Commit Graph

144 Commits

Author SHA1 Message Date
Evan Cheng
d120ffd26f MachineInstr can change. Store indexes instead.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44612 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-05 10:24:35 +00:00
Evan Cheng
adf8590690 If a split live interval is spilled again, remove the kill marker on its last use.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44611 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-05 09:51:10 +00:00
Evan Cheng
b50bb8cf19 Fix kill info for split intervals.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44609 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-05 08:16:32 +00:00
Evan Cheng
018f9b020b - Mark last use of a split interval as kill instead of letting spiller track it.
This allows an important optimization to be re-enabled.
- If all uses / defs of a split interval can be folded, give the interval a
  low spill weight so it would not be picked in case spilling is needed (avoid
  pushing other intervals in the same BB to be spilled).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44601 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-05 03:22:34 +00:00
Evan Cheng
d64b5c82b9 Add a argument to storeRegToStackSlot and storeRegToAddr to specify whether
the stored register is killed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44600 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-05 03:14:33 +00:00
Evan Cheng
dd86ce3d57 Remove a unsafe optimization. This fixes 401.bzip2.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44587 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-04 23:57:55 +00:00
Evan Cheng
35a3e4abb9 Spiller unfold optimization bug: do not clobber a reusable stack slot value unless it can be modified.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44575 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-04 19:19:45 +00:00
Evan Cheng
e4b39007c9 Bug fixes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44549 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-03 21:31:55 +00:00
Evan Cheng
70306f8348 Update kill info for uses of split intervals.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44531 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-03 09:58:48 +00:00
Evan Cheng
aee4af68ae Remove redundant foldMemoryOperand variants and other code clean up.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44517 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-02 08:30:39 +00:00
Evan Cheng
0cbb1164b3 Fixed various live interval splitting bugs / compile time issues.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44428 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-29 01:06:25 +00:00
Evan Cheng
cada245d06 Recover compile time regression.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44386 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-28 01:28:46 +00:00
Evan Cheng
81a0382181 Live interval splitting:
When a live interval is being spilled, rather than creating short, non-spillable
intervals for every def / use, split the interval at BB boundaries. That is, for
every BB where the live interval is defined or used, create a new interval that
covers all the defs and uses in the BB.

This is designed to eliminate one common problem: multiple reloads of the same
value in a single basic block. Note, it does *not* decrease the number of spills
since no copies are inserted so the split intervals are *connected* through
spill and reloads (or rematerialization). The newly created intervals can be
spilled again, in that case, since it does not span multiple basic blocks, it's
spilled in the usual manner. However, it can reuse the same stack slot as the
previously split interval.

This is currently controlled by -split-intervals-at-bb.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44198 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-17 00:40:40 +00:00
Evan Cheng
c498b0281f Clean up sub-register implementation by moving subReg information back to
MachineOperand auxInfo. Previous clunky implementation uses an external map
to track sub-register uses. That works because register allocator uses
a new virtual register for each spilled use. With interval splitting (coming
soon), we may have multiple uses of the same register some of which are
of using different sub-registers from others. It's too fragile to constantly
update the information.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44104 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-14 07:59:08 +00:00
Evan Cheng
7277a7d031 One more extract_subreg coalescing bug.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43644 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-02 17:35:08 +00:00
Evan Cheng
cbfb9b27ef - Only perform the unfolding optimization when the folding in question is modref.
- Remove a bogus assertion.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43211 91177308-0d34-0410-b5e6-96231b3b80d8
2007-10-22 03:01:44 +00:00
Evan Cheng
66f7163545 Local spiller optimization:
Turn a store folding instruction into a load folding instruction. e.g.
     xorl  %edi, %eax
     movl  %eax, -32(%ebp)
     movl  -36(%ebp), %eax
     orl   %eax, -32(%ebp)
=>
     xorl  %edi, %eax
     orl   -36(%ebp), %eax
     mov   %eax, -32(%ebp)
This enables the unfolding optimization for a subsequent instruction which will
also eliminate the newly introduced store instruction.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43192 91177308-0d34-0410-b5e6-96231b3b80d8
2007-10-19 21:23:22 +00:00
Evan Cheng
7f56625447 Local spiller optimization:
Turn this:
movswl  %ax, %eax
movl    %eax, -36(%ebp)
xorl    %edi, -36(%ebp)
into
movswl  %ax, %eax
xorl    %edi, %eax
movl    %eax, -36(%ebp)
by unfolding the load / store xorl into an xorl and a store when we know the
value in the spill slot is available in a register. This doesn't change the
number of instructions but reduce the number of times memory is accessed.

Also unfold some load folding instructions and reuse the value when similar
situation presents itself.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@42947 91177308-0d34-0410-b5e6-96231b3b80d8
2007-10-13 02:50:24 +00:00
Evan Cheng
32dfbeada7 EXTRACT_SUBREG coalescing support. The coalescer now treats EXTRACT_SUBREG like
(almost) a register copy. However, it always coalesced to the register of the
RHS (the super-register). All uses of the result of a EXTRACT_SUBREG are sub-
register uses which adds subtle complications to load folding, spiller rewrite,
etc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@42899 91177308-0d34-0410-b5e6-96231b3b80d8
2007-10-12 08:50:34 +00:00
Evan Cheng
9efce638d3 Allow copyRegToReg to emit cross register classes copies.
Tested with "make check"!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@42346 91177308-0d34-0410-b5e6-96231b3b80d8
2007-09-26 06:25:56 +00:00
Dan Gohman
92dfe2001e Remove isReg, isImm, and isMBB, and change all their users to use
isRegister, isImmediate, and isMachineBasicBlock, which are equivalent,
and more popular.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41958 91177308-0d34-0410-b5e6-96231b3b80d8
2007-09-14 20:33:02 +00:00
David Greene
04fa32f9aa Add instruction dump output. This helps find bugs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41744 91177308-0d34-0410-b5e6-96231b3b80d8
2007-09-06 16:36:39 +00:00
Evan Cheng
90a43c3ae3 If the source of a move is in spill slot, the reload may be folded to essentially a load from stack slot. It's ok to mark the stack slot value as available for reuse. But it should not be clobbered since the destination of the move is live.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41109 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-15 20:20:34 +00:00
Evan Cheng
b6ca4b370e - If a def is dead, do not spill it.
- If the defs of a spilled rematerializable MI are dead after the spill store is deleted, delete
  the def MI as well.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41086 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-14 23:25:37 +00:00
Evan Cheng
c91f0b8068 If a MI's def is remat as well as spilled, and the store is later deemed dead, mark the def operand as isDead.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41083 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-14 20:23:13 +00:00
Evan Cheng
fff3e191b9 If a spilled value is being reused and the use is a kill, that means there are
no more uses within the MBB and the spilled value isn't live out of the MBB.
Then it's safe to delete the spill store.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41069 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-14 09:11:18 +00:00
Evan Cheng
dc6be19859 If a rematerializable def is not deleted, i.e. it is also spilled, check if the
spilled value is available for reuse.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41067 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-14 05:42:54 +00:00
Evan Cheng
549f27d307 Re-implement trivial rematerialization. This allows def MIs whose live intervals that are coalesced to be rematerialized.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41060 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-13 23:45:17 +00:00
Evan Cheng
28bb462d4c Missed a couple of places where new instructions are added due to spill / restore.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@39748 91177308-0d34-0410-b5e6-96231b3b80d8
2007-07-11 19:17:18 +00:00
Evan Cheng
b9591c667d No longer need to track last def / use.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@38534 91177308-0d34-0410-b5e6-96231b3b80d8
2007-07-11 08:47:44 +00:00
Evan Cheng
0c40d72b01 Fix for PR1545: Revamp code that update kill information due to register reuse.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@38525 91177308-0d34-0410-b5e6-96231b3b80d8
2007-07-11 05:28:39 +00:00
Dan Gohman
82a87a0172 Replace M_REMATERIALIZIBLE and the newly-added isOtherReMaterializableLoad
with a general target hook to identify rematerializable instructions. Some
instructions are only rematerializable with specific operands, such as loads
from constant pools, while others are always rematerializable. This hook
allows both to be identified as being rematerializable with the same
mechanism.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37644 91177308-0d34-0410-b5e6-96231b3b80d8
2007-06-19 01:48:05 +00:00
Dan Gohman
c101e95cb6 Add a target hook to allow loads from constant pools to be rematerialized, and an
implementation for x86.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37576 91177308-0d34-0410-b5e6-96231b3b80d8
2007-06-14 20:50:44 +00:00
Evan Cheng
faa510726f Rename findRegisterUseOperand to findRegisterUseOperandIdx to avoid confusion.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36483 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-26 19:00:32 +00:00
Evan Cheng
6c087e5585 Match MachineFunction::UsedPhysRegs changes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36452 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-25 22:13:27 +00:00
Evan Cheng
9193514e2e Re-materialize all loads from fixed stack slots.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35660 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-04 07:40:01 +00:00
Evan Cheng
7cb33c8652 Don't add the same MI to register reuse "last def/use" twice if it reads the
register more than once.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35513 91177308-0d34-0410-b5e6-96231b3b80d8
2007-03-30 20:21:35 +00:00
Evan Cheng
018d6e1537 Don't call getOperandConstraint() if operand index is greater than
TID->numOperands.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35375 91177308-0d34-0410-b5e6-96231b3b80d8
2007-03-27 00:48:28 +00:00
Evan Cheng
ad7ccf34b5 Fix for PR1266. Don't mark a two address operand IsKill.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35365 91177308-0d34-0410-b5e6-96231b3b80d8
2007-03-26 22:40:42 +00:00
Evan Cheng
2638e1a6b9 First cut trivial re-materialization support.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35208 91177308-0d34-0410-b5e6-96231b3b80d8
2007-03-20 08:13:50 +00:00
Evan Cheng
a7288df62d Only propagate IsKill if the last use is a kill.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34878 91177308-0d34-0410-b5e6-96231b3b80d8
2007-03-03 06:32:37 +00:00
Evan Cheng
6b448092bf - Keep track all def and uses of stack slot available in register.
- Available value use may be deleted (e.g. noop move).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34841 91177308-0d34-0410-b5e6-96231b3b80d8
2007-03-02 08:52:00 +00:00
Evan Cheng
c3dd314b78 Invalidate last use of a reused register if the use is a deleted noop copy.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34839 91177308-0d34-0410-b5e6-96231b3b80d8
2007-03-02 05:41:42 +00:00
Evan Cheng
c0ba1bc49b A restore is promoted to copy (or deleted entirely), remove the kill from the last use of the targetted register.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34773 91177308-0d34-0410-b5e6-96231b3b80d8
2007-03-01 02:27:30 +00:00
Evan Cheng
de4e942faa A couple of more places where a register liveness has been extended and its last kill should be updated accordingly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34597 91177308-0d34-0410-b5e6-96231b3b80d8
2007-02-25 09:51:27 +00:00
Evan Cheng
50d25d7ff7 Reuse extends the liveness of a register. Transfer the kill to the operand that reuse it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34536 91177308-0d34-0410-b5e6-96231b3b80d8
2007-02-23 21:47:50 +00:00
Evan Cheng
91e2390818 A spill kills the register being stored. But it is later being reused by spiller, its live range has to be extended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34517 91177308-0d34-0410-b5e6-96231b3b80d8
2007-02-23 01:13:26 +00:00
Evan Cheng
957840b3e1 Use BitVector instead. No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34460 91177308-0d34-0410-b5e6-96231b3b80d8
2007-02-21 02:22:03 +00:00
Evan Cheng
667089de04 Dead code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34435 91177308-0d34-0410-b5e6-96231b3b80d8
2007-02-20 01:29:10 +00:00
Evan Cheng
f50d09ad21 Fixed a long standing spiller bug that's exposed by Thumb:
The code sequence before the spiller is something like:
                 = tMOVrr
        %reg1117 = tMOVrr
        %reg1078 = tLSLri %reg1117, 2

The it starts spilling:
        %r0 = tRestore <fi#5>, 0
        %r1 = tRestore <fi#7>, 0
        %r1 = tMOVrr %r1<kill>
        tSpill %r1, <fi#5>, 0
        %reg1078 = tLSLri %reg1117, 2

It restores the value while processing the first tMOVrr. At this point, the
spiller remembers fi#5 is available in %r0. Next it processes the second move.
It restores the source before the move and spills the result afterwards. The
move becomes a noop and is deleted. However, a spill has been inserted and that
should invalidate reuse of %r0 for fi#5 and add reuse of %r1 for fi#5.
Therefore, %reg1117 (which is also assigned fi#5) should get %r1, not %r0.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34039 91177308-0d34-0410-b5e6-96231b3b80d8
2007-02-08 06:04:54 +00:00