From 4039168bcabe49375109baf7ac4aaf76db983901 Mon Sep 17 00:00:00 2001
From: Henri Verbeet <hverbeet@locutus.nl>
Date: Tue, 11 Nov 2025 17:24:38 +0100
Subject: [PATCH] vkd3d-shader/hlsl: Consider scalars to be equivalent to
 1-component vectors in hlsl_add_conditional().

---
 libs/vkd3d-shader/hlsl_codegen.c   |  8 ++++++--
 tests/hlsl/conditional.shader_test | 30 ++++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/libs/vkd3d-shader/hlsl_codegen.c b/libs/vkd3d-shader/hlsl_codegen.c
index 8334ffdf7..382e0cebc 100644
--- a/libs/vkd3d-shader/hlsl_codegen.c
+++ b/libs/vkd3d-shader/hlsl_codegen.c
@@ -5490,10 +5490,14 @@ static struct hlsl_ir_node *lower_casts_to_bool(struct hlsl_ctx *ctx,
 struct hlsl_ir_node *hlsl_add_conditional(struct hlsl_ctx *ctx, struct hlsl_block *instrs,
         struct hlsl_ir_node *condition, struct hlsl_ir_node *if_true, struct hlsl_ir_node *if_false)
 {
+    struct hlsl_type *false_type = if_false->data_type;
     struct hlsl_type *cond_type = condition->data_type;
     struct hlsl_ir_node *operands[HLSL_MAX_OPERANDS];
+    struct hlsl_type *true_type = if_true->data_type;
 
-    VKD3D_ASSERT(hlsl_types_are_equal(if_true->data_type, if_false->data_type));
+    VKD3D_ASSERT(hlsl_types_are_equal(true_type, false_type)
+            || (hlsl_is_vec1(true_type) && hlsl_is_vec1(false_type)
+            && true_type->e.numeric.type == false_type->e.numeric.type));
 
     if (cond_type->e.numeric.type != HLSL_TYPE_BOOL)
     {
@@ -5505,7 +5509,7 @@ struct hlsl_ir_node *hlsl_add_conditional(struct hlsl_ctx *ctx, struct hlsl_bloc
     operands[0] = condition;
     operands[1] = if_true;
     operands[2] = if_false;
-    return hlsl_block_add_expr(ctx, instrs, HLSL_OP3_TERNARY, operands, if_true->data_type, &condition->loc);
+    return hlsl_block_add_expr(ctx, instrs, HLSL_OP3_TERNARY, operands, true_type, &condition->loc);
 }
 
 static struct hlsl_ir_node *lower_int_division_sm4(struct hlsl_ctx *ctx,
diff --git a/tests/hlsl/conditional.shader_test b/tests/hlsl/conditional.shader_test
index 3e99b91f3..48e63270b 100644
--- a/tests/hlsl/conditional.shader_test
+++ b/tests/hlsl/conditional.shader_test
@@ -70,10 +70,40 @@ float main() : sv_target
         return float4(0.9, 0.8, 0.7, 0.6);
 }
 
+[vertex shader]
+void main(float4 p : position, out float t[4] : texcoord, out float4 position : sv_position)
+{
+    t[0] = (p.x + 1.0) / 2.0;
+    t[2] = 0.0;
+    t[1] = (p.y + 1.0) / 2.0;
+    t[3] = 1.0;
+    position = p;
+}
+
+[pixel shader]
+float4 main(float t[4] : texcoord) : sv_target
+{
+    if (t[0] > 0.5)
+        return floor(float4(t) * 128.0 + 0.5) / 128.0;
+    return float4(0.0, 1.0, 0.0, 1.0);
+}
+
+[test]
+todo(msl & sm>=6) draw quad
+probe (160, 120) f32(0.00, 1.00, 0.0, 1.0)
+probe (480, 120) f32(0.75, 0.75, 0.0, 1.0)
+probe (160, 360) f32(0.00, 1.00, 0.0, 1.0)
+probe (480, 360) f32(0.75, 0.25, 0.0, 1.0)
+
 % Using older profiles fails to compile with forced control flow instruction
 [require]
 shader model >= 3.0
 
+[vertex shader]
+float4 main(float4 p : position) : sv_position
+{
+    return p;
+}
 
 [pixel shader]
 uniform float a;