commit 11c9a325399b282cb4ea7d1d24d42fceeec2a09a
author Andrew Scull <ascull@google.com> Fri Aug 28 14:24:14 2015 -0700
committer Andrew Scull <ascull@google.com> Fri Aug 28 14:24:14 2015 -0700
tree 351ff0336a0789b72500fde2c83a9426a4e9ba3a
parent 25529f7bdaf3dfa08455b87642a120e84961d6d6

Weight variables for register allocation by their number of uses.

Count the number of instructions that use a variable following the heuristic
that more uses implies higher register priority. This is currently very simple
but is precursor work for weighting variables by loop nest depth.

BUG=
R=jvoung@chromium.org

Review URL: https://codereview.chromium.org/1312433004.

src/IceTargetLoweringX8632.cpp

diff --git a/src/IceTargetLoweringX8632.cpp b/src/IceTargetLoweringX8632.cpp
index e9f9989..a4ceac0 100644
--- a/src/IceTargetLoweringX8632.cpp
+++ b/src/IceTargetLoweringX8632.cpp
@@ -429,7 +429,7 @@
       [&VariablesLinkedToSpillSlots](Variable *Var) {
         if (auto *SpillVar =
                 llvm::dyn_cast<typename Traits::SpillVariable>(Var)) {
-          assert(Var->getWeight().isZero());
+          assert(Var->mustNotHaveReg());
           if (SpillVar->getLinkedTo() && !SpillVar->getLinkedTo()->hasReg()) {
             VariablesLinkedToSpillSlots.push_back(Var);
             return true;