From: Matthias Braun <matze@braunis.de>
Date: Fri, 3 Mar 2017 23:27:20 +0000 (+0000)
Subject: RegAllocGreedy: Follow-up to r296722
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=7ed12a092504309f00bb250cbe9775828125e779;p=llvm

RegAllocGreedy: Follow-up to r296722

We can now end up in situations where we initiate LiveIntervalUnion
queries with different SubRanges against the same register unit, so the
assert() no longer holds in all cases. Just recalculate now when we know
the cache is out of date.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296928 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/RegAllocGreedy.cpp b/lib/CodeGen/RegAllocGreedy.cpp
index 6ec0c821e9d..06500289c97 100644
--- a/lib/CodeGen/RegAllocGreedy.cpp
+++ b/lib/CodeGen/RegAllocGreedy.cpp
@@ -849,7 +849,11 @@ void RAGreedy::evictInterference(LiveInterval &VirtReg, unsigned PhysReg,
   SmallVector<LiveInterval*, 8> Intfs;
   for (MCRegUnitIterator Units(PhysReg, TRI); Units.isValid(); ++Units) {
     LiveIntervalUnion::Query &Q = Matrix->query(VirtReg, *Units);
-    assert(Q.seenAllInterferences() && "Didn't check all interfererences.");
+    // We usually have the interfering VRegs cached so collectInterferingVRegs()
+    // should be fast, we may need to recalculate if when different physregs
+    // overlap the same register unit so we had different SubRanges queried
+    // against it.
+    Q.collectInterferingVRegs();
     ArrayRef<LiveInterval*> IVR = Q.interferingVRegs();
     Intfs.append(IVR.begin(), IVR.end());
   }