adds findLSB and findMSB from std.450 to glsl_compat.hlsl

Author: Fletterio

include/nbl/builtin/hlsl/glsl_compat/core.hlsl

@@ -7,6 +7,7 @@
 #include "nbl/builtin/hlsl/cpp_compat.hlsl"
 #include "nbl/builtin/hlsl/spirv_intrinsics/core.hlsl"
 #include "nbl/builtin/hlsl/type_traits.hlsl"
+#include "nbl/builtin/hlsl/bit.hlsl"
 
 namespace nbl 
 {
@@ -135,6 +136,61 @@ float32_t2 unpackSnorm2x16(uint32_t p)
     return spirv::unpackSnorm2x16(p);
 }
 
+// No better way to get a vector type of same length as Integral but made up of `int32_t` s?
+
+template<typename T>
+vector<int32_t, uint32_t(sizeof(T) / sizeof(scalar_type_t<T>))> findLSB(T value)
+{
+    using return_t = vector<int32_t, uint32_t(sizeof(T) / sizeof(scalar_type_t<T>))>;
+    return bit_cast<return_t, T>(spirv::findILsb<T>(value));
+}
+
+namespace impl
+{
+    template<typename T, bool isSigned, bool isIntegral>
+    struct findMSB {};
+
+    template<typename T, bool isSigned>
+    struct findMSB<T, isSigned, false>
+    {
+        using return_t = vector<int32_t, uint32_t(sizeof(T) / sizeof(scalar_type_t<T>))>;
+
+        static return_t __call(T value)
+        {
+            static_assert(is_integral<T>::value, "T is not an integral type!");
+            return value;
+        }
+    };
+
+    template<typename T>
+    struct findMSB<T, true, true>
+    {
+        using return_t = vector<int32_t, uint32_t(sizeof(T) / sizeof(scalar_type_t<T>))>;
+
+        static return_t __call(T value)
+        {
+            return bit_cast<return_t, T>(spirv::findSMsb<T>(value));
+        }
+    };
+
+    template<typename T>
+    struct findMSB<T, false, true>
+    {
+        using return_t = vector<int32_t, uint32_t(sizeof(T) / sizeof(scalar_type_t<T>))>;
+
+        static return_t __call(T value)
+        {
+            return bit_cast<return_t, T>(spirv::findUMsb<T>(value));
+        }
+    };
+} // namespace impl
+
+template<typename T>
+vector<int32_t, uint32_t(sizeof(T) / sizeof(scalar_type_t<T>))> findMSB(T value)
+{
+    return impl::findMSB<T, is_signed_v<T>, is_integral_v<T> >::__call(value);
+}
+
 /**
  * For Vertex Shaders
  */

include/nbl/builtin/hlsl/spirv_intrinsics/core.hlsl

@@ -203,6 +203,20 @@ float32_t4 unpackSnorm4x8(uint32_t p);
 [[vk::ext_instruction(GLSLstd450UnpackUnorm4x8, "GLSL.std.450")]]
 float32_t4 unpackUnorm4x8(uint32_t p);
 
+// Find MSB and LSB restricted to 32-bit width component types https://registry.khronos.org/SPIR-V/specs/unified1/GLSL.std.450.html
+
+template<typename Integral NBL_FUNC_REQUIRES(is_integral_v<Integral> && (sizeof(scalar_type_t<Integral>) == 4))
+[[vk::ext_instruction(GLSLstd450::GLSLstd450FindILsb, "GLSL.std.450")]]
+Integral findILsb(Integral value);
+
+template<typename Integral NBL_FUNC_REQUIRES(is_integral_v<Integral> && (sizeof(scalar_type_t<Integral>) == 4))
+[[vk::ext_instruction(GLSLstd450::GLSLstd450FindSMsb, "GLSL.std.450")]]
+Integral findSMsb(Integral value);
+
+template<typename Integral NBL_FUNC_REQUIRES(is_integral_v<Integral> && (sizeof(scalar_type_t<Integral>) == 4))
+[[vk::ext_instruction(GLSLstd450::GLSLstd450FindUMsb, "GLSL.std.450")]]
+Integral findUMsb(Integral value);
+
 // Memory Semantics link here: https://registry.khronos.org/SPIR-V/specs/unified1/SPIRV.html#Memory_Semantics_-id-
 
 // https://registry.khronos.org/SPIR-V/specs/unified1/SPIRV.html#_memory_semantics_id
@@ -234,13 +248,13 @@ template<class T, class U>
 [[vk::ext_instruction(spv::OpBitcast)]]
 T bitcast(U);
 
-template<typename Unsigned>
+template<typename Integral>
 [[vk::ext_instruction( spv::OpBitFieldUExtract )]]
-enable_if_t<is_unsigned_v<Unsigned>, Unsigned> bitFieldUExtract( Unsigned val, uint32_t offsetBits, uint32_t numBits );
+enable_if_t<is_integral_v<Integral>, Integral> bitFieldUExtract( Integral val, uint32_t offsetBits, uint32_t numBits );
 
-template<typename Signed>
+template<typename Integral>
 [[vk::ext_instruction( spv::OpBitFieldSExtract )]]
-enable_if_t<is_signed_v<Signed>, Signed> bitFieldSExtract( Signed val, uint32_t offsetBits, uint32_t numBits );
+enable_if_t<is_integral_v<Integral>, Integral> bitFieldSExtract( Integral val, uint32_t offsetBits, uint32_t numBits );
 
 template<typename Integral>
 [[vk::ext_instruction( spv::OpBitFieldInsert )]]

include/nbl/builtin/hlsl/type_traits.hlsl

@@ -613,6 +613,9 @@ template<class T>
 NBL_CONSTEXPR bool is_scalar_v = is_scalar<T>::value;
 template<class T>
 NBL_CONSTEXPR uint32_t alignment_of_v = alignment_of<T>::value;
+template<class T, uint32_t N = 0>
+NBL_CONSTEXPR uint64_t extent_v = extent<T, N>::value;
+
 
 // Overlapping definitions
 template<typename T>