From acafcdc94dc148b2bf9c8faef173e5b2b54e1ac5 Mon Sep 17 00:00:00 2001 From: Eddie Hung Date: Sun, 28 Apr 2019 13:04:34 -0700 Subject: [PATCH] Copy with 1'bx padding in $shiftx --- passes/techmap/shregmap.cc | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/passes/techmap/shregmap.cc b/passes/techmap/shregmap.cc index a541b33be..75eedfbcc 100644 --- a/passes/techmap/shregmap.cc +++ b/passes/techmap/shregmap.cc @@ -178,7 +178,17 @@ struct ShregmapTechXilinx7 : ShregmapTech // Only map if $shiftx exclusively covers the shift register if (shiftx->type == "$shiftx") { - if (GetSize(taps) != shiftx->getParam("\\A_WIDTH").as_int()) + if (GetSize(taps) > shiftx->getParam("\\A_WIDTH").as_int()) + return false; + // Due to padding the most significant bits of A may be 1'bx, + // and if so, discount them + if (GetSize(taps) < shiftx->getParam("\\A_WIDTH").as_int()) { + const SigSpec A = shiftx->getPort("\\A"); + const int A_width = shiftx->getParam("\\A_WIDTH").as_int(); + for (int i = GetSize(taps); i < A_width; ++i) + if (A[i] != RTLIL::Sx) return false; + } + else if (GetSize(taps) != shiftx->getParam("\\A_WIDTH").as_int()) return false; } else if (shiftx->type == "$mux") {