[libc][NFC] Simplify logic in sqrt (#80426)

llvm · Feb 2, 2024 · b629414 · b629414
1 parent 3050311
commit b629414
Show file tree

Hide file tree

Showing 2 changed files with 12 additions and 22 deletions.
diff --git a/libc/src/__support/FPUtil/generic/sqrt.h b/libc/src/__support/FPUtil/generic/sqrt.h
@@ -78,21 +78,16 @@ LIBC_INLINE cpp::enable_if_t<cpp::is_floating_point_v<T>, T> sqrt(T x) {
 
     FPBits_t bits(x);
 
-    if (bits.is_inf_or_nan()) {
-      if (bits.is_neg() && (bits.get_mantissa() == 0)) {
-        // sqrt(-Inf) = NaN
-        return FLT_NAN;
-      } else {
-        // sqrt(NaN) = NaN
-        // sqrt(+Inf) = +Inf
-        return x;
-      }
-    } else if (bits.is_zero()) {
+    if (bits == FPBits_t::inf(Sign::POS) || bits.is_zero() || bits.is_nan()) {
+      // sqrt(+Inf) = +Inf
       // sqrt(+0) = +0
       // sqrt(-0) = -0
+      // sqrt(NaN) = NaN
+      // sqrt(-NaN) = -NaN
       return x;
     } else if (bits.is_neg()) {
-      // sqrt( negative numbers ) = NaN
+      // sqrt(-Inf) = NaN
+      // sqrt(-x) = NaN
       return FLT_NAN;
     } else {
       int x_exp = bits.get_exponent();

diff --git a/libc/src/__support/FPUtil/generic/sqrt_80_bit_long_double.h b/libc/src/__support/FPUtil/generic/sqrt_80_bit_long_double.h
@@ -43,21 +43,16 @@ LIBC_INLINE long double sqrt(long double x) {
 
   LDBits bits(x);
 
-  if (bits.is_inf_or_nan()) {
-    if (bits.is_neg() && (bits.get_mantissa() == 0)) {
-      // sqrt(-Inf) = NaN
-      return LDNAN;
-    } else {
-      // sqrt(NaN) = NaN
-      // sqrt(+Inf) = +Inf
-      return x;
-    }
-  } else if (bits.is_zero()) {
+  if (bits == LDBits::inf(Sign::POS) || bits.is_zero() || bits.is_nan()) {
+    // sqrt(+Inf) = +Inf
     // sqrt(+0) = +0
     // sqrt(-0) = -0
+    // sqrt(NaN) = NaN
+    // sqrt(-NaN) = -NaN
     return x;
   } else if (bits.is_neg()) {
-    // sqrt( negative numbers ) = NaN
+    // sqrt(-Inf) = NaN
+    // sqrt(-x) = NaN
     return LDNAN;
   } else {
     int x_exp = bits.get_explicit_exponent();