From: Mikko Rasa <tdb@tdb.fi>
Date: Thu, 11 Nov 2021 10:49:08 +0000 (+0200)
Subject: Propagate locations from existing variables before optimization
X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=commitdiff_plain;h=89de98315588ec89ad66e9a4f3f90bf03e1f7733

Propagate locations from existing variables before optimization

Uniform location and binding qualifiers should apply to all copies of the
variable even if the one originally containing them is optimized out.
---

diff --git a/source/glsl/compiler.cpp b/source/glsl/compiler.cpp
index e676fcc8..4e9f94d8 100644
--- a/source/glsl/compiler.cpp
+++ b/source/glsl/compiler.cpp
@@ -75,6 +75,7 @@ void Compiler::compile(Mode mode)
 	for(Stage &s: module->stages)
 		generate(s);
 	ConstantIdAssigner().apply(*module, features);
+	LocationAllocator().apply(*module, features, false);
 
 	for(Stage &s: module->stages)
 		validate(s);
diff --git a/source/glsl/finalize.cpp b/source/glsl/finalize.cpp
index 7eb0165d..cb304aa3 100644
--- a/source/glsl/finalize.cpp
+++ b/source/glsl/finalize.cpp
@@ -62,8 +62,9 @@ void StructOrganizer::visit(VariableDeclaration &var)
 }
 
 
-void LocationAllocator::apply(Module &module, const Features &features)
+void LocationAllocator::apply(Module &module, const Features &features, bool a)
 {
+	alloc_new = a;
 	for(Stage &s: module.stages)
 		apply(s);
 
@@ -111,6 +112,9 @@ void LocationAllocator::allocate_locations(const string &iface)
 			}
 		}
 
+		if(!alloc_new)
+			continue;
+
 		set<unsigned> &used = used_locations[(*i)->interface];
 
 		unsigned size = LocationCounter().apply(**i);
@@ -142,7 +146,7 @@ void LocationAllocator::bind_uniform(RefPtr<Layout> &layout, const string &name,
 	auto i = uniforms.find(name);
 	if(i!=uniforms.end() && i->second.bind_point>=0)
 		add_layout_qualifier(layout, Layout::Qualifier("binding", i->second.bind_point));
-	else
+	else if(alloc_new)
 	{
 		set<unsigned> &used = used_bindings[0];
 
diff --git a/source/glsl/finalize.h b/source/glsl/finalize.h
index bde0618a..ab4276f5 100644
--- a/source/glsl/finalize.h
+++ b/source/glsl/finalize.h
@@ -36,6 +36,7 @@ private:
 		Uniform(): location(-1), desc_set(-1), bind_point(-1) { }
 	};
 
+	bool alloc_new = true;
 	std::map<std::string, std::set<unsigned> > used_locations;
 	std::map<std::string, Uniform> uniforms;
 	std::map<unsigned, std::set<unsigned> > used_bindings;
@@ -44,7 +45,7 @@ private:
 	std::vector<InterfaceBlock *> unbound_blocks;
 
 public:
-	void apply(Module &, const Features &);
+	void apply(Module &, const Features &, bool = true);
 private:
 	void apply(Stage &);