From d2a40a5f6938f30f44b536e997e1e89bb62b971c Mon Sep 17 00:00:00 2001 From: Mateja Marjanovic Date: Tue, 2 Apr 2019 14:11:49 +0200 Subject: target/mips: Make the results of DIV_. the same as on hardware MSA instructions DIV_. 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 141, 142). [1] MIPS Architecture for Programmers Volume IV-j: The MIPS64 SIMD Architecture Module, Revision 1.12 Signed-off-by: Mateja Marjanovic Signed-off-by: Aleksandar Markovic Reviewed-by: Aleksandar Markovic Message-Id: <1554207110-9113-2-git-send-email-mateja.marjanovic@rt-rk.com> --- target/mips/msa_helper.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'target') diff --git a/target/mips/msa_helper.c b/target/mips/msa_helper.c index c74e3cdc65..596190b82f 100644 --- a/target/mips/msa_helper.c +++ b/target/mips/msa_helper.c @@ -641,14 +641,15 @@ static inline int64_t msa_div_s_df(uint32_t df, int64_t arg1, int64_t arg2) if (arg1 == DF_MIN_INT(df) && arg2 == -1) { return DF_MIN_INT(df); } - return arg2 ? arg1 / arg2 : 0; + return arg2 ? arg1 / arg2 + : arg1 >= 0 ? -1 : 1; } static inline int64_t msa_div_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 arg2 ? u_arg1 / u_arg2 : -1; } static inline int64_t msa_mod_s_df(uint32_t df, int64_t arg1, int64_t arg2) -- cgit v1.2.3