Merge pull request ziglang#19337 from Snektron/spirv-globals

spirv: rework generic global

src/codegen/spirv/Assembler.zig

@@ -194,6 +194,11 @@ inst: struct {
 /// This map maps results to their tracked values.
 value_map: AsmValueMap = .{},
 
+/// This set is used to quickly transform from an opcode name to the
+/// index in its instruction set. The index of the key is the
+/// index in `spec.InstructionSet.core.instructions()`.
+instruction_map: std.StringArrayHashMapUnmanaged(void) = .{},
+
 /// Free the resources owned by this assembler.
 pub fn deinit(self: *Assembler) void {
     for (self.errors.items) |err| {
@@ -204,9 +209,20 @@ pub fn deinit(self: *Assembler) void {
     self.inst.operands.deinit(self.gpa);
     self.inst.string_bytes.deinit(self.gpa);
     self.value_map.deinit(self.gpa);
+    self.instruction_map.deinit(self.gpa);
 }
 
 pub fn assemble(self: *Assembler) Error!void {
+    // Populate the opcode map if it isn't already
+    if (self.instruction_map.count() == 0) {
+        const instructions = spec.InstructionSet.core.instructions();
+        try self.instruction_map.ensureUnusedCapacity(self.gpa, @intCast(instructions.len));
+        for (spec.InstructionSet.core.instructions(), 0..) |inst, i| {
+            const entry = try self.instruction_map.getOrPut(self.gpa, inst.name);
+            assert(entry.index == i);
+        }
+    }
+
     try self.tokenize();
     while (!self.testToken(.eof)) {
         try self.parseInstruction();
@@ -475,12 +491,14 @@ fn parseInstruction(self: *Assembler) !void {
     }
 
     const opcode_text = self.tokenText(opcode_tok);
-    @setEvalBranchQuota(10000);
-    self.inst.opcode = std.meta.stringToEnum(Opcode, opcode_text) orelse {
+    const index = self.instruction_map.getIndex(opcode_text) orelse {
         return self.fail(opcode_tok.start, "invalid opcode '{s}'", .{opcode_text});
     };
 
-    const expected_operands = self.inst.opcode.operands();
+    const inst = spec.InstructionSet.core.instructions()[index];
+    self.inst.opcode = @enumFromInt(inst.opcode);
+
+    const expected_operands = inst.operands;
     // This is a loop because the result-id is not always the first operand.
     const requires_lhs_result = for (expected_operands) |op| {
         if (op.kind == .IdResult) break true;

src/codegen/spirv/Cache.zig

@@ -134,7 +134,10 @@ const Tag = enum {
     /// data is (bool) type
     bool_false,
 
-    const SimpleType = enum { void, bool };
+    const SimpleType = enum {
+        void,
+        bool,
+    };
 
     const VectorType = Key.VectorType;
     const ArrayType = Key.ArrayType;
@@ -287,11 +290,12 @@ pub const Key = union(enum) {
     pub const PointerType = struct {
         storage_class: StorageClass,
         child_type: Ref,
+        /// Ref to a .fwd_ptr_type.
         fwd: Ref,
         // TODO: Decorations:
         // - Alignment
-        // - ArrayStride,
-        // - MaxByteOffset,
+        // - ArrayStride
+        // - MaxByteOffset
     };
 
     pub const ForwardPointerType = struct {
@@ -728,6 +732,9 @@ pub fn resolve(self: *Self, spv: *Module, key: Key) !Ref {
         // },
         .ptr_type => |ptr| Item{
             .tag = .type_ptr_simple,
+            // For this variant we need to steal the ID of the forward-declaration, instead
+            // of allocating one manually. This will make sure that we get a single result-id
+            // any possibly forward declared pointer type.
             .result_id = self.resultId(ptr.fwd),
             .data = try self.addExtra(spv, Tag.SimplePointerType{
                 .storage_class = ptr.storage_class,
@@ -896,24 +903,6 @@ pub fn lookup(self: *const Self, ref: Ref) Key {
                 },
             };
         },
-        // .type_ptr_generic => .{
-        //     .ptr_type = .{
-        //         .storage_class = .Generic,
-        //         .child_type = @enumFromInt(data),
-        //     },
-        // },
-        // .type_ptr_crosswgp => .{
-        //     .ptr_type = .{
-        //         .storage_class = .CrossWorkgroup,
-        //         .child_type = @enumFromInt(data),
-        //     },
-        // },
-        // .type_ptr_function => .{
-        //     .ptr_type = .{
-        //         .storage_class = .Function,
-        //         .child_type = @enumFromInt(data),
-        //     },
-        // },
         .type_ptr_simple => {
             const payload = self.extraData(Tag.SimplePointerType, data);
             return .{