This doesn't change functionality (much), but it allows for a more fine-grained
eviction policy. The current policy only compares spill weights, and that is not
always the best thing to do.  Spill weights are designed to serve linear scan,
and they don't consider live range splitting.

Add a mechanism so canEvict() can request that a live range be evicted and
split/spilled. This is to avoid infinite eviction loops.

llvm-svn: 132101

Rewrite fast-isel integer cast handling to handle more cases, and to be simpler and more consistent.

The practical effects here are that x86-64 fast-isel can now handle trunc from i8 to i1, and ARM fast-isel can handle many more constructs involving integers narrower than 32 bits (including loads, stores, and many integer casts).

rdar://9437928 .

llvm-svn: 132099

llvm-svn: 132087

LTO friendly as we can now correctly merge files compiled with or without
-fasynchronous-unwind-tables.

llvm-svn: 132033

llvm-svn: 131974

llvm-svn: 131952

llvm-svn: 131951

  non-zero.
- Teach X86 cmov optimization to eliminate the cmov from ctlz, cttz extension
  when the source of X86ISD::BSR / X86ISD::BSF is proven to be non-zero.

rdar://9490949

llvm-svn: 131948

llvm-svn: 131940

llvm-svn: 131936

llvm-svn: 131926

Patch by Micah Villmow

llvm-svn: 131908

llvm-svn: 131907

when we're just going to throw the result away.  No functionality change.

llvm-svn: 131880

should eventually convert to PMBuilder, but I don't plan to do this.

llvm-svn: 131819

llvm-svn: 131800

actually fixes most of the VerifyCoalescing failures in test-suite.

llvm-svn: 131768

llvm-svn: 131765

llvm-svn: 131763

llvm-svn: 131760

llvm-svn: 131757

llvm-svn: 131756

the phikill flag.

llvm-svn: 131717

similarly for stores. Now "make check" passes with the MachineVerifier forced
on with the VerifyCoalescing option!

llvm-svn: 131705

llvm-svn: 131663

on CodeGen/X86/2007-05-07-InvokeSRet.ll. There is probably a bug here that was
fixed by r128961, but since there is no test or reference to a source file I have
to revert it.

llvm-svn: 131618

Original log entry:
Refactor getActionType and getTypeToTransformTo ; place all of the 'decision'
code in one place.

llvm-svn: 131536

code in one place.

llvm-svn: 131534

llvm-svn: 131524

The 'last use' may not be in the same basic block, and we still want a correct
live range.

llvm-svn: 131523

LiveInterval::shrinkToUses recomputes the live range from scratch instead of
removing snippets. This should avoid the problem with dangling live ranges.

Leave physreg identity copies alone. They can be created when joining a virtreg
with a physreg. They don't affect register allocation, and they will be removed
by the rewriter.

llvm-svn: 131521

Make fast-isel miss counting in -stats and -fast-isel-verbose take terminators into account; since there are many fewer isel misses with recent changes, misses caused by terminators are more significant.

llvm-svn: 131502

llvm-svn: 131497

llvm-svn: 131495

llvm-svn: 131469

passed as the fifth parameter, insure it's passed correctly (in R9).
rdar://problem/6920088

llvm-svn: 131467

The greedy register allocator has live range splitting and register class
inflation, so it can actually fully undo this join, including restoring the
original register classes.

We still don't want to do this for long live ranges, mostly because of the high
register pressure of there are many constrained live ranges overlapping.

llvm-svn: 131466

When instructions are deleted, they leave tombstone SlotIndex entries.
The isZeroLength method should ignore these null indexes.

This causes RABasic to sometimes spill a callee-saved register in the
abi-isel.ll test, so don't run that test with -regalloc=basic.  Prioritizing
register allocation according to spill weight can cause more registers to be
used.

llvm-svn: 131436

llvm-svn: 131430

llvm-svn: 131429