From f24e2536c657346853ac71b8483eca004f695d0e Mon Sep 17 00:00:00 2001
From: Jannis Harder <me@jix.one>
Date: Mon, 15 Apr 2024 14:08:58 +0200
Subject: [PATCH] kernel/rtlil: Add `SigBit operator[](int offset)` to
 `SigChunk`

This is already supported by `SigSpec` and since both `SigChunk` and
`SigSpec` implement `extract` which is the multi-bit variant of this,
there is no good reason for `SigChunk` to not support
`SigBit operator[](int offset)`.
---
 kernel/rtlil.cc | 14 ++++++++++++++
 kernel/rtlil.h  |  1 +
 2 files changed, 15 insertions(+)

diff --git a/kernel/rtlil.cc b/kernel/rtlil.cc
index d3946a620..b77f8f5fe 100644
--- a/kernel/rtlil.cc
+++ b/kernel/rtlil.cc
@@ -3754,6 +3754,20 @@ RTLIL::SigChunk RTLIL::SigChunk::extract(int offset, int length) const
 	return ret;
 }
 
+RTLIL::SigBit RTLIL::SigChunk::operator[](int offset) const
+{
+	log_assert(offset >= 0);
+	log_assert(offset <= width);
+	RTLIL::SigBit ret;
+	if (wire) {
+		ret.wire = wire;
+		ret.offset = this->offset + offset;
+	} else {
+		ret.data = data[offset];
+	}
+	return ret;
+}
+
 bool RTLIL::SigChunk::operator <(const RTLIL::SigChunk &other) const
 {
 	if (wire && other.wire)
diff --git a/kernel/rtlil.h b/kernel/rtlil.h
index f9da29495..685acf904 100644
--- a/kernel/rtlil.h
+++ b/kernel/rtlil.h
@@ -769,6 +769,7 @@ struct RTLIL::SigChunk
 	SigChunk(const RTLIL::SigBit &bit);
 
 	RTLIL::SigChunk extract(int offset, int length) const;
+	RTLIL::SigBit operator[](int offset) const;
 	inline int size() const { return width; }
 	inline bool is_wire() const { return wire != NULL; }