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author | Chih-Min Chao <chihmin.chao@sifive.com> | 2020-06-08 00:36:37 -0700 |
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committer | Chih-Min Chao <chihmin.chao@sifive.com> | 2020-06-10 11:40:57 -0700 |
commit | fefd356697bbbe732c22b0e6dc6121b8aeca2946 (patch) | |
tree | 71eb390d092e7615e3ddcbd204a5760372fbe35a /customext/dummy_rocc.cc | |
parent | 33a6eb57564c257037780ddd2691ca621c44a55b (diff) | |
download | riscv-isa-sim-fefd356697bbbe732c22b0e6dc6121b8aeca2946.zip riscv-isa-sim-fefd356697bbbe732c22b0e6dc6121b8aeca2946.tar.gz riscv-isa-sim-fefd356697bbbe732c22b0e6dc6121b8aeca2946.tar.bz2 |
ext: rename libdummy_rocc by libcustomext
make library name general for multiple custom extension built in one
shared library.
Signed-off-by: Chih-Min Chao <chihmin.chao@sifive.com>
Diffstat (limited to 'customext/dummy_rocc.cc')
-rw-r--r-- | customext/dummy_rocc.cc | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/customext/dummy_rocc.cc b/customext/dummy_rocc.cc new file mode 100644 index 0000000..85ab7aa --- /dev/null +++ b/customext/dummy_rocc.cc @@ -0,0 +1,47 @@ +#include "rocc.h" +#include "mmu.h" +#include <cstring> + +class dummy_rocc_t : public rocc_t +{ + public: + const char* name() { return "dummy_rocc"; } + + reg_t custom0(rocc_insn_t insn, reg_t xs1, reg_t xs2) + { + reg_t prev_acc = acc[insn.rs2]; + + if (insn.rs2 >= num_acc) + illegal_instruction(); + + switch (insn.funct) + { + case 0: // acc <- xs1 + acc[insn.rs2] = xs1; + break; + case 1: // xd <- acc (the only real work is the return statement below) + break; + case 2: // acc[rs2] <- Mem[xs1] + acc[insn.rs2] = p->get_mmu()->load_uint64(xs1); + break; + case 3: // acc[rs2] <- accX + xs1 + acc[insn.rs2] += xs1; + break; + default: + illegal_instruction(); + } + + return prev_acc; // in all cases, xd <- previous value of acc[rs2] + } + + dummy_rocc_t() + { + memset(acc, 0, sizeof(acc)); + } + + private: + static const int num_acc = 4; + reg_t acc[num_acc]; +}; + +REGISTER_EXTENSION(dummy_rocc, []() { return new dummy_rocc_t; }) |