uint64_t helper_xscvdpspn(CPUPPCState *env, uint64_t xb)
{
- uint64_t result;
+ uint64_t result, sign, exp, frac;
float_status tstat = env->fp_status;
set_float_exception_flags(0, &tstat);
- result = (uint64_t)float64_to_float32(xb, &tstat);
+ sign = extract64(xb, 63, 1);
+ exp = extract64(xb, 52, 11);
+ frac = extract64(xb, 0, 52) | 0x10000000000000ULL;
+
+ if (unlikely(exp == 0 && extract64(frac, 0, 52) != 0)) {
+ /* DP denormal operand. */
+ /* Exponent override to DP min exp. */
+ exp = 1;
+ /* Implicit bit override to 0. */
+ frac = deposit64(frac, 53, 1, 0);
+ }
+
+ if (unlikely(exp < 897 && frac != 0)) {
+ /* SP tiny operand. */
+ if (897 - exp > 63) {
+ frac = 0;
+ } else {
+ /* Denormalize until exp = SP min exp. */
+ frac >>= (897 - exp);
+ }
+ /* Exponent override to SP min exp - 1. */
+ exp = 896;
+ }
+
+ result = sign << 31;
+ result |= extract64(exp, 10, 1) << 30;
+ result |= extract64(exp, 0, 7) << 23;
+ result |= extract64(frac, 29, 23);
+
/* hardware replicates result to both words of the doubleword result. */
return (result << 32) | result;
}