From: Richard Henderson <richard.hender...@linaro.org> 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: Richard Henderson <richard.hender...@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com> Message-id: 20200320160622.8040-4-richard.hender...@linaro.org Reviewed-by: Peter Maydell <peter.mayd...@linaro.org> Signed-off-by: Peter Maydell <peter.mayd...@linaro.org> --- target/arm/translate-a64.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c index 032478614c4..7580e463674 100644 --- a/target/arm/translate-a64.c +++ b/target/arm/translate-a64.c @@ -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)); -- 2.20.1