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/buffer/storage/static_index/write.wgsl.expected.msl b/test/tint/buffer/storage/static_index/write.wgsl.expected.msl
index ae3ab67..afb9718 100644
--- a/test/tint/buffer/storage/static_index/write.wgsl.expected.msl
+++ b/test/tint/buffer/storage/static_index/write.wgsl.expected.msl
@@ -12,12 +12,20 @@
return vec<T, M>(lhs) * rhs;
}
-struct Inner {
- /* 0x0000 */ int x;
+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 {
- /* 0x0000 */ Inner arr[4];
+struct Inner {
+ /* 0x0000 */ int x;
};
struct S {
@@ -30,8 +38,8 @@
/* 0x0030 */ float2x3 g;
/* 0x0050 */ float3x2 h;
/* 0x0068 */ Inner i;
- /* 0x006c */ tint_array_wrapper j;
- /* 0x007c */ int8_t tint_pad[4];
+ /* 0x006c */ tint_array<Inner, 4> j;
+ /* 0x007c */ tint_array<int8_t, 4> tint_pad;
};
kernel void tint_symbol(device S* tint_symbol_3 [[buffer(0)]]) {
@@ -45,7 +53,7 @@
(*(tint_symbol_3)).h = float3x2(float2(0.0f), float2(0.0f), float2(0.0f));
Inner const tint_symbol_1 = {};
(*(tint_symbol_3)).i = tint_symbol_1;
- tint_array_wrapper const tint_symbol_2 = {.arr={}};
+ tint_array<Inner, 4> const tint_symbol_2 = tint_array<Inner, 4>{};
(*(tint_symbol_3)).j = tint_symbol_2;
return;
}
