spirv: basic shader support

Author: alichraghi

lib/std/Target.zig

@@ -1221,6 +1221,7 @@ pub const Cpu = struct {
                 .fs, .gs, .ss => arch == .x86_64 or arch == .x86,
                 .global, .constant, .local, .shared => is_gpu,
                 .param => is_nvptx,
+                .input, .output, .uniform => is_spirv,
                 // TODO this should also check how many flash banks the cpu has
                 .flash, .flash1, .flash2, .flash3, .flash4, .flash5 => arch == .avr,
             };
@@ -2353,7 +2354,7 @@ pub fn c_type_bit_size(target: Target, c_type: CType) u16 {
             .longdouble => return 128,
         },
 
-        .opencl => switch (c_type) {
+        .opencl, .vulkan => switch (c_type) {
             .char => return 8,
             .short, .ushort => return 16,
             .int, .uint, .float => return 32,
@@ -2386,7 +2387,6 @@ pub fn c_type_bit_size(target: Target, c_type: CType) u16 {
         .hermit,
         .hurd,
         .glsl450,
-        .vulkan,
         .driverkit,
         .shadermodel,
         .liteos,

lib/std/builtin.zig

@@ -205,6 +205,9 @@ pub const CallingConvention = enum(u8) {
     Win64,
     /// AMD GPU, NVPTX, or SPIR-V kernel
     Kernel,
+    // Vulkan-only
+    Fragment,
+    Vertex,
 };
 
 /// This data structure is used by the Zig language code generation and
@@ -222,6 +225,9 @@ pub const AddressSpace = enum(u5) {
     param,
     shared,
     local,
+    input,
+    output,
+    uniform,
 
     // AVR address spaces.
     flash,

src/Sema.zig

@@ -9741,6 +9741,10 @@ fn finishFunc(
             .nvptx, .nvptx64, .amdgcn, .spirv32, .spirv64 => null,
             else => "nvptx, amdgcn and SPIR-V",
         },
+        .Fragment, .Vertex => switch (arch) {
+            .spirv32, .spirv64 => null,
+            else => "SPIR-V",
+        },
     })) |allowed_platform| {
         return sema.fail(block, cc_src, "callconv '{s}' is only available on {s}, not {s}", .{
             @tagName(cc_resolved),
@@ -37917,6 +37921,7 @@ pub fn analyzeAddressSpace(
         .gs, .fs, .ss => (arch == .x86 or arch == .x86_64) and ctx == .pointer,
         // TODO: check that .shared and .local are left uninitialized
         .param => is_nv,
+        .input, .output, .uniform => is_spirv,
         .global, .shared, .local => is_gpu,
         .constant => is_gpu and (ctx == .constant),
         // TODO this should also check how many flash banks the cpu has

src/codegen/llvm.zig

@@ -10848,6 +10848,7 @@ fn toLlvmCallConv(cc: std.builtin.CallingConvention, target: std.Target) Builder
             .amdgcn => .amdgpu_kernel,
             else => unreachable,
         },
+        .Vertex, .Fragment => unreachable,
     };
 }