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

works only on MinGW32. On 64-bit, the function to call is "__chkstk".
Patch by KS Sreeram!

llvm-svn: 122934

beginning of the "main" function. The assembler complains about the invalid
suffix for the 'call' instruction. The right instruction is "callq __main".
Patch by KS Sreeram!

llvm-svn: 122933

worklist, the key will need to become std::pair<BasicBlock*, Value*>.

llvm-svn: 122932

llvm-svn: 122929

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

llvm-svn: 122925

llvm-svn: 122921

llvm-svn: 122920

calculated.

llvm-svn: 122912

llvm-svn: 122911

llvm-svn: 122909

in the predecessor block, leading to an incorrect conclusion for the edge value.  Found by inspection.

llvm-svn: 122908

hasBlockValue() that was causing iterator invalidations.  Many thanks to Dimitry Andric for
tracking down those invalidations!

llvm-svn: 122906

llvm-svn: 122893

llvm-svn: 122891

Commit 122778 broke DWARF debug output when using the MBlaze backend. Fixed by overriding TargetFrameInfo::getFrameIndexOffset to take into account the new frame index information.

llvm-svn: 122889

regressing code quality.

llvm-svn: 122887

llvm-svn: 122884

llvm-svn: 122883

llvm-svn: 122882

llvm-svn: 122881

llvm-svn: 122879

llvm-svn: 122876

step is to only process instructions in subloops if they have been modified by
an earlier simplification.

llvm-svn: 122869

skipping them, but it should probably use a worklist and only revisit those
instructions in subloops that have actually changed. It should probably also
use a worklist after the first iteration like instsimplify now does. Regardless,
it's only 0.3% of opt -O2 time on 403.gcc if it replaces the instcombine placed
in the middle of the loop passes.

llvm-svn: 122868

llvm-svn: 122849

Don't bother value numbering instructions with void types in GVN. In theory this should allow us to insert
fewer things into the value numbering maps, but any speedup is beneath the noise threshold on my machine
on 403.gcc.

llvm-svn: 122844

bundles in the pass.

llvm-svn: 122833

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

warning is overzealous but gcc is what it is.)

llvm-svn: 122829

llvm-svn: 122828

llvm-svn: 122827

llvm-svn: 122826

Clarify terminology, settling on referring to what was the "number table" as the "leader table", and
rename methods to make it much more clear what they're doing.

llvm-svn: 122823

llvm-svn: 122822

case where a static caller is itself inlined everywhere else, and
thus may go away if it doesn't get too big due to inlining other
things into it.  If there are references to the caller other than
calls, it will not be removed; account for this.
This results in same-day completion of the case in PR8853.

llvm-svn: 122821

Branch instructions don't produce values, so there's no need to generate a value number for them.  This
avoids adding them to the various value numbering tables, resulting in a minor (~3%) speedup for GVN
on 40.gcc.

llvm-svn: 122819