softfloat: Fix float64_to_uint64_round_to_zero

The float64_to_uint64_round_to_zero routine is incorrect.

For example, the following test pattern:

    46697351FF4AEC29 / 0x1.97351ff4aec29p+103

currently produces 8000000000000000 instead of FFFFFFFFFFFFFFFF.

This patch re-implements the routine to temporarily force the
rounding mode and use the float64_to_uint64 routine.

This contribution can be licensed under either the softfloat-2a or -2b
license.

Signed-off-by: Tom Musta <tommusta@gmail.com>
Message-id: 1387397961-4894-4-git-send-email-tommusta@gmail.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Tom Musta 2014-01-07 17:17:50 +00:00 committed by Peter Maydell
parent 2f18bbf984
commit 0a87a3107d

View File

@ -6792,13 +6792,11 @@ uint64_t float64_to_uint64(float64 a STATUS_PARAM)
uint64_t float64_to_uint64_round_to_zero (float64 a STATUS_PARAM)
{
int64_t v;
v = float64_val(int64_to_float64(INT64_MIN STATUS_VAR));
v += float64_val(a);
v = float64_to_int64_round_to_zero(make_float64(v) STATUS_VAR);
return v - INT64_MIN;
signed char current_rounding_mode = STATUS(float_rounding_mode);
set_float_rounding_mode(float_round_to_zero STATUS_VAR);
int64_t v = float64_to_uint64(a STATUS_VAR);
set_float_rounding_mode(current_rounding_mode STATUS_VAR);
return v;
}
#define COMPARE(s, nan_exp) \