From b847c88559553c7e56d345657c86c349d0a383f0 Mon Sep 17 00:00:00 2001
From: Hans-Kristian Arntzen <hans-kristian.arntzen@arm.com>
Date: Fri, 18 Nov 2016 17:06:49 +0100
Subject: [PATCH] Cleanup, and make cfg analysis optional.

---
 main.cpp         |  6 +++++-
 spirv_common.hpp |  1 +
 spirv_cross.hpp  |  4 ----
 spirv_glsl.cpp   | 12 ++++++++++--
 spirv_glsl.hpp   |  3 +++
 5 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/main.cpp b/main.cpp
index c1b9f632..ebb10f60 100644
--- a/main.cpp
+++ b/main.cpp
@@ -401,11 +401,13 @@ struct CLIArguments
 	bool metal = false;
 	bool vulkan_semantics = false;
 	bool remove_unused = false;
+	bool cfg_analysis = true;
 };
 
 static void print_help()
 {
-	fprintf(stderr, "Usage: spirv-cross [--output <output path>] [SPIR-V file] [--es] [--no-es] [--version <GLSL "
+	fprintf(stderr, "Usage: spirv-cross [--output <output path>] [SPIR-V file] [--es] [--no-es] [--no-cfg-analysis] "
+	                "[--version <GLSL "
 	                "version>] [--dump-resources] [--help] [--force-temporary] [--cpp] [--cpp-interface-name <name>] "
 	                "[--metal] [--vulkan-semantics] [--flatten-ubo] [--fixup-clipspace] [--iterations iter] [--pls-in "
 	                "format input-name] [--pls-out format output-name] [--remap source_name target_name components] "
@@ -519,6 +521,7 @@ int main(int argc, char *argv[])
 		args.version = parser.next_uint();
 		args.set_version = true;
 	});
+	cbs.add("--no-cfg-analysis", [&args](CLIParser &) { args.cfg_analysis = false; });
 	cbs.add("--dump-resources", [&args](CLIParser &) { args.dump_resources = true; });
 	cbs.add("--force-temporary", [&args](CLIParser &) { args.force_temporary = true; });
 	cbs.add("--flatten-ubo", [&args](CLIParser &) { args.flatten_ubo = true; });
@@ -623,6 +626,7 @@ int main(int argc, char *argv[])
 	opts.force_temporary = args.force_temporary;
 	opts.vulkan_semantics = args.vulkan_semantics;
 	opts.vertex.fixup_clipspace = args.fixup;
+	opts.cfg_analysis = args.cfg_analysis;
 	compiler->set_options(opts);
 
 	ShaderResources res;
diff --git a/spirv_common.hpp b/spirv_common.hpp
index 1bb464ca..d9e2ccd6 100644
--- a/spirv_common.hpp
+++ b/spirv_common.hpp
@@ -513,6 +513,7 @@ struct SPIRFunction : IVariant
 	bool active = false;
 	bool flush_undeclared = true;
 	bool do_combined_parameters = true;
+	bool analyzed_variable_scope = false;
 };
 
 struct SPIRVariable : IVariant
diff --git a/spirv_cross.hpp b/spirv_cross.hpp
index a271b57c..36c5bc5e 100644
--- a/spirv_cross.hpp
+++ b/spirv_cross.hpp
@@ -578,10 +578,6 @@ private:
 	ShaderResources get_shader_resources(const std::unordered_set<uint32_t> *active_variables) const;
 
 	VariableTypeRemapCallback variable_remap_callback;
-
-	SPIRBlock &find_common_dominator(
-	    const SPIRBlock &entry, uint32_t variable,
-	    const std::unordered_map<uint32_t, std::unordered_set<uint32_t>> &block_to_variable_map);
 };
 }
 
diff --git a/spirv_glsl.cpp b/spirv_glsl.cpp
index e78976f2..042a98c2 100644
--- a/spirv_glsl.cpp
+++ b/spirv_glsl.cpp
@@ -5232,9 +5232,17 @@ void CompilerGLSL::emit_function(SPIRFunction &func, uint64_t return_flags)
 		}
 	}
 
-	analyze_variable_scope(func);
-
 	auto &entry_block = get<SPIRBlock>(func.entry_block);
+
+	if (!func.analyzed_variable_scope)
+	{
+		if (options.cfg_analysis)
+			analyze_variable_scope(func);
+		else
+			entry_block.dominated_variables = func.local_variables;
+		func.analyzed_variable_scope = true;
+	}
+
 	entry_block.loop_dominator = SPIRBlock::NoDominator;
 	emit_block_chain(entry_block);
 
diff --git a/spirv_glsl.hpp b/spirv_glsl.hpp
index 04a03bff..41372a34 100644
--- a/spirv_glsl.hpp
+++ b/spirv_glsl.hpp
@@ -60,6 +60,9 @@ public:
 		bool es = false;
 		bool force_temporary = false;
 
+		// If true, variables will be moved to their appropriate scope through CFG analysis.
+		bool cfg_analysis = true;
+
 		// If true, Vulkan GLSL features are used instead of GL-compatible features.
 		// Mostly useful for debugging SPIR-V files.
 		bool vulkan_semantics = false;