Author: Joseph Huber Date: 2026-01-08T12:01:15-06:00 New Revision: f8b68c7b74704892ce308049fbc045e4b8b30d4d
URL: https://github.com/llvm/llvm-project/commit/f8b68c7b74704892ce308049fbc045e4b8b30d4d DIFF: https://github.com/llvm/llvm-project/commit/f8b68c7b74704892ce308049fbc045e4b8b30d4d.diff LOG: [SPIR-V] Add builtin/intrinsic for subgroup ballot (#174862) Summary: This patch adds an LLVM intrinsic and lowering for a subgroup ballot and a corresponding clang builtin. This uses the already present support but provides in a way accessible to other targets. With this and https://github.com/llvm/llvm-project/pull/174655 we should be able to most of the basic functions, like shuffling, active masks, and reductions. More work will be needed for canonicalizing / exposing the SPIR-V functions, but these are the fundamental builtins I need. Added: clang/test/CodeGenSPIRV/Builtins/subgroup.c clang/test/SemaSPIRV/BuiltIns/subgroup-errors.c Modified: clang/include/clang/Basic/BuiltinsSPIRVCommon.td llvm/include/llvm/IR/IntrinsicsSPIRV.td Removed: ################################################################################ diff --git a/clang/include/clang/Basic/BuiltinsSPIRVCommon.td b/clang/include/clang/Basic/BuiltinsSPIRVCommon.td index d2ef6f99a0502..495851ed1727a 100644 --- a/clang/include/clang/Basic/BuiltinsSPIRVCommon.td +++ b/clang/include/clang/Basic/BuiltinsSPIRVCommon.td @@ -21,3 +21,5 @@ def subgroup_local_invocation_id : SPIRVBuiltin<"uint32_t()", [NoThrow, Const]>; def distance : SPIRVBuiltin<"void(...)", [NoThrow, Const]>; def length : SPIRVBuiltin<"void(...)", [NoThrow, Const]>; def smoothstep : SPIRVBuiltin<"void(...)", [NoThrow, Const, CustomTypeChecking]>; + +def subgroup_ballot : SPIRVBuiltin<"_ExtVector<4, uint32_t>(bool)", [NoThrow, Const]>; diff --git a/clang/test/CodeGenSPIRV/Builtins/subgroup.c b/clang/test/CodeGenSPIRV/Builtins/subgroup.c new file mode 100644 index 0000000000000..2ae2013c3c23e --- /dev/null +++ b/clang/test/CodeGenSPIRV/Builtins/subgroup.c @@ -0,0 +1,15 @@ +// RUN: %clang_cc1 -O1 -triple spirv64 -fsycl-is-device -x c++ %s -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK +// RUN: %clang_cc1 -O1 -triple spirv64 -cl-std=CL3.0 -x cl %s -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK +// RUN: %clang_cc1 -O1 -triple spirv32 -cl-std=CL3.0 -x cl %s -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK + +#if defined(__cplusplus) +typedef bool _Bool; +#endif +typedef unsigned __attribute__((ext_vector_type(4))) int4; + +// CHECK: @{{.*}}test_subgroup_shuffle{{.*}}( +// CHECK-NEXT: [[ENTRY:.*:]] +// CHECK-NEXT: tail call <4 x i32> @llvm.spv.wave.ballot(i1 %i) +[[clang::sycl_external]] int4 test_subgroup_shuffle(_Bool i) { + return __builtin_spirv_subgroup_ballot(i); +} diff --git a/clang/test/SemaSPIRV/BuiltIns/subgroup-errors.c b/clang/test/SemaSPIRV/BuiltIns/subgroup-errors.c new file mode 100644 index 0000000000000..5ef9f499efd31 --- /dev/null +++ b/clang/test/SemaSPIRV/BuiltIns/subgroup-errors.c @@ -0,0 +1,13 @@ +// RUN: %clang_cc1 -O1 -Wno-unused-value -triple spirv64 -fsycl-is-device -verify %s -o - +// RUN: %clang_cc1 -O1 -Wno-unused-value -triple spirv64 -verify %s -cl-std=CL3.0 -x cl -o - +// RUN: %clang_cc1 -O1 -Wno-unused-value -triple spirv32 -verify %s -cl-std=CL3.0 -x cl -o - + +typedef unsigned __attribute__((ext_vector_type(4))) int4; + +void ballot(_Bool c) { + int4 x; + x = __builtin_spirv_subgroup_ballot(c); + x = __builtin_spirv_subgroup_ballot(1); + x = __builtin_spirv_subgroup_ballot(x); // expected-error{{parameter of incompatible type}} + int y = __builtin_spirv_subgroup_ballot(c); // expected-error{{with an expression of incompatible type}} +} diff --git a/llvm/include/llvm/IR/IntrinsicsSPIRV.td b/llvm/include/llvm/IR/IntrinsicsSPIRV.td index 0e23d19a01c20..bcb533780b58c 100644 --- a/llvm/include/llvm/IR/IntrinsicsSPIRV.td +++ b/llvm/include/llvm/IR/IntrinsicsSPIRV.td @@ -120,7 +120,8 @@ def int_spv_rsqrt : DefaultAttrsIntrinsic<[LLVMMatchType<0>], [llvm_anyfloat_ty] def int_spv_wave_active_countbits : DefaultAttrsIntrinsic<[llvm_i32_ty], [llvm_i1_ty], [IntrConvergent, IntrNoMem]>; def int_spv_wave_all : DefaultAttrsIntrinsic<[llvm_i1_ty], [llvm_i1_ty], [IntrConvergent, IntrNoMem]>; def int_spv_wave_any : DefaultAttrsIntrinsic<[llvm_i1_ty], [llvm_i1_ty], [IntrConvergent, IntrNoMem]>; - def int_spv_wave_ballot : DefaultAttrsIntrinsic<[llvm_v4i32_ty], [llvm_i1_ty], [IntrConvergent, IntrNoMem]>; + def int_spv_wave_ballot : ClangBuiltin<"__builtin_spirv_subgroup_ballot">, + DefaultAttrsIntrinsic<[llvm_v4i32_ty], [llvm_i1_ty], [IntrConvergent, IntrNoMem]>; def int_spv_wave_reduce_umax : DefaultAttrsIntrinsic<[llvm_any_ty], [LLVMMatchType<0>], [IntrConvergent, IntrNoMem]>; def int_spv_wave_reduce_max : DefaultAttrsIntrinsic<[llvm_any_ty], [LLVMMatchType<0>], [IntrConvergent, IntrNoMem]>; def int_spv_wave_reduce_min : DefaultAttrsIntrinsic<[llvm_any_ty], [LLVMMatchType<0>], [IntrConvergent, IntrNoMem]>; _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
