aboutsummaryrefslogtreecommitdiffstats
path: root/backends/smt2/smt2.cc
diff options
context:
space:
mode:
authorXiretza <xiretza@xiretza.xyz>2020-04-08 19:30:47 +0200
committerXiretza <xiretza@xiretza.xyz>2020-05-28 22:59:03 +0200
commit17163cf43a6b6eec9aac44f6a4463dda54b8ed68 (patch)
tree02dd1e144c36eb40565cbb792726c7d8d4573eb4 /backends/smt2/smt2.cc
parent0d99522b3c2ca2502129110e09f9988874e37abc (diff)
downloadyosys-17163cf43a6b6eec9aac44f6a4463dda54b8ed68.tar.gz
yosys-17163cf43a6b6eec9aac44f6a4463dda54b8ed68.tar.bz2
yosys-17163cf43a6b6eec9aac44f6a4463dda54b8ed68.zip
Add flooring modulo operator
The $div and $mod cells use truncating division semantics (rounding towards 0), as defined by e.g. Verilog. Another rounding mode, flooring (rounding towards negative infinity), can be used in e.g. VHDL. The new $modfloor cell provides this flooring modulo (also known as "remainder" in several languages, but this name is ambiguous). This commit also fixes the handling of $mod in opt_expr, which was previously optimized as if it was $modfloor.
Diffstat (limited to 'backends/smt2/smt2.cc')
-rw-r--r--backends/smt2/smt2.cc10
1 files changed, 10 insertions, 0 deletions
diff --git a/backends/smt2/smt2.cc b/backends/smt2/smt2.cc
index 3e67e55f2..26f17bcb3 100644
--- a/backends/smt2/smt2.cc
+++ b/backends/smt2/smt2.cc
@@ -590,7 +590,17 @@ struct Smt2Worker
if (cell->type == ID($sub)) return export_bvop(cell, "(bvsub A B)");
if (cell->type == ID($mul)) return export_bvop(cell, "(bvmul A B)");
if (cell->type == ID($div)) return export_bvop(cell, "(bvUdiv A B)", 'd');
+ // "rem" = truncating modulo
if (cell->type == ID($mod)) return export_bvop(cell, "(bvUrem A B)", 'd');
+ // "mod" = flooring modulo
+ if (cell->type == ID($modfloor)) {
+ // bvumod doesn't exist because it's the same as bvurem
+ if (cell->getParam(ID::A_SIGNED).as_bool()) {
+ return export_bvop(cell, "(bvsmod A B)", 'd');
+ } else {
+ return export_bvop(cell, "(bvurem A B)", 'd');
+ }
+ }
if (cell->type.in(ID($reduce_and), ID($reduce_or), ID($reduce_bool)) &&
2*GetSize(cell->getPort(ID::A).chunks()) < GetSize(cell->getPort(ID::A))) {