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| author | Aurelien Jarno <aurelien@aurel32.net> | 2011-04-20 13:04:23 +0200 |
|---|---|---|
| committer | Aurelien Jarno <aurelien@aurel32.net> | 2011-04-25 11:18:33 +0200 |
| commit | c9ad19c57b4e35dda507ec636443069048a4ad72 (patch) | |
| tree | 220a380adbcd9db4683be29cbd5afd84ba5016f8 | |
| parent | 788e733664aab69e65bf5d5d228767cf4371f3ab (diff) | |
| download | qemu-c9ad19c57b4e35dda507ec636443069048a4ad72.zip qemu-c9ad19c57b4e35dda507ec636443069048a4ad72.tar.gz qemu-c9ad19c57b4e35dda507ec636443069048a4ad72.tar.bz2 | |
target-i386: fix helper_fxtract() wrt softfloat
With softfloat it's not possible to play with the overflow of an
unsigned value to get the 0 case partially correct. Use a special case
for that. Using a division to generate an infinity is the easiest way
that works for both softfloat and softfloat-native.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
| -rw-r--r-- | target-i386/op_helper.c | 23 |
1 files changed, 16 insertions, 7 deletions
diff --git a/target-i386/op_helper.c b/target-i386/op_helper.c index 943d217..4850c63 100644 --- a/target-i386/op_helper.c +++ b/target-i386/op_helper.c @@ -4005,15 +4005,24 @@ void helper_fpatan(void) void helper_fxtract(void) { CPU86_LDoubleU temp; - unsigned int expdif; temp.d = ST0; - expdif = EXPD(temp) - EXPBIAS; - /*DP exponent bias*/ - ST0 = expdif; - fpush(); - BIASEXPONENT(temp); - ST0 = temp.d; + + if (floatx_is_zero(ST0)) { + /* Easy way to generate -inf and raising division by 0 exception */ + ST0 = floatx_div(floatx_chs(floatx_one), floatx_zero, &env->fp_status); + fpush(); + ST0 = temp.d; + } else { + int expdif; + + expdif = EXPD(temp) - EXPBIAS; + /*DP exponent bias*/ + ST0 = int32_to_floatx(expdif, &env->fp_status); + fpush(); + BIASEXPONENT(temp); + ST0 = temp.d; + } } void helper_fprem1(void) |