From 12f3eb871d107a02aa768a9fcc6b7a92261748c8 Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Fri, 7 Jan 2022 10:59:31 -0800
Subject: [PATCH] ircd::simt: Fix buffer and ordering hokey-pokey.

---
 include/ircd/simt/mean.h | 16 ++++++++++------
 include/ircd/simt/norm.h |  7 ++++---
 2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/include/ircd/simt/mean.h b/include/ircd/simt/mean.h
index f120c2f33..396f9c534 100644
--- a/include/ircd/simt/mean.h
+++ b/include/ircd/simt/mean.h
@@ -30,17 +30,21 @@ struct ircd_math_mean
 /// ln = local group size
 ///
 inline void
-ircd_simt_math_mean_f4lldr(__local float4 *const restrict out,
-                           __local const float4 *const restrict in,
+ircd_simt_math_mean_f4lldr(__local float4 *const buf,
                            const uint ln,
                            const uint li)
 {
-	out[li] = in[li];
-	ircd_simt_reduce_add_f4lldr(out, ln, li);
+	ircd_simt_reduce_add_f4lldr(buf, ln, li);
 
 	if(li == 0)
-		out[li] = ircd_simt_reduce_add_f4(out[li]) / (ln * 4);
+	{
+		const float
+		sum = ircd_simt_reduce_add_f4(buf[li]),
+		res = sum / (ln * 4);
 
-	ircd_simt_broadcast_f4lldr(out, ln, li);
+		buf[li] = res;
+	}
+
+	ircd_simt_broadcast_f4lldr(buf, ln, li);
 }
 #endif
diff --git a/include/ircd/simt/norm.h b/include/ircd/simt/norm.h
index bb4705746..fa47b4050 100644
--- a/include/ircd/simt/norm.h
+++ b/include/ircd/simt/norm.h
@@ -21,17 +21,18 @@ ircd_simt_math_norm_f4lldr(__local float4 *const out,
                            const uint ln,
                            const uint li)
 {
-	ircd_simt_math_mean_f4lldr(tmp, in, ln, li);
+	tmp[li] = in[li];
+	ircd_simt_math_mean_f4lldr(tmp, ln, li);
 
 	const float4
 	sub_mean = in[li] - tmp[li];
 
 	tmp[li] = pow(sub_mean, 2);
-	ircd_simt_math_mean_f4lldr(out, tmp, ln, li);
+	ircd_simt_math_mean_f4lldr(tmp, ln, li);
 
 	const float4
 	epsilon = 0.00001f,
-	s = sqrt(out[li] + epsilon);
+	s = sqrt(tmp[li] + epsilon);
 
 	out[li] = sub_mean / s;
 }