From f7685a4639f5f69a3f974a56e52ab32d2d0ced0b Mon Sep 17 00:00:00 2001
From: Claes Redestad <redestad@openjdk.org>
Date: Thu, 12 Nov 2020 14:20:48 +0000
Subject: [PATCH] 8256203: Simplify RegMask::Empty

Reviewed-by: thartmann, chagedorn
---
 src/hotspot/share/opto/regmask.cpp | 7 +------
 src/hotspot/share/opto/regmask.hpp | 4 +++-
 2 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/src/hotspot/share/opto/regmask.cpp b/src/hotspot/share/opto/regmask.cpp
index f024387c985..70f2b12c7bb 100644
--- a/src/hotspot/share/opto/regmask.cpp
+++ b/src/hotspot/share/opto/regmask.cpp
@@ -49,12 +49,7 @@ void OptoReg::dump(int r, outputStream *st) {
 
 
 //=============================================================================
-const RegMask RegMask::Empty(
-# define BODY(I) 0,
-  FORALL_BODY
-# undef BODY
-  0
-);
+const RegMask RegMask::Empty;
 
 //=============================================================================
 bool RegMask::is_vector(uint ireg) {
diff --git a/src/hotspot/share/opto/regmask.hpp b/src/hotspot/share/opto/regmask.hpp
index bed1c416e1a..6f4fe652530 100644
--- a/src/hotspot/share/opto/regmask.hpp
+++ b/src/hotspot/share/opto/regmask.hpp
@@ -136,7 +136,9 @@ class RegMask {
   }
 
   // Construct an empty mask
-  RegMask() : _RM_UP(), _lwm(_RM_SIZE - 1), _hwm(0) {}
+  RegMask() : _RM_UP(), _lwm(_RM_SIZE - 1), _hwm(0) {
+    assert(valid_watermarks(), "post-condition");
+  }
 
   // Construct a mask with a single bit
   RegMask(OptoReg::Name reg) : RegMask() {