From 1ece0cc3abbea9b39df6b58e4bb07b158f556caf Mon Sep 17 00:00:00 2001
From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Sat, 23 Dec 2023 17:38:59 +0000
Subject: [PATCH] bug 1155: add new idea by jacob to do x+y+z mode for bigmul
 remap

---
 src/openpower/decoder/isa/remapyield.py | 49 +++++++++++++++++--------
 1 file changed, 33 insertions(+), 16 deletions(-)

diff --git a/src/openpower/decoder/isa/remapyield.py b/src/openpower/decoder/isa/remapyield.py
index d7b4bdef..82eb13b8 100644
--- a/src/openpower/decoder/isa/remapyield.py
+++ b/src/openpower/decoder/isa/remapyield.py
@@ -51,9 +51,11 @@ def iterate_indices(SVSHAPE):
                         # those to be knocked out
                         if SVSHAPE.skip == i+1: continue
                         #print ("select %d %s" % (i, dbg))
-                        idx *= mult   # shifts up by previous dimension(s)
+                        if SVSHAPE.mode == 0b00:
+                            idx *= mult   # shifts up by previous dimension(s)
                         result += idx # adds on this dimension
-                        mult *= lim   # for the next dimension
+                        if SVSHAPE.mode == 0b00:
+                            mult *= lim   # for the next dimension
 
                     loopends = (x_end |
                                ((y_end and x_end)<<1) |
@@ -64,18 +66,25 @@ def iterate_indices(SVSHAPE):
                     yield result + SVSHAPE.offset, loopends
                     step += 1
 
+def dump_shape(SVSHAPE0):
+    # enumerate over the iterator function, getting new indices
+    for idx, (new_idx, end) in enumerate(iterate_indices(SVSHAPE0)):
+        estring = bin(end)[2:] if end else ''
+        print ("%2d->%-2d" % (idx, new_idx), "%2s" % estring, end=' ')
+        if end != 0:
+            print()
+        if end == 0b111:
+            break
+
+
 def demo():
-    # set the dimension sizes here
-    xdim = 3
-    ydim = 2
-    zdim = 4
+    xdim, ydim, zdim = 3, 2, 4 # set the dimension sizes here
+    VL = xdim * ydim * zdim    # set total (can repeat, e.g. VL=x*y*z*4)
 
-    # set total (can repeat, e.g. VL=x*y*z*4)
-    VL = xdim * ydim * zdim
+    class SVSHAPE: pass # dummy class
 
-    # set up an SVSHAPE
-    class SVSHAPE:
-        pass
+    # set up an SVSHAPE with matrix mode
+    print("matrix", xdim, ydim, zdim)
     SVSHAPE0 = SVSHAPE()
     SVSHAPE0.lims = [xdim, ydim, zdim]
     SVSHAPE0.order = [1,0,2]  # experiment with different permutations, here
@@ -84,11 +93,19 @@ def demo():
     SVSHAPE0.offset = 0       # experiment with different offset, here
     SVSHAPE0.invxyz = [0,0,0] # inversion if desired
 
-    # enumerate over the iterator function, getting new indices
-    for idx, (new_idx, end) in enumerate(iterate_indices(SVSHAPE0)):
-        if idx >= VL:
-            break
-        print ("%d->%d" % (idx, new_idx), "end", bin(end)[2:])
+    dump_shape(SVSHAPE0)
+
+    # rhombus - see https://bugs.libre-soc.org/show_bug.cgi?id=1155#c17
+    print("\ntriangular, skip-x", xdim, ydim, zdim)
+    SVSHAPE0 = SVSHAPE()
+    SVSHAPE0.lims = [xdim, ydim, zdim]
+    SVSHAPE0.order = [0,1,2]  # experiment with different permutations, here
+    SVSHAPE0.mode = 0b11
+    SVSHAPE0.skip = 0b01      # try skipping x-dimension (for fun)
+    SVSHAPE0.offset = 0       # experiment with different offset, here
+    SVSHAPE0.invxyz = [0,0,0] # inversion if desired
+
+    dump_shape(SVSHAPE0)
 
 # run the demo
 if __name__ == '__main__':
-- 
2.30.2