From b9a012156bbf3b13eb16027c0a75c186f172366a Mon Sep 17 00:00:00 2001 From: Dan Gohman Date: Tue, 16 Dec 2008 03:35:01 +0000 Subject: Add initial support for back-scheduling address computations, especially in the case of addresses computed from loop induction variables. llvm-svn: 61075 --- llvm/lib/CodeGen/LatencyPriorityQueue.cpp | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'llvm/lib/CodeGen/LatencyPriorityQueue.cpp') diff --git a/llvm/lib/CodeGen/LatencyPriorityQueue.cpp b/llvm/lib/CodeGen/LatencyPriorityQueue.cpp index 7ad9ac9b51c..2e7b89c494f 100644 --- a/llvm/lib/CodeGen/LatencyPriorityQueue.cpp +++ b/llvm/lib/CodeGen/LatencyPriorityQueue.cpp @@ -19,6 +19,14 @@ using namespace llvm; bool latency_sort::operator()(const SUnit *LHS, const SUnit *RHS) const { + // The isScheduleHigh flag allows nodes with wraparound dependencies that + // cannot easily be modeled as edges with latencies to be scheduled as + // soon as possible in a top-down schedule. + if (LHS->isScheduleHigh && !RHS->isScheduleHigh) + return false; + if (!LHS->isScheduleHigh && RHS->isScheduleHigh) + return true; + unsigned LHSNum = LHS->NodeNum; unsigned RHSNum = RHS->NodeNum; -- cgit v1.2.3