From: lkcl <lkcl@web>
Date: Sun, 3 Jul 2022 10:12:26 +0000 (+0100)
Subject: (no commit message)
X-Git-Tag: opf_rfc_ls005_v1~1395
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=b4ae726faeddb30958a8e90f85e4e9dd3cfdc566;p=libreriscv.git

---

diff --git a/openpower/sv/setvl.mdwn b/openpower/sv/setvl.mdwn
index a93fceaf2..d6cb15dc0 100644
--- a/openpower/sv/setvl.mdwn
+++ b/openpower/sv/setvl.mdwn
@@ -189,92 +189,9 @@ calling of functions, however SVSTATE (and any associated SVSTATE) should be sto
 
 Sub-vector elements are not be considered "Vertical". The vec2/3/4
 is to be considered as if the "single element".  Caveats exist for
-[[sv/mv.swizzle]] and [[sv/mv.vec]] when Pack/Unpack is enabled.
-
-# Pseudocode
-
-    // instruction fields:
-    rd = get_rt_field();         // bits 6..10
-    ra = get_ra_field();         // bits 11..15
-    vf = get_vf_field();         // bit 23
-    vs = get_vs_field();         // bit 24
-    ms = get_ms_field();         // bit 25
-    Rc = get_Rc_field();         // bit 31
-
-    if vf and not vs and not ms {
-        // increment src/dest step mode
-        // NOTE! this is in no way complete! predication is not included
-        // and neither is SUBVL mode
-        srcstep = SPR[SV].srcstep
-        dststep = SPR[SV].dststep
-        VL = SPR[SV].VL
-        srcstep++
-        dststep++
-        rollover = (srcstep == VL or dststep == VL)
-        if rollover:
-            // Reset srcstep, dststep, and also exit "Vertical First" mode
-            srcstep = 0
-            dststep = 0
-            MSR[6] = 0
-        SPR[SV].srcstep = srcstep
-        SPR[SV].dststep = dststep
-
-        // write CR? helps for doing Vertical loops, detects end
-        // of Vector Elements
-        if Rc = 1 {
-            // update CR to indicate that srcstep/dststep "rolled over"
-            CR0.eq = rollover
-        }
-    } else {
-        // add one. MVL/VL=1..64 not 0..63
-        vlimmed = get_immed_field()+1; //  16..22
-
-        // set VL (or not).
-        // 4 options: from SPR, from immed, from ra, from CTR
-        if vs {
-           // VL to be sourced from fields/regs
-           if ra != 0 {
-               VL = GPR[ra]
-           } else {
-               VL = vlimmed
-           }
-        } else {
-           // VL not to change (except if MVL is reduced)
-           // read from SPRs
-           VL = SPR[SV_VL]
-        }
-
-        // set MVL (or not).
-        // 2 options: from SPR, from immed
-        if ms {
-           MVL = vlimmed
-        } else {
-           // MVL not to change, read from SPRs
-           MVL = SPR[SV_MVL]
-        }
-
-        // calculate (limit) VL
-        VL = min(VL, MVL)
-
-        // store VL, MVL
-        SVSTATE.VL = VL
-        SVSTATE.MVL = MVL
-
-        // write rd
-        if rt != 0 {
-            // rt is not zero
-            regs[rt] = VL;
-        }
-        // write CR?
-        if Rc = 1 {
-            // update CR from VL (not rt)
-            CR0.eq = (VL == 0)
-            ...
-            ...
-        }
-        // write Vertical-First mode
-        SVSTATE.vf = vf
-    }
+[[sv/mv.swizzle]] and [[sv/mv.vec]] when Pack/Unpack is enabled,
+due to the order in which VL and SUBVL loops are applied being
+swapped (outer-inner becomes inner-outer)
 
 # Examples