From 721c201bd55ffb73cb2ba8d39e0570fa38c44e15 Mon Sep 17 00:00:00 2001 From: dim Date: Wed, 15 Aug 2012 19:34:23 +0000 Subject: Vendor import of llvm trunk r161861: http://llvm.org/svn/llvm-project/llvm/trunk@161861 --- lib/CodeGen/SpillPlacement.cpp | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'lib/CodeGen/SpillPlacement.cpp') diff --git a/lib/CodeGen/SpillPlacement.cpp b/lib/CodeGen/SpillPlacement.cpp index 6f33f54..320128a 100644 --- a/lib/CodeGen/SpillPlacement.cpp +++ b/lib/CodeGen/SpillPlacement.cpp @@ -207,6 +207,17 @@ void SpillPlacement::activate(unsigned n) { return; ActiveNodes->set(n); nodes[n].clear(); + + // Very large bundles usually come from big switches, indirect branches, + // landing pads, or loops with many 'continue' statements. It is difficult to + // allocate registers when so many different blocks are involved. + // + // Give a small negative bias to large bundles such that 1/32 of the + // connected blocks need to be interested before we consider expanding the + // region through the bundle. This helps compile time by limiting the number + // of blocks visited and the number of links in the Hopfield network. + if (bundles->getBlocks(n).size() > 100) + nodes[n].Bias = -0.0625f; } -- cgit v1.1