For now, this pass is fairly conservative. It only perform the replacement when both the pre- and post- extension values are used in the block. It will miss cases where the post-extension values are live, but not used.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93278 91177308-0d34-0410-b5e6-96231b3b80d8
(OP (trunc x), (trunc y)) -> (trunc (OP x, y))
Unfortunately this simple change causes dag combine to infinite looping. The problem is the shrink demanded ops optimization tend to canonicalize expressions in the opposite manner. That is badness. This patch disable those optimizations in dag combine but instead it is done as a late pass in sdisel.
This also exposes some deficiencies in dag combine and x86 setcc / brcond lowering. Teach them to look pass ISD::TRUNCATE in various places.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92849 91177308-0d34-0410-b5e6-96231b3b80d8
An instruction like this:
%reg1097:1<def> = VMOVSR %R3<kill>, 14, %reg0
Must be replaced with this when substituting physical registers:
%S0<def> = VMOVSR %R3<kill>, 14, %reg0, %D0<imp-def>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92812 91177308-0d34-0410-b5e6-96231b3b80d8
clear what information these functions are actually using.
This is also a micro-optimization, as passing a SDNode * around is
simpler than passing a { SDNode *, int } by value or reference.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92564 91177308-0d34-0410-b5e6-96231b3b80d8
This fixes an in-place update bug where code inserted at the end of basic blocks may not be covered by existing intervals which were live across the entire block. It is also consistent with the way ranges are specified for live intervals.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91859 91177308-0d34-0410-b5e6-96231b3b80d8
- Move DisableScheduling flag into TargetOption.h
- Move SDNodeOrdering into its own header file. Give it a minimal interface that
doesn't conflate construction with storage.
- Move assigning the ordering into the SelectionDAGBuilder.
This isn't used yet, so there should be no functional changes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91727 91177308-0d34-0410-b5e6-96231b3b80d8
LegalizeDAG.cpp. Unlike the code it replaces, which simply decrements the simple
type by one, getHalfSizedIntegerVT() searches for the smallest simple integer
type that is at least half the size of the type it is called on. This approach
has the advantage that it will continue working if a new value type (such as
i24) is added to MVT.
Also, in preparation for new value types, remove the assertions that
non-power-of-2 8-bit-mutiple types are Extended when legalizing extload and
truncstore operations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91614 91177308-0d34-0410-b5e6-96231b3b80d8
remove start/finishGVStub and the BufferState helper class from the
MachineCodeEmitter interface. It has the side-effect of not setting the
indirect global writable and then executable on ARM, but that shouldn't be
necessary.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91464 91177308-0d34-0410-b5e6-96231b3b80d8
isPodLike type trait. This is a generally useful type trait for
more than just DenseMap, and we really care about whether something
acts like a pod, not whether it really is a pod.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91421 91177308-0d34-0410-b5e6-96231b3b80d8
stuff isn't used just yet.
We want to model the GCC `-fno-schedule-insns' and `-fno-schedule-insns2'
flags. The hypothesis is that the people who use these flags know what they are
doing, and have hand-optimized the C code to reduce latencies and other
conflicts.
The idea behind our scheme to turn off scheduling is to create a map "on the
side" during DAG generation. It will order the nodes by how they appeared in the
code. This map is then used during scheduling to get the ordering.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91392 91177308-0d34-0410-b5e6-96231b3b80d8
- Loosen the restrictions when checking of it branches to a landing pad.
- Make the loop more efficient by checking the '.insert' return value.
- Do cheaper checks first.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91101 91177308-0d34-0410-b5e6-96231b3b80d8
more than one successor. Normally, these extra successors are dead. However,
some of them may branch to exception handling landing pads. If we remove those
successors, then the landing pads could go away if all predecessors to it are
removed. Before, it was checking if the direct successor was the landing
pad. But it could be the result of jumping through multiple basic blocks to get
to it. If we were to only check for the existence of an EH_LABEL in the basic
block and not remove successors if it's in there, then it could stop actually
dead basic blocks from being removed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91092 91177308-0d34-0410-b5e6-96231b3b80d8
The coalescer is supposed to clean these up, but when setting up parameters
for a function call, there may be copies to physregs. If the defining
instruction has been LICM'ed far away, the coalescer won't touch it.
The register allocation hint does not always work - when the register
allocator is backtracking, it clears the hints.
This patch is more conservative than r90502, and does not break
483.xalancbmk/i686. It still breaks the PowerPC bootstrap, so it is disabled
by default, and can be enabled with the -trivial-coalesce-ends option.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91049 91177308-0d34-0410-b5e6-96231b3b80d8
When a call is placed to spill an interval this spiller will first try to
break the interval up into its component values. Single value intervals and
intervals which have already been split (or are the result of previous splits)
are spilled by the default spiller.
Splitting intervals as described above may improve the performance of generated
code in some circumstances. This work is experimental however, and it still
miscompiles many benchmarks. It's not recommended for general use yet.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90951 91177308-0d34-0410-b5e6-96231b3b80d8
The coalescer is supposed to clean these up, but when setting up parameters
for a function call, there may be copies to physregs. If the defining
instruction has been LICM'ed far away, the coalescer won't touch it.
The register allocation hint does not always work - when the register
allocator is backtracking, it clears the hints.
This patch takes care of a few more cases that r90163 missed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90502 91177308-0d34-0410-b5e6-96231b3b80d8
We want LiveVariables clients to use methods rather than accessing the
getVarInfo data structure directly. That way it will be possible to change the
LiveVariables representation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90240 91177308-0d34-0410-b5e6-96231b3b80d8
divide/remainder since these operations can trap by unroll them and adding undefs
for the resulting vector.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90108 91177308-0d34-0410-b5e6-96231b3b80d8
running tail duplication when doing branch folding for if-conversion, and
we also want to be able to run tail duplication earlier to fix some
reg alloc problems. Move the CanFallThrough function from BranchFolding
to MachineBasicBlock so that it can be shared by TailDuplication.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89904 91177308-0d34-0410-b5e6-96231b3b80d8
Note that "hasDotLocAndDotFile"-style debug info was already broken;
people wanting this functionality should implement it in the
AsmPrinter/DwarfWriter code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89711 91177308-0d34-0410-b5e6-96231b3b80d8
It's probably better in the long run to replace the
indirect-GlobalVariable system. That'll be done after a subsequent
patch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89708 91177308-0d34-0410-b5e6-96231b3b80d8
When splitting a critical edge, the registers live through the edge are:
- Used in a PHI instruction, or
- Live out from the predecessor, and
- Live in to the successor.
This allows the coalescer to eliminate even more phi joins.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89530 91177308-0d34-0410-b5e6-96231b3b80d8
slots. The AsmPrinter will use this information to determine whether to
print a spill/reload comment.
Remove default argument values. It's too easy to pass a wrong argument
value when multiple arguments have default values. Make everything
explicit to trap bugs early.
Update all targets to adhere to the new interfaces..
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@87022 91177308-0d34-0410-b5e6-96231b3b80d8
making it visible to clients and adding LLVM-style cast capability.
This will be used by AsmPrinter to determine when to emit spill comments
for an instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@87019 91177308-0d34-0410-b5e6-96231b3b80d8
emitting comments. These flags carry semantic information not otherwise
easily derivable from the IR text.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@87016 91177308-0d34-0410-b5e6-96231b3b80d8
- Edges are split before any phis are eliminated, so the code is SSA.
- Create a proper IR BasicBlock for the split edges.
- LiveVariables::addNewBlock now has same syntax as
MachineDominatorTree::addNewBlock. Algorithm calculates predecessor live-out
set rather than successor live-in set.
This feature still causes some miscompilations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86867 91177308-0d34-0410-b5e6-96231b3b80d8
Critical edges leading to a PHI node are split when the PHI source variable is
live out from the predecessor block. This help the coalescer eliminate more
PHI joins.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86725 91177308-0d34-0410-b5e6-96231b3b80d8
