From 7c6923136718aab50fc20a327e47c0c23517dda2 Mon Sep 17 00:00:00 2001
From: Robin Voetter <robin@voetter.nl>
Date: Sun, 20 Oct 2024 16:59:32 +0200
Subject: [PATCH] spirv: use PhysicalStorageBuffer64 for global pointers under
 vk

We can use real pointers with this storage class!!
---
 src/codegen/spirv.zig |  9 +++++++--
 src/link/SpirV.zig    | 30 +++++++++++++++++++++---------
 2 files changed, 28 insertions(+), 11 deletions(-)

diff --git a/src/codegen/spirv.zig b/src/codegen/spirv.zig
index da527c9ac8..b0253ff2cf 100644
--- a/src/codegen/spirv.zig
+++ b/src/codegen/spirv.zig
@@ -1843,11 +1843,16 @@ const NavGen = struct {
         return switch (as) {
             .generic => switch (target.os.tag) {
                 .vulkan => .Private,
-                else => .Generic,
+                .opencl => .Generic,
+                else => unreachable,
             },
             .shared => .Workgroup,
             .local => .Private,
-            .global => .CrossWorkgroup,
+            .global => switch (target.os.tag) {
+                .opencl => .CrossWorkgroup,
+                .vulkan => .PhysicalStorageBuffer,
+                else => unreachable,
+            },
             .constant => .UniformConstant,
             .input => .Input,
             .output => .Output,
diff --git a/src/link/SpirV.zig b/src/link/SpirV.zig
index 59ca27d48e..045bd05d84 100644
--- a/src/link/SpirV.zig
+++ b/src/link/SpirV.zig
@@ -296,9 +296,8 @@ fn writeCapabilities(spv: *SpvModule, target: std.Target) !void {
     // TODO: Integrate with a hypothetical feature system
     const caps: []const spec.Capability = switch (target.os.tag) {
         .opencl => &.{ .Kernel, .Addresses, .Int8, .Int16, .Int64, .Float64, .Float16, .Vector16, .GenericPointer },
-        .opengl => &.{.Shader},
-        .vulkan => &.{ .Shader, .VariablePointersStorageBuffer, .Int8, .Int16, .Int64, .Float64, .Float16 },
-        else => unreachable, // TODO
+        .vulkan => &.{ .Shader, .PhysicalStorageBufferAddresses, .StoragePushConstant16, .Int8, .Int16, .Int64, .Float64, .Float16 },
+        else => unreachable,
     };
 
     for (caps) |cap| {
@@ -306,19 +305,32 @@ fn writeCapabilities(spv: *SpvModule, target: std.Target) !void {
             .capability = cap,
         });
     }
+
+    switch (target.os.tag) {
+        .vulkan => {
+            try spv.sections.extensions.emit(gpa, .OpExtension, .{
+                .name = "SPV_KHR_physical_storage_buffer",
+            });
+        },
+        else => {},
+    }
 }
 
 fn writeMemoryModel(spv: *SpvModule, target: std.Target) !void {
     const gpa = spv.gpa;
 
-    const addressing_model = switch (target.os.tag) {
+    const addressing_model: spec.AddressingModel = switch (target.os.tag) {
         .opencl => switch (target.cpu.arch) {
-            .spirv32 => spec.AddressingModel.Physical32,
-            .spirv64 => spec.AddressingModel.Physical64,
-            else => unreachable, // TODO
+            .spirv32 => .Physical32,
+            .spirv64 => .Physical64,
+            else => unreachable,
         },
-        .opengl, .vulkan => spec.AddressingModel.Logical,
-        else => unreachable, // TODO
+        .opengl, .vulkan => switch (target.cpu.arch) {
+            .spirv32 => .Logical, // TODO: I don't think this will ever be implemented.
+            .spirv64 => .PhysicalStorageBuffer64,
+            else => unreachable,
+        },
+        else => unreachable,
     };
 
     const memory_model: spec.MemoryModel = switch (target.os.tag) {