From d6b656641c107ade3e078e4dc0210f6d9713a1d1 Mon Sep 17 00:00:00 2001
From: Nikolay Sivov <nsivov@codeweavers.com>
Date: Fri, 27 Jan 2023 19:07:10 +0300
Subject: [PATCH] vkd3d-shader/hlsl: Support rsqrt() intrinsic.

---
 libs/vkd3d-shader/hlsl.y | 12 ++++++++++++
 tests/sqrt.shader_test   | 13 +++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/libs/vkd3d-shader/hlsl.y b/libs/vkd3d-shader/hlsl.y
index e011ea24..10ac3179 100644
--- a/libs/vkd3d-shader/hlsl.y
+++ b/libs/vkd3d-shader/hlsl.y
@@ -2941,6 +2941,17 @@ static bool intrinsic_round(struct hlsl_ctx *ctx,
     return !!add_unary_arithmetic_expr(ctx, params->instrs, HLSL_OP1_ROUND, arg, loc);
 }
 
+static bool intrinsic_rsqrt(struct hlsl_ctx *ctx,
+        const struct parse_initializer *params, const struct vkd3d_shader_location *loc)
+{
+    struct hlsl_ir_node *arg;
+
+    if (!(arg = intrinsic_float_convert_arg(ctx, params, params->args[0], loc)))
+        return false;
+
+    return !!add_unary_arithmetic_expr(ctx, params->instrs, HLSL_OP1_RSQ, arg, loc);
+}
+
 static bool intrinsic_saturate(struct hlsl_ctx *ctx,
         const struct parse_initializer *params, const struct vkd3d_shader_location *loc)
 {
@@ -3208,6 +3219,7 @@ intrinsic_functions[] =
     {"pow",                                 2, true,  intrinsic_pow},
     {"reflect",                             2, true,  intrinsic_reflect},
     {"round",                               1, true,  intrinsic_round},
+    {"rsqrt",                               1, true,  intrinsic_rsqrt},
     {"saturate",                            1, true,  intrinsic_saturate},
     {"sin",                                 1, true,  intrinsic_sin},
     {"smoothstep",                          3, true,  intrinsic_smoothstep},
diff --git a/tests/sqrt.shader_test b/tests/sqrt.shader_test
index 5d048b4f..78d89d38 100644
--- a/tests/sqrt.shader_test
+++ b/tests/sqrt.shader_test
@@ -10,3 +10,16 @@ float4 main() : sv_target
 uniform 0 float4 1.0 9.0 32.3 46.5
 draw quad
 probe all rgba (1.0, 3.0, 5.683309, 6.819091) 1
+
+[pixel shader]
+uniform float4 f;
+
+float4 main() : sv_target
+{
+    return rsqrt(f);
+}
+
+[test]
+uniform 0 float4 1.0 9.0 4.0 16.0
+draw quad
+probe all rgba (1.0, 0.33333333, 0.5, 0.25) 1