sim: bfin: tweak saturation handling with TFU/FU modes and MM bit

This too should have been squashed into an earlier change.  It covers
a few more cases in the V/VS saturation patch when working with TFU
and FU modes of dsp insns.

Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

diff --git a/sim/bfin/ChangeLog b/sim/bfin/ChangeLog
index 31efa11..5033c22 100644 (file)
--- a/sim/bfin/ChangeLog
+++ b/sim/bfin/ChangeLog
@@ -1,5 +1,10 @@
 2011-06-18  Robin Getz  <robin.getz@analog.com>
 
+       * bfin-sim.c (decode_macfunc): Handle MM when mmod is M_TFU.
+       Check MM once when mmod is M_FU to match M_TFU better.
+
+2011-06-18  Robin Getz  <robin.getz@analog.com>
+
        * bfin-sim.c (decode_dsp32shiftimm_0): When shift is greater than
        32, perform a left shift.  Update the corresponding AV bit.  Set
        AZ when the low 32bits are also zero.

diff --git a/sim/bfin/bfin-sim.c b/sim/bfin/bfin-sim.c
index b982aaf..20602b7 100644 (file)
--- a/sim/bfin/bfin-sim.c
+++ b/sim/bfin/bfin-sim.c
@@ -1617,10 +1617,20 @@ decode_macfunc (SIM_CPU *cpu, int which, int op, int h0, int h1, int src0,
            acc = 0x7fffffffffull, sat = 1;
          break;
        case M_TFU:
-         if (!MM && (bs64)acc < 0)
-           acc = 0, sat = 1;
-         if (!MM && (bs64)acc > 0xFFFFFFFFFFull)
-           acc = 0xFFFFFFFFFFull, sat = 1;
+         if (MM)
+           {
+             if ((bs64)acc < -((bs64)1 << 39))
+               acc = -((bu64)1 << 39), sat = 1;
+             if ((bs64)acc > 0x7FFFFFFFFFll)
+               acc = 0x7FFFFFFFFFull, sat = 1;
+           }
+         else
+           {
+             if ((bs64)acc < 0)
+               acc = 0, sat = 1;
+             if ((bs64)acc > 0xFFFFFFFFFFull)
+               acc = 0xFFFFFFFFFFull, sat = 1;
+           }
          break;
        case M_IU:
          if (!MM && acc & 0x8000000000000000ull)
@@ -1633,16 +1643,22 @@ decode_macfunc (SIM_CPU *cpu, int which, int op, int h0, int h1, int src0,
            acc |= 0xffffff0000000000ull;
          break;
        case M_FU:
-         if (!MM && (bs64)acc < 0)
-           acc = 0x0, sat = 1;
-         if (MM && (bs64)acc < -((bs64)1 << 39))
-           acc = -((bu64)1 << 39), sat = 1;
-         if (!MM && (bs64)acc > (bs64)0xFFFFFFFFFFll)
-           acc = 0xFFFFFFFFFFull, sat = 1;
-         if (MM && acc > 0xFFFFFFFFFFull)
-           acc &= 0xFFFFFFFFFFull;
-         if (MM && acc & 0x8000000000ull)
-           acc |= 0xffffff0000000000ull;
+         if (MM)
+           {
+             if ((bs64)acc < -((bs64)1 << 39))
+               acc = -((bu64)1 << 39), sat = 1;
+             if ((bs64)acc > 0x7FFFFFFFFFll)
+               acc = 0x7FFFFFFFFFull, sat = 1;
+             else if (acc & 0x8000000000ull)
+               acc |= 0xffffff0000000000ull;
+           }
+         else
+           {
+             if ((bs64)acc < 0)
+               acc = 0x0, sat = 1;
+             else if ((bs64)acc > (bs64)0xFFFFFFFFFFll)
+               acc = 0xFFFFFFFFFFull, sat = 1;
+           }
          break;
        case M_IH:
          if ((bs64)acc < -0x80000000ll)