Commit 0670a7b6 authored by Peter Maydell's avatar Peter Maydell Committed by Aurelien Jarno
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target-arm: Fix signed VRSHL by large shift counts 



Correctly handle VRSHL of signed values by a shift count of the
width of the data type or larger, which must be special-cased in the
rshl_s* helper functions.

Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: default avatarAurelien Jarno <aurelien@aurel32.net>
parent 4bd4ee07

target-arm/neon_helper.c

+3 −14
Original line number Diff line number Diff line
@@ -543,14 +543,9 @@ uint64_t HELPER(neon_shl_s64)(uint64_t valop, uint64_t shiftop) 
#define NEON_FN(dest, src1, src2) do { \

    int8_t tmp; \

    tmp = (int8_t)src2; \

    if (tmp >= (ssize_t)sizeof(src1) * 8) { \

    if ((tmp >= (ssize_t)sizeof(src1) * 8) \

        || (tmp <= -(ssize_t)sizeof(src1) * 8)) { \

        dest = 0; \

    } else if (tmp < -(ssize_t)sizeof(src1) * 8) { \

        dest = src1 >> (sizeof(src1) * 8 - 1); \

    } else if (tmp == -(ssize_t)sizeof(src1) * 8) { \

        dest = src1 >> (tmp - 1); \

        dest++; \

        dest >>= 1; \

    } else if (tmp < 0) { \

        dest = (src1 + (1 << (-1 - tmp))) >> -tmp; \

    } else { \
@@ -584,14 +579,8 @@ uint64_t HELPER(neon_rshl_s64)(uint64_t valop, uint64_t shiftop) 
{

    int8_t shift = (int8_t)shiftop;

    int64_t val = valop;

    if (shift >= 64) {

    if ((shift >= 64) || (shift <= -64)) {

        val = 0;

    } else if (shift < -64) {

        val >>= 63;

    } else if (shift == -63) {

        val >>= 63;

        val++;

        val >>= 1;

    } else if (shift < 0) {

        val >>= (-shift - 1);

        if (val == INT64_MAX) {