-TODO
+# LD/ST-Update-PostIncrement
+
+TODO (key stub notes below)
* <https://bugs.libre-soc.org/show_bug.cgi?id=1048>
+The following instructions are proposed to be added in EXT2xx,
+duplicating LD/ST-Update functionality but moving the update
+of RA to *after* the Memory operation. These types of
+instructions are already present in x86 (sort-of).
+
+* x86 chose that store should be pre-indexed and load should be post-indexed
+* Power ISA chose everything to be pre-indexed
+
+<https://azeria-labs.com/memory-instructions-load-and-store-part-4/>
+
+
+```
+# LD/ST-Postincrement
+lbzup, ls011, high, PO, yes, EXT2xx, no, isa/pifixedload, 1R2W
+lbzupx, ls011, high, 10, yes, EXT2xx, no, isa/pifixedload, 2R2W
+lhzup, ls011, high, PO, yes, EXT2xx, no, isa/pifixedload, 1R2W
+lhzupx, ls011, high, 10, yes, EXT2xx, no, isa/pifixedload, 2R2W
+lhaup, ls011, high, PO, yes, EXT2xx, no, isa/pifixedload, 1R2W
+lhaupx, ls011, high, 10, yes, EXT2xx, no, isa/pifixedload, 2R2W
+lwzup, ls011, high, PO, yes, EXT2xx, no, isa/pifixedload, 1R2W
+lwzupx, ls011, high, 10, yes, EXT2xx, no, isa/pifixedload, 2R2W
+lwaupx, ls011, high, 10, yes, EXT2xx, no, isa/pifixedload, 2R2W
+ldup, ls011, high, PO, yes, EXT2xx, no, isa/pifixedload, 1R2W
+ldupx, ls011, high, 10, yes, EXT2xx, no, isa/pifixedload, 2R2W
+stbup, ls011, high, PO, yes, EXT2xx, no, isa/pifixedstore, 2R1W
+stbupx, ls011, high, 10, yes, EXT2xx, no, isa/pifixedstore, 3R1W
+sthup, ls011, high, PO, yes, EXT2xx, no, isa/pifixedstore, 2R1W
+sthupx, ls011, high, 10, yes, EXT2xx, no, isa/pifixedstore, 3R1W
+stwup, ls011, high, PO, yes, EXT2xx, no, isa/pifixedstore, 2R1W
+stwupx, ls011, high, 10, yes, EXT2xx, no, isa/pifixedstore, 3R1W
+stdup, ls011, high, PO, yes, EXT2xx, no, isa/pifixedstore, 2R1W
+stdupx, ls011, high, 10, yes, EXT2xx, no, isa/pifixedstore, 3R1W
+# FP LD/ST-Postincrement
+lfdu, ls011, high, PO, yes, EXT2xx, no, isa/pifixedload, 1R2W
+lfsu, ls011, high, PO, yes, EXT2xx, no, isa/pifixedload, 1R2W
+lfdux, ls011, high, 10, yes, EXT2xx, no, isa/pifixedload, 2R2W
+lsdux, ls011, high, 10, yes, EXT2xx, no, isa/pifixedload, 2R2W
+stfdu, ls011, high, PO, yes, EXT2xx, no, isa/pifixedstore, 2R1W
+stfsu, ls011, high, PO, yes, EXT2xx, no, isa/pifixedstore, 2R1W
+stfdux, ls011, high, 10, yes, EXT2xx, no, isa/pifixedstore, 3R1W
+stfsux, ls011, high, 10, yes, EXT2xx, no, isa/pifixedstore, 3R1W
+```
+
+# Example
+
+** Load Byte and Zero with Post-Update**
+
+D-Form
+
+* lbzup RT,D(RA)
+
+Pseudo-code:
+
+```
+ EA <- (RA)
+ RT <- ([0] * (XLEN-8)) || MEM(EA, 1)
+ RA <- (RA) + EXTS(D)
+```
+
+Special Registers Altered:
+
+```
+ None
+```
+
+where the same pseudocode for `lbzu` is:
+
+```
+ EA <- (RA) + EXTS(D)
+ RT <- ([0] * (XLEN-8)) || MEM(EA, 1)
+ RA <- EA
+```
+
[[!tag opf_rfc]]