abi layout: minor code cleanups

Author: Firestar99

crates/rustc_codegen_spirv/src/abi.rs

@@ -1008,8 +1008,8 @@ fn trans_intrinsic_type<'tcx>(
     }
 }
 
-/// A struct with multiple fields of the same kind
-/// Used for `#[spirv(vector)]` and `#[spirv(matrix)]`
+/// A struct with multiple fields of the same kind.
+/// Used for `#[spirv(vector)]` and `#[spirv(matrix)]`.
 fn trans_glam_like_struct<'tcx>(
     cx: &CodegenCx<'tcx>,
     span: Span,

tests/difftests/tests/lang/abi/vector_layout/cpu/src/cpu_driver.rs

@@ -1,12 +1,12 @@
 use crate::glam_features::GlamFeatures;
-use crate::layout::{LAYOUT_COUNT, LAYOUT_LEN, eval_layouts};
+use crate::layout::{LAYOUT_LEN, LAYOUT_RANGE, eval_layouts};
 use difftest::config::Config;
 
 pub fn run(glam_feature: GlamFeatures) {
     glam_feature.assert();
     let config = Config::from_path(std::env::args().nth(1).unwrap()).unwrap();
     let mut out = vec![0; LAYOUT_LEN];
-    for gid in 0..LAYOUT_COUNT {
+    for gid in LAYOUT_RANGE {
         eval_layouts(gid as u32, &mut out);
     }
     config.write_result(&out).unwrap()

tests/difftests/tests/lang/abi/vector_layout/cpu/src/layout.rs

@@ -1,4 +1,5 @@
 use core::mem::offset_of;
+use core::ops::Range;
 use experiments::*;
 use spirv_std::glam::*;
 
@@ -29,11 +30,12 @@ macro_rules! write_layout {
 	};
 }
 
-/// gid is checked between `0..LAYOUT_COUNT`
-pub const LAYOUT_COUNT: usize = 0x60;
+/// gid is checked within this range. Note this is a range, so it **must be +1 from the max entry you use**.
+/// (Must always start at 0, `InclusiveRange` doesn't work due to constness)
+pub const LAYOUT_RANGE: Range<usize> = 0..0x56;
 /// at byte offset 0x100 * N starts layout N
 pub const LAYOUT_MAX_SIZE: usize = 0x100 / 0x4;
-pub const LAYOUT_LEN: usize = LAYOUT_COUNT * LAYOUT_MAX_SIZE;
+pub const LAYOUT_LEN: usize = LAYOUT_RANGE.end * LAYOUT_MAX_SIZE;
 
 pub fn eval_layouts(gid: u32, out: &mut [u32]) {
     let mut offset = BumpAlloc(gid as usize * LAYOUT_MAX_SIZE);
@@ -120,6 +122,7 @@ pub fn eval_layouts(gid: u32, out: &mut [u32]) {
         0x54 => write_layout!(out, offset, BVec4(x, y, z, w)),
         0x55 => write_layout!(out, offset, BVec4A()),
 
+        // IMPORTANT: when adding new rows, remember to adjust `LAYOUT_COUNT` to be the maximum + 1!
         _ => {}
     }
 }

tests/difftests/tests/lang/abi/vector_layout/cpu/src/shader_driver.rs

@@ -1,14 +1,15 @@
 use crate::glam_features::GlamFeatures;
-use crate::layout::{LAYOUT_COUNT, LAYOUT_LEN};
+use crate::layout::{LAYOUT_LEN, LAYOUT_RANGE};
 use difftest::config::Config;
 use difftest::scaffold::compute::{BufferConfig, RustComputeShader, WgpuComputeTestMultiBuffer};
 
 pub fn run(glam_feature: GlamFeatures) {
     glam_feature.assert();
     let config = Config::from_path(std::env::args().nth(1).unwrap()).unwrap();
+    assert_eq!(0, LAYOUT_RANGE.start);
     let test = WgpuComputeTestMultiBuffer::new(
         RustComputeShader::default(),
-        [LAYOUT_COUNT as u32, 1, 1],
+        [LAYOUT_RANGE.end as u32, 1, 1],
         Vec::from(&[BufferConfig::writeback(LAYOUT_LEN * size_of::<u32>())]),
     );
     test.run_test(&config).unwrap();