From 332cc29b04d4aba0c06f6831f511f6c82d4cdd7b Mon Sep 17 00:00:00 2001
From: annuges <33180039+annuges@users.noreply.github.com>
Date: Thu, 5 Oct 2023 20:45:09 +0200
Subject: [PATCH] restore allocation free maxdiff

The mapreduce based version allocates which is undesirable.
This change restores the previous allocation free code for normal Arrays while still allowing gpu arrays using mapreduce
---
 src/utilities/maxdiff.jl | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/utilities/maxdiff.jl b/src/utilities/maxdiff.jl
index a8bf2117e..d25a8e7f6 100644
--- a/src/utilities/maxdiff.jl
+++ b/src/utilities/maxdiff.jl
@@ -1,3 +1,16 @@
+# generic version for gpu support
 function maxdiff(x::AbstractArray, y::AbstractArray)
     return mapreduce((a, b) -> abs(a - b), max, x, y)
 end
+
+# allocation free version for normal arrays
+function maxdiff(x::Array, y::Array)
+    res = real(zero(x[1] - y[1]))
+    @inbounds for i in 1:length(x)
+        delta = abs(x[i] - y[i])
+        if delta > res
+            res = delta
+        end
+    end
+    return res
+end