done explicitly through a branch
statement. The EH landing pad is added as a successor to the throwing
BB. Because of that however, the branch folding pass could mistakenly think that
it could merge the throwing BB with another BB. This isn't safe to do.
<rdar://problem/10334833>

llvm-svn: 143001
2011-10-26 01:10:25 +00:00
Duncan Sands 6ca458e49a Revert commit 142891. Takumi bisected the tablegen miscompiles
down to this commit.  Original commit message:

An MBB which branches to an EH landing pad shouldn't be considered for tail merging.

In SjLj EH, the jump to the landing pad is not done explicitly through a branch
statement. The EH landing pad is added as a successor to the throwing
BB. Because of that however, the branch folding pass could mistakenly think that
it could merge the throwing BB with another BB. This isn't safe to do.
<rdar://problem/10334833>

llvm-svn: 142920
2011-10-25 12:30:22 +00:00
Bill Wendling 38ced995f6 An MBB which branches to an EH landing pad shouldn't be considered for tail merging.
In SjLj EH, the jump to the landing pad is not done explicitly through a branch
statement. The EH landing pad is added as a successor to the throwing
BB. Because of that however, the branch folding pass could mistakenly think that
it could merge the throwing BB with another BB. This isn't safe to do.
<rdar://problem/10334833>

llvm-svn: 142891
2011-10-25 00:54:05 +00:00
Jakob Stoklund Olesen d633abebf6 Fix liveness computations in BranchFolding.
The old code would look at kills and defs in one pass over the
instruction operands, causing problems with this code:

  %R0<def>, %CPSR<def,dead> = tLSLri %R5<kill>, 2, pred:14, pred:%noreg
  %R0<def>, %CPSR<def,dead> = tADDrr %R4<kill>, %R0<kill>, pred:14, %pred:%noreg

The last instruction kills and redefines %R0, so it is still live after
the instruction.

This caused a register scavenger crash when compiling 483.xalancbmk for
armv6. I am not including a test case because it requires too much bad
luck to expose this old bug.

First you need to convince the register allocator to use %R0 twice on
the tADDrr instruction, then you have to convince BranchFolding to do
something that causes it to run the register scavenger on he bad block.

<rdar://problem/9898200>

llvm-svn: 136973
2011-08-05 18:47:07 +00:00
Eli Friedman bf007364bf When tail-merging multiple blocks, make sure to correctly update the live-in list on the merged block to correctly account for the live-outs of all the predecessors. They might not be the same in all cases (the testcase I have involves a PHI node where one of the operands is an IMPLICIT_DEF).
Unfortunately, the testcase I have is large and confidential, so I don't have a test to commit at the moment; I'll see if I can come up with something smaller where this issue reproduces.

<rdar://problem/9716278>

llvm-svn: 134565
2011-07-06 23:41:48 +00:00
Evan Cheng 6cc775f905 - Rename TargetInstrDesc, TargetOperandInfo to MCInstrDesc and MCOperandInfo and
sink them into MC layer.
- Added MCInstrInfo, which captures the tablegen generated static data. Chang
TargetInstrInfo so it's based off MCInstrInfo.

llvm-svn: 134021
2011-06-28 19:10:37 +00:00
Rafael Espindola 3aeaf9e4c1 Add 132986 back, but avoid non-determinism if a bb address gets reused.
llvm-svn: 132995
2011-06-14 15:31:54 +00:00
Rafael Espindola 06ba7a68de revert 132986 to see if the bots go green.
llvm-svn: 132988
2011-06-14 12:48:26 +00:00
Rafael Espindola da24f2f8e1 Make the threshold used by branch folding softer. Before we would get a
sharp all or nothing transition when one extra predecessor was added. Now
we still test first ones for merging.

llvm-svn: 132974
2011-06-14 04:41:17 +00:00
Devang Patel cdec11413b Add comment.
llvm-svn: 132149
2011-05-26 21:49:28 +00:00
Devang Patel 42ddaa10d3 During branch folding avoid inserting redundant DBG_VALUE machine instructions.
llvm-svn: 132148
2011-05-26 21:47:59 +00:00
Evan Cheng 8a88026ae3 Update comment.
llvm-svn: 131258
2011-05-12 22:35:48 +00:00
Evan Cheng 43054e6159 Re-enable branchfolding common code hoisting optimization. Fixed a liveness test bug and also taught it to update liveins.
llvm-svn: 131241
2011-05-12 20:30:01 +00:00
Evan Cheng 33469b2cae Temporarily disable the transformation. It's breaking 186.crafty in some configuration.
llvm-svn: 131235
2011-05-12 18:44:58 +00:00
Evan Cheng cfdf33904b Re-commit 131172 with fix. MachineInstr identity checks should check dead
markers. In some cases a register def is dead on one path, but not on
another.

This is passing Clang self-hosting.

llvm-svn: 131214
2011-05-12 00:56:58 +00:00
Rafael Espindola 2a09d65979 Revert 131172 as it is causing clang to miscompile itself. I will try
to provide a reduced testcase.

llvm-svn: 131176
2011-05-11 03:27:17 +00:00