From 1aafc99b993b25a83a7d632d8bf47354a95c9fbd Mon Sep 17 00:00:00 2001
From: sgasho <SuganoShota1999@gmail.com>
Date: Fri, 6 Nov 2026 21:26:57 +0900
Subject: [PATCH 1/2] offload: simplify build commands by removing
 --emit=llvm-bc,llvm-ir -Csave-temps and pass the linked device image to the
 host pass

---
 src/offload/usage.md | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/src/offload/usage.md b/src/offload/usage.md
index 90e72b9858..1e3a5f41aa 100644
--- a/src/offload/usage.md
+++ b/src/offload/usage.md
@@ -82,25 +82,24 @@ These are often referred to as "LLVM target names"[^list].
 
 First we generate the manifest from the host code:
 ```
-RUSTFLAGS="--emit=llvm-bc,llvm-ir -Csave-temps -Zoffload=HostMetadata=/absolute/path/to/offload.manifest -Zunstable-options" cargo +offload build -r
+RUSTFLAGS="-Zoffload=HostMetadata=/absolute/path/to/offload.manifest -Zunstable-options" cargo +offload build -r
 ```
 This pass only writes the manifest.
 
 Now we generate the device (GPU) code, passing the manifest:
 ```
-RUSTFLAGS="-Ctarget-cpu=gfx90a --emit=llvm-bc,llvm-ir -Zoffload=Device=/absolute/path/to/offload.manifest -Csave-temps -Zunstable-options" cargo +offload build -Zunstable-options -r -v --target amdgcn-amd-amdhsa -Zbuild-std=core
+RUSTFLAGS="-Ctarget-cpu=gfx90a -Zoffload=Device=/absolute/path/to/offload.manifest -Zunstable-options" cargo +offload build -Zunstable-options -r -v --target amdgcn-amd-amdhsa -Zbuild-std=core
 ```
 
 Next we generate the host (CPU) code.
 ```
-DEVICE_BC=$(find $PWD/target/amdgcn-amd-amdhsa/release/build -name '<crate_name>.bc')
-RUSTFLAGS="-C lto=fat -C embed-bitcode=yes --emit=llvm-bc,llvm-ir -Csave-temps -Zoffload=Host=$DEVICE_BC -Zunstable-options" cargo +offload build -r
+RUSTFLAGS="-C lto=fat -C embed-bitcode=yes -Zoffload=Host=$PWD/target/amdgcn-amd-amdhsa/release/<crate_name>.elf -Zunstable-options" cargo +offload build -r
 ```
 
 In the final step, you can now run your binary
 
 ```
-./target/x86_64-unknown-linux-gnu/release/binary-name
+./target/release/binary-name
 all checks passed!
 ```
 

From d99a37abe65a5ae3ffdb82c33ebe321079abc48e Mon Sep 17 00:00:00 2001
From: sgasho <SuganoShota1999@gmail.com>
Date: Sat, 7 Nov 2026 13:37:59 +0900
Subject: [PATCH 2/2] offload: update compile instructions and warning on
 usage.md

---
 src/offload/usage.md | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/src/offload/usage.md b/src/offload/usage.md
index 1e3a5f41aa..b308ceeab3 100644
--- a/src/offload/usage.md
+++ b/src/offload/usage.md
@@ -61,11 +61,6 @@ fn main() {
 ```
 
 ## Compile instructions
-It is important to use a clang compiler build on the same LLVM as rustc.
-Just calling clang without the full path will likely use your system clang,
-which probably will be incompatible.
-So either substitute clang/lld invocations below with absolute path, or set your `PATH` accordingly.
-
 The compilation runs three passes:
 1. `HostMetadata`: compile the host code, writing a manifest that lists the kernel
    instantiations (including generic ones) required by the host code.
@@ -75,8 +70,9 @@ The compilation runs three passes:
 
 <div class="warning">
 
-Replace the `target-cpu` (gfx90a) with the right code for your GPU.
-These are often referred to as "LLVM target names"[^list].
+The commands below target an AMD GPU. For your GPU, change:
+- `-Ctarget-cpu=gfx90a` to your GPU's target CPU (e.g. `sm_86` on NVIDIA)[^list]
+- on NVIDIA, `amdgcn-amd-amdhsa` to `nvptx64-nvidia-cuda` (in `--target` and in the `-Zoffload=Host` path), and `.elf` to `.ptx`
 
 </div>