[PATCH 0/1] MR375: vkd3d-shader/hlsl: Remove conditional branching when condition is a compile time constant.

[Nikolay Sivov (＠nsivov)]

Signed-off-by: Nikolay Sivov

[PATCH 1/1] vkd3d-shader/hlsl: Remove conditional branching when condition is a compile time constant.

[Nikolay Sivov]

From: Nikolay Sivov

Signed-off-by: Nikolay Sivov 
---
 libs/vkd3d-shader/hlsl_codegen.c          | 20 ++++++++++++++++++++
 tests/hlsl/conditional.shader_test        | 17 +++++++++++++++++
 tests/hlsl/static-initializer.shader_test |  4 ++--
 3 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/libs/vkd3d-shader/hlsl_codegen.c b/libs/vkd3d-shader/hlsl_codegen.c
index 76572cf93..a958bedb7 100644
--- a/libs/vkd3d-shader/hlsl_codegen.c
+++ b/libs/vkd3d-shader/hlsl_codegen.c
@@ -2062,6 +2062,25 @@ static bool remove_trivial_swizzles(struct hlsl_ctx *ctx, struct hlsl_ir_node *i
     return true;
 }

+static bool remove_trivial_conditional_branches(struct hlsl_ctx *ctx, struct hlsl_ir_node *instr, void *context)
+{
+    struct hlsl_ir_constant *condition;
+    struct hlsl_ir_if *iff;
+
+    if (instr->type != HLSL_IR_IF)
+        return false;
+    iff = hlsl_ir_if(instr);
+    if (iff->condition.node->type != HLSL_IR_CONSTANT)
+        return false;
+    condition = hlsl_ir_constant(iff->condition.node);
+
+    list_move_before(&instr->entry, condition->value.u[0].u ? &iff->then_block.instrs : &iff->else_block.instrs);
+    list_remove(&instr->entry);
+    hlsl_free_instr(instr);
+
+    return true;
+}
+
 static bool lower_nonconstant_vector_derefs(struct hlsl_ctx *ctx, struct hlsl_ir_node *instr, struct hlsl_block *block)
 {
     struct hlsl_ir_node *idx;
@@ -4408,6 +4427,7 @@ int hlsl_emit_bytecode(struct hlsl_ctx *ctx, struct hlsl_ir_function_decl *entry
         progress |= hlsl_copy_propagation_execute(ctx, body);
         progress |= hlsl_transform_ir(ctx, fold_swizzle_chains, body, NULL);
         progress |= hlsl_transform_ir(ctx, remove_trivial_swizzles, body, NULL);
+        progress |= hlsl_transform_ir(ctx, remove_trivial_conditional_branches, body, NULL);
     }
     while (progress);

diff --git a/tests/hlsl/conditional.shader_test b/tests/hlsl/conditional.shader_test
index b3b18dc1a..810f7366a 100644
--- a/tests/hlsl/conditional.shader_test
+++ b/tests/hlsl/conditional.shader_test
@@ -82,3 +82,20 @@ float4 main(uniform float4 u) : sv_target
 uniform 0 float4 0.0 0.0 0.0 0.0
 draw quad
 probe all rgba (0.9, 0.8, 0.7, 0.6)
+
+[pixel shader]
+float4 main() : sv_target
+{
+    bool c = false;
+    float a = -1.0f;
+    if (c)
+        return float4(1.0, 2.0, 3.0, 4.0);
+    else if (a > 0)
+        return float4(5.0, 6.0, 7.0, 8.0);
+    else
+        return float4(9.0, 10.0, 11.0, 12.0);
+}
+
+[test]
+draw quad
+probe all rgba (9.0, 10.0, 11.0, 12.0)
diff --git a/tests/hlsl/static-initializer.shader_test b/tests/hlsl/static-initializer.shader_test
index 8415d851a..394b4a9af 100644
--- a/tests/hlsl/static-initializer.shader_test
+++ b/tests/hlsl/static-initializer.shader_test
@@ -85,7 +85,7 @@ float4 main() : sv_target
 }

-[pixel shader todo]
+[pixel shader]
 // This is allowed in 10.0.10011.16384 but not in 9.29.952.3111
 static Texture2D tex;
 sampler sam;
@@ -177,7 +177,7 @@ size (1, 1)
 0.5

-[pixel shader todo]
+[pixel shader]
 // This is allowed in 10.0.10011.16384 but not in 9.29.952.3111
 static RWTexture2D<float> tex;

[PATCH 0/1] MR375: vkd3d-shader/hlsl: Remove conditional branching when condition is a compile time constant. - approved

[Giovanni Mascellani (＠giomasce)]

This merge request was approved by Giovanni Mascellani.

[PATCH 0/1] MR375: vkd3d-shader/hlsl: Remove conditional branching when condition is a compile time constant. - approved

[Zebediah Figura (＠zfigura)]

This merge request was approved by Zebediah Figura.

[PATCH 0/1] MR375: vkd3d-shader/hlsl: Remove conditional branching when condition is a compile time constant. - approved

[Henri Verbeet (＠hverbeet)]

This merge request was approved by Henri Verbeet.