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[libreriscv.git] / openpower / sv / remap.py

diff --git a/openpower/sv/remap.py b/openpower/sv/remap.py
index 2b5c4f373ee823dd86a78f04fa6748ecf9610c15..4721d8148bed66e907099bfeb5cb66d80b128548 100644 (file)
--- a/openpower/sv/remap.py
+++ b/openpower/sv/remap.py
@@ -1,3 +1,7 @@
+# Finite State Machine version of the REMAP system.  much more likely
+# to end up being actually used in actual hardware
+
+# up to three dimensions permitted
 xdim = 3
 ydim = 2
 zdim = 1
@@ -5,17 +9,21 @@ zdim = 1
 VL = xdim * ydim * zdim # set total (can repeat, e.g. VL=x*y*z*4)
 
 lims = [xdim, ydim, zdim]
-idxs = [0,0,0] # starting indices
-order = [1,0,2] # experiment with different permutations, here
-offset = 0     # experiment with different offsetet, here
-invxyz = [0,1,0]
+idxs = [0,0,0]   # starting indices
+applydim = [1, 1]   # apply lower dims
+order = [1,0,2]  # experiment with different permutations, here
+offset = 0       # experiment with different offsetet, here
+invxyz = [0,1,0] # inversion allowed
 
+# pre-prepare the index state: run for "offset" times before
+# actually starting.  this algorithm can also be used for re-entrancy
+# if exceptions occur and a REMAP has to be started from where the
+# interrupt left off.
 for idx in range(offset):
     for i in range(3):
         idxs[order[i]] = idxs[order[i]] + 1
         if (idxs[order[i]] != lims[order[i]]):
             break
-        print
         idxs[order[i]] = 0
 
 break_count = 0 # for pretty-printing
@@ -26,12 +34,20 @@ for idx in range(VL):
         ix[i] = idxs[i]
         if invxyz[i]:
             ix[i] = lims[i] - 1 - ix[i]
-    new_idx = ix[0] + ix[1] * xdim + ix[2] * xdim * ydim
+    new_idx = ix[2]
+    if applydim[1]:
+        new_idx = new_idx * ydim + ix[1]
+    if applydim[0]:
+        new_idx = new_idx * xdim + ix[0]
     print ("%d->%d" % (idx, new_idx)),
     break_count += 1
     if break_count == lims[order[0]]:
         print ("")
         break_count = 0
+    # this is the exact same thing as the pre-preparation stage
+    # above.  step 1: count up to the limit of the current dimension
+    # step 2: if limit reached, zero it, and allow the *next* dimension
+    # to increment.  repeat for 3 dimensions.
     for i in range(3):
         idxs[order[i]] = idxs[order[i]] + 1
         if (idxs[order[i]] != lims[order[i]]):