[clang] [SYCL] Allow neon attributes for ARM host (PR #94229)

[Harald van Dijk via cfe-commits]

https://github.com/hvdijk created https://github.com/llvm/llvm-project/pull/94229

We permit neon attributes in CUDA device code, but this permission was only for CUDA device code. The same permission makes sense for SYCL device code as well, especially now that neon attributes are used in glibc headers.

>From 13fb2b9d867d353ec67aab96159b8eea690e87d0 Mon Sep 17 00:00:00 2001
From: Harald van Dijk <harald.vandijk at codeplay.com>
Date: Mon, 3 Jun 2024 14:47:15 +0100
Subject: [PATCH] [SYCL] Allow neon attributes for ARM host

We permit neon attributes in CUDA device code, but this permission was
only for CUDA device code. The same permission makes sense for SYCL
device code as well, especially now that neon attributes are used in
glibc headers.
---
 clang/lib/Sema/SemaType.cpp        | 12 ++++++------
 clang/test/SemaSYCL/neon-attrs.cpp | 16 ++++++++++++++++
 2 files changed, 22 insertions(+), 6 deletions(-)
 create mode 100644 clang/test/SemaSYCL/neon-attrs.cpp

diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 7cec82c701028..a8a1463522d03 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -8077,10 +8077,10 @@ static bool verifyValidIntegerConstantExpr(Sema &S, const ParsedAttr &Attr,
 /// match one of the standard Neon vector types.
 static void HandleNeonVectorTypeAttr(QualType &CurType, const ParsedAttr &Attr,
                                      Sema &S, VectorKind VecKind) {
-  bool IsTargetCUDAAndHostARM = false;
-  if (S.getLangOpts().CUDAIsDevice) {
+  bool IsTargetDeviceAndHostARM = false;
+  if (S.getLangOpts().CUDAIsDevice || S.getLangOpts().SYCLIsDevice) {
     const TargetInfo *AuxTI = S.getASTContext().getAuxTargetInfo();
-    IsTargetCUDAAndHostARM =
+    IsTargetDeviceAndHostARM =
         AuxTI && (AuxTI->getTriple().isAArch64() || AuxTI->getTriple().isARM());
   }
 
@@ -8090,7 +8090,7 @@ static void HandleNeonVectorTypeAttr(QualType &CurType, const ParsedAttr &Attr,
         S.Context.getTargetInfo().hasFeature("mve") ||
         S.Context.getTargetInfo().hasFeature("sve") ||
         S.Context.getTargetInfo().hasFeature("sme") ||
-        IsTargetCUDAAndHostARM) &&
+        IsTargetDeviceAndHostARM) &&
       VecKind == VectorKind::Neon) {
     S.Diag(Attr.getLoc(), diag::err_attribute_unsupported)
         << Attr << "'neon', 'mve', 'sve' or 'sme'";
@@ -8099,7 +8099,7 @@ static void HandleNeonVectorTypeAttr(QualType &CurType, const ParsedAttr &Attr,
   }
   if (!(S.Context.getTargetInfo().hasFeature("neon") ||
         S.Context.getTargetInfo().hasFeature("mve") ||
-        IsTargetCUDAAndHostARM) &&
+        IsTargetDeviceAndHostARM) &&
       VecKind == VectorKind::NeonPoly) {
     S.Diag(Attr.getLoc(), diag::err_attribute_unsupported)
         << Attr << "'neon' or 'mve'";
@@ -8121,7 +8121,7 @@ static void HandleNeonVectorTypeAttr(QualType &CurType, const ParsedAttr &Attr,
 
   // Only certain element types are supported for Neon vectors.
   if (!isPermittedNeonBaseType(CurType, VecKind, S) &&
-      !IsTargetCUDAAndHostARM) {
+      !IsTargetDeviceAndHostARM) {
     S.Diag(Attr.getLoc(), diag::err_attribute_invalid_vector_type) << CurType;
     Attr.setInvalid();
     return;
diff --git a/clang/test/SemaSYCL/neon-attrs.cpp b/clang/test/SemaSYCL/neon-attrs.cpp
new file mode 100644
index 0000000000000..ec79fa5033308
--- /dev/null
+++ b/clang/test/SemaSYCL/neon-attrs.cpp
@@ -0,0 +1,16 @@
+// Host compilation on ARM with neon enabled (no errors expected).
+// RUN: %clang_cc1 -triple aarch64-linux-gnu -target-feature +neon -fsyntax-only -verify=quiet %s
+
+// Host compilation on ARM with neon disabled.
+// RUN: %clang_cc1 -triple aarch64-linux-gnu -target-feature -neon -fsyntax-only -verify %s
+
+// Device compilation on ARM (no errors expected).
+// RUN: %clang_cc1 -triple spirv64 -aux-triple aarch64-linux-gnu -fsycl-is-device -fsyntax-only -verify=quiet %s
+
+// quiet-no-diagnostics
+typedef __attribute__((neon_vector_type(4))) float float32x4_t;
+// expected-error at -1 {{'neon_vector_type' attribute is not supported on targets missing 'neon', 'mve', 'sve' or 'sme'}}
+// expect
+typedef unsigned char poly8_t;
+typedef __attribute__((neon_polyvector_type(8))) poly8_t poly8x8_t;
+// expected-error at -1 {{'neon_polyvector_type' attribute is not supported on targets missing 'neon' or 'mve'}}