[SYCL] Correct handling of enumeration specialization constants (#12925)

Lower enumeration specialization constants to `SpecConstant` in SPIR-V
instead of `SpecConstantComposite`, thus handling them using their
underlying integral types.

---------

Signed-off-by: Victor Perez <victor.perez@codeplay.com>

Author: victor-eds

sycl/include/sycl/kernel_handler.hpp

@@ -67,7 +67,7 @@ class __SYCL_TYPE(kernel_handler) kernel_handler {
   template <
       auto &S,
       typename T = typename std::remove_reference_t<decltype(S)>::value_type,
-      std::enable_if_t<std::is_fundamental_v<T>> * = nullptr>
+      std::enable_if_t<std::is_scalar_v<T>> * = nullptr>
   __SYCL_ALWAYS_INLINE T getSpecializationConstantOnDevice() {
     const char *SymbolicID = __builtin_sycl_unique_stable_id(S);
     return __sycl_getScalar2020SpecConstantValue<T>(
@@ -76,7 +76,7 @@ class __SYCL_TYPE(kernel_handler) kernel_handler {
   template <
       auto &S,
       typename T = typename std::remove_reference_t<decltype(S)>::value_type,
-      std::enable_if_t<std::is_compound_v<T>> * = nullptr>
+      std::enable_if_t<!std::is_scalar_v<T>> * = nullptr>
   __SYCL_ALWAYS_INLINE T getSpecializationConstantOnDevice() {
     const char *SymbolicID = __builtin_sycl_unique_stable_id(S);
     return __sycl_getComposite2020SpecConstantValue<T>(

sycl/test/basic_tests/SYCL-2020-spec-constants.cpp

@@ -4,7 +4,7 @@
 // RUN: sycl-post-link %t.bc -spec-const=emulation -o %t-split2.txt
 // RUN: cat %t-split2_0.prop | FileCheck %s -check-prefixes=CHECK,CHECK-DEF
 // RUN: llvm-spirv -o %t-split1_0.spv -spirv-max-version=1.1 -spirv-ext=+all %t-split1_0.bc
-// RUN: llvm-spirv -o %t-split2_0.spv -spirv-max-version=1.1 -spirv-ext=+all %t-split2_0.bc
+// RUN: llvm-spirv -o - --to-text %t-split1_0.spv | FileCheck %s -check-prefixes=CHECK-SPV
 //
 //==----------- SYCL-2020-spec-constants.cpp -------------------------------==//
 //
@@ -61,6 +61,10 @@ struct composite {
 
 constexpr sycl::specialization_id<composite> composite_id(12, 13);
 
+enum class enumeration { a, b, c };
+
+constexpr sycl::specialization_id<enumeration> enumeration_id(enumeration::c);
+
 class SpecializedKernel;
 
 int main() {
@@ -88,11 +92,12 @@ int main() {
         auto f32 = kh.get_specialization_constant<float_id>();
         auto f64 = kh.get_specialization_constant<double_id>();
         auto c = kh.get_specialization_constant<composite_id>();
+        auto e = kh.get_specialization_constant<enumeration_id>();
 
         // see FIXMEs above about bool and half types support
         acc[0] = /*i1 +*/ i8 + u8 + i16 + u16 + i32 + u32 + i64 + u64 +
-                 //f16.get() +
-                 f32 + f64 + c.a + c.b;
+                 // f16.get() +
+                 f32 + f64 + c.a + c.b + static_cast<float>(e);
       });
     });
   }
@@ -114,6 +119,7 @@ int main() {
 // CHECK-DAG: [[UNIQUE_PREFIX]]____ZL9uint16_id=2|
 // CHECK-DAG: [[UNIQUE_PREFIX]]____ZL9uint32_id=2|
 // CHECK-DAG: [[UNIQUE_PREFIX]]____ZL9uint64_id=2|
+// CHECK-DAG: [[UNIQUE_PREFIX]]____ZL14enumeration_id=2|
 // FIXME: check line for half constant
 
 // CHECK-RT: [SYCL/specialization constants default values]
@@ -133,6 +139,7 @@ int main() {
 // CHECK-NEXT-LOG:[[UNIQUE_PREFIX]]____ZL9double_id={9, 0, 8}
 // CHECK-NEXT-LOG:[[UNIQUE_PREFIX]]____ZL12composite_id={10, 0, 4}
 // CHECK-NEXT-LOG:[[UNIQUE_PREFIX]]____ZL12composite_id={11, 4, 4}
+// CHECK-NEXT-LOG:[[UNIQUE_PREFIX]]____ZL14enumeration_id={12, 0, 4}
 // CHECK-NEXT-LOG:{0, 1, 42}
 // CHECK-NEXT-LOG:{1, 1, 26}
 // CHECK-NEXT-LOG:{2, 2, 34}
@@ -145,3 +152,40 @@ int main() {
 // CHECK-NEXT-LOG:{34, 8, 1.100000e+01}
 // CHECK-NEXT-LOG:{42, 4, 12}
 // CHECK-NEXT-LOG:{46, 4, 13}
+// CHECK-NEXT-LOG:{50, 4, 2}
+
+// CHECK-SPV-DAG: Decorate [[#SPEC0:]] SpecId 0
+// CHECK-SPV-DAG: Decorate [[#SPEC1:]] SpecId 1
+// CHECK-SPV-DAG: Decorate [[#SPEC2:]] SpecId 2
+// CHECK-SPV-DAG: Decorate [[#SPEC3:]] SpecId 3
+// CHECK-SPV-DAG: Decorate [[#SPEC4:]] SpecId 4
+// CHECK-SPV-DAG: Decorate [[#SPEC5:]] SpecId 5
+// CHECK-SPV-DAG: Decorate [[#SPEC6:]] SpecId 6
+// CHECK-SPV-DAG: Decorate [[#SPEC7:]] SpecId 7
+// CHECK-SPV-DAG: Decorate [[#SPEC8:]] SpecId 8
+// CHECK-SPV-DAG: Decorate [[#SPEC9:]] SpecId 9
+// CHECK-SPV-DAG: Decorate [[#SPEC10:]] SpecId 10
+// CHECK-SPV-DAG: Decorate [[#SPEC11:]] SpecId 11
+// CHECK-SPV-DAG: Decorate [[#SPEC12:]] SpecId 12
+
+// CHECK-SPV-DAG: TypeInt [[#I64TY:]] 64 0
+// CHECK-SPV-DAG: TypeInt [[#I32TY:]] 32 0
+// CHECK-SPV-DAG: TypeInt [[#I8TY:]]  8 0
+// CHECK-SPV-DAG: TypeInt [[#I16TY:]] 16 0
+// CHECK-SPV-DAG: TypeFloat [[#F32TY:]] 32
+// CHECK-SPV-DAG: TypeFloat [[#F64TY:]] 64
+// CHECK-SPV-DAG: TypeStruct [[#COMPTY:]] [[#I32TY]] [[#I32TY]]
+// CHECK-SPV-DAG: SpecConstant [[#I8TY]]  [[#SPEC0]] 42
+// CHECK-SPV-DAG: SpecConstant [[#I8TY]]  [[#SPEC1]] 26
+// CHECK-SPV-DAG: SpecConstant [[#I16TY]] [[#SPEC2]] 34
+// CHECK-SPV-DAG: SpecConstant [[#I16TY]] [[#SPEC3]] 14
+// CHECK-SPV-DAG: SpecConstant [[#I32TY]] [[#SPEC4]] 52
+// CHECK-SPV-DAG: SpecConstant [[#I32TY]] [[#SPEC5]] 46
+// CHECK-SPV-DAG: SpecConstant [[#I64TY]] [[#SPEC6]] 27 0
+// CHECK-SPV-DAG: SpecConstant [[#I64TY]] [[#SPEC7]] 81 0
+// CHECK-SPV-DAG: SpecConstant [[#F32TY]] [[#SPEC8]] 1144094720
+// CHECK-SPV-DAG: SpecConstant [[#F64TY]] [[#SPEC9]] 0 1076232192
+// CHECK-SPV-DAG: SpecConstant [[#I32TY]] [[#SPEC10]] 12
+// CHECK-SPV-DAG: SpecConstant [[#I32TY]] [[#SPEC11]] 13
+// CHECK-SPV-DAG: SpecConstant [[#I32TY]] [[#SPEC12]] 2
+// CHECK-SPV-DAG: SpecConstantComposite [[#COMPTY]] {{.*}} [[#SPEC10]] [[#SPEC11]]