tint/writer/msl: Generate an array<T,N> helper
And remove the WrapArraysInStructs transform.
Wrapping arrays in structures becomes troublesome for `const` arrays, as
currently WGSL does not allow `const` structures.
MSL 2.0+ has a builtin array<> helper, but we're targetting MSL 1.2, so
we have to emit our own. Fortunately, it can be done with a few lines of
templated code.
This produces significantly cleaner output.
Change-Id: Ifc92ef21e09befa252a07c856c4b5afdc51cc2e4
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/94540
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Ben Clayton <bclayton@chromium.org>
Reviewed-by: David Neto <dneto@google.com>
diff --git a/test/tint/let/global/global.wgsl.expected.msl b/test/tint/let/global/global.wgsl.expected.msl
index 72d5df7..d4ded52 100644
--- a/test/tint/let/global/global.wgsl.expected.msl
+++ b/test/tint/let/global/global.wgsl.expected.msl
@@ -1,12 +1,21 @@
#include <metal_stdlib>
using namespace metal;
-struct MyStruct {
- float f1;
+
+template<typename T, size_t N>
+struct tint_array {
+ const constant T& operator[](size_t i) const constant { return elements[i]; }
+ device T& operator[](size_t i) device { return elements[i]; }
+ const device T& operator[](size_t i) const device { return elements[i]; }
+ thread T& operator[](size_t i) thread { return elements[i]; }
+ const thread T& operator[](size_t i) const thread { return elements[i]; }
+ threadgroup T& operator[](size_t i) threadgroup { return elements[i]; }
+ const threadgroup T& operator[](size_t i) const threadgroup { return elements[i]; }
+ T elements[N];
};
-struct tint_array_wrapper {
- float arr[10];
+struct MyStruct {
+ float f1;
};
constant int v1 = 1;
@@ -25,7 +34,7 @@
constant MyStruct v8 = {};
-constant tint_array_wrapper v9 = {.arr={}};
+constant tint_array<float, 10> v9 = tint_array<float, 10>{};
struct tint_symbol_1 {
float4 value [[color(0)]];
