From 4414f0245005c8cfcd02b51ea394d612cc5776c4 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sun, 7 Mar 2021 11:36:17 +0200
Subject: [PATCH] Additional rules for bit shift operators

---
 source/glsl/generate.cpp            | 10 ++++++++--
 tests/glsl/binary_operators.glsl    | 11 +++++++++--
 tests/glsl/invalid_expressions.glsl |  3 +++
 3 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/source/glsl/generate.cpp b/source/glsl/generate.cpp
index f29d65f5..1e57ed64 100644
--- a/source/glsl/generate.cpp
+++ b/source/glsl/generate.cpp
@@ -657,11 +657,17 @@ void ExpressionResolver::visit(BinaryExpression &binary, bool assign)
 	}
 	else if((oper=='<' || oper=='>') && oper2==oper)
 	{
-		// Shifts only apply to integers.
-		if(basic_left->kind!=BasicTypeDeclaration::INT || basic_right->kind!=BasicTypeDeclaration::INT)
+		// Shifts apply to integer scalars and vectors, with some restrictions.
+		if(elem_left->kind!=BasicTypeDeclaration::INT || elem_right->kind!=BasicTypeDeclaration::INT)
+			return;
+		unsigned left_size = (basic_left->kind==BasicTypeDeclaration::INT ? 1 : basic_left->kind==BasicTypeDeclaration::VECTOR ? basic_left->size : 0);
+		unsigned right_size = (basic_right->kind==BasicTypeDeclaration::INT ? 1 : basic_right->kind==BasicTypeDeclaration::VECTOR ? basic_right->size : 0);
+		if(!left_size || (left_size==1 && right_size!=1) || (left_size>1 && right_size!=1 && right_size!=left_size))
 			return;
 
 		type = basic_left;
+		// Don't perform conversion even if the operands are of different sizes.
+		compat = SAME_TYPE;
 	}
 	else if(oper=='+' || oper=='-' || oper=='*' || oper=='/')
 	{
diff --git a/tests/glsl/binary_operators.glsl b/tests/glsl/binary_operators.glsl
index 8e2520c8..a99b4446 100644
--- a/tests/glsl/binary_operators.glsl
+++ b/tests/glsl/binary_operators.glsl
@@ -14,6 +14,10 @@ void main()
 	j = j<<(i%5);
 	b = b || i!=j;
 
+	ivec2 iv;
+	i = i<<j;
+	iv = iv>>i;
+
 	mat4x2 m1;
 	mat2x4 m2;
 	mat4 m3 = m2*m1*5;
@@ -21,7 +25,7 @@ void main()
 	vec4 v2;
 	v2 = m3*v1;
 	vec2 v3;
-	v3 = v1*m2+v2.xy;
+	v3 = v1*m2+v2.xy+iv;
 
 	if(b)
 		++v3;
@@ -41,11 +45,14 @@ void main()
 	i = i|1;
 	j = j<<(i%5);
 	b = b||i!=j;
+	ivec2 iv;
+	i = i<<j;
+	iv = iv>>i;
 	mat4x2 m1;
 	mat2x4 m2;
 	vec4 v1 = vec4(1.0);
 	vec2 v3;
-	v3 = v1*m2+(m2*m1*float(5)*v1).xy;
+	v3 = v1*m2+(m2*m1*float(5)*v1).xy+vec2(iv);
 	if(b)
 		++v3;
 }
diff --git a/tests/glsl/invalid_expressions.glsl b/tests/glsl/invalid_expressions.glsl
index 996b0d35..2e67b76e 100644
--- a/tests/glsl/invalid_expressions.glsl
+++ b/tests/glsl/invalid_expressions.glsl
@@ -12,6 +12,8 @@ void main()
 	vec3 v;
 	m*m;
 	v*m;
+	ivec3 iv;
+	i<<iv;
 }
 
 /* Expected error:
@@ -24,4 +26,5 @@ void main()
 <test>:10: No matching operator '/' found for 'int' and 'float'
 <test>:13: No matching operator '*' found for 'mat3x2' and 'mat3x2'
 <test>:14: No matching operator '*' found for 'vec3' and 'mat3x2'
+<test>:16: No matching operator '<<' found for 'int' and 'ivec3'
 */
-- 
2.43.0