From e28abba21cd6affeeeec30c7866b2bfcfeaf865c Mon Sep 17 00:00:00 2001
From: Weile Wei <lokwei9@gmail.com>
Date: Thu, 18 May 2023 09:45:41 -0700
Subject: [PATCH] Use double precision for stdpar and avoid division by zero in
 RelDiff computation

---
 stdpar/src/lulesh-util.cc | 2 +-
 stdpar/src/lulesh.h       | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/stdpar/src/lulesh-util.cc b/stdpar/src/lulesh-util.cc
index d2a014c..9b8133e 100644
--- a/stdpar/src/lulesh-util.cc
+++ b/stdpar/src/lulesh-util.cc
@@ -205,7 +205,7 @@ void VerifyAndWriteFinalOutput(Real_t elapsed_time,
 
          if (MaxAbsDiff <AbsDiff) MaxAbsDiff = AbsDiff;
 
-         Real_t RelDiff = AbsDiff / locDom.e(k*nx+j);
+         Real_t RelDiff = FABS(locDom.e(k*nx+j)) > 1e-8 ? AbsDiff / locDom.e(k*nx+j) : 0.0;
 
          if (MaxRelDiff <RelDiff)  MaxRelDiff = RelDiff;
       }
diff --git a/stdpar/src/lulesh.h b/stdpar/src/lulesh.h
index b13eedd..a2e16c5 100644
--- a/stdpar/src/lulesh.h
+++ b/stdpar/src/lulesh.h
@@ -35,7 +35,7 @@ typedef long double  real10 ;  // 10 bytes on x86
 typedef int32_t Int4_t ;
 typedef int64_t Int8_t ;
 typedef Int4_t  Index_t ; // array subscript and loop index
-typedef real4   Real_t ;  // floating point representation
+typedef real8   Real_t ;  // floating point representation
 typedef Int4_t  Int_t ;   // integer representation
 
 enum { VolumeError = -1, QStopError = -2 } ;