aboutsummaryrefslogtreecommitdiff
path: root/qtmips_machine/alu.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'qtmips_machine/alu.cpp')
-rw-r--r--qtmips_machine/alu.cpp8
1 files changed, 4 insertions, 4 deletions
diff --git a/qtmips_machine/alu.cpp b/qtmips_machine/alu.cpp
index 85bc804..912ccf5 100644
--- a/qtmips_machine/alu.cpp
+++ b/qtmips_machine/alu.cpp
@@ -8,15 +8,15 @@ std::uint32_t alu_operate(enum AluOp operation, std::uint32_t s, std::uint32_t t
case ALU_OP_SRL:
return t >> sa;
case ALU_OP_SRA:
- // TODO is this correct implementation? (Shouldn't we be masking top most bit?)
- return (t >> sa) | (t & 0x80000000);
+ // TODO is this correct implementation? (Should we be masking top most bit?)
+ return ((t & 0x7fffffff) >> sa) | (t & 0x80000000);
case ALU_OP_SLLV:
return t << s;
case ALU_OP_SRLV:
return t >> s;
case ALU_OP_SRAV:
- // TODO is this correct implementation? (Shouldn't we be masking top most bit?)
- return (t >> s) | (t & 0x80000000);
+ // TODO is this correct implementation? (Should we be masking top most bit?)
+ return ((t & 0x7fffffff) >> s) | (t & 0x80000000);
case ALU_OP_ADD:
if (s > (0xFFFFFFFF - t))
throw QTMIPS_EXCEPTION(Overflow, "ADD operation overflow/underflow", QString::number(s) + QString(" + ") + QString::number(t));