Enable live debug variables pass.

llvm-svn: 123032

llvm-svn: 123031

Also fix an off-by-one in SelectionDAGBuilder that was preventing shuffle
vectors from being translated to EXTRACT_SUBVECTOR.
Patch by Tim Northover.

The test changes are needed to keep those spill-q tests from testing aligned
spills and restores.  If the only aligned stack objects are spill slots, we
no longer realign the stack frame.  Prior to this patch, an EXTRACT_SUBVECTOR
was legalized by loading from the stack, which created an aligned frame index.
Now, however, there is nothing except the spill slot in the stack frame, so
I added an aligned alloca.

llvm-svn: 122995

llvm-svn: 122994

We were never generating any of these nodes with variable indices, and there
was one legalizer function asserting on a non-constant index.  If we ever have
a need to support variable indices, we can add this back again.

llvm-svn: 122993

we have invokes, so there is no functionality change here.

llvm-svn: 122990

Nadav Rotem.

llvm-svn: 122983

typed atomics. This will lower exclusively to libcalls at the moment.

llvm-svn: 122979

This fixes PR 8913 crash.

llvm-svn: 122971

etc. takes an option OptSize. If OptSize is true, it would return
the inline limit for functions with attribute OptSize.

llvm-svn: 122952

llvm-svn: 122949

Simplify RALinScan::DowngradeRegister with TRI::getOverlaps while we are there.

llvm-svn: 122940

This pass precomputes CFG block frequency information that can be used by the
register allocator to find optimal spill code placement.

Given an interference pattern, placeSpills() will compute which basic blocks
should have the current variable enter or exit in a register, and which blocks
prefer the stack.

The algorithm is ready to consume block frequencies from profiling data, but for
now it gets by with the static estimates used for spill weights.

This is a work in progress and still not hooked up to RegAllocGreedy.

llvm-svn: 122938

up freebsd bootloader. However, this doesn't make much sense for Darwin, whose
-Os is meant to optimize for size only if it doesn't hurt performance.
rdar://8821501

llvm-svn: 122936

the original type of the switch statement key.
rdar://8781238

llvm-svn: 122935

  r1025 = s/zext r1024, 4
  r1026 = extract_subreg r1025, 4
to:
  r1026 = copy r1024

llvm-svn: 122925

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