working on function calls; ci skip

example/main.zig

@@ -19,7 +19,7 @@ pub fn main() !void {
         try rt.callEntryPoint(allocator, try rt.getEntryPointByName("main"));
         var output: [4]f32 = undefined;
         try rt.readOutput(f32, output[0..output.len], try rt.getResultByName("color"));
-        std.log.info("Output: Vec4[{d}, {d}, {d}, {d}]", .{ output[0], output[1], output[2], output[3] });
+        std.log.info("Output: Vec4{any}", .{output});
     }
     std.log.info("Successfully executed", .{});
 }

example/shader.nzsl

@@ -1,24 +1,21 @@
- [nzsl_version("1.1")]
- [feature(float64)]
- module;
- 
- struct FragOut
- {
-     [location(0)] color: vec4[f32]
- }
+[nzsl_version("1.1")]
+[feature(float64)]
+module;
 
- [entry(frag)]
- fn main() -> FragOut
- {
-     let op1: f64 = 0.0;
-     let op2: f64 = 9.0;
-     let color: f32;
-     if (op1 == op2)
-         color = f32(op1);
-     else
-         color = f32(op2);
+struct FragOut
+{
+    [location(0)] color: vec4[f32]
+}
 
-     let output: FragOut;
-     output.color = vec4[f32](color, color, color, color);
-     return output;
- }
+fn computeColor() -> f32
+{
+	return 1.0;
+}
+
+[entry(frag)]
+fn main() -> FragOut
+{
+    let output: FragOut;
+    output.color = vec4[f32](computeColor(), computeColor(), computeColor(), computeColor());
+    return output;
+}

example/shader.spv.txt

@@ -1,70 +1,50 @@
 Version 1.0
 Generator: 2560130
-Bound: 42
+Bound: 27
 Schema: 0
       OpCapability Capability(Shader)
       OpCapability Capability(Float64)
       OpMemoryModel AddressingModel(Logical) MemoryModel(GLSL450)
-      OpEntryPoint ExecutionModel(Fragment) %17 "main" %6
-      OpExecutionMode %17 ExecutionMode(OriginUpperLeft)
+      OpEntryPoint ExecutionModel(Fragment) %14 "main" %8
+      OpExecutionMode %14 ExecutionMode(OriginUpperLeft)
       OpSource SourceLanguage(NZSL) 4198400
       OpSourceExtension "Version: 1.1"
-      OpName %7 "FragOut"
-      OpMemberName %7 0 "color"
-      OpName %6 "color"
-      OpName %17 "main"
-      OpDecorate %6 Decoration(Location) 0
-      OpMemberDecorate %7 0 Decoration(Offset) 0
- %1 = OpTypeVoid
+      OpName %9 "FragOut"
+      OpMemberName %9 0 "color"
+      OpName %8 "color"
+      OpName %13 "computeColor"
+      OpName %14 "main"
+      OpDecorate %8 Decoration(Location) 0
+      OpMemberDecorate %9 0 Decoration(Offset) 0
+ %1 = OpTypeFloat 32
  %2 = OpTypeFunction %1
- %3 = OpTypeFloat 32
- %4 = OpTypeVector %3 4
- %5 = OpTypePointer StorageClass(Output) %4
- %7 = OpTypeStruct %4
- %8 = OpTypeFloat 64
- %9 = OpConstant %8 f64(0)
-%10 = OpTypePointer StorageClass(Function) %8
-%11 = OpConstant %8 f64(9)
-%12 = OpTypePointer StorageClass(Function) %3
-%13 = OpTypeBool
-%14 = OpTypePointer StorageClass(Function) %7
-%15 = OpTypeInt 32 1
-%16 = OpConstant %15 i32(0)
-%39 = OpTypePointer StorageClass(Function) %4
- %6 = OpVariable %5 StorageClass(Output)
-%17 = OpFunction %1 FunctionControl(0) %2
-%18 = OpLabel
-%19 = OpVariable %10 StorageClass(Function)
-%20 = OpVariable %10 StorageClass(Function)
-%21 = OpVariable %12 StorageClass(Function)
-%22 = OpVariable %14 StorageClass(Function)
-      OpStore %19 %9
-      OpStore %20 %11
-%26 = OpLoad %8 %19
-%27 = OpLoad %8 %20
-%28 = OpFOrdEqual %13 %26 %27
-      OpSelectionMerge %23 SelectionControl(0)
-      OpBranchConditional %28 %24 %25
-%24 = OpLabel
-%29 = OpLoad %8 %19
-%30 = OpFConvert %3 %29
-      OpStore %21 %30
-      OpBranch %23
-%25 = OpLabel
-%31 = OpLoad %8 %20
-%32 = OpFConvert %3 %31
-      OpStore %21 %32
-      OpBranch %23
-%23 = OpLabel
-%33 = OpLoad %3 %21
-%34 = OpLoad %3 %21
-%35 = OpLoad %3 %21
-%36 = OpLoad %3 %21
-%37 = OpCompositeConstruct %4 %33 %34 %35 %36
-%38 = OpAccessChain %39 %22 %16
-      OpStore %38 %37
-%40 = OpLoad %7 %22
-%41 = OpCompositeExtract %4 %40 0
-      OpStore %6 %41
+ %3 = OpConstant %1 f32(1)
+ %4 = OpTypeVoid
+ %5 = OpTypeFunction %4
+ %6 = OpTypeVector %1 4
+ %7 = OpTypePointer StorageClass(Output) %6
+ %9 = OpTypeStruct %6
+%10 = OpTypePointer StorageClass(Function) %9
+%11 = OpTypeInt 32 1
+%12 = OpConstant %11 i32(0)
+%24 = OpTypePointer StorageClass(Function) %6
+ %8 = OpVariable %7 StorageClass(Output)
+%13 = OpFunction %1 FunctionControl(0) %2
+%15 = OpLabel
+      OpReturnValue %3
+      OpFunctionEnd
+%14 = OpFunction %4 FunctionControl(0) %5
+%16 = OpLabel
+%17 = OpVariable %10 StorageClass(Function)
+%18 = OpFunctionCall %1 %13
+%19 = OpFunctionCall %1 %13
+%20 = OpFunctionCall %1 %13
+%21 = OpFunctionCall %1 %13
+%22 = OpCompositeConstruct %6 %18 %19 %20 %21
+%23 = OpAccessChain %24 %17 %12
+      OpStore %23 %22
+%25 = OpLoad %9 %17
+%26 = OpCompositeExtract %6 %25 0
+      OpStore %8 %26
       OpReturn
       OpFunctionEnd

src/opcodes.zig

@@ -36,6 +36,152 @@ const CondOp = enum {
     LessEqual,
 };
 
+pub const OpCodeFunc = *const fn (std.mem.Allocator, SpvWord, *Runtime) RuntimeError!void;
+
+pub const SetupDispatcher = block: {
+    @setEvalBranchQuota(65535);
+    break :block std.EnumMap(spv.SpvOp, OpCodeFunc).init(.{
+        .Bitcast = autoSetupConstant,
+        .Capability = opCapability,
+        .CompositeConstruct = autoSetupConstant,
+        .Constant = opConstant,
+        .ConvertFToS = autoSetupConstant,
+        .ConvertFToU = autoSetupConstant,
+        .ConvertPtrToU = autoSetupConstant,
+        .ConvertSToF = autoSetupConstant,
+        .ConvertUToF = autoSetupConstant,
+        .ConvertUToPtr = autoSetupConstant,
+        .Decorate = opDecorate,
+        .EntryPoint = opEntryPoint,
+        .ExecutionMode = opExecutionMode,
+        .FAdd = autoSetupConstant,
+        .FConvert = autoSetupConstant,
+        .FDiv = autoSetupConstant,
+        .FMod = autoSetupConstant,
+        .FMul = autoSetupConstant,
+        .FOrdEqual = autoSetupConstant,
+        .FOrdGreaterThan = autoSetupConstant,
+        .FOrdGreaterThanEqual = autoSetupConstant,
+        .FOrdLessThan = autoSetupConstant,
+        .FOrdLessThanEqual = autoSetupConstant,
+        .FOrdNotEqual = autoSetupConstant,
+        .FSub = autoSetupConstant,
+        .FUnordEqual = autoSetupConstant,
+        .FUnordGreaterThan = autoSetupConstant,
+        .FUnordGreaterThanEqual = autoSetupConstant,
+        .FUnordLessThan = autoSetupConstant,
+        .FUnordLessThanEqual = autoSetupConstant,
+        .FUnordNotEqual = autoSetupConstant,
+        .Function = opFunction,
+        .FunctionCall = autoSetupConstant,
+        .FunctionEnd = opFunctionEnd,
+        .IAdd = autoSetupConstant,
+        .IEqual = autoSetupConstant,
+        .IMul = autoSetupConstant,
+        .INotEqual = autoSetupConstant,
+        .ISub = autoSetupConstant,
+        .Label = opLabel,
+        .Load = autoSetupConstant,
+        .MemberDecorate = opDecorateMember,
+        .MemberName = opMemberName,
+        .MemoryModel = opMemoryModel,
+        .Name = opName,
+        .QuantizeToF16 = autoSetupConstant,
+        .SConvert = autoSetupConstant,
+        .SDiv = autoSetupConstant,
+        .SGreaterThan = autoSetupConstant,
+        .SGreaterThanEqual = autoSetupConstant,
+        .SLessThan = autoSetupConstant,
+        .SLessThanEqual = autoSetupConstant,
+        .SMod = autoSetupConstant,
+        .SatConvertSToU = autoSetupConstant,
+        .SatConvertUToS = autoSetupConstant,
+        .Source = opSource,
+        .SourceExtension = opSourceExtension,
+        .TypeBool = opTypeBool,
+        .TypeFloat = opTypeFloat,
+        .TypeFunction = opTypeFunction,
+        .TypeInt = opTypeInt,
+        .TypeMatrix = opTypeMatrix,
+        .TypePointer = opTypePointer,
+        .TypeStruct = opTypeStruct,
+        .TypeVector = opTypeVector,
+        .TypeVoid = opTypeVoid,
+        .UConvert = autoSetupConstant,
+        .UDiv = autoSetupConstant,
+        .UGreaterThan = autoSetupConstant,
+        .UGreaterThanEqual = autoSetupConstant,
+        .ULessThan = autoSetupConstant,
+        .ULessThanEqual = autoSetupConstant,
+        .UMod = autoSetupConstant,
+        .Variable = opVariable,
+    });
+};
+
+pub const RuntimeDispatcher = block: {
+    @setEvalBranchQuota(65535);
+    break :block std.EnumMap(spv.SpvOp, OpCodeFunc).init(.{
+        .AccessChain = opAccessChain,
+        .Bitcast = opBitcast,
+        .Branch = opBranch,
+        .BranchConditional = opBranchConditional,
+        .CompositeConstruct = opCompositeConstruct,
+        .CompositeExtract = opCompositeExtract,
+        .ConvertFToS = ConversionEngine(.Float, .SInt).op,
+        .ConvertFToU = ConversionEngine(.Float, .UInt).op,
+        .ConvertSToF = ConversionEngine(.SInt, .Float).op,
+        .ConvertUToF = ConversionEngine(.UInt, .Float).op,
+        .FAdd = MathEngine(.Float, .Add).op,
+        .FConvert = ConversionEngine(.Float, .Float).op,
+        .FDiv = MathEngine(.Float, .Div).op,
+        .FMod = MathEngine(.Float, .Mod).op,
+        .FMul = MathEngine(.Float, .Mul).op,
+        .FOrdEqual = CondEngine(.Float, .Equal).op,
+        .FOrdGreaterThan = CondEngine(.Float, .Greater).op,
+        .FOrdGreaterThanEqual = CondEngine(.Float, .GreaterEqual).op,
+        .FOrdLessThan = CondEngine(.Float, .Less).op,
+        .FOrdLessThanEqual = CondEngine(.Float, .LessEqual).op,
+        .FOrdNotEqual = CondEngine(.Float, .NotEqual).op,
+        .FSub = MathEngine(.Float, .Sub).op,
+        .FUnordEqual = CondEngine(.Float, .Equal).op,
+        .FUnordGreaterThan = CondEngine(.Float, .Greater).op,
+        .FUnordGreaterThanEqual = CondEngine(.Float, .GreaterEqual).op,
+        .FUnordLessThan = CondEngine(.Float, .Less).op,
+        .FUnordLessThanEqual = CondEngine(.Float, .LessEqual).op,
+        .FUnordNotEqual = CondEngine(.Float, .NotEqual).op,
+        .FunctionCall = opFunctionCall,
+        .IAdd = MathEngine(.SInt, .Add).op,
+        .IEqual = CondEngine(.SInt, .Equal).op,
+        .IMul = MathEngine(.SInt, .Mul).op,
+        .INotEqual = CondEngine(.SInt, .NotEqual).op,
+        .ISub = MathEngine(.SInt, .Sub).op,
+        .Load = opLoad,
+        .Return = opReturn,
+        .ReturnValue = opReturnValue,
+        .SConvert = ConversionEngine(.SInt, .SInt).op,
+        .SDiv = MathEngine(.SInt, .Div).op,
+        .SGreaterThan = CondEngine(.SInt, .Greater).op,
+        .SGreaterThanEqual = CondEngine(.SInt, .GreaterEqual).op,
+        .SLessThan = CondEngine(.SInt, .Less).op,
+        .SLessThanEqual = CondEngine(.SInt, .LessEqual).op,
+        .SMod = MathEngine(.SInt, .Mod).op,
+        .Store = opStore,
+        .UConvert = ConversionEngine(.UInt, .UInt).op,
+        .UDiv = MathEngine(.UInt, .Div).op,
+        .UGreaterThan = CondEngine(.UInt, .Greater).op,
+        .UGreaterThanEqual = CondEngine(.UInt, .GreaterEqual).op,
+        .ULessThan = CondEngine(.UInt, .Less).op,
+        .ULessThanEqual = CondEngine(.UInt, .LessEqual).op,
+        .UMod = MathEngine(.UInt, .Mod).op,
+
+        //.QuantizeToF16  = ,
+        //.ConvertPtrToU  = ,
+        //.SatConvertSToU = ,
+        //.SatConvertUToS = ,
+        //.ConvertUToPtr  = ,
+    });
+};
+
 fn CondEngine(comptime T: ValueType, comptime Op: CondOp) type {
     return struct {
         fn op(_: std.mem.Allocator, _: SpvWord, rt: *Runtime) RuntimeError!void {
@@ -156,148 +302,6 @@ fn ConversionEngine(comptime From: ValueType, comptime To: ValueType) type {
     };
 }
 
-pub const OpCodeFunc = *const fn (std.mem.Allocator, SpvWord, *Runtime) RuntimeError!void;
-
-pub const SetupDispatcher = block: {
-    @setEvalBranchQuota(65535);
-    break :block std.EnumMap(spv.SpvOp, OpCodeFunc).init(.{
-        .Capability = opCapability,
-        .CompositeConstruct = autoSetupConstant,
-        .Constant = opConstant,
-        .Decorate = opDecorate,
-        .EntryPoint = opEntryPoint,
-        .ExecutionMode = opExecutionMode,
-        .FAdd = autoSetupConstant,
-        .FDiv = autoSetupConstant,
-        .FMod = autoSetupConstant,
-        .FMul = autoSetupConstant,
-        .FOrdEqual = autoSetupConstant,
-        .FOrdGreaterThan = autoSetupConstant,
-        .FOrdGreaterThanEqual = autoSetupConstant,
-        .FOrdLessThan = autoSetupConstant,
-        .FOrdLessThanEqual = autoSetupConstant,
-        .FOrdNotEqual = autoSetupConstant,
-        .FSub = autoSetupConstant,
-        .FUnordEqual = autoSetupConstant,
-        .FUnordGreaterThan = autoSetupConstant,
-        .FUnordGreaterThanEqual = autoSetupConstant,
-        .FUnordLessThan = autoSetupConstant,
-        .FUnordLessThanEqual = autoSetupConstant,
-        .FUnordNotEqual = autoSetupConstant,
-        .Function = opFunction,
-        .FunctionEnd = opFunctionEnd,
-        .IAdd = autoSetupConstant,
-        .IEqual = autoSetupConstant,
-        .IMul = autoSetupConstant,
-        .INotEqual = autoSetupConstant,
-        .ISub = autoSetupConstant,
-        .Label = opLabel,
-        .Load = autoSetupConstant,
-        .MemberDecorate = opDecorateMember,
-        .MemberName = opMemberName,
-        .MemoryModel = opMemoryModel,
-        .Name = opName,
-        .SDiv = autoSetupConstant,
-        .SGreaterThan = autoSetupConstant,
-        .SGreaterThanEqual = autoSetupConstant,
-        .SLessThan = autoSetupConstant,
-        .SLessThanEqual = autoSetupConstant,
-        .SMod = autoSetupConstant,
-        .Source = opSource,
-        .SourceExtension = opSourceExtension,
-        .TypeBool = opTypeBool,
-        .TypeFloat = opTypeFloat,
-        .TypeFunction = opTypeFunction,
-        .TypeInt = opTypeInt,
-        .TypeMatrix = opTypeMatrix,
-        .TypePointer = opTypePointer,
-        .TypeStruct = opTypeStruct,
-        .TypeVector = opTypeVector,
-        .TypeVoid = opTypeVoid,
-        .UDiv = autoSetupConstant,
-        .UGreaterThan = autoSetupConstant,
-        .UGreaterThanEqual = autoSetupConstant,
-        .ULessThan = autoSetupConstant,
-        .ULessThanEqual = autoSetupConstant,
-        .UMod = autoSetupConstant,
-        .Variable = opVariable,
-
-        .ConvertFToU = autoSetupConstant,
-        .ConvertFToS = autoSetupConstant,
-        .ConvertSToF = autoSetupConstant,
-        .ConvertUToF = autoSetupConstant,
-        .UConvert = autoSetupConstant,
-        .SConvert = autoSetupConstant,
-        .FConvert = autoSetupConstant,
-        .QuantizeToF16 = autoSetupConstant,
-        .ConvertPtrToU = autoSetupConstant,
-        .SatConvertSToU = autoSetupConstant,
-        .SatConvertUToS = autoSetupConstant,
-        .ConvertUToPtr = autoSetupConstant,
-    });
-};
-
-pub const RuntimeDispatcher = block: {
-    @setEvalBranchQuota(65535);
-    break :block std.EnumMap(spv.SpvOp, OpCodeFunc).init(.{
-        .AccessChain = opAccessChain,
-        .Branch = opBranch,
-        .BranchConditional = opBranchConditional,
-        .CompositeConstruct = opCompositeConstruct,
-        .CompositeExtract = opCompositeExtract,
-        .FAdd = MathEngine(.Float, .Add).op,
-        .FDiv = MathEngine(.Float, .Div).op,
-        .FMod = MathEngine(.Float, .Mod).op,
-        .FMul = MathEngine(.Float, .Mul).op,
-        .FOrdEqual = CondEngine(.Float, .Equal).op,
-        .FOrdGreaterThan = CondEngine(.Float, .Greater).op,
-        .FOrdGreaterThanEqual = CondEngine(.Float, .GreaterEqual).op,
-        .FOrdLessThan = CondEngine(.Float, .Less).op,
-        .FOrdLessThanEqual = CondEngine(.Float, .LessEqual).op,
-        .FOrdNotEqual = CondEngine(.Float, .NotEqual).op,
-        .FSub = MathEngine(.Float, .Sub).op,
-        .FUnordEqual = CondEngine(.Float, .Equal).op,
-        .FUnordGreaterThan = CondEngine(.Float, .Greater).op,
-        .FUnordGreaterThanEqual = CondEngine(.Float, .GreaterEqual).op,
-        .FUnordLessThan = CondEngine(.Float, .Less).op,
-        .FUnordLessThanEqual = CondEngine(.Float, .LessEqual).op,
-        .FUnordNotEqual = CondEngine(.Float, .NotEqual).op,
-        .IAdd = MathEngine(.SInt, .Add).op,
-        .IEqual = CondEngine(.SInt, .Equal).op,
-        .IMul = MathEngine(.SInt, .Mul).op,
-        .INotEqual = CondEngine(.SInt, .NotEqual).op,
-        .ISub = MathEngine(.SInt, .Sub).op,
-        .Load = opLoad,
-        .Return = opReturn,
-        .SDiv = MathEngine(.SInt, .Div).op,
-        .SGreaterThan = CondEngine(.SInt, .Greater).op,
-        .SGreaterThanEqual = CondEngine(.SInt, .GreaterEqual).op,
-        .SLessThan = CondEngine(.SInt, .Less).op,
-        .SLessThanEqual = CondEngine(.SInt, .LessEqual).op,
-        .SMod = MathEngine(.SInt, .Mod).op,
-        .Store = opStore,
-        .UDiv = MathEngine(.UInt, .Div).op,
-        .UGreaterThan = CondEngine(.UInt, .Greater).op,
-        .UGreaterThanEqual = CondEngine(.UInt, .GreaterEqual).op,
-        .ULessThan = CondEngine(.UInt, .Less).op,
-        .ULessThanEqual = CondEngine(.UInt, .LessEqual).op,
-        .UMod = MathEngine(.UInt, .Mod).op,
-
-        .ConvertFToU = ConversionEngine(.Float, .UInt).op,
-        .ConvertFToS = ConversionEngine(.Float, .SInt).op,
-        .ConvertSToF = ConversionEngine(.SInt, .Float).op,
-        .ConvertUToF = ConversionEngine(.UInt, .Float).op,
-        .UConvert = ConversionEngine(.UInt, .UInt).op,
-        .SConvert = ConversionEngine(.SInt, .SInt).op,
-        .FConvert = ConversionEngine(.Float, .Float).op,
-        //.QuantizeToF16  = autoSetupConstant,
-        //.ConvertPtrToU  = autoSetupConstant,
-        //.SatConvertSToU = autoSetupConstant,
-        //.SatConvertUToS = autoSetupConstant,
-        //.ConvertUToPtr  = autoSetupConstant,
-    });
-};
-
 fn MathEngine(comptime T: ValueType, comptime Op: MathOp) type {
     return struct {
         fn op(_: std.mem.Allocator, _: SpvWord, rt: *Runtime) RuntimeError!void {
@@ -405,6 +409,35 @@ fn autoSetupConstant(allocator: std.mem.Allocator, _: SpvWord, rt: *Runtime) Run
     _ = try setupConstant(allocator, rt);
 }
 
+fn opBitcast(_: std.mem.Allocator, _: SpvWord, rt: *Runtime) RuntimeError!void {
+    _ = rt.it.skip();
+    const to_value = try rt.results[try rt.it.next()].getValue();
+    const from_value = try rt.results[try rt.it.next()].getValue();
+
+    const caster = struct {
+        /// Asumes that values passed are primitives ints or floats
+        fn cast(to: *Result.Value, from: *const Result.Value) RuntimeError!void {
+            const from_bytes: u64 = switch (from.*) {
+                .Float => |f| @bitCast(f.float64),
+                .Int => |i| i.uint64,
+                else => return RuntimeError.InvalidSpirV,
+            };
+
+            switch (to.*) {
+                .Float => |*f| f.float64 = @bitCast(from_bytes),
+                .Int => |*i| i.uint64 = from_bytes,
+                else => return RuntimeError.InvalidSpirV,
+            }
+        }
+    };
+
+    switch (to_value.*) {
+        .Int, .Float => try caster.cast(to_value, from_value),
+        .Vector => |vec| for (vec, from_value.Vector) |*t, *f| try caster.cast(t, f),
+        else => return RuntimeError.InvalidSpirV,
+    }
+}
+
 fn copyValue(dst: *Result.Value, src: *const Result.Value) void {
     if (src.getCompositeDataOrNull()) |src_slice| {
         if (dst.getCompositeDataOrNull()) |dst_slice| {
@@ -742,6 +775,18 @@ fn opName(allocator: std.mem.Allocator, word_count: SpvWord, rt: *Runtime) Runti
 }
 
 fn opReturn(_: std.mem.Allocator, _: SpvWord, rt: *Runtime) RuntimeError!void {
+    rt.last_return_id = null;
+    _ = rt.function_stack.pop();
+    if (rt.function_stack.getLastOrNull()) |function| {
+        _ = rt.it.jumpToSourceLocation(function.source_location);
+        rt.current_function = function.result;
+    } else {
+        rt.current_function = null;
+        rt.it.skipToEnd();
+    }
+}
+
+fn opReturnValue(_: std.mem.Allocator, _: SpvWord, rt: *Runtime) RuntimeError!void {
     _ = rt.function_stack.pop();
     if (rt.function_stack.getLastOrNull()) |function| {
         _ = rt.it.jumpToSourceLocation(function.source_location);

test/casts.zig

@@ -0,0 +1,62 @@
+const std = @import("std");
+const root = @import("root.zig");
+const compileNzsl = root.compileNzsl;
+const case = root.case;
+
+test "Primitives casts" {
+    const allocator = std.testing.allocator;
+    const types = [_][2]type{
+        [2]type{ f32, u32 },
+        [2]type{ f32, i32 },
+        [2]type{ u32, f32 },
+        [2]type{ u32, i32 },
+        [2]type{ i32, f32 },
+        [2]type{ i32, u32 },
+        [2]type{ f32, f64 },
+        [2]type{ f64, f32 },
+        [2]type{ f64, u32 },
+        [2]type{ f64, i32 },
+        [2]type{ u32, f64 },
+        [2]type{ i32, f64 },
+    };
+
+    inline for (types) |T| {
+        const base = case.random(T[0]);
+        const expected = std.math.lossyCast(T[1], base);
+
+        const shader = try std.fmt.allocPrint(
+            allocator,
+            \\ [nzsl_version("1.1")]
+            \\ [feature(float64)]
+            \\ module;
+            \\ 
+            \\ struct FragOut
+            \\ {{
+            \\     [location(0)] color: vec4[{s}]
+            \\ }}
+            \\
+            \\ [entry(frag)]
+            \\ fn main() -> FragOut
+            \\ {{
+            \\     let base = {s}({d});
+            \\     let color = {s}(base);
+            \\
+            \\     let output: FragOut;
+            \\     output.color = vec4[{s}](color, color, color, color);
+            \\     return output;
+            \\ }}
+        ,
+            .{
+                @typeName(T[1]),
+                @typeName(T[0]),
+                base,
+                @typeName(T[1]),
+                @typeName(T[1]),
+            },
+        );
+        defer allocator.free(shader);
+        const code = try compileNzsl(allocator, shader);
+        defer allocator.free(code);
+        try case.expectOutput(T[1], 4, code, "color", &.{ expected, expected, expected, expected });
+    }
+}

test/root.zig

@@ -58,5 +58,6 @@ pub const case = struct {
 test {
     std.testing.refAllDecls(@import("basics.zig"));
     std.testing.refAllDecls(@import("branching.zig"));
+    std.testing.refAllDecls(@import("casts.zig"));
     std.testing.refAllDecls(@import("maths.zig"));
 }