diff --git a/target/ppc/translate.c b/target/ppc/translate.c index 29939bd923..e810842925 100644 --- a/target/ppc/translate.c +++ b/target/ppc/translate.c @@ -6443,6 +6443,14 @@ static inline void get_fpr(TCGv_i64 dst, int regno) static inline void set_fpr(int regno, TCGv_i64 src) { tcg_gen_st_i64(src, cpu_env, fpr_offset(regno)); + /* + * Before PowerISA v3.1 the result of doubleword 1 of the VSR + * corresponding to the target FPR was undefined. However, + * most (if not all) real hardware were setting the result to 0. + * Starting at ISA v3.1, the result for doubleword 1 is now defined + * to be 0. + */ + tcg_gen_st_i64(tcg_constant_i64(0), cpu_env, vsr64_offset(regno, false)); } static inline void get_avr64(TCGv_i64 dst, int regno, bool high)