From: Mikko Rasa <tdb@tdb.fi>
Date: Tue, 9 Mar 2021 08:39:58 +0000 (+0200)
Subject: Use accurate assignment targets in ExpressionInliner
X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=commitdiff_plain;h=daff631cf87db75bcae616605e759d281258d9e4

Use accurate assignment targets in ExpressionInliner

This fixes an issue where it inline an assignment to a subfield in place
of a reference to the whole variable.
---

diff --git a/source/glsl/optimize.cpp b/source/glsl/optimize.cpp
index 215466b2..87410d5a 100644
--- a/source/glsl/optimize.cpp
+++ b/source/glsl/optimize.cpp
@@ -393,35 +393,31 @@ void ExpressionInliner::visit(Block &block)
 {
 	TraversingVisitor::visit(block);
 
-	for(map<VariableDeclaration *, ExpressionInfo>::iterator i=expressions.begin(); i!=expressions.end(); )
+	for(map<string, VariableDeclaration *>::iterator i=block.variables.begin(); i!=block.variables.end(); ++i)
 	{
-		map<string, VariableDeclaration *>::iterator j = block.variables.find(i->first->name);
-		if(j!=block.variables.end() && j->second==i->first)
+		map<Assignment::Target, ExpressionInfo>::iterator j = expressions.lower_bound(i->second);
+		for(; (j!=expressions.end() && j->first.declaration==i->second); )
 		{
-			if(i->second.expression && i->second.inline_point)
-				inline_expression(*i->second.expression, *i->second.inline_point, i->second.outer_oper, i->second.inner_oper, i->second.inline_on_rhs);
+			if(j->second.expression && j->second.inline_point)
+				inline_expression(*j->second.expression, *j->second.inline_point, j->second.outer_oper, j->second.inner_oper, j->second.inline_on_rhs);
 
-			expressions.erase(i++);
-		}
-		else
-		{
-			/* The expression was assigned in this block and may depend on local
-			variables of the block.  If this is a conditionally executed block,
-			the assignment might not always happen.  Mark the expression as not
-			available to any outer blocks. */
-			if(i->second.assign_scope==&block)
-				i->second.available = false;
-
-			++i;
+			expressions.erase(j++);
 		}
 	}
+
+	/* Expressions assigned in this block may depend on local variables of the
+	block.  If this is a conditionally executed block, the assignments might not
+	always happen.  Mark the expressions as not available to any outer blocks. */
+	for(map<Assignment::Target, ExpressionInfo>::iterator i=expressions.begin(); i!=expressions.end(); ++i)
+		if(i->second.assign_scope==&block)
+			i->second.available = false;
 }
 
 void ExpressionInliner::visit(VariableReference &var)
 {
 	if(var.declaration)
 	{
-		map<VariableDeclaration *, ExpressionInfo>::iterator i = expressions.find(var.declaration);
+		map<Assignment::Target, ExpressionInfo>::iterator i = expressions.find(var.declaration);
 		if(i!=expressions.end())
 		{
 			/* If a non-trivial expression is referenced multiple times, don't
@@ -479,19 +475,16 @@ void ExpressionInliner::visit(Assignment &assign)
 	r_oper = 0;
 	visit_and_record(assign.right, assign.oper, true);
 
-	if(VariableDeclaration *target_var = dynamic_cast<VariableDeclaration *>(assign.target.declaration))
+	map<Assignment::Target, ExpressionInfo>::iterator i = expressions.find(assign.target);
+	if(i!=expressions.end())
 	{
-		map<VariableDeclaration *, ExpressionInfo>::iterator i = expressions.find(target_var);
-		if(i!=expressions.end())
-		{
-			/* Self-referencing assignments can't be inlined without additional
-			work.  Just clear any previous expression. */
-			i->second.expression = (assign.self_referencing ? 0 : assign.right.get());
-			i->second.assign_scope = current_block;
-			i->second.inline_point = 0;
-			i->second.inner_oper = r_oper;
-			i->second.available = true;
-		}
+		/* Self-referencing assignments can't be inlined without additional
+		work.  Just clear any previous expression. */
+		i->second.expression = (assign.self_referencing ? 0 : assign.right.get());
+		i->second.assign_scope = current_block;
+		i->second.inline_point = 0;
+		i->second.inner_oper = r_oper;
+		i->second.available = true;
 	}
 
 	r_oper = assign.oper;
diff --git a/source/glsl/optimize.h b/source/glsl/optimize.h
index 4f3bf8cc..4663c12e 100644
--- a/source/glsl/optimize.h
+++ b/source/glsl/optimize.h
@@ -120,7 +120,7 @@ private:
 		ExpressionInfo();
 	};
 
-	std::map<VariableDeclaration *, ExpressionInfo> expressions;
+	std::map<Assignment::Target, ExpressionInfo> expressions;
 	ExpressionInfo *r_ref_info;
 	bool r_any_inlined;
 	bool r_trivial;