For "msbu", subtract unsigned product from ACC,

[deliverable/binutils-gdb.git] / sim / d10v / simops.c

diff --git a/sim/d10v/simops.c b/sim/d10v/simops.c
index 222d2d4f67654429ff66398846996854c464d42c..64c8a33f1efef8de4f1d56bb02174b3ec1aa64e4 100644 (file)
--- a/sim/d10v/simops.c
+++ b/sim/d10v/simops.c
@@ -1352,13 +1352,17 @@ OP_1A00 ()
 void
 OP_3A00 ()
 {
-  int64 tmp;
+  uint64 tmp;
+  uint32 src1;
+  uint32 src2;
 
   trace_input ("macu", OP_ACCUM, OP_REG, OP_REG);
-  tmp = SEXT40 (State.regs[OP[1]] * State.regs[OP[2]]);
+  src1 = (uint16) State.regs[OP[1]];
+  src2 = (uint16) State.regs[OP[2]];
+  tmp = src1 * src2;
   if (State.FX)
-    tmp = SEXT40( (tmp << 1) & MASK40);
-  State.a[OP[0]] = (SEXT40 (State.a[OP[0]]) + tmp) & MASK40;
+    tmp = (tmp << 1);
+  State.a[OP[0]] = (State.a[OP[0]] + tmp) & MASK40;
   trace_output (OP_ACCUM);
 }
 
@@ -1514,14 +1518,18 @@ OP_1800 ()
 void
 OP_3800 ()
 {
-  int64 tmp;
+  uint64 tmp;
+  uint32 src1;
+  uint32 src2;
 
   trace_input ("msbu", OP_ACCUM, OP_REG, OP_REG);
-  tmp = SEXT40 (State.regs[OP[1]] * State.regs[OP[2]]);
+  src1 = (uint16) State.regs[OP[1]];
+  src2 = (uint16) State.regs[OP[2]];
+  tmp = src1 * src2;
   if (State.FX)
-    tmp = SEXT40( (tmp << 1) & MASK40);
+    tmp = (tmp << 1);
 
-  State.a[OP[0]] = (SEXT40 (State.a[OP[0]]) - tmp) & MASK40;
+  State.a[OP[0]] = (State.a[OP[0]] - tmp) & MASK40;
   trace_output (OP_ACCUM);
 }
 
@@ -1573,11 +1581,14 @@ OP_1C00 ()
 void
 OP_3C00 ()
 {
-  int64 tmp;
+  uint64 tmp;
+  uint32 src1;
+  uint32 src2;
 
   trace_input ("mulxu", OP_ACCUM_OUTPUT, OP_REG, OP_REG);
-  tmp = SEXT40 (State.regs[OP[1]] * State.regs[OP[2]]);
-
+  src1 = (uint16) State.regs[OP[1]];
+  src2 = (uint16) State.regs[OP[2]];
+  tmp = src1 * src2;
   if (State.FX)
     tmp <<= 1;
 
@@ -2483,7 +2494,7 @@ OP_1000 ()
   /* see ../common/sim-alu.h for a more extensive discussion on how to
      compute the carry/overflow bits */
   tmp = a - b;
-  State.C = (a < b);
+  State.C = (a >= b);
   State.regs[OP[0]] = (tmp >> 16) & 0xffff;
   State.regs[OP[0]+1] = tmp & 0xffff;
   trace_output (OP_DREG);
@@ -2585,7 +2596,8 @@ OP_1 ()
 
   trace_input ("subi", OP_REG, OP_CONSTANT16, OP_VOID);
   /* see ../common/sim-alu.h for a more extensive discussion on how to
-     compute the carry/overflow bits */
+     compute the carry/overflow bits. */
+  /* since OP[1] is never <= 0, -OP[1] == ~OP[1]+1 can never overflow */
   tmp = ((unsigned)(unsigned16) State.regs[OP[0]]
         + (unsigned)(unsigned16) ( - OP[1]));
   State.C = (tmp >= (1 << 16));