[FFmpeg-devel] [PATCH 03/18] configure/riscv: detect fast CLZ

2022-09-12 Thread remi
From: Rémi Denis-Courmont RISC-V defines the CLZ instruction as part of the ratified Zbb subset of the (not yet ratified) bit mapulation extension (B). We can detect it from the __riscv_zbb predefined constant. At least GCC 12 already supports this correctly. Note that the macro will be non-zero

[FFmpeg-devel] [PATCH 03/18] configure/riscv: detect fast CLZ

2022-09-09 Thread remi
From: Rémi Denis-Courmont RISC-V defines the CLZ instruction as part of the ratified Zbb subset of the (not yet ratified) bit mapulation extension (B). We can detect it from the __riscv_zbb predefined constant. At least GCC 12 already supports this correctly. Note that the macro will be non-zero