From 59c63ec5841dc01fac15dd2a0772b61f55b77a03 Mon Sep 17 00:00:00 2001
From: Nikolay Sivov <nsivov@codeweavers.com>
Date: Thu, 20 Apr 2023 22:25:23 -0400
Subject: [PATCH] vkd3d-shader/hlsl: Handle discard statement.

Signed-off-by: Ethan Lee <flibitijibibo@gmail.com>
Signed-off-by: Nikolay Sivov <nsivov@codeweavers.com>
---
 libs/vkd3d-shader/hlsl.y | 14 ++++++++++++++
 libs/vkd3d-shader/tpf.c  | 16 ++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/libs/vkd3d-shader/hlsl.y b/libs/vkd3d-shader/hlsl.y
index 194d21f4..2074f365 100644
--- a/libs/vkd3d-shader/hlsl.y
+++ b/libs/vkd3d-shader/hlsl.y
@@ -4075,6 +4075,7 @@ static void validate_texture_format_type(struct hlsl_ctx *ctx, struct hlsl_type
 %type <list> conditional_expr
 %type <list> declaration
 %type <list> declaration_statement
+%type <list> discard_statement
 %type <list> equality_expr
 %type <list> expr
 %type <list> expr_optional
@@ -5322,6 +5323,7 @@ statement:
       declaration_statement
     | expr_statement
     | compound_statement
+    | discard_statement
     | jump_statement
     | selection_statement
     | loop_statement
@@ -5341,6 +5343,18 @@ jump_statement:
                 YYABORT;
         }
 
+discard_statement:
+      KW_DISCARD ';'
+        {
+            struct hlsl_ir_node *discard;
+
+            if (!($$ = make_empty_list(ctx)))
+                YYABORT;
+            if (!(discard = hlsl_new_jump(ctx, HLSL_IR_JUMP_DISCARD, &@1)))
+                return false;
+            list_add_tail($$, &discard->entry);
+        }
+
 selection_statement:
       KW_IF '(' expr ')' if_body
         {
diff --git a/libs/vkd3d-shader/tpf.c b/libs/vkd3d-shader/tpf.c
index f15593b0..f3a15305 100644
--- a/libs/vkd3d-shader/tpf.c
+++ b/libs/vkd3d-shader/tpf.c
@@ -4327,6 +4327,22 @@ static void write_sm4_jump(struct hlsl_ctx *ctx,
             instr.opcode = VKD3D_SM4_OP_BREAK;
             break;
 
+        case HLSL_IR_JUMP_DISCARD:
+        {
+            struct sm4_register *reg = &instr.srcs[0].reg;
+
+            instr.opcode = VKD3D_SM4_OP_DISCARD | VKD3D_SM4_CONDITIONAL_NZ;
+
+            memset(&instr.srcs[0], 0, sizeof(*instr.srcs));
+            instr.srcs[0].swizzle_type = VKD3D_SM4_SWIZZLE_NONE;
+            instr.src_count = 1;
+            reg->type = VKD3D_SM4_RT_IMMCONST;
+            reg->dim = VKD3D_SM4_DIMENSION_SCALAR;
+            reg->immconst_uint[0] = ~0u;
+
+            break;
+        }
+
         case HLSL_IR_JUMP_RETURN:
             vkd3d_unreachable();