From 8f5d6f46e3c17e94717db22766ccd7a5451f3f62 Mon Sep 17 00:00:00 2001
From: lkcl <lkcl@web>
Date: Fri, 14 Apr 2023 18:30:07 +0100
Subject: [PATCH]

---
 openpower/sv/svstep.mdwn | 110 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 109 insertions(+), 1 deletion(-)

diff --git a/openpower/sv/svstep.mdwn b/openpower/sv/svstep.mdwn
index e080bbe4d..4a5fc363d 100644
--- a/openpower/sv/svstep.mdwn
+++ b/openpower/sv/svstep.mdwn
@@ -153,13 +153,121 @@ not normally found in Vector ISAs.
     if SVi = 6 then return SVSTATE.dststep
     if SVi = 7 then return SVSTATE.ssubstep # SUBVL source step
     if SVi = 8 then return SVSTATE.dsubstep # SUBVL dest step
-    ADVANCE_STEPS()
+    # SVi=0, explicit iteration requezted
+    src_iterate();
+    dst_iterate();
     return 0
 ```
 
 **ADVANCE_STEPS**
 
 ```
+    def src_iterate(): # source-stepping iterator
+        subvl = self.subvl
+        vl = self.svstate.vl
+        pack = self.svstate.pack
+        unpack = self.svstate.unpack
+        ssubstep = self.svstate.ssubstep
+        end_ssub = ssubstep == subvl
+        end_src = self.svstate.srcstep == vl-1
+        # first source step
+        srcstep = self.svstate.srcstep
+        srcmask = self.srcmask
+        if pack:
+            # pack advances subvl in *outer* loop
+            while True:
+                assert srcstep <= vl-1
+                end_src = srcstep == vl-1
+                if end_src:
+                    if end_ssub:
+                        self.loopend = True
+                    else:
+                        self.svstate.ssubstep += SelectableInt(1, 2)
+                    srcstep = 0  # reset
+                    break
+                else:
+                    srcstep += 1  # advance srcstep
+                    if not self.srcstep_skip:
+                        break
+                    if ((1 << srcstep) & srcmask) != 0:
+                        break
+        else:
+            # advance subvl in *inner* loop
+            if end_ssub:
+                while True:
+                    assert srcstep <= vl-1
+                    end_src = srcstep == vl-1
+                    if end_src:  # end-point
+                        self.loopend = True
+                        srcstep = 0
+                        break
+                    else:
+                        srcstep += 1
+                    if not self.srcstep_skip:
+                        break
+                    if ((1 << srcstep) & srcmask) != 0:
+                        break
+                    else:
+                        log("      sskip", bin(srcmask), bin(1 << srcstep))
+                self.svstate.ssubstep = SelectableInt(0, 2)  # reset
+            else:
+                # advance ssubstep
+                self.svstate.ssubstep += SelectableInt(1, 2)
+
+        self.svstate.srcstep = SelectableInt(srcstep, 7)
+
+    def dst_iterate(): # dest step iterator
+        vl = self.svstate.vl
+        subvl = self.subvl
+        pack = self.svstate.pack
+        unpack = self.svstate.unpack
+        dsubstep = self.svstate.dsubstep
+        end_dsub = dsubstep == subvl
+        dststep = self.svstate.dststep
+        end_dst = dststep == vl-1
+        dstmask = self.dstmask
+        # now dest step
+        if unpack:
+            # unpack advances subvl in *outer* loop
+            while True:
+                assert dststep <= vl-1
+                end_dst = dststep == vl-1
+                if end_dst:
+                    if end_dsub:
+                        self.loopend = True
+                    else:
+                        self.svstate.dsubstep += SelectableInt(1, 2)
+                    dststep = 0  # reset
+                    break
+                else:
+                    dststep += 1  # advance dststep
+                    if not self.dststep_skip:
+                        break
+                    if ((1 << dststep) & dstmask) != 0:
+                        break
+        else:
+            # advance subvl in *inner* loop
+            if end_dsub:
+                while True:
+                    assert dststep <= vl-1
+                    end_dst = dststep == vl-1
+                    if end_dst:  # end-point
+                        self.loopend = True
+                        dststep = 0
+                        break
+                    else:
+                        dststep += 1
+                    if not self.dststep_skip:
+                        break
+                    if ((1 << dststep) & dstmask) != 0:
+                        break
+                self.svstate.dsubstep = SelectableInt(0, 2)  # reset
+            else:
+                # advance ssubstep
+                self.svstate.dsubstep += SelectableInt(1, 2)
+
+        self.svstate.dststep = SelectableInt(dststep, 7)
+
 ```
 
 [[!tag standards]]
-- 
2.30.2