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authorPeter Maydell <peter.maydell@linaro.org>2014-01-07 17:19:12 +0000
committerPeter Maydell <peter.maydell@linaro.org>2014-01-08 19:07:22 +0000
commitf9288a76f1819c2dbf8d2873aebab6aec0f461f5 (patch)
tree2dd23209dc6a2cf78d917e3ca6ecfebee548c6a8 /include/fpu
parentdc355b764de890e1b5872d0b402dccfd9a9b5286 (diff)
downloadqemu-arm-f9288a76f1819c2dbf8d2873aebab6aec0f461f5.tar.gz
softfloat: Add support for ties-away rounding
IEEE754-2008 specifies a new rounding mode: "roundTiesToAway: the floating-point number nearest to the infinitely precise result shall be delivered; if the two nearest floating-point numbers bracketing an unrepresentable infinitely precise result are equally near, the one with larger magnitude shall be delivered." Implement this new mode (it is needed for ARM). The general principle is that the required code is exactly like the ties-to-even code, except that we do not need to do the "in case of exact tie clear LSB to round-to-even", because the rounding operation naturally causes the exact tie to round up in magnitude. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net>
Diffstat (limited to 'include/fpu')
-rw-r--r--include/fpu/softfloat.h3
1 files changed, 2 insertions, 1 deletions
diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index 83d324aca8..806ae13780 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -152,7 +152,8 @@ enum {
float_round_nearest_even = 0,
float_round_down = 1,
float_round_up = 2,
- float_round_to_zero = 3
+ float_round_to_zero = 3,
+ float_round_ties_away = 4,
};
/*----------------------------------------------------------------------------