Commit 489ed4bb authored by Petar Jovanovic's avatar Petar Jovanovic Committed by Aurelien Jarno
Browse files

target-mips: fix incorrect behaviour for EXTP 



The mask for EXTP instruction when size=31 has not been correctly
calculated.

The test (mips32-dsp/extp.c) has been extended to include the case that
triggers the issue.

Signed-off-by: default avatarPetar Jovanovic <petar.jovanovic@imgtec.com>
Signed-off-by: default avatarAurelien Jarno <aurelien@aurel32.net>
parent 91b96cdc

target-mips/dsp_helper.c

+1 −2
Original line number Diff line number Diff line
@@ -3415,8 +3415,7 @@ target_ulong helper_extp(target_ulong ac, target_ulong size, CPUMIPSState *env) 
    if (sub >= -1) {

        acc = ((uint64_t)env->active_tc.HI[ac] << 32) |

              ((uint64_t)env->active_tc.LO[ac] & MIPSDSP_LLO);

        temp = (acc >> (start_pos - size)) &

               (((uint32_t)0x01 << (size + 1)) - 1);

        temp = (acc >> (start_pos - size)) & (~0U >> (31 - size));

        set_DSPControl_efi(0, env);

    } else {

        set_DSPControl_efi(1, env);

tests/tcg/mips/mips32-dsp/extp.c

+18 −0
Original line number Diff line number Diff line
@@ -40,5 +40,23 @@ int main() 
    dsp = (dsp >> 14) & 0x01;

    assert(dsp == 1);



    ach = 0;

    acl = 0x80000001;

    dsp = 0x1F;

    result = 0x80000001;



    __asm

        ("wrdsp %1\n\t"

         "mthi %2, $ac2\n\t"

         "mtlo %3, $ac2\n\t"

         "extp %0, $ac2, 0x1F\n\t"

         "rddsp %1\n\t"

         : "=r"(rt), "+r"(dsp)

         : "r"(ach), "r"(acl)

        );

    dsp = (dsp >> 14) & 0x01;

    assert(dsp == 0);

    assert(result == rt);



    return 0;

}