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| author | Alex Bennée <alex.bennee@linaro.org> | 2022-03-07 18:41:59 +0000 |
|---|---|---|
| committer | Alex Bennée <alex.bennee@linaro.org> | 2022-03-23 10:37:09 +0000 |
| commit | 276de33f3db65199689b8748bde836e031e461c0 (patch) | |
| tree | 2f423a6ede743d2d61bf43b8902eb29d3807e4b8 | |
| parent | 425d6aba9994277da5edbf2cbd97502a107a794a (diff) | |
| download | qemu-276de33f3db65199689b8748bde836e031e461c0.zip qemu-276de33f3db65199689b8748bde836e031e461c0.tar.gz qemu-276de33f3db65199689b8748bde836e031e461c0.tar.bz2 | |
target/i386: force maximum rounding precision for fildl[l]
The instruction description says "It is loaded without rounding
errors." which implies we should have the widest rounding mode
possible.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/888
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220315121251.2280317-4-alex.bennee@linaro.org>
| -rw-r--r-- | target/i386/tcg/fpu_helper.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/target/i386/tcg/fpu_helper.c b/target/i386/tcg/fpu_helper.c index cdd8e9f..ebf5e73 100644 --- a/target/i386/tcg/fpu_helper.c +++ b/target/i386/tcg/fpu_helper.c @@ -237,24 +237,37 @@ void helper_fldl_ST0(CPUX86State *env, uint64_t val) merge_exception_flags(env, old_flags); } +static FloatX80RoundPrec tmp_maximise_precision(float_status *st) +{ + FloatX80RoundPrec old = get_floatx80_rounding_precision(st); + set_floatx80_rounding_precision(floatx80_precision_x, st); + return old; +} + void helper_fildl_ST0(CPUX86State *env, int32_t val) { int new_fpstt; + FloatX80RoundPrec old = tmp_maximise_precision(&env->fp_status); new_fpstt = (env->fpstt - 1) & 7; env->fpregs[new_fpstt].d = int32_to_floatx80(val, &env->fp_status); env->fpstt = new_fpstt; env->fptags[new_fpstt] = 0; /* validate stack entry */ + + set_floatx80_rounding_precision(old, &env->fp_status); } void helper_fildll_ST0(CPUX86State *env, int64_t val) { int new_fpstt; + FloatX80RoundPrec old = tmp_maximise_precision(&env->fp_status); new_fpstt = (env->fpstt - 1) & 7; env->fpregs[new_fpstt].d = int64_to_floatx80(val, &env->fp_status); env->fpstt = new_fpstt; env->fptags[new_fpstt] = 0; /* validate stack entry */ + + set_floatx80_rounding_precision(old, &env->fp_status); } uint32_t helper_fsts_ST0(CPUX86State *env) |