branches only to a landing pad. Without this check, the compiler would go into
an infinite loop because the branch to a landing pad is an "abnormal" edge which
wasn't being taken into account.
This is the meat of that fix:
if (!PrevBB.canFallThrough() && !MBB->BranchesToLandingPad(MBB)) {
The other stuff is simplification of the "branches to a landing pad" code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91161 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
Create global variable DIEs after creating subprogram DIEs. This allows function level static variable's to find their context at the time of DIE creation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91055 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
and that Instruction only. Implement this by setting the "current debug position"
back to Unknown after processing each instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90632 91177308-0d34-0410-b5e6-96231b3b80d8
Don't print "SrcLine"; just print the filename and line number, which
is obvious enough and more informative.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90631 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
Pointed out by Javier Martinez (who also provided a patch). Since
this logic is not used on (for example) x86, I guess nobody noticed.
Tested by generating SHL, SRL, SRA on various choices of i64 for all
possible shift amounts, and comparing with gcc. Since I did this on
x86-32, I had to force the use of ExpandShiftWithUnknownAmountBit.
What I'm saying here is that I don't have a testcase I can add to the
repository.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90482 91177308-0d34-0410-b5e6-96231b3b80d8
Add a testcase for the above transformation.
Fix a bogus use of APInt noticed while tracking this down.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90423 91177308-0d34-0410-b5e6-96231b3b80d8
The MO reference to a MachineOperand can be invalidated by
MachineInstr::addOperand. Don't even use it for debugging.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90381 91177308-0d34-0410-b5e6-96231b3b80d8
- A valno should be set HasRedefByEC if there is an early clobber def in the middle of its live ranges. It should not be set if the def of the valno is defined by an early clobber.
- If a physical register def is tied to an use and it's an early clobber, it just means the HasRedefByEC is set since it's still one continuous live range.
- Add a couple of missing checks for HasRedefByEC in the coalescer. In general, it should not coalesce a vr with a physical register if the physical register has a early clobber def somewhere. This is overly conservative but that's the price for using such a nasty inline asm "feature".
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90269 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
This means that well connected blocks are copy coalesced before the less connected blocks. Connected blocks are more difficult to
coalesce because intervals are more complicated, so handling them first gives a greater chance of success.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90194 91177308-0d34-0410-b5e6-96231b3b80d8
This helps us avoid silly copies when rematting values that are copied to a physical register:
leaq _.str44(%rip), %rcx
movq %rcx, %rsi
call _strcmp
becomes:
leaq _.str44(%rip), %rsi
call _strcmp
The coalescer will not touch the movq because that would tie down the physical register.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90163 91177308-0d34-0410-b5e6-96231b3b80d8
branches even when optimizing for code size. Unless we find evidence to the
contrary in the future, the special treatment for indirect branches does not
have a significant effect on code size, and performance still matters with -Os.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90147 91177308-0d34-0410-b5e6-96231b3b80d8
for all the processors where I have tried it, and even when it might not help
performance, the cost is quite low. The opportunities for duplicating
indirect branches are limited by other factors so code size does not change
much due to tail duplicating indirect branches aggressively.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90144 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
Make tail duplication of indirect branches much more aggressive (for targets
that indicate that it is profitable), based on further experience with
this transformation. I compiled 3 large applications with and without
this more aggressive tail duplication and measured minimal changes in code
size. ("size" on Darwin seems to round the text size up to the nearest
page boundary, so I can only say that any code size increase was less than
one 4k page.) Radar 7421267.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89814 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
of SelectionDAGBuild.h/cpp into its own files, to help separate
general lowering logic from SelectionDAG-specific lowering logic.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89667 91177308-0d34-0410-b5e6-96231b3b80d8
tell debug info which base register to use to reference a frame index on a
per-index basis. This is useful, for example, in the presence of dynamic
stack realignment when local variables are indexed via the stack pointer and
stack-based arguments via the frame pointer.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89620 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
DIEs are created from MDNode, which are already uniqued. And DwarfDebug already uses ValueMaps to find and use existing DIE for a given MDNode.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89518 91177308-0d34-0410-b5e6-96231b3b80d8
which was an expensive checks failure due to a bug in the checking. This
patch in essence reverts the original fix for PR3393, and refixes it by a
tweak to the way expensive checking is done.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89454 91177308-0d34-0410-b5e6-96231b3b80d8
critical edges in PHIElimination.
This has a huge impact on regalloc performance, and we recover almost all of
the 10% compile time regression that edge splitting introduced.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89381 91177308-0d34-0410-b5e6-96231b3b80d8
Add a -linearscan-skip-count argument (default to 0) that tells the
allocator to remember the last N registers it allocated and skip them
when looking for a register candidate. This tends to spread out
register usage and free up post-allocation scheduling at the cost of
slightly more register pressure. The primary benefit is the ability
to backschedule reloads.
This is turned off by default.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89356 91177308-0d34-0410-b5e6-96231b3b80d8
All spiller calls in RegAllocLinearScan now go through the new Spiller interface.
The "-new-spill-framework" command line option has been removed. To use the trivial in-place spiller you should now pass "-spiller=trivial -rewriter=trivial".
(Note the trivial spiller/rewriter are only meant to serve as examples of the new in-place modification work. Enabling them will yield terrible, though hopefully functional, code).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89311 91177308-0d34-0410-b5e6-96231b3b80d8
When TwoAddressInstructionPass deletes a dead instruction, make sure that all
register kills are accounted for. The 2-addr register does not get special
treatment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89246 91177308-0d34-0410-b5e6-96231b3b80d8
when LiveVariables is available.
The -split-phi-edges is now gone, and so is the hack to disable it when using
the local register allocator. The PHIElimination pass no longer has
LiveVariables as a prerequisite - that is what broke the local allocator.
Instead we do critical edge splitting when possible - that is when
LiveVariables is available.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89213 91177308-0d34-0410-b5e6-96231b3b80d8
contents of the block to be duplicated. Use this for ARM Cortex A8/9 to
be more aggressive tail duplicating indirect branches, since it makes it
much more likely that they will be predicted in the branch target buffer.
Testcase coming soon.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89187 91177308-0d34-0410-b5e6-96231b3b80d8
The local register allocator doesn't like it when LiveVariables is run.
We should also disable edge splitting under -O0, but that has to wait a bit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89125 91177308-0d34-0410-b5e6-96231b3b80d8
unnecessary. It is broken because the "isIdenticalTo" check should be
negated. If that is fixed, this code causes the CodeGen/X86/tail-opts.ll
test to fail, in the dont_merge_oddly function. And, I confirmed that the
regression is real -- the generated code is worse. As far as I can tell,
that tail-opts.ll test is checking for what this code is supposed to handle
and we're doing the right thing anyway.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89121 91177308-0d34-0410-b5e6-96231b3b80d8
unconditional branches or fallthroghes. Instcombine/SimplifyCFG
should be simplifying branches with known conditions.
This fixes some problems caused by these transformations not
updating the MachineBasicBlock CFG.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89017 91177308-0d34-0410-b5e6-96231b3b80d8
Have the asm printer emit a comment if an instruction is a spill or
reload and have the spiller mark copies it introdues so the asm printer
can also annotate those.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@88911 91177308-0d34-0410-b5e6-96231b3b80d8
Make sure when ProcessImplicitDefs removes a copy which kills its source reg that it
removes the copy from said reg's Kills list.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@88881 91177308-0d34-0410-b5e6-96231b3b80d8
- If destination is a physical register and it has a subreg index, use the
sub-register instead.
This fixes PR5423.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@88745 91177308-0d34-0410-b5e6-96231b3b80d8
When splitting an edge after a machine basic block with fall-through, we
forgot to insert a jump instruction. Fix this by calling updateTerminator() on
the fall-through block when relevant.
Also be more precise in PHIElimination::isLiveIn.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@88728 91177308-0d34-0410-b5e6-96231b3b80d8
The BasicBlock associated with a MachineBasicBlock does not necessarily
correspond to the code in the MBB.
Don't insert a new IR BasicBlock when splitting critical edges. We are not
supposed to modify the IR during codegen, and we should be able to do just
fine with a NULL BB.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@88707 91177308-0d34-0410-b5e6-96231b3b80d8
target-specific AsmPrinters. Not all comments need DebugInfo.
Re-enable the line numbers comment test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@88697 91177308-0d34-0410-b5e6-96231b3b80d8
code-size win, and not when it's only likely to be code-size neutral,
such as when only a single instruction would be eliminated and a new
branch would be required.
This fixes rdar://7392894.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@88692 91177308-0d34-0410-b5e6-96231b3b80d8
D0<def,dead> = ...
...
= S0<use, kill>
S0<def> = ...
...
D0<def> =
The first D0 def is correctly marked dead, however, livevariables should have
added an implicit def of S0 or we end up with a use without a def.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@88690 91177308-0d34-0410-b5e6-96231b3b80d8
and don't assume that the call doesn't throw. It would be nice if there were a
way to determine which is the callee and which is a parameter. In practice, the
architecture we care about normally only have one operand for a call instruction
(x86 and arm).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@87023 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
instead of typedefs for std::pair. This simplifies the type of
SameTails, which previously was std::vector<std::pair<std::vector<std::pair<unsigned, MachineBasicBlock *> >::iterator, MachineBasicBlock::iterator>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86885 91177308-0d34-0410-b5e6-96231b3b80d8
tail merging support to handle more cases.
- Recognize several cases where tail merging is beneficial even when
the tail size is smaller than the generic threshold.
- Make use of MachineInstrDesc::isBarrier to help detect
non-fallthrough blocks.
- Check for and avoid disrupting fall-through edges in more cases.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86871 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
constant whose component type is not a legal type for the target.
(If the target ConstantPool cannot handle this type either, it has
an opportunity to merge elements. In practice any target with
8-bit bytes must support i8 *as data*). 7320806 (partial).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86751 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
