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| author | Eddie Hung <eddie@fpgeh.com> | 2019-08-01 10:00:49 -0700 |
|---|---|---|
| committer | Eddie Hung <eddie@fpgeh.com> | 2019-08-01 10:00:49 -0700 |
| commit | c54a39069d1f536da7a830fa2fa504bc72c20c18 (patch) | |
| tree | cba5574162edda2da40ff34c2dfa8583fa70d19c /passes/pmgen | |
| parent | e3c39cc450a0317ad7e8234bb866d55465548c9c (diff) | |
| download | yosys-c54a39069d1f536da7a830fa2fa504bc72c20c18.tar.gz yosys-c54a39069d1f536da7a830fa2fa504bc72c20c18.tar.bz2 yosys-c54a39069d1f536da7a830fa2fa504bc72c20c18.zip | |
CO is sign extension only if signed multiplier
Diffstat (limited to 'passes/pmgen')
| -rw-r--r-- | passes/pmgen/ice40_dsp.cc | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/passes/pmgen/ice40_dsp.cc b/passes/pmgen/ice40_dsp.cc index 00794ca0d..f88cd62dd 100644 --- a/passes/pmgen/ice40_dsp.cc +++ b/passes/pmgen/ice40_dsp.cc @@ -147,7 +147,12 @@ void create_ice40_dsp(ice40_dsp_pm &pm) int O_width = GetSize(O); if (O_width == 33) { log_assert(st.addAB); - cell->setPort("\\CO", O[-1]); + // If we have a signed multiply-add, then perform sign extension + // TODO: Need to check CD[31:16] is sign extension of CD[15:0]? + if (st.addAB->getParam("\\A_SIGNED").as_bool() && st.addAB->getParam("\\B_SIGNED").as_bool()) + pm.module->connect(O[-1], O[-2]); + else + cell->setPort("\\CO", O[-1]); O.remove(O_width-1); } else |