[VENTUS][fix] Fix softfloat lib (__fixint_single and __fixuint_double) (#184)

Co-authored-by: ivan lei <ivanlei0@163.com>

libclc/riscv32/lib/compiler-rt/fixsfdi.cl

@@ -40,16 +40,36 @@ static __inline fixint_t __fixint(fp_t a) {
     return sign * ((fixint_t)significand << (exponent - 52));
 }
 
-du_int __fixuint(fp_t a) {
-
+static __inline du_int __fixuint_double(fp_t a) {
   const rep_t aRep = toRep(a);
   const rep_t aAbs =
-      aRep & ((1U << (23 + ((sizeof(rep_t) * 8) - 23 - 1))) - 1U);
+      aRep & ((1UL << (52 + ((sizeof(rep_t) * 8) - 52 - 1))) - 1U);
   const int sign =
-      aRep & (1U << (23 + ((sizeof(rep_t) * 8) - 23 - 1))) ? -1 : 1;
+      aRep & (1UL << (52 + ((sizeof(rep_t) * 8) - 52 - 1))) ? -1 : 1;
   const int exponent =
-      (aAbs >> 23) - (((1 << ((sizeof(rep_t) * 8) - 23 - 1)) - 1) >> 1);
-  const rep_t significand = (aAbs & ((1U << 23) - 1U)) | (1U << 23);
+      (aAbs >> 52) - (((1 << ((sizeof(rep_t) * 8) - 52 - 1)) - 1) >> 1);
+  const rep_t significand = (aAbs & ((1UL << 52) - 1U)) | (1UL << 52);
+
+  if (sign == -1 || exponent < 0)
+    return 0;
+
+  if ((unsigned)exponent >= sizeof(fixuint_t) * 8)
+    return ~(fixuint_t)0;
+
+  if (exponent < 52)
+    return significand >> (52 - exponent);
+  else
+    return (fixuint_t)significand << (exponent - 52);
+}
+
+static __inline du_int __fixuint_single(float a) {
+  union { float f; uint32_t i; } u = { .f = a };
+  const uint32_t aRep = u.i;
+  
+  const uint32_t aAbs = aRep & 0x7FFFFFFF;
+  const int sign = (aRep & 0x80000000) ? -1 : 1; 
+  const int exponent = (aAbs >> 23) - 127; 
+  const uint32_t significand = (aAbs & 0x007FFFFF) | 0x00800000; 
 
   if (sign == -1 || exponent < 0)
     return 0;
@@ -63,10 +83,33 @@ du_int __fixuint(fp_t a) {
     return (fixuint_t)significand << (exponent - 23);
 }
 
-du_int __fixunssfdi(fp_t a) { return __fixuint(a); }
+static __inline di_int __fixint_single(float a) {
+  const di_int fixint_max = (di_int)((~(du_int)0) / 2);
+  const di_int fixint_min = -fixint_max - 1;
 
- di_int __fixsfdi(fp_t a) { return __fixint(a); }
-su_int __fixunsdfsi(fp_t a) { return __fixuint(a); }
-du_int __fixunsdfdi(fp_t a) { return __fixuint(a); }
+  union { float f; uint32_t i; } u = { .f = a };
+  const uint32_t aRep = u.i;
+  
+  const uint32_t aAbs = aRep & 0x7FFFFFFF;
+  const int sign = (aRep & 0x80000000) ? -1 : 1;
+  const int exponent = (aAbs >> 23) - 127;
+  const uint32_t significand = (aAbs & 0x007FFFFF) | 0x00800000;
+
+  if (exponent < 0)
+    return 0;
+
+  if ((unsigned)exponent >= sizeof(di_int) * 8)
+    return sign == 1 ? fixint_max : fixint_min;
+
+  if (exponent < 23)
+    return sign * (significand >> (23 - exponent));
+  else
+    return sign * ((di_int)significand << (exponent - 23));
+}
+
+du_int __fixunssfdi(float a) { return __fixuint_single(a); } 
+di_int __fixsfdi(float a) { return __fixint_single(a); }     
+su_int __fixunsdfsi(fp_t a) { return (su_int)__fixuint_double(a); }
+du_int __fixunsdfdi(fp_t a) { return __fixuint_double(a); }
 
 #endif