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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/firrtl
parent0d99522b3c2ca2502129110e09f9988874e37abc (diff)
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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 $modfloor.
Diffstat (limited to 'backends/firrtl')
-rw-r--r--backends/firrtl/firrtl.cc1
1 files changed, 1 insertions, 0 deletions
diff --git a/backends/firrtl/firrtl.cc b/backends/firrtl/firrtl.cc
index a90b0b87a..b1d8500bb 100644
--- a/backends/firrtl/firrtl.cc
+++ b/backends/firrtl/firrtl.cc
@@ -585,6 +585,7 @@ struct FirrtlWorker
firrtl_is_signed = a_signed | b_signed;
firrtl_width = a_width;
} else if (cell->type == ID($mod)) {
+ // "rem" = truncating modulo
primop = "rem";
firrtl_width = min(a_width, b_width);
} else if (cell->type.in(ID($and), ID($_AND_))) {