long live interval that has low usage density.
1. Change order of coalescing to join physical registers with virtual
   registers first before virtual register intervals become too long.
2. Check size and usage density to determine if it's worthwhile to join.
3. If joining is aborted, assign virtual register live interval allocation
   preference field to the physical register.
4. Register allocator should try to allocate to the preferred register
   first (if available) to create identify moves that can be eliminated.

llvm-svn: 36218

llvm-svn: 36217

llvm-svn: 36216

llvm-svn: 36215

llvm-svn: 36214

llvm-svn: 36213

a chance to hack on it.  This compiles:

int baz(long long a) { return (short)(((int)(a >>24)) >> 9); }

into:
_baz:
        slwi r2, r3, 8
        srwi r2, r2, 9
        extsh r3, r2
        blr

instead of:

_baz:
        srwi r2, r4, 24
        rlwimi r2, r3, 8, 0, 23
        srwi r2, r2, 9
        extsh r3, r2
        blr

This implements CodeGen/PowerPC/sign_ext_inreg1.ll

llvm-svn: 36212

llvm-svn: 36211

pointer from ilist, storing it in the prev pointer of the first node in the
list instead.

This shrinks ilist from 8 to 4 bytes, BasicBlock from 40->36 bytes, Function
from 76->68 bytes, Module from 52->44 bytes.

llvm-svn: 36210

llvm-svn: 36209

gets called.

llvm-svn: 36208

llvm-svn: 36207

llvm-svn: 36206

llvm-svn: 36205

llvm-svn: 36204

llvm-svn: 36203

llvm-svn: 36202

llvm-svn: 36201

llvm-svn: 36200

llvm-svn: 36199

llvm-svn: 36198

llvm-svn: 36197

it is defined in.

llvm-svn: 36196

Also, fixed static case in presence of eax livin. This fixes PR331

PS: Why don't we still have push/pop instructions? :)
llvm-svn: 36195

llvm-svn: 36194

llvm-svn: 36193

field into SubclassData in Value.  This shrinks GlobalVAlue from 48->40
bytes, Function from 88->76, and GlobalVariable from 76->68.  This trims
4640 bytes off my testcase, reading a bc file without materializing any
functions.

llvm-svn: 36192

llvm-svn: 36191

llvm-svn: 36190

object is always constant.  As such, evaluate it at compile time instead of storing
it as an ivar in SymbolTableListTraits.  This shrinks every SymbolTableListTraits
ilist by a word, shrinking BasicBlock from 44->40 bytes, Function from 96->88 bytes,
and Module from 60->52 bytes.

llvm-svn: 36189

of two.  This shrinkifies Function by 8 bytes (104->96) and Module by 8
bytes (68->60).  On a testcase of mine, this reduces the memory used to
read a module header from 565680b to 561024, a little over 4K.

llvm-svn: 36188

llvm-svn: 36187

extensions.

llvm-svn: 36186

llvm-svn: 36185

llvm-svn: 36184

llvm-svn: 36183

Fix
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20070416/047888.html

llvm-svn: 36182

llvm-svn: 36181

llvm-svn: 36180

llvm-svn: 36179