From 12a3a8b100b7af4110cdc30de4def7d8f8d8c148 Mon Sep 17 00:00:00 2001
From: Robin Voetter <robin@voetter.nl>
Date: Sun, 11 Dec 2022 13:39:29 +0100
Subject: [PATCH] spirv: slice constants

Implements lowering slice constants in the SPIR-V backend
---
 src/codegen/spirv.zig | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/codegen/spirv.zig b/src/codegen/spirv.zig
index 7df4360c41..fb5cdbd126 100644
--- a/src/codegen/spirv.zig
+++ b/src/codegen/spirv.zig
@@ -586,7 +586,23 @@ pub const DeclGen = struct {
                     try self.genDeclRef(decl_result_id, decl_index);
                     try self.variable(.global, result_id, result_ty_ref, decl_result_id);
                 },
-                else => return self.todo("constant pointer of value type {s}", .{@tagName(val.tag())}),
+                .slice => {
+                    const slice = val.castTag(.slice).?.data;
+                    var buf: Type.SlicePtrFieldTypeBuffer = undefined;
+
+                    const ptr_id = self.spv.allocId();
+                    try self.genConstant(ptr_id, ty.slicePtrFieldType(&buf), slice.ptr, .indirect);
+                    const len_id = self.spv.allocId();
+                    try self.genConstant(len_id, Type.usize, slice.len, .indirect);
+
+                    const constituents = [_]IdRef{ ptr_id, len_id };
+                    try section.emit(self.spv.gpa, .OpSpecConstantComposite, .{
+                        .id_result_type = result_ty_id,
+                        .id_result = result_id,
+                        .constituents = &constituents,
+                    });
+                },
+                else => return self.todo("pointer of value type {s}", .{@tagName(val.tag())}),
             },
             .Fn => switch (repr) {
                 .direct => unreachable,