Commit 33ebc293 authored by Peter Maydell's avatar Peter Maydell Committed by Aurelien Jarno
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target-arm: Fix unsigned VQRSHL by large shift counts 



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

Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: default avatarAurelien Jarno <aurelien@aurel32.net>
parent 7b6ecf5b

target-arm/neon_helper.c

+34 −3
Original line number Diff line number Diff line
@@ -818,7 +818,18 @@ uint64_t HELPER(neon_qshlu_s64)(CPUState *env, uint64_t valop, 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 = ~0; \

        } else { \

            dest = 0; \

        } \

    } else if (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 < 0) { \

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

    } else { \

        dest = src1 << tmp; \
@@ -837,7 +848,18 @@ uint32_t HELPER(neon_qrshl_u32)(CPUState *env, uint32_t val, uint32_t shiftop) 
{

    uint32_t dest;

    int8_t shift = (int8_t)shiftop;

    if (shift < 0) {

    if (shift >= 32) {

        if (val) {

            SET_QC();

            dest = ~0;

        } else {

            dest = 0;

        }

    } else if (shift < -32) {

        dest = 0;

    } else if (shift == -32) {

        dest = val >> 31;

    } else if (shift < 0) {

        uint64_t big_dest = ((uint64_t)val + (1 << (-1 - shift)));

        dest = big_dest >> -shift;

    } else {
@@ -855,7 +877,16 @@ uint32_t HELPER(neon_qrshl_u32)(CPUState *env, uint32_t val, uint32_t shiftop) 
uint64_t HELPER(neon_qrshl_u64)(CPUState *env, uint64_t val, uint64_t shiftop)

{

    int8_t shift = (int8_t)shiftop;

    if (shift < 0) {

    if (shift >= 64) {

        if (val) {

            SET_QC();

            val = ~0;

        }

    } else if (shift < -64) {

        val = 0;

    } else if (shift == -64) {

        val >>= 63;

    } else if (shift < 0) {

        val >>= (-shift - 1);

        if (val == UINT64_MAX) {

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