update file comment

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26573 91177308-0d34-0410-b5e6-96231b3b80d8
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Chris Lattner 2006-03-06 17:58:04 +00:00
parent adc5e5c85f
commit 6af7ef8da8

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//
//===----------------------------------------------------------------------===//
//
// This implements a simple two pass scheduler. The first pass attempts to push
// backward any lengthy instructions and critical paths. The second pass packs
// instructions into semi-optimal time slots.
// This implements bottom-up and top-down list schedulers, using standard
// algorithms. The basic approach uses a priority queue of available nodes to
// schedule. One at a time, nodes are taken from the priority queue (thus in
// priority order), checked for legality to schedule, and emitted if legal.
//
// Nodes may not be legal to schedule either due to structural hazards (e.g.
// pipeline or resource constraints) or because an input to the instruction has
// not completed execution.
//
//===----------------------------------------------------------------------===//