Another workaround for NVIDIA driver 496.13 shader bug (#2750)

* Another workaround for NVIDIA driver 496.13 shader bug

This might work better than the other one. Give this a test to see if it fixes/doesn't fix issues with the other one.

The problem seems to be when any variable assignment happens with a negation. `temp_1 = -temp_0;` seems to trigger weird behaviour, but `temp_1 = 0.0 - temp_0;` does not. This also might to extend towards integer types?

* Update cache version

* Add disclaimer comment

* Wording

Ryujinx.Graphics.Gpu/Shader/ShaderCache.cs

@@ -40,7 +40,7 @@ namespace Ryujinx.Graphics.Gpu.Shader
         /// <summary>
         /// Version of the codegen (to be changed when codegen or guest format change).
         /// </summary>
-        private const ulong ShaderCodeGenVersion = 2534;
+        private const ulong ShaderCodeGenVersion = 2750;
 
         // Progress reporting helpers
         private volatile int _shaderCount;

Ryujinx.Graphics.Shader/CodeGen/Glsl/Instructions/InstGen.cs

@@ -27,6 +27,22 @@ namespace Ryujinx.Graphics.Shader.CodeGen.Glsl.Instructions
             throw new ArgumentException($"Invalid node type \"{node?.GetType().Name ?? "null"}\".");
         }
 
+        public static string Negate(CodeGenContext context, AstOperation operation, InstInfo info)
+        {
+            IAstNode src = operation.GetSource(0);
+
+            VariableType type = GetSrcVarType(operation.Inst, 0);
+
+            string srcExpr = GetSoureExpr(context, src, type);
+
+            NumberFormatter.TryFormat(0, type, out string zero);
+
+            // Starting in the 496.13 NVIDIA driver, there's an issue with assigning variables to negated expressions.
+            // (-expr) does not work, but (0.0 - expr) does. This should be removed once the issue is resolved.
+
+            return $"{zero} - {Enclose(srcExpr, src, operation.Inst, info, false)}";
+        }
+
         private static string GetExpression(CodeGenContext context, AstOperation operation)
         {
             Instruction inst = operation.Inst;
@@ -120,7 +136,7 @@ namespace Ryujinx.Graphics.Shader.CodeGen.Glsl.Instructions
             }
             else if ((info.Type & InstType.Special) != 0)
             {
-                switch (inst)
+                switch (inst & Instruction.Mask)
                 {
                     case Instruction.Ballot:
                         return Ballot(context, operation);
@@ -151,6 +167,9 @@ namespace Ryujinx.Graphics.Shader.CodeGen.Glsl.Instructions
                     case Instruction.Lod:
                         return Lod(context, operation);
 
+                    case Instruction.Negate:
+                        return Negate(context, operation, info);
+
                     case Instruction.PackDouble2x32:
                         return PackDouble2x32(context, operation);
 

Ryujinx.Graphics.Shader/CodeGen/Glsl/Instructions/InstGenHelper.cs

@@ -97,7 +97,7 @@ namespace Ryujinx.Graphics.Shader.CodeGen.Glsl.Instructions
             Add(Instruction.Multiply,                 InstType.OpBinaryCom,    "*",               1);
             Add(Instruction.MultiplyHighS32,          InstType.CallBinary,     HelperFunctionNames.MultiplyHighS32);
             Add(Instruction.MultiplyHighU32,          InstType.CallBinary,     HelperFunctionNames.MultiplyHighU32);
-            Add(Instruction.Negate,                   InstType.OpUnary,        "-",               0);
+            Add(Instruction.Negate,                   InstType.Special);
             Add(Instruction.ReciprocalSquareRoot,     InstType.CallUnary,      "inversesqrt");
             Add(Instruction.Return,                   InstType.OpNullary,      "return");
             Add(Instruction.Round,                    InstType.CallUnary,      "roundEven");