From 6f4ed269b9f4d8296f2002f5d96fcc5d8a9ef7b1 Mon Sep 17 00:00:00 2001
From: Matthias Braun <matze@braunis.de>
Date: Tue, 3 Nov 2015 01:53:36 +0000
Subject: [PATCH] RegisterPressure: Improve assert message

llvm-svn: 251885
---
 llvm/lib/CodeGen/RegisterPressure.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/llvm/lib/CodeGen/RegisterPressure.cpp b/llvm/lib/CodeGen/RegisterPressure.cpp
index 57dde2f2e2d0..6ff16e551be2 100644
--- a/llvm/lib/CodeGen/RegisterPressure.cpp
+++ b/llvm/lib/CodeGen/RegisterPressure.cpp
@@ -862,7 +862,8 @@ getUpwardPressureDelta(const MachineInstr *MI, /*const*/ PressureDiff &PDiff,
     unsigned MNew = MOld;
     // Ignore DeadDefs here because they aren't captured by PressureChange.
     unsigned PNew = POld + PDiffI->getUnitInc();
-    assert((PDiffI->getUnitInc() >= 0) == (PNew >= POld) && "PSet overflow");
+    assert((PDiffI->getUnitInc() >= 0) == (PNew >= POld)
+           && "PSet overflow/underflow");
     if (PNew > MOld)
       MNew = PNew;
     // Check if current pressure has exceeded the limit.