X-Git-Url: https://git.libre-soc.org/?p=soc.git;a=blobdiff_plain;f=src%2Fsoc%2Fdecoder%2Fisa%2Fcaller.py;h=488df5ceeaa88289edbb157ccf6ab622060e4266;hp=b3b2c17132db8afbc299e8ee50f23e18635f884f;hb=0c3689e8f95c8b2d08100055c9b9c3711d366f1c;hpb=6891172f1bffde3f2b322a9151c21964b8f6f35d

diff --git a/src/soc/decoder/isa/caller.py b/src/soc/decoder/isa/caller.py
index b3b2c171..488df5ce 100644
--- a/src/soc/decoder/isa/caller.py
+++ b/src/soc/decoder/isa/caller.py
@@ -9,7 +9,8 @@ from functools import wraps
 from soc.decoder.orderedset import OrderedSet
 from soc.decoder.selectable_int import (FieldSelectableInt, SelectableInt,
                                         selectconcat)
-from soc.decoder.power_enums import spr_dict, XER_bits, insns, InternalOp
+from soc.decoder.power_enums import (spr_dict, spr_byname, XER_bits,
+                                     insns, InternalOp)
 from soc.decoder.helpers import exts, trunc_div, trunc_rem
 from collections import namedtuple
 import math
@@ -186,7 +187,14 @@ class SPR(dict):
     def __init__(self, dec2, initial_sprs={}):
         self.sd = dec2
         dict.__init__(self)
-        self.update(initial_sprs)
+        for key, v in initial_sprs.items():
+            if isinstance(key, SelectableInt):
+                key = key.value
+            key = special_sprs.get(key, key)
+            info = spr_byname[key]
+            if not isinstance(v, SelectableInt):
+                v = SelectableInt(v, info.length)
+            self[key] = v
 
     def __getitem__(self, key):
         # if key in special_sprs get the special spr, otherwise return key
@@ -271,7 +279,9 @@ class ISACaller:
         # "undefined", just set to variable-bit-width int (use exts "max")
         self.undefined = SelectableInt(0, 256) # TODO, not hard-code 256!
 
-        self.namespace = {'GPR': self.gpr,
+        self.namespace = {}
+        self.namespace.update(self.spr)
+        self.namespace.update({'GPR': self.gpr,
                           'MEM': self.mem,
                           'SPR': self.spr,
                           'memassign': self.memassign,
@@ -282,7 +292,8 @@ class ISACaller:
                           'undefined': self.undefined,
                           'mode_is_64bit': True,
                           'SO': XER_bits['SO']
-                          }
+                          })
+
 
         # field-selectable versions of Condition Register TODO check bitranges?
         self.crl = []
@@ -365,7 +376,7 @@ class ISACaller:
         if not (2 & already_done):
             self.spr['XER'][XER_bits['CA32']] = cy32
 
-    def handle_overflow(self, inputs, outputs):
+    def handle_overflow(self, inputs, outputs, div_overflow):
         inv_a = yield self.dec2.e.invert_a
         if inv_a:
             inputs[0] = ~inputs[0]
@@ -375,8 +386,16 @@ class ISACaller:
             imm = yield self.dec2.e.imm_data.data
             inputs.append(SelectableInt(imm, 64))
         assert len(outputs) >= 1
-        print ("handle_overflow", inputs, outputs)
-        if len(inputs) >= 2:
+        print ("handle_overflow", inputs, outputs, div_overflow)
+        if len(inputs) < 2 and div_overflow != 1:
+            return
+
+        # div overflow is different: it's returned by the pseudo-code
+        # because it's more complex than can be done by analysing the output
+        if div_overflow == 1:
+            ov, ov32 = 1, 1
+        # arithmetic overflow can be done by analysing the input and output
+        elif len(inputs) >= 2:
             output = outputs[0]
 
             # OV (64-bit)
@@ -391,11 +410,11 @@ class ISACaller:
             ov32 = 1 if input32_sgn[0] == input32_sgn[1] and \
                 output32_sgn != input32_sgn[0] else 0
 
-            self.spr['XER'][XER_bits['OV']] = ov
-            self.spr['XER'][XER_bits['OV32']] = ov32
-            so = self.spr['XER'][XER_bits['SO']]
-            so = so | ov
-            self.spr['XER'][XER_bits['SO']] = so
+        self.spr['XER'][XER_bits['OV']] = ov
+        self.spr['XER'][XER_bits['OV32']] = ov32
+        so = self.spr['XER'][XER_bits['SO']]
+        so = so | ov
+        self.spr['XER'][XER_bits['SO']] = so
 
     def handle_comparison(self, outputs):
         out = outputs[0]
@@ -527,10 +546,20 @@ class ISACaller:
         carry_en = yield self.dec2.e.output_carry
         if carry_en:
             yield from self.handle_carry_(inputs, results, already_done)
+
+        # detect if overflow was in return result
+        overflow = None
+        if info.write_regs:
+            for name, output in zip(output_names, results):
+                if name == 'overflow':
+                    overflow = output
+
         ov_en = yield self.dec2.e.oe.oe
         ov_ok = yield self.dec2.e.oe.ok
+        print ("internal overflow", overflow)
         if ov_en & ov_ok:
-            yield from self.handle_overflow(inputs, results)
+            yield from self.handle_overflow(inputs, results, overflow)
+
         rc_en = yield self.dec2.e.rc.data
         if rc_en:
             self.handle_comparison(results)
@@ -538,6 +567,8 @@ class ISACaller:
         # any modified return results?
         if info.write_regs:
             for name, output in zip(output_names, results):
+                if name == 'overflow': # ignore, done already (above)
+                    continue
                 if isinstance(output, int):
                     output = SelectableInt(output, 256)
                 if name in ['CA', 'CA32']: