Add header guards to files that were missing guards. Remove #endif comments
as they don't seem common in LLVM (we can easily add them back if we decide
they're useful)
Changes made by clang-tidy with minor tweaks.
llvm-svn: 215558
sequence - target independent framework
When the DAGcombiner selects instruction sequences
it could increase the critical path or resource len.
For example, on arm64 there are multiply-accumulate instructions (madd,
msub). If e.g. the equivalent multiply-add sequence is not on the
crictial path it makes sense to select it instead of the combined,
single accumulate instruction (madd/msub). The reason is that the
conversion from add+mul to the madd could lengthen the critical path
by the latency of the multiply.
But the DAGCombiner would always combine and select the madd/msub
instruction.
This patch uses machine trace metrics to estimate critical path length
and resource length of an original instruction sequence vs a combined
instruction sequence and picks the faster code based on its estimates.
This patch only commits the target independent framework that evaluates
and selects code sequences. The machine instruction combiner is turned
off for all targets and expected to evolve over time by gradually
handling DAGCombiner pattern in the target specific code.
This framework lays the groundwork for fixing
rdar://16319955
llvm-svn: 214666
The new instruction scheduling models provide information about the
number of cycles consumed on each processor resource. This makes it
possible to estimate ILP more accurately than simply counting
instructions / issue width.
The functions getResourceDepth() and getResourceLength() now identify
the limiting processor resource, and return a cycle count based on that.
This gives more precise resource information, particularly in traces
that use one resource a lot more than others.
llvm-svn: 178553
In very rare cases caused by irreducible control flow, the dominating
block can have the same trace head without actually being part of the
trace.
As long as such a dominator still has valid instruction depths, it is OK
to use it for computing instruction depths.
Rename the function to avoid lying, and add a check that instruction
depths are computed for the dominator.
llvm-svn: 176668
