wehub-resource-sync
21 lines
794 B
C++
21 lines
794 B
C++
#include <riscv_vector.h>
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void MNNRGBToGRAY(const unsigned char* source, unsigned char* dest, size_t count) {
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size_t i = 0;
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while (i < count) {
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size_t vl = __riscv_vsetvl_e8m4(count - i);
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vuint8m4_t channel = __riscv_vlse8_v_u8m4(source + 3 * i + 0, 3, vl);
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vuint16m8_t sum = __riscv_vwmulu_vx_u16m8(channel, 19, vl);
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channel = __riscv_vlse8_v_u8m4(source + 3 * i + 1, 3, vl);
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sum = __riscv_vwmaccu_vx_u16m8(sum, 38, channel, vl);
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channel = __riscv_vlse8_v_u8m4(source + 3 * i + 2, 3, vl);
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sum = __riscv_vwmaccu_vx_u16m8(sum, 7, channel, vl);
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vuint8m4_t result = __riscv_vnsrl_wx_u8m4(sum, 6, vl);
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__riscv_vse8_v_u8m4(dest + i, result, vl);
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i += vl;
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}
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}
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