From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Mon, 29 Aug 2022 11:36:33 +0000 (+0100)
Subject: add setvl and other sv* management instructions to the list
X-Git-Tag: sv_maxu_works-initial~68
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=e498d63a77f30366c0b47167afff105d2c6f0e2b;p=openpower-isa.git

add setvl and other sv* management instructions to the list
for which OE is ignored.
https://bugs.libre-soc.org/show_bug.cgi?id=914
really the solution here is to add a new CSV column, OE
---

diff --git a/src/openpower/decoder/isa/caller.py b/src/openpower/decoder/isa/caller.py
index 03db3ff7..5ab5a06a 100644
--- a/src/openpower/decoder/isa/caller.py
+++ b/src/openpower/decoder/isa/caller.py
@@ -1439,7 +1439,7 @@ class ISACaller(ISACallerHelper, ISAFPHelpers):
             else:
                 ov_en = False
                 ov_ok = False
-            log("internal overflow", overflow, ov_en, ov_ok)
+            log("internal overflow", ins_name, overflow, "en?", ov_en, ov_ok)
             if ov_en & ov_ok:
                 yield from self.handle_overflow(inputs, results, overflow)
 
diff --git a/src/openpower/decoder/power_decoder2.py b/src/openpower/decoder/power_decoder2.py
index fc1d35b0..70258d78 100644
--- a/src/openpower/decoder/power_decoder2.py
+++ b/src/openpower/decoder/power_decoder2.py
@@ -576,10 +576,18 @@ class DecodeOE(Elaboratable):
         comb = m.d.comb
         op = self.op
 
+        # default: clear OE.
+        comb += self.oe_out.data.eq(0)
+        comb += self.oe_out.ok.eq(0)
+
         with m.Switch(op.internal_op):
 
             # mulhw, mulhwu, mulhd, mulhdu - these *ignore* OE
-            # also rotate
+            # also rotate.  and setvl and all other sv* management
+            # basically the HDL below bypasses normal decode and
+            # goes directly and explicitly to bit 30 (self.dec.OE).
+            # on the list of instructions below (really this should
+            # be in the CSV files) they must be told *not* to do that.
             # XXX ARGH! ignoring OE causes incompatibility with microwatt
             # http://lists.libre-soc.org/pipermail/libre-soc-dev/2020-August/000302.html
             with m.Case(MicrOp.OP_MUL_H64, MicrOp.OP_MUL_H32,
@@ -587,6 +595,9 @@ class DecodeOE(Elaboratable):
                         MicrOp.OP_SHL, MicrOp.OP_SHR, MicrOp.OP_RLC,
                         MicrOp.OP_LOAD, MicrOp.OP_STORE,
                         MicrOp.OP_RLCL, MicrOp.OP_RLCR,
+                        MicrOp.OP_SETVL, MicrOp.OP_SVSHAPE,
+                        MicrOp.OP_SVINDEX, MicrOp.OP_SVREMAP,
+                        MicrOp.OP_SVSTEP,
                         MicrOp.OP_EXTSWSLI, MicrOp.OP_GREV, MicrOp.OP_TERNLOG):
                 pass