The problem occurred when trying to reload this instruction:

MOV32mr %reg2326, 8, %reg2297, 4, %reg2295

The value of reg2326 was available in EBX, so it was reused from there, instead
of reloading it into EDX.

The value of reg2297 was available in EDX, so it was reused from there, instead
of reloading it into EDI.

The value of reg2295 was not available, so we tried reloading it into EBX, its
assigned register.  However, we checked and saw that we already reloaded
something into EBX, so we chose what reg2326 was assigned to (EDX) and reloaded
into that register instead.

Unfortunately EDX had already been used by reg2297, so reloading into EDX
clobbered the value used by the reg2326 operand, breaking the program.

The fix for this is to check that the newly picked register is ok.  In this
case we now find that EDX is already used and try using EDI, which succeeds.

llvm-svn: 17006

llvm-svn: 17005

llvm-svn: 16633

it was a use, def, or both.  This allows us to be less pessimistic in our
analysis of them.  In practice, this doesn't make a big difference, but it
doesn't hurt either.

llvm-svn: 16632

and delete them if they turn out to be dead.  This is a useful little hack
that even speeds up some programs.  For example, it speeds up Ptrdist/ks
from 17.53s to 15.59s, and 188.ammp from 149s to 146s.

This also speeds up llc :)

llvm-svn: 16630

generated code over the simple spiller.  The new local spiller generates
substantially better code than the simple one in some cases, by reusing
values that are loaded out of stack slots and kept available in registers.

This primarily helps programs that are spilling a lot, and there is still
stuff that can be done to improve it.  This patch makes the local spiller
the default, as it's only a tiny bit slower than the simple spiller (it
increases the runtime of llc by < 1%).

Here are some numbers with speedups.

Program    #reuse  old(s)    new(s)  Speedup

Povray:     3452,  16.87 ->  15.93   (5.5%)
177.mesa:   2176,   2.77 ->   2.76   (0%)
179.art:      35,  28.43 ->  28.01   (1.5%)
183.equake:   55,  61.44 ->  61.41   (0%)
188.ammp:    869, 174    -> 149      (15%)

164.gzip:     43,  40.73 ->  40.71   (0%)
175.vpr:     351,  18.54 ->  17.34   (6.5%)
176.gcc:    2471,   5.01 ->   4.92   (1.8%)
181.mcf       42,  79.30 ->  75.20   (5.2%)
186.crafty:  484,  29.73 ->  30.04   (-1%)
197.parser:  251,  10.47 ->  10.67   (-1%)
252.eon:    1501,   1.98 ->   1.75   (12%)
253.perlbm: 1183,  14.83 ->  14.42   (2.8%)
254.gap:     825,   7.46 ->   7.29   (2.3%)
255.vortex:  285,  10.51 ->  10.27   (2.3%)
256.bzip2:    63,  55.70 ->  55.20   (0.9%)
300.twolf:   830,  21.63 ->  22.00   (-1%)

PtrDist/ks    14,  32.75 -> 17.53    (46.5%)
Olden/tsp     46,   8.71 ->  8.24    (5.4%)
Free/distray  70,   1.09 ->  0.99    (9.2%)

llvm-svn: 16629

targets that supported multiple memory operands.

llvm-svn: 16614

llvm-svn: 16613

llvm-svn: 16609

two spillers produce perfectly identical code (at least on povray and eon),
but the simple spiller is substantially faster than the local spiller. Once
the local spiller is improved, we can switch back.

Switching cuts 5.2% off of the llc time for povray (about 1.3s).

llvm-svn: 16608

use a simple vector.  This speeds up -spiller=simple from taking 22s to taking
.1s on povray (debug build).  This change does not modify the generated code.

llvm-svn: 16607

data structures).  Fix the print method to send to the right ostream, not
always cerr.  Delete typedefs that are only used once.

llvm-svn: 16606

prune #includes, add print/dump methods, etc.  No functionality changes.

llvm-svn: 16604

Move include/Config and include/Support into include/llvm/Config,
include/llvm/ADT and include/llvm/Support. From here on out, all LLVM
public header files must be under include/llvm/.

llvm-svn: 16137

llvm-svn: 15775

llvm-svn: 15774

llvm-svn: 15089

llvm-svn: 14866

Made a fix so that you can print out MachineInstrs that belong to a MachineBasicBlock that is not yet attached to a MachineFunction. This change includes changing the third operand (TargetMachine) to a pointer for the MachineInstr::print function.

llvm-svn: 14389

llvm-svn: 13956

new one.

llvm-svn: 13895

llvm-svn: 12260

llvm-svn: 12189

llvm-svn: 12188

Add a spiller option to llc. A simple spiller will come soon. When we get CFG in the machine code represenation a global spiller will also be possible. Also document the linear scan register allocator but mark it as experimental for now.

llvm-svn: 12062

llvm-svn: 12058

that they are as far away from the loads as possible.

llvm-svn: 11895

llvm-svn: 11892

MRegisterInfo::is{Physical,Virtual}Register.

llvm-svn: 11849

to objects.

llvm-svn: 11840

allocator.

The implementation is completely rewritten and now employs several
optimizations not exercised before. For example for 164.gzip we have
997 loads and 699 stores vs the 1221 loads and 880 stores we have
before.

llvm-svn: 11798

251 (providing a generic machine code rewriter/spiller).

llvm-svn: 11780