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authorWill Newton <will.newton@linaro.org>2013-12-06 17:01:41 +0000
committerPeter Maydell <peter.maydell@linaro.org>2013-12-10 13:28:50 +0000
commite17ab310e98c55bd5cb8026c1086f9d19d181d3d (patch)
tree9f50af95e43d0520e2f8f865f7870ef2c76b647c /fpu
parente70614eaa0b8c6a2c948efa3ad71e75cd1f8ff8a (diff)
downloadqemu-arm-e17ab310e98c55bd5cb8026c1086f9d19d181d3d.tar.gz
softfloat: Add minNum() and maxNum() functions to softfloat.
Add floatnn_minnum() and floatnn_maxnum() functions which are equivalent to the minNum() and maxNum() functions from IEEE 754-2008. They are similar to min() and max() but differ in the handling of QNaN arguments. Signed-off-by: Will Newton <will.newton@linaro.org> Message-id: 1386158099-9239-5-git-send-email-will.newton@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'fpu')
-rw-r--r--fpu/softfloat.c32
1 files changed, 29 insertions, 3 deletions
diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 97bf627629..dbda61bc8e 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -6705,10 +6705,17 @@ int float128_compare_quiet( float128 a, float128 b STATUS_PARAM )
/* min() and max() functions. These can't be implemented as
* 'compare and pick one input' because that would mishandle
* NaNs and +0 vs -0.
+ *
+ * minnum() and maxnum() functions. These are similar to the min()
+ * and max() functions but if one of the arguments is a QNaN and
+ * the other is numerical then the numerical argument is returned.
+ * minnum() and maxnum correspond to the IEEE 754-2008 minNum()
+ * and maxNum() operations. min() and max() are the typical min/max
+ * semantics provided by many CPUs which predate that specification.
*/
#define MINMAX(s) \
INLINE float ## s float ## s ## _minmax(float ## s a, float ## s b, \
- int ismin STATUS_PARAM ) \
+ int ismin, int isieee STATUS_PARAM) \
{ \
flag aSign, bSign; \
uint ## s ## _t av, bv; \
@@ -6716,6 +6723,15 @@ INLINE float ## s float ## s ## _minmax(float ## s a, float ## s b, \
b = float ## s ## _squash_input_denormal(b STATUS_VAR); \
if (float ## s ## _is_any_nan(a) || \
float ## s ## _is_any_nan(b)) { \
+ if (isieee) { \
+ if (float ## s ## _is_quiet_nan(a) && \
+ !float ## s ##_is_any_nan(b)) { \
+ return b; \
+ } else if (float ## s ## _is_quiet_nan(b) && \
+ !float ## s ## _is_any_nan(a)) { \
+ return a; \
+ } \
+ } \
return propagateFloat ## s ## NaN(a, b STATUS_VAR); \
} \
aSign = extractFloat ## s ## Sign(a); \
@@ -6739,12 +6755,22 @@ INLINE float ## s float ## s ## _minmax(float ## s a, float ## s b, \
\
float ## s float ## s ## _min(float ## s a, float ## s b STATUS_PARAM) \
{ \
- return float ## s ## _minmax(a, b, 1 STATUS_VAR); \
+ return float ## s ## _minmax(a, b, 1, 0 STATUS_VAR); \
} \
\
float ## s float ## s ## _max(float ## s a, float ## s b STATUS_PARAM) \
{ \
- return float ## s ## _minmax(a, b, 0 STATUS_VAR); \
+ return float ## s ## _minmax(a, b, 0, 0 STATUS_VAR); \
+} \
+ \
+float ## s float ## s ## _minnum(float ## s a, float ## s b STATUS_PARAM) \
+{ \
+ return float ## s ## _minmax(a, b, 1, 1 STATUS_VAR); \
+} \
+ \
+float ## s float ## s ## _maxnum(float ## s a, float ## s b STATUS_PARAM) \
+{ \
+ return float ## s ## _minmax(a, b, 0, 1 STATUS_VAR); \
}
MINMAX(32)