Commit 7b6ecf5b authored by Peter Maydell's avatar Peter Maydell Committed by Aurelien Jarno
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target-arm: Fix signed VQRSHL by large shift counts 



Handle the case of signed VQRSHL by a shift count of the width of the
data type or larger, which must be special cased in the qrshl_s*
helper functions.

Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: default avatarAurelien Jarno <aurelien@aurel32.net>
parent 0b36f4cd

target-arm/neon_helper.c

+31 −3
Original line number Diff line number Diff line
@@ -880,7 +880,19 @@ uint64_t HELPER(neon_qrshl_u64)(CPUState *env, uint64_t val, uint64_t shiftop) 
#define NEON_FN(dest, src1, src2) do { \

    int8_t tmp; \

    tmp = (int8_t)src2; \

    if (tmp < 0) { \

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

        if (src1) { \

            SET_QC(); \

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

            if (src1 > 0) { \

                dest--; \

            } \

        } else { \

            dest = 0; \

        } \

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

        dest = 0; \

    } else if (tmp < 0) { \

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

    } else { \

        dest = src1 << tmp; \
@@ -903,7 +915,16 @@ uint32_t HELPER(neon_qrshl_s32)(CPUState *env, uint32_t valop, uint32_t shiftop) 
    int32_t dest;

    int32_t val = (int32_t)valop;

    int8_t shift = (int8_t)shiftop;

    if (shift < 0) {

    if (shift >= 32) {

        if (val) {

            SET_QC();

            dest = (val >> 31) ^ ~SIGNBIT;

        } else {

            dest = 0;

        }

    } else if (shift <= -32) {

        dest = 0;

    } else if (shift < 0) {

        int64_t big_dest = ((int64_t)val + (1 << (-1 - shift)));

        dest = big_dest >> -shift;

    } else {
@@ -923,7 +944,14 @@ uint64_t HELPER(neon_qrshl_s64)(CPUState *env, uint64_t valop, uint64_t shiftop) 
    int8_t shift = (uint8_t)shiftop;

    int64_t val = valop;



    if (shift < 0) {

    if (shift >= 64) {

        if (val) {

            SET_QC();

            val = (val >> 63) ^ ~SIGNBIT64;

        }

    } else if (shift <= -64) {

        val = 0;

    } else if (shift < 0) {

        val >>= (-shift - 1);

        if (val == INT64_MAX) {

            /* In this case, it means that the rounding constant is 1,