From 4b273a4ae9e4fc43b9580de82015a56d4095c85b Mon Sep 17 00:00:00 2001
From: Jannis Harder <me@jix.one>
Date: Tue, 15 Apr 2025 12:04:09 +0200
Subject: [PATCH] share: Cleanup and additional testing

Fixes a typo and adds another test case that triggers the fallback
behavior as the existing tests all trigger the new optimization.
---
 passes/opt/share.cc | 16 ++++++++--------
 tests/sat/share.v   | 23 +++++++++++++++++++++++
 tests/sat/share.ys  |  6 +++++-
 3 files changed, 36 insertions(+), 9 deletions(-)

diff --git a/passes/opt/share.cc b/passes/opt/share.cc
index 580549e4d..1d7ba7d98 100644
--- a/passes/opt/share.cc
+++ b/passes/opt/share.cc
@@ -1013,10 +1013,10 @@ struct ShareWorker
 		return bits;
 	}
 
-	bool onesided_restrict_activiation_patterns(
+	bool onesided_restrict_activation_patterns(
 			pool<ssc_pair_t> &activation_patterns, const pool<std::pair<SigBit, State>> &other_bits)
 	{
-		pool<ssc_pair_t> new_activiation_patterns;
+		pool<ssc_pair_t> new_activation_patterns;
 
 		bool simplified = false;
 
@@ -1032,22 +1032,22 @@ struct ShareWorker
 					simplified = true;
 				}
 			}
-			new_activiation_patterns.emplace(std::move(new_pair));
+			new_activation_patterns.emplace(std::move(new_pair));
 		}
 
-		activation_patterns = std::move(new_activiation_patterns);
+		activation_patterns = std::move(new_activation_patterns);
 		return simplified;
 	}
 
 	// Only valid if the patterns on their own (i.e. without considering their input cone) are mutually exclusive!
-	bool restrict_activiation_patterns(pool<ssc_pair_t> &activation_patterns, pool<ssc_pair_t> &other_activation_patterns)
+	bool restrict_activation_patterns(pool<ssc_pair_t> &activation_patterns, pool<ssc_pair_t> &other_activation_patterns)
 	{
 		pool<std::pair<SigBit, State>> bits = pattern_bits(activation_patterns);
 		pool<std::pair<SigBit, State>> other_bits = pattern_bits(other_activation_patterns);
 
 		bool simplified = false;
-		simplified |= onesided_restrict_activiation_patterns(activation_patterns, other_bits);
-		simplified |= onesided_restrict_activiation_patterns(other_activation_patterns, bits);
+		simplified |= onesided_restrict_activation_patterns(activation_patterns, other_bits);
+		simplified |= onesided_restrict_activation_patterns(other_activation_patterns, bits);
 
 		optimize_activation_patterns(activation_patterns);
 		optimize_activation_patterns(other_activation_patterns);
@@ -1401,7 +1401,7 @@ struct ShareWorker
 				} else {
 					log("      According to the SAT solver this pair of cells can be shared. (Pattern only case)\n");
 
-					if (restrict_activiation_patterns(optimized_cell_activation_patterns, optimized_other_cell_activation_patterns)) {
+					if (restrict_activation_patterns(optimized_cell_activation_patterns, optimized_other_cell_activation_patterns)) {
 						for (auto &p : optimized_cell_activation_patterns)
 							log("      Simplified activation pattern for cell %s: %s = %s\n", log_id(cell), log_signal(p.first), log_signal(p.second));
 
diff --git a/tests/sat/share.v b/tests/sat/share.v
index e06fc8f1e..29e423137 100644
--- a/tests/sat/share.v
+++ b/tests/sat/share.v
@@ -30,3 +30,26 @@ module test_2(
 	end
 endmodule
 
+
+module test_3(
+	input [3:0] s,
+	input [7:0] a, b, c,
+	output reg [7:0] y0,
+	output reg [7:0] y1,
+	output reg [7:0] y2,
+	output reg [7:0] y3,
+);
+	wire is_onehot = s & (s - 1);
+
+	always @* begin
+		y0 <= 0;
+		y1 <= 0;
+		y2 <= 0;
+		y3 <= 0;
+		if (s < 3) y0 <= b / c;
+		if (3 <= s && s < 6) y1 <= c / b;
+		if (6 <= s && s < 9) y2 <= a / b;
+		if (9 <= s && s < 12) y3 <= b / a;
+	end
+endmodule
+
diff --git a/tests/sat/share.ys b/tests/sat/share.ys
index f2f5d649d..ef88d55c3 100644
--- a/tests/sat/share.ys
+++ b/tests/sat/share.ys
@@ -3,11 +3,13 @@ proc;;
 
 copy test_1 gold_1
 copy test_2 gold_2
-share test_1 test_2;;
+copy test_3 gold_3
+share test_1 test_2 test_3;;
 
 select -assert-count 1 test_1/t:$mul
 select -assert-count 1 test_2/t:$mul
 select -assert-count 1 test_2/t:$div
+select -assert-count 1 test_3/t:$div
 
 miter -equiv -flatten -make_outputs -make_outcmp gold_1 test_1 miter_1
 sat -verify -prove trigger 0 -show-inputs -show-outputs miter_1
@@ -15,3 +17,5 @@ sat -verify -prove trigger 0 -show-inputs -show-outputs miter_1
 miter -equiv -flatten -make_outputs -make_outcmp gold_2 test_2 miter_2
 sat -verify -prove trigger 0 -show-inputs -show-outputs miter_2
 
+miter -equiv -flatten -make_outputs -make_outcmp gold_3 test_3 miter_3
+sat -verify -prove trigger 0 -show-inputs -show-outputs miter_3