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libFLAC: Add a workaround for a bug in MSVC2105 update2

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MSVC2105 update2 compiles the C code:

    abs_residual_partition_sums[partition] =
                  (FLAC__uint32)_mm_cvtsi128_si32(mm_sum);

into this:

    movq    QWORD PTR [rsi], xmm2

while it should be:

    movd    eax, xmm2
    mov     QWORD PTR [rsi], rax

With this patch, MSVC emits:

    movq    QWORD PTR [rsi], xmm2
    mov     DWORD PTR [rsi+4], r9d

so the price of this workaround is 1 extra write instruction per
partition.

Patch-from: lvqcl <lvqcl.mail@gmail.com>
This commit is contained in:
Erik de Castro Lopo
2016-05-05 17:21:20 +10:00
parent 387992bd64
commit 94a61241b0
3 changed files with 12 additions and 0 deletions
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4
src/libFLAC/stream_encoder_intrin_avx2.c
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@@ -84,6 +84,10 @@ void FLAC__precompute_partition_info_sums_intrin_avx2(const FLAC__int32 residual
sum128 = _mm_hadd_epi32(sum128, sum128);
sum128 = _mm_hadd_epi32(sum128, sum128);
abs_residual_partition_sums[partition] = (FLAC__uint32)_mm_cvtsi128_si32(sum128);
/* workaround for a bug in MSVC2015U2 - see https://connect.microsoft.com/VisualStudio/feedback/details/2659191/incorrect-code-generation-for-x86-64 */
#if (defined _MSC_VER) && (_MSC_FULL_VER == 190023918) && (defined FLAC__CPU_X86_64)
abs_residual_partition_sums[partition] &= 0xFFFFFFFF; /**/
#endif
}
}
else { /* have to pessimistically use 64 bits for accumulator */