calculated.

llvm-svn: 122912

llvm-svn: 122909

llvm-svn: 122849

The analysis will be needed by both the greedy register allocator and the
X86FloatingPoint pass. It only needs to be computed once when the CFG doesn't
change.

This pass is very fast, usually showing up as 0.0% wall time.

llvm-svn: 122832

makes getLeader() nonrecursive.

llvm-svn: 122811

spent in StrongPHIElimination on 403.gcc.

llvm-svn: 122803

llvm-svn: 122795

a 28% speedup of MachineCSE time on 403.gcc.

llvm-svn: 122735

so that Dominators.h is *just* domtree.  Also prune #includes a bit.

llvm-svn: 122714

This allows us to compile:
  void test(char *s, int a) {
    __builtin_memset(s, a, 15);
  }
into 1 mul + 3 stores instead of 3 muls + 3 stores.

llvm-svn: 122710

Lower the i8 extension in memset to a multiply instead of a potentially long series of shifts and ors.

We could implement a DAGCombine to turn x * 0x0101 back into logic operations
on targets that doesn't support the multiply or it is slow (p4) if someone cares
enough.

Example code:
  void test(char *s, int a) {
      __builtin_memset(s, a, 4);
  }
before:
  _test:                                  ## @test
    movzbl  8(%esp), %eax
    movl  %eax, %ecx
    shll  $8, %ecx
    orl %eax, %ecx
    movl  %ecx, %eax
    shll  $16, %eax
    orl %ecx, %eax
    movl  4(%esp), %ecx
    movl  %eax, 4(%ecx)
    movl  %eax, (%ecx)
    ret
after:
  _test:                                  ## @test
    movzbl  8(%esp), %eax
    imull $16843009, %eax, %eax   ## imm = 0x1010101
    movl  4(%esp), %ecx
    movl  %eax, 4(%ecx)
    movl  %eax, (%ecx)
    ret

llvm-svn: 122707

with 2-address instructions, for about a 3.5% speedup of StrongPHIElimination on
403.gcc.

llvm-svn: 122635

llvm-svn: 122628

process those instructions that define phi sources. This is a 47% speedup of
StrongPHIElimination compile time on 403.gcc.

llvm-svn: 122627

llvm-svn: 122625

llvm-svn: 122617

in the most obvious way.

llvm-svn: 122610

it relies on assumptions that may not be true in the future.

llvm-svn: 122608

we are only interested in the defs when discovering interferences.

This is a 28% speedup running StrongPHIElimination on 403.gcc.

llvm-svn: 122596

in this function, but the compiler was warning that it might be when
doing a release build.

llvm-svn: 122595

llvm-svn: 122586

when running without the verifier, and I have not yet checked them to see if
the new results are still correct. There are more verifier failures, but they
all seem to be additional occurrences of verifier failures that occur with the
existing PHIElimination pass. There are a few obvious issues with the code:

1) It doesn't properly update the register equivalence classes during copy
insertion, and instead recomputes them before merging live intervals and
renaming registers. I wanted to keep this first patch simple for debugging
purposes, but it shouldn't be very hard to do this.

2) It doesn't mix the renaming and live interval merging with the copy insertion
process, which leads to a lot of virtual register churn. Virtual registers and
live intervals are created, only to later be merged into others. The code should
be smarter and only create a new virtual register if there is no existing
register in the same congruence class.

3) In one place the code uses a DenseMap per basic block, which is unnecessary
heap allocation. There should be an inline storage version of DenseMap.

I did a quick compile-time test of running llc on 403.gcc with and without
StrongPHIElimination. It is slightly slower with StrongPHIElimination, because
the small decrease in the coalescer runtime can't beat the increase in phi
elimination runtime. Perhaps fixing the above performance issues will narrow
the gap.

I also haven't yet run any tests of the quality of the generated code.

llvm-svn: 122582

valno verification. The "Different value live out of predecessor" check is
incorrect in the case of phi-def valnos, so just skip that check for phi-def
valnos and instead check that all of the valnos for predecessors have phi-kill.
Fixes PR8863.

llvm-svn: 122581

llvm-svn: 122545

Fix a few cases where the scheduler is not checking for phys reg copies. The scheduling node may have a NULL DAG node, yuck.

llvm-svn: 122544

DAG scheduling during isel. Most new functionality is currently
guarded by -enable-sched-cycles and -enable-sched-hazard.

Added InstrItineraryData::IssueWidth field, currently derived from
ARM itineraries, but could be initialized differently on other targets.

Added ScheduleHazardRecognizer::MaxLookAhead to indicate whether it is
active, and if so how many cycles of state it holds.

Added SchedulingPriorityQueue::HasReadyFilter to allowing gating entry
into the scheduler's available queue.

ScoreboardHazardRecognizer now accesses the ScheduleDAG in order to
get information about it's SUnits, provides RecedeCycle for bottom-up
scheduling, correctly computes scoreboard depth, tracks IssueCount, and
considers potential stall cycles when checking for hazards.

ScheduleDAGRRList now models machine cycles and hazards (under
flags). It tracks MinAvailableCycle, drives the hazard recognizer and
priority queue's ready filter, manages a new PendingQueue, properly
accounts for stall cycles, etc.

llvm-svn: 122541

llvm-svn: 122539

llvm-svn: 122537

llvm-svn: 122509

llvm-svn: 122507

llvm-svn: 122491

Converted LiveRegCycles to LiveRegGens. It's easier to work with and allows multiple nodes per cycle.

llvm-svn: 122474

llvm-svn: 122473

In the bottom-up selection DAG scheduling, handle two-address
instructions that read/write unspillable registers. Treat
the entire chain of two-address nodes as a single live range.

llvm-svn: 122472

new gcc warning that complains on self-assignments and
self-initializations.

llvm-svn: 122458

DAGCombine add (sext i1), X into sub X, (zext i1) if sext from i1 is illegal.  The latter usually compiles into smaller code.

example code:
unsigned foo(unsigned x, unsigned y) {
  if (x != 0) y--;
  return y;
}

before:
  _foo:                           ## @foo
    cmpl  $1, 4(%esp)             ## encoding: [0x83,0x7c,0x24,0x04,0x01]
    sbbl  %eax, %eax              ## encoding: [0x19,0xc0]
    notl  %eax                    ## encoding: [0xf7,0xd0]
    addl  8(%esp), %eax           ## encoding: [0x03,0x44,0x24,0x08]
    ret                           ## encoding: [0xc3]

after:
  _foo:                           ## @foo
    cmpl  $1, 4(%esp)             ## encoding: [0x83,0x7c,0x24,0x04,0x01]
    movl  8(%esp), %eax           ## encoding: [0x8b,0x44,0x24,0x08]
    adcl  $-1, %eax               ## encoding: [0x83,0xd0,0xff]
    ret                           ## encoding: [0xc3]

llvm-svn: 122455

pick the victim with the lowest total spill weight.

llvm-svn: 122445

llvm-svn: 122444

loads properly.  We miscompiled the testcase into:

_test:                                  ## @test
	movl	$128, (%rdi)
	movzbl	1(%rdi), %eax
	ret

Now we get a proper:

_test:                                  ## @test
	movl	$128, (%rdi)
	movsbl	(%rdi), %eax
	movzbl	%ah, %eax
	ret

This fixes PR8757.

llvm-svn: 122392

unhanded cases faster and simplify code.

llvm-svn: 122391