| Message ID | 20220927064838.3570928-5-gaosong@loongson.cn |
|---|---|
| State | New |
| Headers | show |
| Series | Fix some loongarch tcg bugs | expand |
On 9/26/22 23:48, Song Gao wrote: > if fj ==0 or fj == INT32_MIN/INT64_MIN, LoongArch host set fcsr cause exception FP_DIV0, > So we need set exception flags float_flagdivbyzero if fj ==0. You are correct that ieee754 says that logB(0) should raise divbyzero. This should be fixed in softfloat-parts.c.inc, not here, within case float_class_zero: /* log2(0) = -inf */ a->cls = float_class_inf; a->sign = 1; return; r~
在 2022/9/28 下午11:24, Richard Henderson 写道: > On 9/26/22 23:48, Song Gao wrote: >> if fj ==0 or fj == INT32_MIN/INT64_MIN, LoongArch host set fcsr cause >> exception FP_DIV0, >> So we need set exception flags float_flagdivbyzero if fj ==0. > > You are correct that ieee754 says that logB(0) should raise divbyzero. > This should be fixed in softfloat-parts.c.inc, not here, within > > case float_class_zero: > > /* log2(0) = -inf */ > > a->cls = float_class_inf; > > a->sign = 1; > > return; > > Ok , I will correct it on v3. Thanks. Song Gao > > r~
diff --git a/target/loongarch/fpu_helper.c b/target/loongarch/fpu_helper.c index 1a24667eaf..d40e608bb4 100644 --- a/target/loongarch/fpu_helper.c +++ b/target/loongarch/fpu_helper.c @@ -322,6 +322,13 @@ uint64_t helper_flogb_s(CPULoongArchState *env, uint64_t fj) fp = float32_log2((uint32_t)fj, status); fd = nanbox_s(float32_round_to_int(fp, status)); set_float_rounding_mode(old_mode, status); + /* + * LoongArch host if fj == 0 or INT32_MIN , set the fcsr cause FP_DIV0 + * so we need set exception flags float_flag_divbyzero. + */ + if (((uint32_t)fj == 0) | ((uint32_t)fj == INT32_MIN)) { + set_float_exception_flags(float_flag_divbyzero, status); + } update_fcsr0_mask(env, GETPC(), float_flag_inexact); return fd; } @@ -336,6 +343,13 @@ uint64_t helper_flogb_d(CPULoongArchState *env, uint64_t fj) fd = float64_log2(fj, status); fd = float64_round_to_int(fd, status); set_float_rounding_mode(old_mode, status); + /* + * LoongArch host if fj == 0 or INT64_MIN , set the fcsr cause FP_DIV0 + * so we need set exception flags float_flag_divbyzero. + */ + if ((fj == 0) | (fj == INT64_MIN)) { + set_float_exception_flags(float_flag_divbyzero, status); + } update_fcsr0_mask(env, GETPC(), float_flag_inexact); return fd; }
if fj ==0 or fj == INT32_MIN/INT64_MIN, LoongArch host set fcsr cause exception FP_DIV0, So we need set exception flags float_flagdivbyzero if fj ==0. Signed-off-by: Song Gao <gaosong@loongson.cn> --- target/loongarch/fpu_helper.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)