- Eliminate redundant successors.
- Convert an indirectbr with one successor into a direct branch.
Also, generalize SimplifyCFG to be able to be run on a function entry block.
It knows quite a few simplifications which are applicable to the entry
block, and it only needs a few checks to avoid trouble with the entry block.
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experimental pass that allocates locals relative to one another before
register allocation and then assigns them to actual stack slots as a block
later in PEI. This will eventually allow targets with limited index offset
range to allocate additional base registers (not just FP and SP) to
more efficiently reference locals, as well as handle situations where
locals cannot be referenced via SP or FP at all (dynamic stack realignment
together with variable sized objects, for example). It's currently
incomplete and almost certainly buggy. Work in progress.
Disabled by default and gated via the -enable-local-stack-alloc command
line option.
rdar://8277890
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The earliestStart argument is entirely specific to linear scan allocation, and
can be easily calculated by RegAllocLinearScan.
Replace std::vector with SmallVector.
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when they are the same loop. Don't compare two instructions'
loop depths when they are in the same block.
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When a live range is contained a single block, we can split it around
instruction clusters. The current approach is very primitive, splitting before
and after the largest gap between uses.
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ScalarEvolution::getAddExpr, which can be pretty expensive, when nothing
has changed, which is pretty common.
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since they can support trivial implementations. This avoids potentially
expensive traversals of the operands.
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Tested on Linux and Darwin; please add platform-specific XFAILs/mail me a bug
report if this still fails.
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numbers match. The old check could accidentally leave holes in openli.
Also let useIntv add all ranges for the phi-def value inserted by
enterIntvAtEnd. This works as long at the value mapping is established in
enterIntvAtEnd.
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This can happen if the original interval has been broken into two disconnected
parts. Ideally, we should be able to detect when the graph is disconnected and
create separate intervals, but that code is not implemented yet.
Example:
Two basic blocks are both branching to a loop header. Our interval is defined in
both basic blocks, and live into the loop along both edges.
We decide to split the interval around the loop. The interval is split into an
inside part and an outside part. The outside part now has two disconnected
segments, one in each basic block.
If we later decide to split the outside interval into single blocks, we get one
interval per basic block and an empty dupli for the remainder.
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split intervals. THis means the analysis can be used for multiple splits as long
as curli doesn't shrink.
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