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| author | Mateja Marjanovic <Mateja.Marjanovic@rt-rk.com> | 2019-04-02 14:11:50 +0200 |
|---|---|---|
| committer | Aleksandar Markovic <amarkovic@wavecomp.com> | 2019-05-26 17:32:37 +0200 |
| commit | cf122bf8d2732d5d8647901ebaea596668aaaa3a (patch) | |
| tree | 5271ce67ac3ce3fa918b9376cb1b5dd142c6ba29 /target/mips | |
| parent | d2a40a5f6938f30f44b536e997e1e89bb62b971c (diff) | |
| download | qemu-cf122bf8d2732d5d8647901ebaea596668aaaa3a.zip | |
target/mips: Make the results of MOD_<U|S>.<B|H|W|D> the same as on hardware
MSA instructions MOD_<U|S>.<B|H|W|D> when dividing by zero,
didn't return the same value when executed on a referent hardware
(FPGA MIPS 64 r6, little endian) and when executed on QEMU, which
is not a real bug, because the result when dividing by zero is
UNPREDICTABLE [1] (page 255, 256).
[1] MIPS Architecture for Programmers
Volume IV-j: The MIPS64 SIMD
Architecture Module, Revision 1.12
Signed-off-by: Mateja Marjanovic <mateja.marjanovic@rt-rk.com>
Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Reviewed-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Message-Id: <1554207110-9113-3-git-send-email-mateja.marjanovic@rt-rk.com>
Diffstat (limited to 'target/mips')
| -rw-r--r-- | target/mips/msa_helper.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/target/mips/msa_helper.c b/target/mips/msa_helper.c index 596190b82f..274c6ca058 100644 --- a/target/mips/msa_helper.c +++ b/target/mips/msa_helper.c @@ -657,14 +657,14 @@ static inline int64_t msa_mod_s_df(uint32_t df, int64_t arg1, int64_t arg2) if (arg1 == DF_MIN_INT(df) && arg2 == -1) { return 0; } - return arg2 ? arg1 % arg2 : 0; + return arg2 ? arg1 % arg2 : arg1; } static inline int64_t msa_mod_u_df(uint32_t df, int64_t arg1, int64_t arg2) { uint64_t u_arg1 = UNSIGNED(arg1, df); uint64_t u_arg2 = UNSIGNED(arg2, df); - return u_arg2 ? u_arg1 % u_arg2 : 0; + return u_arg2 ? u_arg1 % u_arg2 : u_arg1; } #define SIGNED_EVEN(a, df) \ |