This changes the SelectionDAG scheduling preference to source
order. Soon, the SelectionDAG scheduler can be bypassed saving
a nice chunk of compile time.
Performance differences that result from this change are often a
consequence of register coalescing. The register coalescer is far from
perfect. Bugs can be filed for deficiencies.
On x86 SandyBridge/Haswell, the source order schedule is often
preserved, particularly for small blocks.
Register pressure is generally improved over the SD scheduler's ILP
mode. However, we are still able to handle large blocks that require
latency hiding, unlike the SD scheduler's BURR mode. MI scheduler also
attempts to discover the critical path in single-block loops and
adjust heuristics accordingly.
The MI scheduler relies on the new machine model. This is currently
unimplemented for AVX, so we may not be generating the best code yet.
Unit tests are updated so they don't depend on SD scheduling heuristics.
llvm-svn: 192750
This was done with the following sed invocation to catch label lines demarking function boundaries:
sed -i '' "s/^;\( *\)\([A-Z0-9_]*\):\( *\)test\([A-Za-z0-9_-]*\):\( *\)$/;\1\2-LABEL:\3test\4:\5/g" test/CodeGen/*/*.ll
which was written conservatively to avoid false positives rather than false negatives. I scanned through all the changes and everything looks correct.
llvm-svn: 186258
Previously LEA64_32r went through virtually the entire backend thinking it was
using 32-bit registers until its blissful illusions were cruelly snatched away
by MCInstLower and 64-bit equivalents were substituted at the last minute.
This patch makes it behave normally, and take 64-bit registers as sources all
the way through. Previous uses (for 32-bit arithmetic) are accommodated via
SUBREG_TO_REG instructions which make the types and classes agree properly.
llvm-svn: 183693
to instructions instead of zero extended ones. This makes the asmprinter
print signed values more consistently. This apparently only really affects
the X86 backend.
llvm-svn: 81265
