Commit Graph

67 Commits

Author SHA1 Message Date
Hal Finkel 34c94d5caa Correct the AggressiveAntiDepBreaker's handling of subregisters defining super registers
As the AggressiveAntiDepBreaker iterated backward through a scheduling region,
we must leave super registers live through subregister definitions so that all
relevant subregister definitions are renamed together. The problem was that we
were also discarding sub-register use locations as the sub-registers are
redefined. The result is that we'd rename the super register along with some,
but not all, subregister definitions.

  R0_D = {R0_L, R1_L}
  R0_L = {R0_S, R1_S}

  %R0_L<def> = TRLi9 16, pred:8, pred:%noreg
  %R1_L<def> = LSRLrr %R1_L<kill>, %R0_S, pred:8, pred:%noreg
  %R0_L<def> = LSRLrr %R2_L, %R0_S, pred:8, pred:%noreg, %R0_L<imp-use,kill>
  %R1_L<def> = ANDLri %R1_L<kill>, 2047, pred:8, pred:%noreg
  %R0_L<def> = ANDLri %R0_L<kill>, 2047, pred:8, pred:%noreg
  %R4_D<def> = ASRDrr %R0_D<kill>, %R6_S

  Anti:   %R4_D<def> = ASRDrr %R0_D<kill>, %R6_S
   Def Groups: R4_D=g213->g215(via R4_S)->g214(via R4_L)->g216(via R5_S)->g216(via R4_L)->g217(via R5_L)
   Use Groups: R0_D=g0->g218(last-use) R1_L->g219(last-use) R6_S=g204->g220(last-use)
  Anti:   %R0_L<def> = ANDLri %R0_L<kill>, 2047, pred:8, pred:%noreg
   Def Groups: R0_L=g208->g209(via R0_S)->g218(via R0_D)->g210(via R1_S)->g210(via R0_D)
   Antidep reg: R0_L (real dependency)
   Use Groups: R0_L=g210->g224(last-use) R0_S->g225(last-use) R1_S->g226(last-use)
  Anti:   %R1_L<def> = ANDLri %R1_L<kill>, 2047, pred:8, pred:%noreg
   Def Groups: R1_L=g219->g210(via R0_D)
   Antidep reg: R1_L (real dependency)
   Use Groups: R1_L=g210->g229(last-use)
  Anti:   %R0_L<def> = LSRLrr %R2_L, %R0_S, pred:8, pred:%noreg, %R0_L<imp-use,kill>
   Def Groups: R0_L=g224->g225(via R0_S)->g210(via R0_D)->g226(via R1_S)->g226(via R0_D)
   Antidep reg: R0_L Use Groups: R2_L=g192 R0_S=g226->g230(last-use) R0_L=g226->g231(last-use) R1_S->g232(last-use)
  Anti:   %R1_L<def> = LSRLrr %R1_L<kill>, %R0_S, pred:8, pred:%noreg
   Def Groups: R1_L=g229->g226(via R0_D)
   Antidep reg: R1_L Use Groups: R1_L=g226->g233(last-use) R0_S=g230
  Anti:   %R0_L<def> = TRLi9 16, pred:8, pred:%noreg
   Def Groups: R0_L=g231->g230(via R0_S)->g226(via R0_D)->g232(via R1_S)->g232(via R0_D)
   Antidep reg: R0_L
   Rename Candidates for Group g232:
    R0_D: elcInt64Regs :: R0_D R1_D R2_D R3_D R4_D R5_D R8_D R9_D R10_D R11_D R12_D R13_D R14_D R15_D R16_D R17_D R18_D R19_D R20_D R21_D R22_D R23_D R24_D R25_D
    R0_L: elcIntRegs :: R0_L R1_L R2_L R3_L R4_L R5_L R8_L R9_L R10_L R11_L R12_L R13_L R14_L R15_L R16_L R17_L R18_L R19_L R20_L R21_L R22_L R23_L R24_L R25_L
    R0_S: elcShrtRegs elcShrtRegs :: R0_S R1_S R2_S R3_S R4_S R5_S R8_S R9_S R10_S R11_S R12_S R13_S R14_S R15_S R16_S R17_S R18_S R19_S R20_S R21_S R22_S R23_S R24_S R25_S
   Find Registers: [R12_D: R12_D R12_L R12_S]
   Breaking anti-dependence edge on R0_L: R0_D->R12_D(1 refs) R0_L->R12_L(2 refs) R0_S->R12_S(2 refs)
   Use Groups:
  ...

  %R12_L<def> = TRLi9 16, pred:8, pred:%noreg
  %R1_L<def> = LSRLrr %R1_L<kill>, %R12_S, pred:8, pred:%noreg
  %R0_L<def> = LSRLrr %R2_L<kill>, %R12_S, pred:8, pred:%noreg, %R12_L<imp-use>
  %R1_L<def> = ANDLri %R1_L<kill>, 2047, pred:8, pred:%noreg
  %R0_L<def> = ANDLri %R0_L<kill>, 2047, pred:8, pred:%noreg
  %R4_D<def> = ASRDrr %R12_D<kill>, %R6_S

With this change, we now produce:

  Anti:   %R4_D<def> = ASRDrr %R0_D<kill>, %R6_S
   Def Groups: R4_D=g213->g215(via R4_S)->g214(via R4_L)->g216(via R5_S)->g216(via R4_L)->g217(via R5_L)
   Use Groups: R0_D=g0->g218(last-use) R1_L->g219(last-use) R6_S=g204->g220(last-use)
  Anti:   %R0_L<def> = ANDLri %R0_L<kill>, 2047, pred:8, pred:%noreg
   Def Groups: R0_L=g208->g209(via R0_S)->g218(via R0_D)->g210(via R1_S)->g210(via R0_D)
   Antidep reg: R0_L (real dependency)
   Use Groups: R0_L=g210
  Anti:   %R1_L<def> = ANDLri %R1_L<kill>, 2047, pred:8, pred:%noreg
   Def Groups: R1_L=g219->g210(via R0_D)
   Antidep reg: R1_L (real dependency)
   Use Groups: R1_L=g210
  Anti:   %R0_L<def> = LSRLrr %R2_L, %R0_S, pred:8, pred:%noreg, %R0_L<imp-use,kill>
   Def Groups: R0_L=g210->g210(via R0_D)->g210(via R0_D)
   Antidep reg: R0_L Use Groups: R2_L=g192 R0_S=g210 R0_L=g210
  Anti:   %R1_L<def> = LSRLrr %R1_L<kill>, %R0_S, pred:8, pred:%noreg
   Def Groups: R1_L=g210->g210(via R0_D)
   Antidep reg: R1_L Use Groups: R1_L=g210 R0_S=g210
  Anti:   %R0_L<def> = TRLi9 16, pred:8, pred:%noreg
   Def Groups: R0_L=g210->g210(via R0_D)->g210(via R0_D)
   Antidep reg: R0_L
   Rename Candidates for Group g210:
    R0_D: elcInt64Regs :: R0_D R1_D R2_D R3_D R4_D R5_D R8_D R9_D R10_D R11_D R12_D R13_D R14_D R15_D R16_D R17_D R18_D R19_D R20_D R21_D R22_D R23_D R24_D R25_D
    R0_L: elcIntRegs elcIntAIRegs elcIntRegs elcIntRegs elcIntRegs elcIntRegs :: R0_L R1_L R2_L R3_L R4_L R5_L R8_L R9_L R10_L R11_L R12_L R13_L R14_L R15_L R16_L R17_L R18_L R19_L R20_L R21_L R22_L R23_L R24_L R25_L
    R1_L: elcIntRegs elcIntRegs elcIntRegs elcIntRegs elcIntRegs :: R0_L R1_L R2_L R3_L R4_L R5_L R8_L R9_L R10_L R11_L R12_L R13_L R14_L R15_L R16_L R17_L R18_L R19_L R20_L R21_L R22_L R23_L R24_L R25_L
    R0_S: elcShrtRegs elcShrtRegs :: R0_S R1_S R2_S R3_S R4_S R5_S R8_S R9_S R10_S R11_S R12_S R13_S R14_S R15_S R16_S R17_S R18_S R19_S R20_S R21_S R22_S R23_S R24_S R25_S
   Find Registers: [R12_D: R12_D R12_L R13_L R12_S]
   Breaking anti-dependence edge on R0_L: R0_D->R12_D(1 refs) R0_L->R12_L(7 refs) R1_L->R13_L(5 refs) R0_S->R12_S(2 refs)
   Use Groups:
  ...

  %R12_L<def> = TRLi9 16, pred:8, pred:%noreg
  %R13_L<def> = LSRLrr %R13_L<kill>, %R12_S, pred:8, pred:%noreg
  %R12_L<def> = LSRLrr %R2_L<kill>, %R12_S<kill>, pred:8, pred:%noreg, %R12_L<imp-use,kill>
  %R13_L<def> = ANDLri %R13_L<kill>, 2047, pred:8, pred:%noreg
  %R12_L<def> = ANDLri %R12_L<kill>, 2047, pred:8, pred:%noreg
  %R4_D<def> = ASRDrr %R12_D, %R6_S, %R12_L<imp-def>, %R12_S<imp-def>, %R13_S<imp-def>

As demonstrated by this example, this is also somewhat unfortunate, because
there is actually no need to rename the super register in this case (it is
fully covered by later subregister definitions), but we don't seem to track
enough information here to exploit that either.

Thanks to Daniil Troshkov for reporting the issue. The debug outputs in this
commit message are from Daniil.

llvm-svn: 227311
2015-01-28 14:44:14 +00:00
Hal Finkel c8cf2b88bc Handle early-clobber registers in the aggressive anti-dep breaker
The aggressive anti-dep breaker, used by the PowerPC backend during post-RA
scheduling (but is available to all targets), did not handle early-clobber MI
operands (at all). When constructing the list of available registers for the
replacement of some def operand, check the using instructions, and remove
registers assigned to early-clobbered defs from the set.

Fixes PR21452.

llvm-svn: 223727
2014-12-09 01:00:59 +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
Craig Topper cf0444ba2a Move register class name strings to a single array in MCRegisterInfo to reduce static table size and number of relocation entries.
Indices into the table are stored in each MCRegisterClass instead of a pointer. A new method, getRegClassName, is added to MCRegisterInfo and TargetRegisterInfo to lookup the string in the table.

llvm-svn: 222118
2014-11-17 05:50:14 +00:00
Eric Christopher 307c2cb26f Remove unnecessary TargetMachine.h includes.
llvm-svn: 219672
2014-10-14 07:22:08 +00:00
Benjamin Kramer 2c99e413ba Reduce double set lookups. NFC.
llvm-svn: 219505
2014-10-10 15:32:50 +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
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
Will Schmidt 44ff8f06ec Disable IsSub subregister assert. pr18663.
This is a follow-up to the activity in the bug at
http://llvm.org/bugs/show_bug.cgi?id=18663 .  The underlying issue has
to do with how the KILL pseudo-instruction is handled.  I defer to
Hal/Jakob/Uli for additional details and background.

This will disable the (bad?) assert, add an associated fixme comment,
and add a pair of tests.

The code change and the pr18663-2.ll test are copied from the referenced
bug.  That test does not immediately fail in my environment, but I have
added the pr18663.ll test which does.

(Comment from Hal)
to provide everyone else with some context, this assert was not bad when
it was written. At that time, we only generated KILL pseudo instructions
around subregister copies. This logic, unfortunately, had its own problems.
In r199797, the relevant logic in MachineCopyPropagation was replaced to
generate KILLs for other kinds of copies too. This change in semantics broke
this now-problematic assumption in AggressiveAntiDepBreaker. The
AggressiveAntiDepBreaker really needs a proper cleanup to deal with the
change, but removing the assert (which just allows the function to return
false) is a safe conservative behavior, and should do for the time being.

llvm-svn: 214429
2014-07-31 19:50:53 +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
Craig Topper 840beec2d0 Make consistent use of MCPhysReg instead of uint16_t throughout the tree.
llvm-svn: 205610
2014-04-04 05:16:06 +00:00
Hal Finkel 121caf6313 Fix the aggressive anti-dep breaker's subregister definition handling
The aggressive anti-dependency breaker scans instructions, bottom-up, within the
scheduling region in order to find opportunities where register renaming can
be used to break anti-dependencies.

Unfortunately, the aggressive anti-dep breaker was treating a register definition
as defining all of that register's aliases (including super registers). This behavior
is incorrect when the super register is live and there are other definitions of
subregisters of the super register.

For example, given the following sequence:

%CR2EQ<def> = CROR %CR3UN, %CR3UN<kill>
%CR2GT<def> = IMPLICIT_DEF
%X4<def> = MFOCRF8 %CR2

the analysis of the first subregister definition would work as expected:
Anti:   %CR2GT<def> = IMPLICIT_DEF
        Def Groups: CR2GT=g194->g0(via CR2)
        Antidep reg: CR2GT (zero group)
        Use Groups:

but the analysis of the second one would not:
Anti:   %CR2EQ<def> = CROR %CR3UN, %CR3UN<kill>
        Def Groups: CR2EQ=g195
        Antidep reg: CR2EQ
        Rename Candidates for Group g195: ...

because, when processing the %CR2GT<def>, we'd mark all super registers of
%CR2GT (%CR2 in this case) as defined. As a result, when processing
%CR2EQ<def>, %CR2 no longer appears to be live, and %CR2EQ<def>'s group is not
%unioned with the %CR2 group.

I don't have an in-tree test case for this yet (and even if I did, I don't have
a small one).

llvm-svn: 202294
2014-02-26 20:20:30 +00:00
Hal Finkel 6f1ff8e1a8 Fix crash in AggressiveAntiDepBreaker with empty CriticalPathSet
If no register classes are added to CriticalPathRCs, then the CriticalPathSet
bitmask will be empty. In that case, ExcludeRegs must remain NULL or else this
line will cause a segfault:

  } else if ((ExcludeRegs != NULL) && ExcludeRegs->test(AntiDepReg)) {

I have no in-tree test case.

llvm-svn: 190584
2013-09-12 04:22:31 +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
Jakob Stoklund Olesen c338679c9d Remove special-casing of return blocks for liveness.
Now that return value registers are return instruction uses, there is no
need for special treatment of return blocks.

llvm-svn: 174416
2013-02-05 18:21:52 +00:00
Roman Divacky a229186a82 Remove duplicate includes.
llvm-svn: 170902
2012-12-21 17:06:44 +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
Jakob Stoklund Olesen bdb55e0c59 Use MCPhysReg for RegisterClassInfo allocation orders.
This saves a bit of memory.

llvm-svn: 168852
2012-11-29 03:34:17 +00:00
Jakob Stoklund Olesen f67bf3e0ea Remove RegisterClassInfo::isReserved() and isAllocatable().
Clients can use the equivalent functions in MRI.

llvm-svn: 165990
2012-10-15 22:41:03 +00:00
Andrew Trick 05ff4667eb Move RegisterClassInfo.h.
Allow targets to access this API. It's required for RegisterPressure.

llvm-svn: 158102
2012-06-06 20:29:31 +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 3c52f0281f Add an MF argument to TRI::getPointerRegClass() and TII::getRegClass().
The getPointerRegClass() hook can return register classes that depend on
the calling convention of the current function (ptr_rc_tailcall).

So far, we have been able to infer the calling convention from the
subtarget alone, but as we add support for multiple calling conventions
per target, that no longer works.

Patch by Yiannis Tsiouris!

llvm-svn: 156328
2012-05-07 22:10:26 +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
Craig Topper 420525ce3b Use uint16_t to store registers in callee saved register tables to reduce size of static data.
llvm-svn: 151996
2012-03-04 03:33:22 +00:00
Hal Finkel 8606e3c7e3 AggressiveAntiDepBreaker needs to skip debug values because a debug value does not have a corresponding SUnit
llvm-svn: 148260
2012-01-16 22:53:41 +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 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
Evan Cheng 0d639a28aa Rename TargetSubtarget to TargetSubtargetInfo for consistency.
llvm-svn: 134259
2011-07-01 21:01:15 +00:00
Evan Cheng 8d71a75777 More refactoring. Move getRegClass from TargetOperandInfo to TargetInstrInfo.
llvm-svn: 133944
2011-06-27 21:26:13 +00:00
Jakob Stoklund Olesen 4f5f84c7e7 Teach antidependency breakers to use RegisterClassInfo.
No functional change was intended.

llvm-svn: 133202
2011-06-16 21:56:21 +00:00
Devang Patel f02a376fbc Update DBG_VALUEs while breaking anti dependencies.
llvm-svn: 132487
2011-06-02 21:26:52 +00:00
Chris Lattner 0ab5e2cded Fix a ton of comment typos found by codespell. Patch by
Luis Felipe Strano Moraes!

llvm-svn: 129558
2011-04-15 05:18:47 +00:00
Jakob Stoklund Olesen be1c8d3a82 Simplify AggressiveAntiDepBreaker's use of register aliases.
llvm-svn: 121805
2010-12-14 23:23:15 +00:00
Jim Grosbach 944aece38a Anti-dependency breaking needs to be careful not to use reserved regs
llvm-svn: 112832
2010-09-02 17:12:55 +00:00
Bill Wendling 51a9c0a1b3 Use std::vector instead of TargetRegisterInfo::FirstVirtualRegister. This time
make sure to allocate enough space in the std::vector.

llvm-svn: 108449
2010-07-15 19:58:14 +00:00
Bill Wendling 5a8d15c553 Reserve a goodly amount of room for the vectors.
llvm-svn: 108448
2010-07-15 19:41:20 +00:00
Bill Wendling 030b0286ec Use std::vector instead of TargetRegisterInfo::FirstVirtualRegister.
llvm-svn: 108440
2010-07-15 18:43:09 +00:00
Chris Lattner c48adb60ca revert bill's patches in an attempt to fix the buildbot.
llvm-svn: 108419
2010-07-15 06:51:46 +00:00
Bill Wendling 1f7071a3e4 Fix headers.
llvm-svn: 108413
2010-07-15 06:05:18 +00:00
Bill Wendling e7e6ca5c57 Use std::vector instead of a hard-coded array. The length of that array could
get *very* large, but we only need it to be the size of the number of pregs.

llvm-svn: 108412
2010-07-15 06:04:38 +00:00
Rafael Espindola 871c724773 Convert the last use of getPhysicalRegisterRegClass and remove it.
AggressiveAntiDepBreaker should not be using getPhysicalRegisterRegClass. An
instruction might be using a register that can only be replaced with one from
a subclass of getPhysicalRegisterRegClass.

With this patch we use getMinimalPhysRegClass. This is correct, but
conservative. We should check the uses of the register and select the
largest register class that can be used in all of them.

llvm-svn: 108122
2010-07-12 02:55:34 +00:00
Evan Cheng f128bdcb55 Make post-ra scheduling, anti-dep breaking, and register scavenger (conservatively) aware of predicated instructions. This enables ARM to move if-conversion before post-ra scheduler.
llvm-svn: 106091
2010-06-16 07:35:02 +00:00
Jim Grosbach 848548300d Not all entries in the range will have an SUnit. Check for that when looking
for debug information.

llvm-svn: 105324
2010-06-02 15:29:36 +00:00
Jim Grosbach 12ac8f0352 Update debug information when breaking anti-dependencies. rdar://7759363
llvm-svn: 105300
2010-06-01 23:48:44 +00:00
Dan Gohman 35bc4d46cb Make BreakAntiDependencies' SUnits argument const, and make the Begin
and End arguments by-value rather than by-reference.

llvm-svn: 101830
2010-04-19 23:11:58 +00:00
Bob Wilson 67dd3a4464 Tidy whitespace.
llvm-svn: 100904
2010-04-09 21:38:26 +00:00
Chris Lattner b06015aa69 move target-independent opcodes out of TargetInstrInfo
into TargetOpcodes.h.  #include the new TargetOpcodes.h
into MachineInstr.  Add new inline accessors (like isPHI())
to MachineInstr, and start using them throughout the 
codebase.

llvm-svn: 95687
2010-02-09 19:54:29 +00:00
Jim Grosbach eb431da074 80 column and whitespace cleanup
llvm-svn: 92837
2010-01-06 16:48:02 +00:00