From: Tom Musta <[email protected]>
The float64_to_uint32 has several flaws:
- for numbers between 2**32 and 2**64, the inexact exception flag
may get incorrectly set. In this case, only the invalid flag
should be set.
test pattern: 425F81378DC0CD1F / 0x1.f81378dc0cd1fp+38
- for numbers between 2**63 and 2**64, incorrect results may
be produced:
test pattern: 43EAAF73F1F0B8BD / 0x1.aaf73f1f0b8bdp+63
This patch re-implements float64_to_uint32 to re-use the
float64_to_uint64 routine (instead of float64_to_int64). For the
saturation case, we ignore any flags which the conversion routine
has set and raise only the invalid flag.
This contribution can be licensed under either the softfloat-2a or -2b
license.
Signed-off-by: Tom Musta <[email protected]>
Message-id: [email protected]
Signed-off-by: Peter Maydell <[email protected]>
Reviewed-by: Richard Henderson <[email protected]>
---
fpu/softfloat.c | 15 +++++++--------
1 file changed, 7 insertions(+), 8 deletions(-)
diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index f782c24..e68a87b 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -6650,19 +6650,18 @@ uint_fast16_t float32_to_uint16_round_to_zero(float32 a
STATUS_PARAM)
uint32 float64_to_uint32( float64 a STATUS_PARAM )
{
- int64_t v;
+ uint64_t v;
uint32 res;
+ int old_exc_flags = get_float_exception_flags(status);
- v = float64_to_int64(a STATUS_VAR);
- if (v < 0) {
- res = 0;
- float_raise( float_flag_invalid STATUS_VAR);
- } else if (v > 0xffffffff) {
+ v = float64_to_uint64(a STATUS_VAR);
+ if (v > 0xffffffff) {
res = 0xffffffff;
- float_raise( float_flag_invalid STATUS_VAR);
} else {
- res = v;
+ return v;
}
+ set_float_exception_flags(old_exc_flags, status);
+ float_raise(float_flag_invalid STATUS_VAR);
return res;
}
--
1.8.5
