whoops, no ability to add comments in between functions in pseudocode

[openpower-isa.git] / src / openpower / decoder / power_svp64_rm.py

diff --git a/src/openpower/decoder/power_svp64_rm.py b/src/openpower/decoder/power_svp64_rm.py
index a91487e1a9ad950616002916f9fa619a34480217..c052924ddb1c2341b0c7384a0da04ecbb613dad9 100644 (file)
--- a/src/openpower/decoder/power_svp64_rm.py
+++ b/src/openpower/decoder/power_svp64_rm.py
@@ -42,7 +42,8 @@ https://libre-soc.org/openpower/sv/svp64/
 https://libre-soc.org/openpower/sv/ldst/
 
 LD/ST immed:
-00     els     sz dz   normal mode
+00     0       dz els  normal mode (with element-stride)
+00     1       dz rsvd bit-reversed mode
 01     inv     CR-bit  Rc=1: ffirst CR sel
 01     inv     els RC1 Rc=0: ffirst z/nonz
 10     N       dz els  sat mode: N=0/1 u/s
@@ -129,13 +130,15 @@ class SVP64RMModeDecode(Elaboratable):
                     (mode2 == 0) &                 # first 2 bits == 0
                     mode[SVP64MODE.REDUCE] &       # bit 2 == 1
                    (~mode[SVP64MODE.PARALLEL])):   # not parallel mapreduce
-            comb += self.reverse_gear.eq(1)        # theeeen finally, whew
+            comb += self.reverse_gear.eq(mode[SVP64MODE.RG]) # finally, whew
 
         # extract zeroing
         with m.Switch(mode2):
             with m.Case(0): # needs further decoding (LDST no mapreduce)
                 with m.If(is_ldst):
-                    comb += self.pred_sz.eq(mode[SVP64MODE.SZ])
+                    # XXX TODO, work out which of these is most appropriate
+                    # set both? or just the one? or one if LD, the other if ST?
+                    comb += self.pred_sz.eq(mode[SVP64MODE.DZ])
                     comb += self.pred_dz.eq(mode[SVP64MODE.DZ])
                 with m.Elif(mode[SVP64MODE.REDUCE]):
                     with m.If(self.rm_in.subvl == Const(0, 2)): # no SUBVL
@@ -179,8 +182,11 @@ class SVP64RMModeDecode(Elaboratable):
                     with m.If(self.rc_in):
                         comb += els.eq(mode[SVP64MODE.ELS_FFIRST_PRED])
 
+            # Bit-reversed Mode
+            with m.If(mode[SVP64MODE.LDST_BITREV]):
+                comb += self.ldstmode.eq(SVP64LDSTmode.BITREVERSE)
             # RA is vectorised
-            with m.If(self.ldst_ra_vec):
+            with m.Elif(self.ldst_ra_vec):
                 comb += self.ldstmode.eq(SVP64LDSTmode.INDEXED)
             # not element-strided, therefore unit...
             with m.Elif(~els):