minor updates

Author: wldfngrs

libc/src/math/generic/CMakeLists.txt

@@ -4044,6 +4044,7 @@ add_entrypoint_object(
     libc.hdr.errno_macros
     libc.hdr.fenv_macros
     libc.src.__support.FPUtil.cast
+    libc.src.__support.FPUtil.except_value_utils
     libc.src.__support.FPUtil.fenv_impl
     libc.src.__support.FPUtil.fp_bits
     libc.src.__support.FPUtil.multiply_add

libc/src/math/generic/acosf16.cpp

@@ -22,10 +22,10 @@
 namespace LIBC_NAMESPACE_DECL {
 
 // Generated by Sollya using the following command:
-// > round(pi/2, D, RN);
-// > round(pi, D, RN);
-static constexpr float PI_2 = 0x1.921fb54442d18p0f;
-static constexpr float PI = 0x1.921fb54442d18p1f;
+// > round(pi/2, SG, RN);
+// > round(pi, SG, RN);
+static constexpr float PI_2 = 0x1.921fb6p0f;
+static constexpr float PI = 0x1.921fb6p1f;
 
 static constexpr size_t N_EXCEPTS = 2;
 
@@ -42,17 +42,6 @@ LLVM_LIBC_FUNCTION(float16, acosf16, (float16 x)) {
   uint16_t x_u = xbits.uintval();
   uint16_t x_abs = x_u & 0x7fff;
   uint16_t x_sign = x_u >> 15;
-  float xf = x;
-
-  // Handle exceptional values
-  if (auto r = ACOSF16_EXCEPTS.lookup(x_u); LIBC_UNLIKELY(r.has_value()))
-    return r.value();
-
-  // |x| == 0x1p0, x is 1 or -1
-  // if x is (-)1, return pi, else
-  // if x is (+)1, return 0
-  if (LIBC_UNLIKELY(x_abs == 0x3c00))
-    return fputil::cast<float16>(x_sign ? 0x1.921fb54442d18p1 : 0.0f);
 
   // |x| > 0x1p0, |x| > 1, or x is NaN.
   if (LIBC_UNLIKELY(x_abs > 0x3c00)) {
@@ -73,6 +62,18 @@ LLVM_LIBC_FUNCTION(float16, acosf16, (float16 x)) {
     return FPBits::quiet_nan().get_val();
   }
 
+  float xf = x;
+
+  // Handle exceptional values
+  if (auto r = ACOSF16_EXCEPTS.lookup(x_u); LIBC_UNLIKELY(r.has_value()))
+    return r.value();
+
+  // |x| == 0x1p0, x is 1 or -1
+  // if x is (-)1, return pi, else
+  // if x is (+)1, return 0
+  if (LIBC_UNLIKELY(x_abs == 0x3c00))
+    return fputil::cast<float16>(x_sign ? PI : 0.0f);
+
   float xsq = xf * xf;
 
   // |x| <= 0x1p-1, |x| <= 0.5