From d1c5b05513012d9515ebabec9308647d1d971ddf Mon Sep 17 00:00:00 2001
From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Sat, 25 Jun 2022 19:46:46 +0100
Subject: [PATCH] add some more preduce examples, remove predicate ORing

---
 openpower/sv/preduce.py | 45 +++++++++++++++++++++++++++++++++++------
 1 file changed, 39 insertions(+), 6 deletions(-)

diff --git a/openpower/sv/preduce.py b/openpower/sv/preduce.py
index 5fb4f26f6..b369778ee 100644
--- a/openpower/sv/preduce.py
+++ b/openpower/sv/preduce.py
@@ -2,7 +2,6 @@ from copy import copy
 
 def preduce(vl, vec, pred):
     vec = copy(vec)
-    pred = copy(pred) # must not damage predicate
     step = 1
     print(" start", step, pred, vec)
     while step < vl:
@@ -14,14 +13,12 @@ def preduce(vl, vec, pred):
                 vec[i] += vec[other]
             elif other_pred:
                 vec[i] = vec[other]
-            pred[i] |= other_pred
         print("   row", step, pred, vec)
     return vec
 
 
 def preducei(vl, vec, pred):
     vec = copy(vec)
-    pred = copy(pred) # must not damage predicate
     step = 1
     ix = list(range(vl)) # indices move rather than copy data
     print(" start", step, pred, vec)
@@ -36,13 +33,11 @@ def preducei(vl, vec, pred):
                 vec[ci] += vec[oi]
             elif other_pred:
                 ix[i] = oi # leave data in-place, copy index instead
-            pred[ci] |= other_pred
         print("   row", step, pred, vec, ix)
     return vec
 
 
 def preduce_yield(vl, vec, pred):
-    pred = copy(pred) # must not damage predicate
     step = 1
     ix = list(range(vl))
     while step < vl:
@@ -56,7 +51,6 @@ def preduce_yield(vl, vec, pred):
                 yield ci, oi
             elif other_pred:
                 ix[i] = oi
-            pred[ci] |= other_pred
 
 
 def preduce_y(vl, vec, pred):
@@ -91,3 +85,42 @@ if __name__ == '__main__':
     print ()
     assert vec == res2
 
+    vec = [1, 2, 3, 4, 9, 5, 6, 8]
+    prd = [0, 0, 0, 0, 1, 1, 1, 1]
+    print (vec)
+    res = preduce(len(vec), vec, prd)
+    print (res)
+    res2 = preducei(len(vec), vec, prd)
+    print (res2)
+    print ()
+    preduce_y(len(vec), vec, prd)
+    print (vec)
+    print ()
+    assert vec == res2
+
+    vec = [1, 2, 3, 4, 9, 5, 6, 8]
+    prd = [0, 1, 0, 0, 0, 1, 0, 1]
+    print (vec)
+    res = preduce(len(vec), vec, prd)
+    print (res)
+    res2 = preducei(len(vec), vec, prd)
+    print (res2)
+    print ()
+    preduce_y(len(vec), vec, prd)
+    print (vec)
+    print ()
+    assert vec == res2
+
+    vec = [1, 2, 3, 4, 9, 5, 6]
+    prd = [1, 0, 1, 1, 0, 0, 1]
+    print (vec)
+    res = preduce(len(vec), vec, prd)
+    print (res)
+    res2 = preducei(len(vec), vec, prd)
+    print (res2)
+    print ()
+    preduce_y(len(vec), vec, prd)
+    print (vec)
+    print ()
+    assert vec == res2
+
-- 
2.30.2