[PATCH v2 2/3] vkd3d-shader/hlsl: Handle discard statement.

[Nikolay Sivov]

From: Nikolay Sivov

---
 libs/vkd3d-shader/hlsl.y     | 14 ++++++++++++++
 libs/vkd3d-shader/hlsl_sm4.c | 16 ++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/libs/vkd3d-shader/hlsl.y b/libs/vkd3d-shader/hlsl.y
index fd1eaf6e..89c71ce5 100644
--- a/libs/vkd3d-shader/hlsl.y
+++ b/libs/vkd3d-shader/hlsl.y
@@ -3933,6 +3933,7 @@ 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
@@ -5145,6 +5146,7 @@ statement:
       declaration_statement
     | expr_statement
     | compound_statement
+    | discard_statement
     | jump_statement
     | selection_statement
     | loop_statement
@@ -5164,6 +5166,18 @@ jump_statement:
                 YYABORT;
         }

+discard_statement:
+      KW_DISCARD ';'
+        {
+            struct hlsl_ir_jump *discard;
+
+            if (!($$ = make_empty_list(ctx)))
+                YYABORT;
+            if (!(discard = hlsl_new_jump(ctx, HLSL_IR_JUMP_DISCARD, @1)))
+                return false;
+            list_add_tail($$, &discard->node.entry);
+        }
+
 selection_statement:
       KW_IF '(' expr ')' if_body
         {
diff --git a/libs/vkd3d-shader/hlsl_sm4.c b/libs/vkd3d-shader/hlsl_sm4.c
index f81be3e9..c3b2dac2 100644
--- a/libs/vkd3d-shader/hlsl_sm4.c
+++ b/libs/vkd3d-shader/hlsl_sm4.c
@@ -2137,6 +2137,22 @@ 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();