The coalescer can in very rare cases leave too large live intervals around after
rematerializing cheap-as-a-move instructions.
Linear scan doesn't really care, but live range splitting gets very confused
when a live range is killed by a ghost instruction.
I will fix this properly in the coalescer after 2.9 branches.
llvm-svn: 127096
This makes lookup slightly more expensive but it's worth it, unused
DenseMaps are common in LLVM code apparently.
1% speedup on clang -O3 bzip2.c
4% speedup on clang -O3 oggenc.c (Release build of clang on i386/linux)
llvm-svn: 127088
regs. This is the only change in this checkin that may affects the
default scheduler. With better register tracking and heuristics, it
doesn't make sense to artificially lower the register limit so much.
Added -sched-high-latency-cycles and X86InstrInfo::isHighLatencyDef to
give the scheduler a way to account for div and sqrt on targets that
don't have an itinerary. It is currently defaults to 10 (the actual
number doesn't matter much), but only takes effect on non-default
schedulers: list-hybrid and list-ilp.
Added several heuristics that can be individually disabled for the
non-default sched=list-ilp mode. This helps us determine how much
better we can do on a given benchmark than the default
scheduler. Certain compute intensive loops run much faster in this
mode with the right set of heuristics, and it doesn't seem to have
much negative impact elsewhere. Not all of the heuristics are needed,
but we still need to experiment to decide which should be disabled by
default for sched=list-ilp.
llvm-svn: 127067
possible. This goes into instcombine and instsimplify because instsimplify
doesn't need to check hasOneUse since it returns (almost exclusively) constants.
This fixes PR9343 #4#5 and #8!
llvm-svn: 127064
This simplifies the code and makes it faster too.
The interference patterns are saved for each candidate register. It will be
reused for actually executing the split. Work in progress.
llvm-svn: 127054
number of threads. In that case make the number of threads
equal to the number of jobs and launch one jobs on each
thread. This makes things work like make -j.
llvm-svn: 127045
inefficient file system buffering if the writes are not a multiple of the desired
buffer size. Avoid this by limiting the large write to a multiple of the buffer
size and copying the remainder into the buffer.
Thanks to Dan for pointing this out.
llvm-svn: 127026
Initially, slot indexes are quad-spaced. There is room for inserting up to 3
new instructions between the original instructions.
When we run out of indexes between two instructions, renumber locally using
double-spaced indexes. The original quad-spacing means that we catch up quickly,
and we only have to renumber a handful of instructions to get a monotonic
sequence. This is much faster than renumbering the whole function as we did
before.
llvm-svn: 127023
You can't really predict how many indexes will be needed from the number of
defs, so let's keep it simple.
Also remove an extra empty index that was inserted after each basic block. It
was intended for live-out ranges, but it was never used that way.
llvm-svn: 127014
