Commit dabf0058 authored by Xiangyu Hu's avatar Xiangyu Hu Committed by Peter Maydell
Browse files

Fix FMULX not squashing denormalized inputs when FZ is set. 



While FMULX returns a 2.0f float when two operators are infinity and
zero, those operators should be unpacked from raw inputs first. Inconsistent
cases would occur when operators are denormalized floats in flush-to-zero
mode. A wrong codepath will be entered and 2.0f will not be returned
without this patch.
Fix by checking whether inputs need to be flushed before running into
different codepaths.

Signed-off-by: default avatarXiangyu Hu <libhu.so@gmail.com>
Message-id: 1422459650-12490-1-git-send-email-libhu.so@gmail.com
Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
parent 375421cc

target-arm/helper-a64.c

+6 −0
Original line number Diff line number Diff line
@@ -135,6 +135,9 @@ float32 HELPER(vfp_mulxs)(float32 a, float32 b, void *fpstp) 
{

    float_status *fpst = fpstp;



    a = float32_squash_input_denormal(a, fpst);

    b = float32_squash_input_denormal(b, fpst);



    if ((float32_is_zero(a) && float32_is_infinity(b)) ||

        (float32_is_infinity(a) && float32_is_zero(b))) {

        /* 2.0 with the sign bit set to sign(A) XOR sign(B) */
@@ -148,6 +151,9 @@ float64 HELPER(vfp_mulxd)(float64 a, float64 b, void *fpstp) 
{

    float_status *fpst = fpstp;



    a = float64_squash_input_denormal(a, fpst);

    b = float64_squash_input_denormal(b, fpst);



    if ((float64_is_zero(a) && float64_is_infinity(b)) ||

        (float64_is_infinity(a) && float64_is_zero(b))) {

        /* 2.0 with the sign bit set to sign(A) XOR sign(B) */