[clang] [Clang][OpenCL] Add support for the cl_intel_subgroup_buffer_prefetch (PR #170532)

[Victor Mustya via cfe-commits]

https://github.com/vmustya updated https://github.com/llvm/llvm-project/pull/170532

>From 12397152f4f861966d12caeeefc4dde97cdb7f35 Mon Sep 17 00:00:00 2001
From: Victor Mustya <victor.mustya at intel.com>
Date: Wed, 3 Dec 2025 10:40:27 -0800
Subject: [PATCH 1/2] Add support for the cl_intel_subgroup_buffer_prefetch

The commit adds support for the cl_intel_subgroup_buffer_prefetch OpenCL
extension. The extension introduces a new built-in functions that allow
prefetching data from a global memory to caches as a subgroup-level
operation.

The extension is defined here: https://registry.khronos.org/OpenCL/extensions/intel/cl_intel_subgroup_buffer_prefetch.html
---
 clang/lib/Headers/opencl-c.h | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/clang/lib/Headers/opencl-c.h b/clang/lib/Headers/opencl-c.h
index f65b4b314cffd..2ea48f2760c76 100644
--- a/clang/lib/Headers/opencl-c.h
+++ b/clang/lib/Headers/opencl-c.h
@@ -17525,6 +17525,13 @@ void       __ovld __conv intel_sub_group_block_write_ui8( __global uint* p, uint
 
 #endif // defined(cl_intel_subgroups_char) || defined(cl_intel_subgroups_short) ||
        // defined(cl_intel_subgroups_long)
+
+#if defined(cl_intel_subgroup_buffer_prefetch)
+void __ovld __conv intel_sub_group_block_prefetch_ui(const __global uint *p);
+void __ovld __conv intel_sub_group_block_prefetch_ui2(const __global uint *p);
+void __ovld __conv intel_sub_group_block_prefetch_ui4(const __global uint *p);
+void __ovld __conv intel_sub_group_block_prefetch_ui8(const __global uint *p);
+#endif // defined(cl_intel_subgroup_buffer_prefetch)
 #endif // cl_intel_subgroups
 
 #if defined(cl_intel_subgroups_short)
@@ -17660,6 +17667,14 @@ void        __ovld __conv intel_sub_group_block_write_us2( __global ushort* p, u
 void        __ovld __conv intel_sub_group_block_write_us4( __global ushort* p, ushort4 data );
 void        __ovld __conv intel_sub_group_block_write_us8( __global ushort* p, ushort8 data );
 void        __ovld __conv intel_sub_group_block_write_us16( __global ushort* p, ushort16 data );
+
+#if defined(cl_intel_subgroup_buffer_prefetch)
+void __ovld __conv intel_sub_group_block_prefetch_us(const __global ushort *p);
+void __ovld __conv intel_sub_group_block_prefetch_us2(const __global ushort *p);
+void __ovld __conv intel_sub_group_block_prefetch_us4(const __global ushort *p);
+void __ovld __conv intel_sub_group_block_prefetch_us8(const __global ushort *p);
+void __ovld __conv intel_sub_group_block_prefetch_us16(const __global ushort *p);
+#endif // defined(cl_intel_subgroup_buffer_prefetch)
 #endif // cl_intel_subgroups_short
 
 #if defined(cl_intel_subgroups_char)
@@ -17795,6 +17810,14 @@ void        __ovld __conv intel_sub_group_block_write_uc2( __global uchar* p, uc
 void        __ovld __conv intel_sub_group_block_write_uc4( __global uchar* p, uchar4 data );
 void        __ovld __conv intel_sub_group_block_write_uc8( __global uchar* p, uchar8 data );
 void        __ovld __conv intel_sub_group_block_write_uc16( __global uchar* p, uchar16 data );
+
+#if defined(cl_intel_subgroup_buffer_prefetch)
+void __ovld __conv intel_sub_group_block_prefetch_uc(const __global uchar *p);
+void __ovld __conv intel_sub_group_block_prefetch_uc2(const __global uchar *p);
+void __ovld __conv intel_sub_group_block_prefetch_uc4(const __global uchar *p);
+void __ovld __conv intel_sub_group_block_prefetch_uc8(const __global uchar *p);
+void __ovld __conv intel_sub_group_block_prefetch_uc16(const __global uchar *p);
+#endif // defined(cl_intel_subgroup_buffer_prefetch)
 #endif // cl_intel_subgroups_char
 
 #if defined(cl_intel_subgroups_long)
@@ -17839,6 +17862,13 @@ void        __ovld __conv intel_sub_group_block_write_ul(  __global ulong* p, ul
 void        __ovld __conv intel_sub_group_block_write_ul2( __global ulong* p, ulong2 data );
 void        __ovld __conv intel_sub_group_block_write_ul4( __global ulong* p, ulong4 data );
 void        __ovld __conv intel_sub_group_block_write_ul8( __global ulong* p, ulong8 data);
+
+#if defined(cl_intel_subgroup_buffer_prefetch)
+void __ovld __conv intel_sub_group_block_prefetch_ul(const __global ulong *p);
+void __ovld __conv intel_sub_group_block_prefetch_ul2(const __global ulong *p);
+void __ovld __conv intel_sub_group_block_prefetch_ul4(const __global ulong *p);
+void __ovld __conv intel_sub_group_block_prefetch_ul8(const __global ulong *p);
+#endif // defined(cl_intel_subgroup_buffer_prefetch)
 #endif // cl_intel_subgroups_long
 
 #if defined(cl_intel_subgroup_local_block_io)

>From 98a306453f1573ab55e53cc270d638e04fa731bd Mon Sep 17 00:00:00 2001
From: Victor Mustya <victor.mustya at intel.com>
Date: Thu, 4 Dec 2025 15:12:06 -0800
Subject: [PATCH 2/2] Apply suggestions from code review
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-authored-by: Mészáros Gergely <maetveis at gmail.com>
---
 clang/lib/Headers/opencl-c.h | 36 ++++++++++++++++++------------------
 1 file changed, 18 insertions(+), 18 deletions(-)

diff --git a/clang/lib/Headers/opencl-c.h b/clang/lib/Headers/opencl-c.h
index 2ea48f2760c76..f9cdb2e706f01 100644
--- a/clang/lib/Headers/opencl-c.h
+++ b/clang/lib/Headers/opencl-c.h
@@ -17527,10 +17527,10 @@ void       __ovld __conv intel_sub_group_block_write_ui8( __global uint* p, uint
        // defined(cl_intel_subgroups_long)
 
 #if defined(cl_intel_subgroup_buffer_prefetch)
-void __ovld __conv intel_sub_group_block_prefetch_ui(const __global uint *p);
-void __ovld __conv intel_sub_group_block_prefetch_ui2(const __global uint *p);
-void __ovld __conv intel_sub_group_block_prefetch_ui4(const __global uint *p);
-void __ovld __conv intel_sub_group_block_prefetch_ui8(const __global uint *p);
+void       __ovld __conv intel_sub_group_block_prefetch_ui(const __global uint *p);
+void       __ovld __conv intel_sub_group_block_prefetch_ui2(const __global uint *p);
+void       __ovld __conv intel_sub_group_block_prefetch_ui4(const __global uint *p);
+void       __ovld __conv intel_sub_group_block_prefetch_ui8(const __global uint *p);
 #endif // defined(cl_intel_subgroup_buffer_prefetch)
 #endif // cl_intel_subgroups
 
@@ -17669,11 +17669,11 @@ void        __ovld __conv intel_sub_group_block_write_us8( __global ushort* p, u
 void        __ovld __conv intel_sub_group_block_write_us16( __global ushort* p, ushort16 data );
 
 #if defined(cl_intel_subgroup_buffer_prefetch)
-void __ovld __conv intel_sub_group_block_prefetch_us(const __global ushort *p);
-void __ovld __conv intel_sub_group_block_prefetch_us2(const __global ushort *p);
-void __ovld __conv intel_sub_group_block_prefetch_us4(const __global ushort *p);
-void __ovld __conv intel_sub_group_block_prefetch_us8(const __global ushort *p);
-void __ovld __conv intel_sub_group_block_prefetch_us16(const __global ushort *p);
+void        __ovld __conv intel_sub_group_block_prefetch_us(const __global ushort *p);
+void        __ovld __conv intel_sub_group_block_prefetch_us2(const __global ushort *p);
+void        __ovld __conv intel_sub_group_block_prefetch_us4(const __global ushort *p);
+void        __ovld __conv intel_sub_group_block_prefetch_us8(const __global ushort *p);
+void        __ovld __conv intel_sub_group_block_prefetch_us16(const __global ushort *p);
 #endif // defined(cl_intel_subgroup_buffer_prefetch)
 #endif // cl_intel_subgroups_short
 
@@ -17812,11 +17812,11 @@ void        __ovld __conv intel_sub_group_block_write_uc8( __global uchar* p, uc
 void        __ovld __conv intel_sub_group_block_write_uc16( __global uchar* p, uchar16 data );
 
 #if defined(cl_intel_subgroup_buffer_prefetch)
-void __ovld __conv intel_sub_group_block_prefetch_uc(const __global uchar *p);
-void __ovld __conv intel_sub_group_block_prefetch_uc2(const __global uchar *p);
-void __ovld __conv intel_sub_group_block_prefetch_uc4(const __global uchar *p);
-void __ovld __conv intel_sub_group_block_prefetch_uc8(const __global uchar *p);
-void __ovld __conv intel_sub_group_block_prefetch_uc16(const __global uchar *p);
+void        __ovld __conv intel_sub_group_block_prefetch_uc(const __global uchar *p);
+void        __ovld __conv intel_sub_group_block_prefetch_uc2(const __global uchar *p);
+void        __ovld __conv intel_sub_group_block_prefetch_uc4(const __global uchar *p);
+void        __ovld __conv intel_sub_group_block_prefetch_uc8(const __global uchar *p);
+void        __ovld __conv intel_sub_group_block_prefetch_uc16(const __global uchar *p);
 #endif // defined(cl_intel_subgroup_buffer_prefetch)
 #endif // cl_intel_subgroups_char
 
@@ -17864,10 +17864,10 @@ void        __ovld __conv intel_sub_group_block_write_ul4( __global ulong* p, ul
 void        __ovld __conv intel_sub_group_block_write_ul8( __global ulong* p, ulong8 data);
 
 #if defined(cl_intel_subgroup_buffer_prefetch)
-void __ovld __conv intel_sub_group_block_prefetch_ul(const __global ulong *p);
-void __ovld __conv intel_sub_group_block_prefetch_ul2(const __global ulong *p);
-void __ovld __conv intel_sub_group_block_prefetch_ul4(const __global ulong *p);
-void __ovld __conv intel_sub_group_block_prefetch_ul8(const __global ulong *p);
+void        __ovld __conv intel_sub_group_block_prefetch_ul(const __global ulong *p);
+void        __ovld __conv intel_sub_group_block_prefetch_ul2(const __global ulong *p);
+void        __ovld __conv intel_sub_group_block_prefetch_ul4(const __global ulong *p);
+void        __ovld __conv intel_sub_group_block_prefetch_ul8(const __global ulong *p);
 #endif // defined(cl_intel_subgroup_buffer_prefetch)
 #endif // cl_intel_subgroups_long