aarch64: Port NEON reduction intrinsics to pragma framework
NEON reduction intrinsics (vaddv, vmaxv, vminv, etc.) are now handled by GCC's pragma-based framework.
Several NEON reduction intrinsics for aarch64, including vaddv, vmaxv, vminv, vmaxnmv, and vminnmv, have been ported to GCC’s pragma-based framework. Some floating-point variants requiring special NaN handling (e.g., vmaxv_f32) were not ported in this patch due to complexities in mapping them to existing instruction patterns. The changes involve adding new function bases and groups and removing many previously defined functions from arm_neon.h.
In Details
This patch ports NEON reduction intrinsics (like vaddv, vmaxv) to the pragma-based intrinsic framework. The new intrinsic bases are defined in aarch64-neon-builtins-base.cc and .def. Floating-point reduction intrinsics with specific NaN semantics (e.g., vmaxv_f32, vminv_f64) are excluded as they require specialized <optab>_nan variants not yet available. The corresponding function definitions are removed from arm_neon.h.
- NEON
- An Advanced SIMD extension for ARM processors, providing accelerated xử lý of vector data.
- intrinsics
- Special functions that map directly to specific hardware instructions, allowing C/C++ code to leverage specialized processor capabilities.
- pragma-based framework
- A mechanism within GCC where compiler behavior, particularly for intrinsics, is controlled by pragmas, enabling more flexible and maintainable handling of built-in functions.
- NaN
- Not a Number; a special floating-point value used to represent undefined or unrepresentable results, often arising from operations like 0/0 or sqrt(-1).