Commit 550a0489 authored by Richard Henderson's avatar Richard Henderson Committed by Peter Maydell
Browse files

target/arm: Move computation of index in handle_simd_dupe 



Coverity reports a BAD_SHIFT with ctz32(imm5), with imm5 == 0.
This is an invalid encoding, but we diagnose that just below
by rejecting size > 3.  Avoid the warning by sinking the
computation of index below the check.

Reported-by: Coverity (CID 1421965)
Signed-off-by: default avatarRichard Henderson <richard.henderson@linaro.org>
Reviewed-by: default avatarPhilippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200320160622.8040-4-richard.henderson@linaro.org
Reviewed-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
parent 3944d58d

target/arm/translate-a64.c

+2 −1
Original line number Diff line number Diff line
@@ -7422,7 +7422,7 @@ static void handle_simd_dupe(DisasContext *s, int is_q, int rd, int rn, 
                             int imm5)

{

    int size = ctz32(imm5);

    int index = imm5 >> (size + 1);

    int index;



    if (size > 3 || (size == 3 && !is_q)) {

        unallocated_encoding(s);
@@ -7433,6 +7433,7 @@ static void handle_simd_dupe(DisasContext *s, int is_q, int rd, int rn, 
        return;

    }



    index = imm5 >> (size + 1);

    tcg_gen_gvec_dup_mem(size, vec_full_reg_offset(s, rd),

                         vec_reg_offset(s, rn, index, size),

                         is_q ? 16 : 8, vec_full_reg_size(s));