[clang] [clang][HLSL] Add sign intrinsic part 3 (PR #101989)

[Farzon Lotfi via cfe-commits]

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@@ -1725,5 +1725,76 @@ _HLSL_AVAILABILITY(shadermodel, 6.0)
 _HLSL_BUILTIN_ALIAS(__builtin_hlsl_wave_get_lane_index)
 __attribute__((convergent)) uint WaveGetLaneIndex();
 
+//===----------------------------------------------------------------------===//
+// sign builtins
+//===----------------------------------------------------------------------===//
+
+/// \fn T sign(T Val)
+/// \brief Returns -1 if \a Val is less than zero; 0 if \a Val equals zero; and
+/// 1 if \a Val is greater than zero. \param Val The input value.
+
+#ifdef __HLSL_ENABLE_16_BIT
+_HLSL_AVAILABILITY(shadermodel, 6.2)
+_HLSL_BUILTIN_ALIAS(__builtin_hlsl_elementwise_sign)
+int sign(int16_t);
+_HLSL_AVAILABILITY(shadermodel, 6.2)
+_HLSL_BUILTIN_ALIAS(__builtin_hlsl_elementwise_sign)
+int2 sign(int16_t2);
+_HLSL_AVAILABILITY(shadermodel, 6.2)
+_HLSL_BUILTIN_ALIAS(__builtin_hlsl_elementwise_sign)
+int3 sign(int16_t3);
+_HLSL_AVAILABILITY(shadermodel, 6.2)
+_HLSL_BUILTIN_ALIAS(__builtin_hlsl_elementwise_sign)
+int4 sign(int16_t4);
+#endif
+
+_HLSL_16BIT_AVAILABILITY(shadermodel, 6.2)
+_HLSL_BUILTIN_ALIAS(__builtin_hlsl_elementwise_sign)
+int sign(half);
+_HLSL_16BIT_AVAILABILITY(shadermodel, 6.2)
+_HLSL_BUILTIN_ALIAS(__builtin_hlsl_elementwise_sign)
+int2 sign(half2);
+_HLSL_16BIT_AVAILABILITY(shadermodel, 6.2)
+_HLSL_BUILTIN_ALIAS(__builtin_hlsl_elementwise_sign)
+int3 sign(half3);
+_HLSL_16BIT_AVAILABILITY(shadermodel, 6.2)
+_HLSL_BUILTIN_ALIAS(__builtin_hlsl_elementwise_sign)
+int4 sign(half4);
+
+_HLSL_BUILTIN_ALIAS(__builtin_hlsl_elementwise_sign)
+int sign(int);
----------------
farzonl wrote:

@llvm-beanz  the `int sign(int)` cases are going to have unecessary code gen. Where would be the approriate place to short-circuit that code gen to just return the input param?

https://github.com/llvm/llvm-project/pull/101989