Commit 037e1d00 authored by Peter Maydell's avatar Peter Maydell
Browse files

target-arm: A64: Avoid left shifting negative integers in disas_pc_rel_addr 



Shifting a negative integer left is undefined behaviour in C.
Avoid it by assembling and shifting the offset fields as
unsigned values and then sign extending as the final action.

Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Message-id: 1423233250-15853-4-git-send-email-peter.maydell@linaro.org
parent e167adc9

target-arm/translate-a64.c

+3 −2
Original line number Diff line number Diff line
@@ -2662,11 +2662,12 @@ static void disas_pc_rel_adr(DisasContext *s, uint32_t insn) 
{

    unsigned int page, rd;

    uint64_t base;

    int64_t offset;

    uint64_t offset;



    page = extract32(insn, 31, 1);

    /* SignExtend(immhi:immlo) -> offset */

    offset = ((int64_t)sextract32(insn, 5, 19) << 2) | extract32(insn, 29, 2);

    offset = sextract64(insn, 5, 19);

    offset = offset << 2 | extract32(insn, 29, 2);

    rd = extract32(insn, 0, 5);

    base = s->pc - 4;