Rockbox open source high quality audio player as a Music Player Daemon
mpris
rockbox
mpd
libadwaita
audio
rust
zig
deno
arm: use optimized find_first_set_bit() on Cortex-M
Use the optimized version based on __buitlin_ctz() which GCC
will compile to two instructions (rbit, ctz) on Cortex-M4/M7;
faster and smaller than the handcoded assembly version.
Change-Id: I33f69ff829b048f1e53fc7ead1bd6ac3c5bd7a4c
authored by
Aidan MacDonald
and committed by
Solomon Peachy
20d31c11
4ceb9e22
+2
-1
+2
-1
firmware/export/system.h
+2
-1
firmware/export/system.h
···
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#endif
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/* returns index of first set bit or 32 if no bits are set */
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-
#if defined(CPU_ARM) && ARM_ARCH >= 5 && !defined(__thumb__)
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+
#if (defined(CPU_ARM) && ARM_ARCH >= 5 && !defined(__thumb__)) || \
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+
defined(CPU_ARM_MICRO)
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static inline int find_first_set_bit(uint32_t val)
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{ return LIKELY(val) ? __builtin_ctz(val) : 32; }
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#else