diff options
Diffstat (limited to 'passes/pmgen/xilinx_dsp.pmg')
| -rw-r--r-- | passes/pmgen/xilinx_dsp.pmg | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/passes/pmgen/xilinx_dsp.pmg b/passes/pmgen/xilinx_dsp.pmg index 604aa222b..0ba529011 100644 --- a/passes/pmgen/xilinx_dsp.pmg +++ b/passes/pmgen/xilinx_dsp.pmg @@ -98,16 +98,16 @@ code sigA sigB sigC sigD sigM clock if (param(dsp, \USE_MULT, Const("MULTIPLY")).decode_string() == "MULTIPLY") { // Only care about those bits that are used int i; - for (i = 0; i < GetSize(P); i++) { - if (nusers(P[i]) <= 1) + for (i = GetSize(P)-1; i >= 0; i--) + if (nusers(P[i]) > 1) break; - sigM.append(P[i]); - } + i++; log_assert(nusers(P.extract_end(i)) <= 1); // This sigM could have no users if downstream sinks (e.g. $add) is // narrower than $mul result, for example - if (sigM.empty()) + if (i == 0) reject; + sigM = P.extract(0, i); } else sigM = P; @@ -460,6 +460,8 @@ arg argD argQ clock code dff = nullptr; + if (GetSize(argQ) == 0) + reject; for (const auto &c : argQ.chunks()) { // Abandon matches when 'Q' is a constant if (!c.wire) |