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author | Tom Musta <tommusta@gmail.com> | 2014-01-07 17:17:51 +0000 |
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committer | Peter Maydell <peter.maydell@linaro.org> | 2014-01-08 19:07:22 +0000 |
commit | 5e7f654fa152de246f2254707bacac31ba50c660 (patch) | |
tree | 7c526839fc03c6b0fd058a558b3683b93b8493e2 /fpu | |
parent | 0a87a3107dad97abff5b06558b0cce6832229086 (diff) | |
download | qemu-5e7f654fa152de246f2254707bacac31ba50c660.zip qemu-5e7f654fa152de246f2254707bacac31ba50c660.tar.gz qemu-5e7f654fa152de246f2254707bacac31ba50c660.tar.bz2 |
softfloat: Fix float64_to_uint32
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 <tommusta@gmail.com>
Message-id: 1387397961-4894-5-git-send-email-tommusta@gmail.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Diffstat (limited to 'fpu')
-rw-r--r-- | fpu/softfloat.c | 15 |
1 files 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; } |