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lib/raid6: use vdupq_n_u8 to avoid endianness warnings

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Clang warns: vector initializers are not compatible with NEON intrinsics
in big endian mode [-Wnonportable-vector-initialization]

While this is usually the case, it's not an issue for this case since
we're initializing the uint8x16_t (16x uint8_t's) with the same value.

Instead, use vdupq_n_u8 which both compilers lower into a single movi
instruction: https://godbolt.org/z/vBrgzt

This avoids the static storage for a constant value.

Link: https://github.com/ClangBuiltLinux/linux/issues/214
Suggested-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
ndesaulniers@google.com
2019-02-25 20:03:42 -08:00
committed by Catalin Marinas
parent 2c97a9cc35
commit 1ad3935b39
2 changed files with 4 additions and 8 deletions
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5
lib/raid6/neon.uc
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@@ -28,7 +28,6 @@
typedef uint8x16_t unative_t;
#define NBYTES(x) ((unative_t){x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x})
#define NSIZE sizeof(unative_t)
/*
@@ -61,7 +60,7 @@ void raid6_neon$#_gen_syndrome_real(int disks, unsigned long bytes, void **ptrs)
int d, z, z0;
register unative_t wd$$, wq$$, wp$$, w1$$, w2$$;
const unative_t x1d = NBYTES(0x1d);
const unative_t x1d = vdupq_n_u8(0x1d);
z0 = disks - 3; /* Highest data disk */
p = dptr[z0+1]; /* XOR parity */
@@ -92,7 +91,7 @@ void raid6_neon$#_xor_syndrome_real(int disks, int start, int stop,
int d, z, z0;
register unative_t wd$$, wq$$, wp$$, w1$$, w2$$;
const unative_t x1d = NBYTES(0x1d);
const unative_t x1d = vdupq_n_u8(0x1d);
z0 = stop; /* P/Q right side optimization */
p = dptr[disks-2]; /* XOR parity */