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authorAlex Bennée <alex.bennee@linaro.org>2017-12-05 17:14:42 +0000
committerAlex Bennée <alex.bennee@linaro.org>2018-02-21 10:21:47 +0000
commit0c4c90929143a530730e2879204a55a30bf63758 (patch)
tree8de5fe0c925eccc2468a53a4e4ca4afff7467543 /fpu
parent89360067071b1844bf745682e18db7dde74cdb8d (diff)
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fpu/softfloat: re-factor compare
The compare function was already expanded from a macro. I keep the macro expansion but move most of the logic into a compare_decomposed. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'fpu')
-rw-r--r--fpu/softfloat.c134
1 files changed, 80 insertions, 54 deletions
diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 7a53c36..4bc425d 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -1783,6 +1783,86 @@ MINMAX(64, maxnummag, false, true, true)
#undef MINMAX
+/* Floating point compare */
+static int compare_floats(FloatParts a, FloatParts b, bool is_quiet,
+ float_status *s)
+{
+ if (is_nan(a.cls) || is_nan(b.cls)) {
+ if (!is_quiet ||
+ a.cls == float_class_snan ||
+ b.cls == float_class_snan) {
+ s->float_exception_flags |= float_flag_invalid;
+ }
+ return float_relation_unordered;
+ }
+
+ if (a.cls == float_class_zero) {
+ if (b.cls == float_class_zero) {
+ return float_relation_equal;
+ }
+ return b.sign ? float_relation_greater : float_relation_less;
+ } else if (b.cls == float_class_zero) {
+ return a.sign ? float_relation_less : float_relation_greater;
+ }
+
+ /* The only really important thing about infinity is its sign. If
+ * both are infinities the sign marks the smallest of the two.
+ */
+ if (a.cls == float_class_inf) {
+ if ((b.cls == float_class_inf) && (a.sign == b.sign)) {
+ return float_relation_equal;
+ }
+ return a.sign ? float_relation_less : float_relation_greater;
+ } else if (b.cls == float_class_inf) {
+ return b.sign ? float_relation_greater : float_relation_less;
+ }
+
+ if (a.sign != b.sign) {
+ return a.sign ? float_relation_less : float_relation_greater;
+ }
+
+ if (a.exp == b.exp) {
+ if (a.frac == b.frac) {
+ return float_relation_equal;
+ }
+ if (a.sign) {
+ return a.frac > b.frac ?
+ float_relation_less : float_relation_greater;
+ } else {
+ return a.frac > b.frac ?
+ float_relation_greater : float_relation_less;
+ }
+ } else {
+ if (a.sign) {
+ return a.exp > b.exp ? float_relation_less : float_relation_greater;
+ } else {
+ return a.exp > b.exp ? float_relation_greater : float_relation_less;
+ }
+ }
+}
+
+#define COMPARE(sz) \
+int float ## sz ## _compare(float ## sz a, float ## sz b, \
+ float_status *s) \
+{ \
+ FloatParts pa = float ## sz ## _unpack_canonical(a, s); \
+ FloatParts pb = float ## sz ## _unpack_canonical(b, s); \
+ return compare_floats(pa, pb, false, s); \
+} \
+int float ## sz ## _compare_quiet(float ## sz a, float ## sz b, \
+ float_status *s) \
+{ \
+ FloatParts pa = float ## sz ## _unpack_canonical(a, s); \
+ FloatParts pb = float ## sz ## _unpack_canonical(b, s); \
+ return compare_floats(pa, pb, true, s); \
+}
+
+COMPARE(16)
+COMPARE(32)
+COMPARE(64)
+
+#undef COMPARE
+
/* Multiply A by 2 raised to the power N. */
static FloatParts scalbn_decomposed(FloatParts a, int n, float_status *s)
{
@@ -6884,60 +6964,6 @@ int float128_unordered_quiet(float128 a, float128 b, float_status *status)
return 0;
}
-#define COMPARE(s, nan_exp) \
-static inline int float ## s ## _compare_internal(float ## s a, float ## s b,\
- int is_quiet, float_status *status) \
-{ \
- flag aSign, bSign; \
- uint ## s ## _t av, bv; \
- a = float ## s ## _squash_input_denormal(a, status); \
- b = float ## s ## _squash_input_denormal(b, status); \
- \
- if (( ( extractFloat ## s ## Exp( a ) == nan_exp ) && \
- extractFloat ## s ## Frac( a ) ) || \
- ( ( extractFloat ## s ## Exp( b ) == nan_exp ) && \
- extractFloat ## s ## Frac( b ) )) { \
- if (!is_quiet || \
- float ## s ## _is_signaling_nan(a, status) || \
- float ## s ## _is_signaling_nan(b, status)) { \
- float_raise(float_flag_invalid, status); \
- } \
- return float_relation_unordered; \
- } \
- aSign = extractFloat ## s ## Sign( a ); \
- bSign = extractFloat ## s ## Sign( b ); \
- av = float ## s ## _val(a); \
- bv = float ## s ## _val(b); \
- if ( aSign != bSign ) { \
- if ( (uint ## s ## _t) ( ( av | bv )<<1 ) == 0 ) { \
- /* zero case */ \
- return float_relation_equal; \
- } else { \
- return 1 - (2 * aSign); \
- } \
- } else { \
- if (av == bv) { \
- return float_relation_equal; \
- } else { \
- return 1 - 2 * (aSign ^ ( av < bv )); \
- } \
- } \
-} \
- \
-int float ## s ## _compare(float ## s a, float ## s b, float_status *status) \
-{ \
- return float ## s ## _compare_internal(a, b, 0, status); \
-} \
- \
-int float ## s ## _compare_quiet(float ## s a, float ## s b, \
- float_status *status) \
-{ \
- return float ## s ## _compare_internal(a, b, 1, status); \
-}
-
-COMPARE(32, 0xff)
-COMPARE(64, 0x7ff)
-
static inline int floatx80_compare_internal(floatx80 a, floatx80 b,
int is_quiet, float_status *status)
{