[PATCH v2 2/4] vkd3d-shader/hlsl: Add constant folding for lshift.

[Nikolay Sivov]

From: Nikolay Sivov

Signed-off-by: Nikolay Sivov 
---
 libs/vkd3d-shader/hlsl_constant_ops.c | 34 +++++++++++++++++++++++++++
 tests/hlsl/bitwise.shader_test        | 15 ++++++++++++
 2 files changed, 49 insertions(+)

diff --git a/libs/vkd3d-shader/hlsl_constant_ops.c b/libs/vkd3d-shader/hlsl_constant_ops.c
index 3b4c86dc..b681b2d3 100644
--- a/libs/vkd3d-shader/hlsl_constant_ops.c
+++ b/libs/vkd3d-shader/hlsl_constant_ops.c
@@ -832,6 +832,36 @@ static bool fold_less(struct hlsl_ctx *ctx, struct hlsl_constant_value *dst, con
     return true;
 }

+static bool fold_lshift(struct hlsl_ctx *ctx, struct hlsl_constant_value *dst, const struct hlsl_type *dst_type,
+        const struct hlsl_ir_constant *src1, const struct hlsl_ir_constant *src2)
+{
+    unsigned int k;
+
+    assert(dst_type->base_type == src1->node.data_type->base_type);
+    assert(src2->node.data_type->base_type == HLSL_TYPE_INT);
+
+    for (k = 0; k < dst_type->dimx; ++k)
+    {
+        unsigned int shift = src2->value.u[k].u % 32;
+
+        switch (src1->node.data_type->base_type)
+        {
+            case HLSL_TYPE_INT:
+                dst->u[k].i = src1->value.u[k].i << shift;
+                break;
+
+            case HLSL_TYPE_UINT:
+                dst->u[k].u = src1->value.u[k].u << shift;
+                break;
+
+            default:
+                vkd3d_unreachable();
+        }
+    }
+
+    return true;
+}
+
 static bool fold_max(struct hlsl_ctx *ctx, struct hlsl_constant_value *dst, const struct hlsl_type *dst_type,
         const struct hlsl_ir_constant *src1, const struct hlsl_ir_constant *src2)
 {
@@ -1169,6 +1199,10 @@ bool hlsl_fold_constant_exprs(struct hlsl_ctx *ctx, struct hlsl_ir_node *instr,
             success = fold_less(ctx, &res, instr->data_type, arg1, arg2);
             break;

+        case HLSL_OP2_LSHIFT:
+            success = fold_lshift(ctx, &res, instr->data_type, arg1, arg2);
+            break;
+
         case HLSL_OP2_MAX:
             success = fold_max(ctx, &res, instr->data_type, arg1, arg2);
             break;
diff --git a/tests/hlsl/bitwise.shader_test b/tests/hlsl/bitwise.shader_test
index 55160037..08f02105 100644
--- a/tests/hlsl/bitwise.shader_test
+++ b/tests/hlsl/bitwise.shader_test
@@ -14,6 +14,21 @@ float4 main() : SV_TARGET
 draw quad
 probe all rgba (0.0, 0.0, 163840.0, 480.0)

+[pixel shader]
+float4 main() : sv_target
+{
+    int x = 1;
+    int y = -1;
+    int z = 34;
+    uint x2 = 1;
+
+    return float4(x << y, x << z, x2 << y, x2 << z);
+}
+
+[test]
+draw quad
+probe all rgba (-2147483648.0, 4.0, 2147483650.0, 4.0)
+
 [pixel shader]
 float4 main() : SV_TARGET
 {