vkd3d-shader/hlsl: Lower int absolute value.

Approved-by: Zebediah Figura (@zfigura)
Approved-by: Henri Verbeet (@hverbeet)
Approved-by: Alexandre Julliard (@julliard)
Merge-Request: https://gitlab.winehq.org/wine/vkd3d/-/merge_requests/28

libs/vkd3d-shader/hlsl_codegen.c

@@ -1284,6 +1284,35 @@ static bool lower_casts_to_bool(struct hlsl_ctx *ctx, struct hlsl_ir_node *instr
     return true;
 }
 
+static bool lower_int_abs(struct hlsl_ctx *ctx, struct hlsl_ir_node *instr, void *context)
+{
+    struct hlsl_type *type = instr->data_type;
+    struct hlsl_ir_node *arg, *neg;
+    struct hlsl_ir_expr *expr;
+
+    if (instr->type != HLSL_IR_EXPR)
+        return false;
+    expr = hlsl_ir_expr(instr);
+
+    if (expr->op != HLSL_OP1_ABS)
+        return false;
+    if (type->type != HLSL_CLASS_SCALAR && type->type != HLSL_CLASS_VECTOR)
+        return false;
+    if (type->base_type != HLSL_TYPE_INT)
+        return false;
+
+    arg = expr->operands[0].node;
+
+    if (!(neg = hlsl_new_unary_expr(ctx, HLSL_OP1_NEG, arg, instr->loc)))
+        return false;
+    list_add_before(&instr->entry, &neg->entry);
+
+    expr->op = HLSL_OP2_MAX;
+    hlsl_src_from_node(&expr->operands[1], neg);
+
+    return true;
+}
+
 static bool dce(struct hlsl_ctx *ctx, struct hlsl_ir_node *instr, void *context)
 {
     switch (instr->type)
@@ -2268,6 +2297,7 @@ int hlsl_emit_bytecode(struct hlsl_ctx *ctx, struct hlsl_ir_function_decl *entry
 
     transform_ir(ctx, lower_narrowing_casts, body, NULL);
     transform_ir(ctx, lower_casts_to_bool, body, NULL);
+    transform_ir(ctx, lower_int_abs, body, NULL);
     do
     {
         progress = transform_ir(ctx, hlsl_fold_constant_exprs, body, NULL);

tests/arithmetic-int-uniform.shader_test

@@ -38,5 +38,5 @@ float4 main() : SV_TARGET
 
 [test]
 uniform 0 float4 5.0 -7.0 0.0 -10.0
-todo draw quad
+draw quad
 probe all rgba (5.0, 7.0, 0.0, 10.0)