Revert 'Fix a typo 'iff' => 'if''. iff is an abreviation of if and only if. See: http://en.wikipedia.org/wiki/If_and_only_if Commit 164767

llvm-svn: 164768

llvm-svn: 164767

- Put statistics in alphabetical order
- Don't use getZextValue when building TableInt, just use APInts
- Introduce Create{Z,S}ExtOrTrunc in IRBuilder.

llvm-svn: 164696

- Finish assert messages with exclamation mark
- Move overflow checking into ShouldBuildLookupTable.

llvm-svn: 164692

tables in bitmaps when they fit in a target-legal register.

This saves some space, and it also allows for building tables that would
otherwise be deemed too sparse.

One interesting case that this hits is example 7 from
http://blog.regehr.org/archives/320. We currently generate good code
for this when lowering the switch to the selection DAG: we build a
bitmask to decide whether to jump to one block or the other. My patch
will result in the same bitmask, but it removes the need for the jump,
as the return value can just be retrieved from the mask.

llvm-svn: 164684

breaking out the building of lookup tables into a separate class.

llvm-svn: 164682

llvm-svn: 164666

Fixed issue with Release build.

llvm-svn: 164654

llvm-svn: 164627

llvm-svn: 164614

We already have HoistThenElseCodeToIf, this patch implements
SinkThenElseCodeToEnd. When END block has only two predecessors and each
predecessor terminates with unconditional branches, we compare instructions in
IF and ELSE blocks backwards and check whether we can sink the common
instructions down.

rdar://12191395

llvm-svn: 164325

llvm-svn: 164238

llvm-svn: 164235

llvm-svn: 164232

two variables where the first variable is returned and the second
ignored.

I don't think this occurs in practice (other passes should have cleaned
up the unused phi node), but it should still be handled correctly.

Also make the logic for determining if we should return early less
sketchy.

llvm-svn: 164225

llvm-svn: 164216

Implementation derived from compiler-rt's implementation of signed and unsigned integer division.

llvm-svn: 164173

and a conditional branch; also when removing dead cases from a switch.

llvm-svn: 164084

Hanlde the case when we split the default edge if the default target has "icmp"
and unconditinal branch.

llvm-svn: 164076

llvm-svn: 164068

destination in SimplifyCondBranchToCondBranch.

llvm-svn: 164054

The cases where no initialization happens should still be checked for logic flaws.

llvm-svn: 164032

destination.

Updated previous implementation to fix a case not covered:
// PBI: br i1 %x, TrueDest, BB
// BI:  br i1 %y, TrueDest, FalseDest
The other case was handled correctly.
// PBI: br i1 %x, BB, FalseDest
// BI:  br i1 %y, TrueDest, FalseDest

Also tried to use 64-bit arithmetic instead of APInt with scale to simplify the
computation. Let me know if you have other opinions about this.

llvm-svn: 163954

case to a conditional branch and when removing dead cases.

llvm-svn: 163942

llvm-svn: 163940

lit config.

llvm-svn: 163928

llvm-svn: 163926

the default target of the first switch is not the basic block the second switch
is in (PredDefault != BB).

llvm-svn: 163916

to the default target.

llvm-svn: 163724

"#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)"

No functional change. Update r163344.

llvm-svn: 163679

a pair of switch/branch where both depend on the value of the same variable and
the default case of the first switch/branch goes to the second switch/branch.

Code clean up and fixed a few issues:
1> handling the case where some cases of the 2nd switch are invalidated
2> correctly calculate the weight for the 2nd switch when it is a conditional eq

Testing case is modified from Alastair's original patch.

llvm-svn: 163635

llvm-svn: 163593

Add a pass that renames everything with metasyntatic names. This works well after using bugpoint to reduce the confusion presented by the original names, which no longer mean what they used to.

llvm-svn: 163592

llvm-svn: 163503

llvm-svn: 163491

Patch and test case by Alastair Murray!

llvm-svn: 163437

llvm-svn: 163378

No functional change.

llvm-svn: 163344

The lookup tables did not get built in a deterministic order.
This makes them get built in the order that the corresponding phi nodes
were found.

llvm-svn: 163305

This adds a transformation to SimplifyCFG that attemps to turn switch
instructions into loads from lookup tables. It works on switches that
are only used to initialize one or more phi nodes in a common successor
basic block, for example:

  int f(int x) {
    switch (x) {
    case 0: return 5;
    case 1: return 4;
    case 2: return -2;
    case 5: return 7;
    case 6: return 9;
    default: return 42;
  }

This speeds up the code by removing the hard-to-predict jump, and
reduces code size by removing the code for the jump targets.

llvm-svn: 163302