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| author | Julian Blake Kongslie | 2022-10-31 19:03:38 -0700 |
|---|---|---|
| committer | Julian Blake Kongslie | 2022-10-31 19:03:38 -0700 |
| commit | 82c461307eba25265867f233a27060621ac6cba4 (patch) | |
| tree | dc6d0bb8ce85b1861146abf13183140e45476c23 /isa/decode.cpp | |
| parent | Fix echo_optimal (was not resetting AC on all loop iterations) (diff) | |
| download | biggolf-82c461307eba25265867f233a27060621ac6cba4.tar.xz | |
TAD is 12-bit addition with carry-complements-link, not 13-bit addition
Diffstat (limited to '')
| -rw-r--r-- | isa/decode.cpp | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/isa/decode.cpp b/isa/decode.cpp index c35118b..af38c64 100644 --- a/isa/decode.cpp +++ b/isa/decode.cpp | |||
| @@ -34,8 +34,8 @@ instruction_context decode(unsigned int dfifb, unsigned int pc, unsigned int bit | |||
| 34 | inst.need_write_acc = true; | 34 | inst.need_write_acc = true; |
| 35 | inst.need_write_link = true; | 35 | inst.need_write_link = true; |
| 36 | inst.ef = [](auto &ctx) { | 36 | inst.ef = [](auto &ctx) { |
| 37 | unsigned int sum = (ctx.link.value() << 12) + ctx.acc.value() + ctx.data.value(); | 37 | unsigned int sum = ctx.acc.value() + ctx.data.value(); |
| 38 | ctx.link = (sum >> 12) & 1; | 38 | ctx.link = ctx.link.value() ^ (sum >> 12); |
| 39 | ctx.acc = sum & 07777; | 39 | ctx.acc = sum & 07777; |
| 40 | }; | 40 | }; |
| 41 | break; | 41 | break; |