Nikolay Sivov : vkd3d-shader/hlsl: Support log() intrinsic.

[Alexandre Julliard]

Module: vkd3d
Branch: master
Commit: a1bd4e080ef5bd0b1bfb073558fb715e9ad54058
URL:    https://gitlab.winehq.org/wine/vkd3d/-/commit/a1bd4e080ef5bd0b1bfb073558fb71...

Author: Nikolay Sivov 
Date:   Tue Feb 21 23:15:50 2023 +0100

vkd3d-shader/hlsl: Support log() intrinsic.

Signed-off-by: Nikolay Sivov

---

libs/vkd3d-shader/hlsl.y | 20 ++++++++++++++++++++
 tests/log.shader_test    | 13 +++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/libs/vkd3d-shader/hlsl.y b/libs/vkd3d-shader/hlsl.y
index e487902e..ce20c00e 100644
--- a/libs/vkd3d-shader/hlsl.y
+++ b/libs/vkd3d-shader/hlsl.y
@@ -2843,6 +2843,25 @@ static bool intrinsic_lit(struct hlsl_ctx *ctx,
     return true;
 }

+static bool intrinsic_log(struct hlsl_ctx *ctx,
+        const struct parse_initializer *params, const struct vkd3d_shader_location *loc)
+{
+    struct hlsl_ir_constant *coeff;
+    struct hlsl_ir_node *log, *arg;
+
+    if (!(arg = intrinsic_float_convert_arg(ctx, params, params->args[0], loc)))
+        return false;
+
+    if (!(log = add_unary_arithmetic_expr(ctx, params->instrs, HLSL_OP1_LOG2, arg, loc)))
+        return false;
+
+    /* ln(2) */
+    if (!(coeff = hlsl_new_float_constant(ctx, 0.69314718055f, loc)))
+        return false;
+
+    return !!add_binary_arithmetic_expr(ctx, params->instrs, HLSL_OP2_MUL, log, &coeff->node, loc);
+}
+
 static bool intrinsic_log10(struct hlsl_ctx *ctx,
         const struct parse_initializer *params, const struct vkd3d_shader_location *loc)
 {
@@ -3330,6 +3349,7 @@ intrinsic_functions[] =
     {"length",                              1, true,  intrinsic_length},
     {"lerp",                                3, true,  intrinsic_lerp},
     {"lit",                                 3, true,  intrinsic_lit},
+    {"log",                                 1, true,  intrinsic_log},
     {"log10",                               1, true,  intrinsic_log10},
     {"log2",                                1, true,  intrinsic_log2},
     {"max",                                 2, true,  intrinsic_max},
diff --git a/tests/log.shader_test b/tests/log.shader_test
index 0a99904a..b0f405d1 100644
--- a/tests/log.shader_test
+++ b/tests/log.shader_test
@@ -23,3 +23,16 @@ float4 main() : sv_target
 uniform 0 float4 10.0 100.0 1.0 0.1
 draw quad
 probe all rgba (1.0, 2.0, 0.0, -1.0) 1
+
+[pixel shader]
+uniform float4 x;
+
+float4 main() : sv_target
+{
+    return log(x);
+}
+
+[test]
+uniform 0 float4 3.0 10.0 1.0 0.1
+draw quad
+probe all rgba (1.0986123, 2.302585, 0.0, -2.302585) 2