From 0d14448b4d92d119724a939a304dd25dceff7edf Mon Sep 17 00:00:00 2001
From: Hans-Kristian Arntzen <hans-kristian.arntzen@arm.com>
Date: Tue, 25 Jul 2017 18:25:03 +0200
Subject: [PATCH] Minor optimization of enclose_expression.

---
 spirv_glsl.cpp | 29 ++++++++++++++++-------------
 1 file changed, 16 insertions(+), 13 deletions(-)

diff --git a/spirv_glsl.cpp b/spirv_glsl.cpp
index 421002a2..0d835b55 100644
--- a/spirv_glsl.cpp
+++ b/spirv_glsl.cpp
@@ -1822,23 +1822,26 @@ string CompilerGLSL::enclose_expression(const string &expr)
 			need_parens = true;
 	}
 
-	uint32_t paren_count = 0;
-	for (auto c : expr)
+	if (!need_parens)
 	{
-		if (c == '(')
-			paren_count++;
-		else if (c == ')')
+		uint32_t paren_count = 0;
+		for (auto c : expr)
 		{
-			assert(paren_count);
-			paren_count--;
-		}
-		else if (c == ' ' && paren_count == 0)
-		{
-			need_parens = true;
-			break;
+			if (c == '(')
+				paren_count++;
+			else if (c == ')')
+			{
+				assert(paren_count);
+				paren_count--;
+			}
+			else if (c == ' ' && paren_count == 0)
+			{
+				need_parens = true;
+				break;
+			}
 		}
+		assert(paren_count == 0);
 	}
-	assert(paren_count == 0);
 
 	// If this expression contains any spaces which are not enclosed by parentheses,
 	// we need to enclose it so we can treat the whole string as an expression.