[llvm] [AMDGPU] Change handling of unsupported non-compute shaders with HSA (PR #126798)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-amdgpu

Author: Robert Imschweiler (ro-i)

<details>
<summary>Changes</summary>

Previous handling in `SITargetLowering::LowerFormalArguments` only reported a diagnostic message and continued execution by returning a non-usable `SDValue`. This results in llvm crashing later with an unrelated error.  This commit changes the detection of an unsupported non-compute shader to be a fatal error right away.

As an example situation, take the usage of an `amdgpu_ps` function and the `amdgcn-unknown-amdhsa` target triple.
```
define amdgpu_ps void @<!-- -->foo(ptr %p, i32 %i) {
        store i32 %i, ptr %p
        ret void
}
```
Compiling this code (with `llc -mtriple=amdgcn-unknown-amdhsa -mcpu=gfx942`, for example) fails with:
```
error: <unknown>:0:0: in function foo void (ptr, i32): unsupported non-compute shaders with HSA

llc:
[...]/git/trunk21.0/llvm-project/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp:11790:
void llvm::SelectionDAGISel::LowerArguments(const llvm::Function&):
Assertion `InVals.size() == Ins.size() && "LowerFormalArguments didn't emit the correct number of values!"' failed.
[...]
```

---
Full diff: https://github.com/llvm/llvm-project/pull/126798.diff


2 Files Affected:

- (modified) llvm/lib/Target/AMDGPU/SIISelLowering.cpp (+1-4) 
- (removed) llvm/test/CodeGen/AMDGPU/no-hsa-graphics-shaders.ll (-19) 


``````````diff
diff --git a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp b/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
index b632c50dae0e3..746bde4de5e9f 100644
--- a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
+++ b/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
@@ -2824,10 +2824,7 @@ SDValue SITargetLowering::LowerFormalArguments(
   SIMachineFunctionInfo *Info = MF.getInfo<SIMachineFunctionInfo>();
 
   if (Subtarget->isAmdHsaOS() && AMDGPU::isGraphics(CallConv)) {
-    DiagnosticInfoUnsupported NoGraphicsHSA(
-        Fn, "unsupported non-compute shaders with HSA", DL.getDebugLoc());
-    DAG.getContext()->diagnose(NoGraphicsHSA);
-    return DAG.getEntryNode();
+    report_fatal_error("unsupported non-compute shaders with HSA");
   }
 
   SmallVector<ISD::InputArg, 16> Splits;
diff --git a/llvm/test/CodeGen/AMDGPU/no-hsa-graphics-shaders.ll b/llvm/test/CodeGen/AMDGPU/no-hsa-graphics-shaders.ll
deleted file mode 100644
index ee6a578c72859..0000000000000
--- a/llvm/test/CodeGen/AMDGPU/no-hsa-graphics-shaders.ll
+++ /dev/null
@@ -1,19 +0,0 @@
-; RUN: not llc -mtriple=amdgcn-unknown-amdhsa < %s 2>&1 | FileCheck %s
-
-; CHECK: in function pixel_s{{.*}}: unsupported non-compute shaders with HSA
-define amdgpu_ps void @pixel_shader() #0 {
-  ret void
-}
-
-; CHECK: in function vertex_s{{.*}}: unsupported non-compute shaders with HSA
-define amdgpu_vs void @vertex_shader() #0 {
-  ret void
-}
-
-; CHECK: in function geometry_s{{.*}}: unsupported non-compute shaders with HSA
-define amdgpu_gs void @geometry_shader() #0 {
-  ret void
-}
-
-!llvm.module.flags = !{!0}
-!0 = !{i32 1, !"amdhsa_code_object_version", i32 400}

``````````

</details>


https://github.com/llvm/llvm-project/pull/126798