From 12b9db50eed370ba94ed4a7c4c9dd2218bad5f48 Mon Sep 17 00:00:00 2001 From: Nathan Bossart Date: Wed, 1 Jul 2026 19:30:59 -0500 Subject: [PATCH v1 1/1] remove switch statement in vector8_shift_{left,right} --- src/include/port/simd.h | 29 +++-------------------------- 1 file changed, 3 insertions(+), 26 deletions(-) diff --git a/src/include/port/simd.h b/src/include/port/simd.h index 50615aec7f4..25a26c81cce 100644 --- a/src/include/port/simd.h +++ b/src/include/port/simd.h @@ -548,10 +548,6 @@ vector8_pack_16(const Vector8 v1, const Vector8 v2) /* * Unsigned shift left of each 32-bit element in the vector by "i" bits. - * - * XXX AArch64 requires an integer literal, so we have to list all expected - * values of "i" from all callers in a switch statement. If you add a new - * caller, be sure your expected values of "i" are handled. */ #ifndef USE_NO_SIMD static inline Vector8 @@ -560,24 +556,13 @@ vector8_shift_left(const Vector8 v1, int i) #ifdef USE_SSE2 return _mm_slli_epi32(v1, i); #elif defined(USE_NEON) - switch (i) - { - case 4: - return (Vector8) vshlq_n_u32((Vector32) v1, 4); - default: - Assert(false); - return vector8_broadcast(0); - } + return (Vector8) vshlq_u32((Vector32) v1, vdupq_n_s32(i)); #endif } #endif /* ! USE_NO_SIMD */ /* * Unsigned shift right of each 32-bit element in the vector by "i" bits. - * - * XXX AArch64 requires an integer literal, so we have to list all expected - * values of "i" from all callers in a switch statement. If you add a new - * caller, be sure your expected values of "i" are handled. */ #ifndef USE_NO_SIMD static inline Vector8 @@ -586,16 +571,8 @@ vector8_shift_right(const Vector8 v1, int i) #ifdef USE_SSE2 return _mm_srli_epi32(v1, i); #elif defined(USE_NEON) - switch (i) - { - case 4: - return (Vector8) vshrq_n_u32((Vector32) v1, 4); - case 8: - return (Vector8) vshrq_n_u32((Vector32) v1, 8); - default: - Assert(false); - return vector8_broadcast(0); - } + /* negative shift count means right shift */ + return (Vector8) vshlq_u32((Vector32) v1, vdupq_n_s32(-i)); #endif } #endif /* ! USE_NO_SIMD */ -- 2.50.1 (Apple Git-155)