catastrophic compilation time in the event of unreasonable LLVM
IR. Code quality is a separate issue--someone upstream needs to do a
better job of reducing to llvm.memcpy. If the situation can be reproduced with
any supported frontend, then it will be a separate bug.
llvm-svn: 118904
it makes no sense for allocation_order iterators to visit reserved regs.
The inline spiller depends on AliasAnalysis.
Manage the Query state to avoid uninitialized or stale results.
llvm-svn: 118800
This is the first small step towards using closed intervals for liveness instead
of the half-open intervals we're using now.
We want to be able to distinguish between a SlotIndex that represents a variable
being live-out of a basic block, and an index representing a variable live-in to
its successor.
That requires two separate indexes between blocks. One for live-outs and one for
live-ins.
With this change, getMBBEndIdx(MBB).getPrevSlot() becomes stable so it stays
greater than any instructions inserted at the end of MBB.
llvm-svn: 118747
Whenever splitting wants to insert a copy, it checks if the value can be
rematerialized cheaply instead.
Missing features:
- Delete instructions when all uses have been rematerialized.
- Truncate live ranges to the remaining uses after rematerialization.
llvm-svn: 118702
benchmarks hitting an assertion.
Adds LiveIntervalUnion::collectInterferingVRegs.
Fixes "late spilling" by checking for any unspillable live vregs among
all physReg aliases.
llvm-svn: 118701
handle cases in which a register is unavailable for spill code.
Adds LiveIntervalUnion::extract. While processing interferences on a
live virtual register, reuses the same Query object for each
physcial reg.
llvm-svn: 118423
Devang Patel
Andrew Trick
Chris Lattner
Lang Hames
Dan Gohman
Jakob Stoklund Olesen
Rafael Espindola
Matt Beaumont-Gay
Dale Johannesen
Che-Liang Chiou