From 276de33f3db65199689b8748bde836e031e461c0 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Alex=20Benn=C3=A9e?= Date: Mon, 7 Mar 2022 18:41:59 +0000 Subject: target/i386: force maximum rounding precision for fildl[l] MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Richard Henderson Message-Id: <20220315121251.2280317-4-alex.bennee@linaro.org> --- target/i386/tcg/fpu_helper.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'target') 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) -- cgit v1.1