This allows us to compile "int cst[] = {-1, -1, -1};" into
  movl  $-1, 16(%rsp)
  movq  $-1, 8(%rsp)
instead of
  movl  _cst+8(%rip), %eax
  movl  %eax, 16(%rsp)
  movq  _cst(%rip), %rax
  movq  %rax, 8(%rsp)

llvm-svn: 122548

llvm-svn: 122547

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

preprocessed .s files and matches darwin gas.  rdar://8798690
Also fix a comment on the next line of AsmParser.cpp after this new code.

llvm-svn: 122531

llvm-svn: 122530

are not the low bits of x, but the bits that WILL be the low bits after the operation completes.

llvm-svn: 122529

llvm-svn: 122528

llvm-svn: 122524

llvm-svn: 122523

If the basic block containing the BCCi64 (or BCCZi64) instruction ends with
an unconditional branch, that branch needs to be deleted before appending
the expansion of the BCCi64 to the end of the block.

llvm-svn: 122521

pipeline to be caught by instcombine, and it's not feasible to catch them in SimplifyCFG because the
use-lists are in an inconsistent state at the point where it could know that it need to simplify them.
Instead, have CodeGenPrepare look for trivially redundant PHIs as part of its general cleanup effort.

llvm-svn: 122516

llvm-svn: 122513

llvm-svn: 122509

llvm-svn: 122507

Remove/fix invalid README entries. The well thought out strcpy function doesn't return a pointer to the end of the string.

llvm-svn: 122496

llvm-svn: 122495

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

llvm-svn: 122462

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

llvm-svn: 122458

llvm-svn: 122456

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

llvm-svn: 122453

  int test(unsigned long a, unsigned long b) { return -(a < b); }
compiles to
  _test:                              ## @test
    cmpq  %rsi, %rdi                  ## encoding: [0x48,0x39,0xf7]
    sbbl  %eax, %eax                  ## encoding: [0x19,0xc0]
    ret                               ## encoding: [0xc3]
instead of
  _test:                              ## @test
    xorl  %ecx, %ecx                  ## encoding: [0x31,0xc9]
    cmpq  %rsi, %rdi                  ## encoding: [0x48,0x39,0xf7]
    movl  $-1, %eax                   ## encoding: [0xb8,0xff,0xff,0xff,0xff]
    cmovael %ecx, %eax                ## encoding: [0x0f,0x43,0xc1]
    ret                               ## encoding: [0xc3]

llvm-svn: 122451

fixed.

llvm-svn: 122448

if we have a lame assembler.

llvm-svn: 122446

pick the victim with the lowest total spill weight.

llvm-svn: 122445

llvm-svn: 122444

better name and matches what is used in the MachO writer.

llvm-svn: 122443

llvm-svn: 122441

llvm-svn: 122427

llvm-svn: 122419

the original instruction, half the cases were missed (making it not
wrong but suboptimal).  Also correct a typo (A <-> B) in the second
chunk. 

llvm-svn: 122414

esp. important given that the LOCAL_SECTDIFF enumeration got redefined.

llvm-svn: 122412