Remove frac_lsb, frac_lsbm1, roundeven_mask. Compute
these from round_mask in parts$N_uncanon_normal.
With floatx80, round_mask will not be tied to frac_shift.
Everything else is easily computable.
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
fpu/softfloat.c | 29 ++++++++++++-----------------
fpu/softfloat-parts.c.inc | 6 +++---
2 files changed, 15 insertions(+), 20 deletions(-)
diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 2f2bea84da..f6adc2c5ec 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -563,9 +563,7 @@ typedef struct {
* frac_size: the size of the fraction field
* frac_shift: shift to normalise the fraction with DECOMPOSED_BINARY_POINT
* The following are computed based the size of fraction
- * frac_lsb: least significant bit of fraction
- * frac_lsbm1: the bit below the least significant bit (for rounding)
- * round_mask/roundeven_mask: masks used for rounding
+ * round_mask: bits below lsb which must be rounded
* The following optional modifiers are available:
* arm_althp: handle ARM Alternative Half Precision
*/
@@ -575,24 +573,21 @@ typedef struct {
int exp_max;
int frac_size;
int frac_shift;
- uint64_t frac_lsb;
- uint64_t frac_lsbm1;
- uint64_t round_mask;
- uint64_t roundeven_mask;
bool arm_althp;
+ uint64_t round_mask;
} FloatFmt;
/* Expand fields based on the size of exponent and fraction */
-#define FLOAT_PARAMS(E, F) \
- .exp_size = E, \
- .exp_bias = ((1 << E) - 1) >> 1, \
- .exp_max = (1 << E) - 1, \
- .frac_size = F, \
- .frac_shift = (-F - 1) & 63, \
- .frac_lsb = 1ull << ((-F - 1) & 63), \
- .frac_lsbm1 = 1ull << ((-F - 2) & 63), \
- .round_mask = (1ull << ((-F - 1) & 63)) - 1, \
- .roundeven_mask = (2ull << ((-F - 1) & 63)) - 1
+#define FLOAT_PARAMS_(E, F) \
+ .exp_size = E, \
+ .exp_bias = ((1 << E) - 1) >> 1, \
+ .exp_max = (1 << E) - 1, \
+ .frac_size = F
+
+#define FLOAT_PARAMS(E, F) \
+ FLOAT_PARAMS_(E, F), \
+ .frac_shift = (-F - 1) & 63, \
+ .round_mask = (1ull << ((-F - 1) & 63)) - 1
static const FloatFmt float16_params = {
FLOAT_PARAMS(5, 10)
diff --git a/fpu/softfloat-parts.c.inc b/fpu/softfloat-parts.c.inc
index d72fe3ab08..b456c1c30c 100644
--- a/fpu/softfloat-parts.c.inc
+++ b/fpu/softfloat-parts.c.inc
@@ -145,10 +145,10 @@ static void partsN(uncanon_normal)(FloatPartsN *p,
float_status *s,
{
const int exp_max = fmt->exp_max;
const int frac_shift = fmt->frac_shift;
- const uint64_t frac_lsb = fmt->frac_lsb;
- const uint64_t frac_lsbm1 = fmt->frac_lsbm1;
const uint64_t round_mask = fmt->round_mask;
- const uint64_t roundeven_mask = fmt->roundeven_mask;
+ const uint64_t frac_lsb = round_mask + 1;
+ const uint64_t frac_lsbm1 = round_mask ^ (round_mask >> 1);
+ const uint64_t roundeven_mask = round_mask | frac_lsb;
uint64_t inc;
bool overflow_norm;
int exp, flags = 0;
--
2.25.1
