From f7ed1bab355c5c9e26d98c9f44700980e87c2043 Mon Sep 17 00:00:00 2001
From: Zac Harrold <zac@harrold.com.au>
Date: Mon, 21 Apr 2025 19:46:25 +1000
Subject: [PATCH 1/2] Rely on `libm` for a `no_std` alternative to
 `round_ties_even`

Update comments around `no_std` CI task
---
 .github/workflows/ci.yml            | 6 ++++--
 CHANGELOG.md                        | 4 ++++
 Cargo.lock                          | 1 +
 naga/Cargo.toml                     | 1 +
 naga/src/back/mod.rs                | 7 +++++++
 naga/src/proc/constant_evaluator.rs | 4 ++--
 6 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a9cfc2d874..c27d0a67a2 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -292,7 +292,7 @@ jobs:
           cargo clippy --target ${{ matrix.target }} ${{ matrix.extra-flags }} -p wgpu-hal --all-features
           cargo clippy --target ${{ matrix.target }} ${{ matrix.extra-flags }} -p wgpu --all-features
 
-      # Building for no_std platforms where every feature is enabled except "std".
+      # Building for no_std platforms.
       - name: Check `no_std`
         if: matrix.kind == 'no_std'
         shell: bash
@@ -301,9 +301,11 @@ jobs:
 
           # check with no features
           cargo clippy --target ${{ matrix.target }} ${{ matrix.extra-flags }} -p wgpu-types --no-default-features
+          cargo clippy --target ${{ matrix.target }} ${{ matrix.extra-flags }} -p naga --no-default-features
 
-          # Check with all features except "std".
+          # Check with all compatible features
           cargo clippy --target ${{ matrix.target }} ${{ matrix.extra-flags }} -p wgpu-types --no-default-features --features strict_asserts,fragile-send-sync-non-atomic-wasm,serde,counters
+          cargo clippy --target ${{ matrix.target }} ${{ matrix.extra-flags }} -p naga --no-default-features --features dot-out,compact
 
       # Building for native platforms with standard tests.
       - name: Check native
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 95c000c9b4..12b49a611f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -42,6 +42,10 @@ Bottom level categories:
 
 ### New Features
 
+#### Naga
+
+- Added `no_std` support with default features disabled. By @Bushrat011899 in [#7585](https://github.com/gfx-rs/wgpu/pull/7585).
+
 #### General
 
 - Add support for rendering to slices of 3D texture views and single layered 2D-Array texture views (this requires `VK_KHR_maintenance1` which should be widely available on newer drivers). By @teoxoy in [#7596](https://github.com/gfx-rs/wgpu/pull/7596)
diff --git a/Cargo.lock b/Cargo.lock
index 94e9041661..9bfd874191 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2513,6 +2513,7 @@ dependencies = [
  "hlsl-snapshots",
  "indexmap",
  "itertools 0.14.0",
+ "libm",
  "log",
  "num-traits",
  "once_cell",
diff --git a/naga/Cargo.toml b/naga/Cargo.toml
index e9a2890003..2a57665552 100644
--- a/naga/Cargo.toml
+++ b/naga/Cargo.toml
@@ -91,6 +91,7 @@ hashbrown.workspace = true
 half = { workspace = true, features = ["num-traits"] }
 rustc-hash.workspace = true
 indexmap.workspace = true
+libm = { version = "0.2", default-features = false }
 log.workspace = true
 num-traits.workspace = true
 once_cell = { workspace = true, features = ["alloc", "race"] }
diff --git a/naga/src/back/mod.rs b/naga/src/back/mod.rs
index 175c5481b3..d7b14475bf 100644
--- a/naga/src/back/mod.rs
+++ b/naga/src/back/mod.rs
@@ -46,6 +46,13 @@ pub type NeedBakeExpressions = crate::FastHashSet<crate::Handle<crate::Expressio
 ///
 /// [`Expression`]: crate::Expression
 /// [`Handle`]: crate::Handle
+#[cfg_attr(
+    not(any(glsl_out, hlsl_out, msl_out, wgsl_out)),
+    allow(
+        dead_code,
+        reason = "shared helpers can be dead if none of the enabled backends need it"
+    )
+)]
 struct Baked(crate::Handle<crate::Expression>);
 
 impl core::fmt::Display for Baked {
diff --git a/naga/src/proc/constant_evaluator.rs b/naga/src/proc/constant_evaluator.rs
index 27d6addc82..dca082ec82 100644
--- a/naga/src/proc/constant_evaluator.rs
+++ b/naga/src/proc/constant_evaluator.rs
@@ -1172,8 +1172,8 @@ impl<'a> ConstantEvaluator<'a> {
             }
             crate::MathFunction::Round => {
                 component_wise_float(self, span, [arg], |e| match e {
-                    Float::Abstract([e]) => Ok(Float::Abstract([e.round_ties_even()])),
-                    Float::F32([e]) => Ok(Float::F32([e.round_ties_even()])),
+                    Float::Abstract([e]) => Ok(Float::Abstract([libm::rint(e)])),
+                    Float::F32([e]) => Ok(Float::F32([libm::rintf(e)])),
                     Float::F16([e]) => {
                         // TODO: `round_ties_even` is not available on `half::f16` yet.
                         //

From 17cef376333cdbc372b67340e46c1187ab3b4abb Mon Sep 17 00:00:00 2001
From: Zac Harrold <zac@harrold.com.au>
Date: Wed, 30 Apr 2025 22:17:25 +1000
Subject: [PATCH 2/2] Update Cargo.toml

---
 naga/Cargo.toml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/naga/Cargo.toml b/naga/Cargo.toml
index 2a57665552..96d0b4b091 100644
--- a/naga/Cargo.toml
+++ b/naga/Cargo.toml
@@ -91,7 +91,8 @@ hashbrown.workspace = true
 half = { workspace = true, features = ["num-traits"] }
 rustc-hash.workspace = true
 indexmap.workspace = true
-libm = { version = "0.2", default-features = false }
+# Earliest version of libm with rint and rintf
+libm = { version = "0.2.6", default-features = false }
 log.workspace = true
 num-traits.workspace = true
 once_cell = { workspace = true, features = ["alloc", "race"] }