Also consider NonSemantic ExtInst in block_is_noop.

reference/shaders-no-opt/comp/loop-resolve-debug-semantics.gV.comp

@@ -8,19 +8,9 @@ layout(binding = 0, std430) buffer SSBO
 
 void main()
 {
-    int i = 0;
-    for (;;)
+    for (int i = 0; i < 4; i++)
     {
-        if (i < 4)
-        {
-            _64.v[i] += 10;
-            i++;
-            continue;
-        }
-        else
-        {
-            break;
-        }
+        _64.v[i] += 10;
     }
 }
 

spirv_common.hpp

@@ -644,7 +644,8 @@ struct SPIRExtension : IVariant
 		SPV_AMD_shader_trinary_minmax,
 		SPV_AMD_gcn_shader,
 		NonSemanticDebugPrintf,
-		NonSemanticShaderDebugInfo
+		NonSemanticShaderDebugInfo,
+		NonSemanticGeneric
 	};
 
 	explicit SPIRExtension(Extension ext_)

spirv_cross.cpp

@@ -1481,18 +1481,26 @@ bool Compiler::block_is_noop(const SPIRBlock &block) const
 		switch (op)
 		{
 		// Non-Semantic instructions.
-		case OpNop:
-		case OpSourceContinued:
-		case OpSource:
-		case OpSourceExtension:
-		case OpName:
-		case OpMemberName:
-		case OpString:
 		case OpLine:
 		case OpNoLine:
-		case OpModuleProcessed:
 			break;
 
+		case OpExtInst:
+		{
+			auto *ops = stream(i);
+			auto ext = get<SPIRExtension>(ops[2]).ext;
+
+			bool ext_is_nonsemantic_only =
+				ext == SPIRExtension::NonSemanticShaderDebugInfo ||
+				ext == SPIRExtension::SPV_debug_info ||
+				ext == SPIRExtension::NonSemanticGeneric;
+
+			if (!ext_is_nonsemantic_only)
+				return false;
+
+			break;
+		}
+
 		default:
 			return false;
 		}

spirv_glsl.cpp

@@ -13320,7 +13320,8 @@ void CompilerGLSL::emit_instruction(const Instruction &instruction)
 			emit_spv_amd_gcn_shader_op(ops[0], ops[1], ops[3], &ops[4], length - 4);
 		}
 		else if (ext == SPIRExtension::SPV_debug_info ||
-		         ext == SPIRExtension::NonSemanticShaderDebugInfo)
+		         ext == SPIRExtension::NonSemanticShaderDebugInfo ||
+		         ext == SPIRExtension::NonSemanticGeneric)
 		{
 			break; // Ignore SPIR-V debug information extended instructions.
 		}

spirv_parser.cpp

@@ -295,6 +295,8 @@ void Parser::parse(const Instruction &instruction)
 			spirv_ext = SPIRExtension::NonSemanticDebugPrintf;
 		else if (ext == "NonSemantic.Shader.DebugInfo.100")
 			spirv_ext = SPIRExtension::NonSemanticShaderDebugInfo;
+		else if (ext.find("NonSemantic.") == 0)
+			spirv_ext = SPIRExtension::NonSemanticGeneric;
 
 		set<SPIRExtension>(id, spirv_ext);
 		// Other SPIR-V extensions which have ExtInstrs are currently not supported.