Don't mask instruction bits

No longer needed, since they are no longer sign-extended.

Fixes #1022 by eliminating undefined behavior (64-bit instructions
resulted in a shift amount equal to the datatype width).

2 files changed, 2 insertions, 2 deletions

diff --git a/riscv/decode.h b/riscv/decode.h
index d56d496..72b4a6b 100644
--- a/riscv/decode.h
+++ b/riscv/decode.h
@@ -79,7 +79,7 @@ class insn_t
 public:
   insn_t() = default;
   insn_t(insn_bits_t bits) : b(bits) {}
-  insn_bits_t bits() { return b & ~((UINT64_MAX) << (length() * 8)); }
+  insn_bits_t bits() { return b; }
   int length() { return insn_length(b); }
   int64_t i_imm() { return xs(20, 12); }
   int64_t shamt() { return x(20, 6); }
diff --git a/riscv/processor.cc b/riscv/processor.cc
index bb41248..c4ca0bc 100644
--- a/riscv/processor.cc
+++ b/riscv/processor.cc
@@ -796,7 +796,7 @@ void processor_t::take_trap(trap_t& t, reg_t epc)
 
 void processor_t::disasm(insn_t insn)
 {
-  uint64_t bits = insn.bits() & ((1ULL << (8 * insn_length(insn.bits()))) - 1);
+  uint64_t bits = insn.bits();
   if (last_pc != state.pc || last_bits != bits) {
     std::stringstream s;  // first put everything in a string, later send it to output