fixup! [libc][math][c23] Add exp10m1f C23 math function

Author: overmighty

libc/src/math/generic/exp10m1f.cpp

@@ -134,7 +134,7 @@ LLVM_LIBC_FUNCTION(float, exp10m1f, (float x)) {
   }
 
   // When x <= log10(2^-25), or x is nan
-  if (LIBC_UNLIKELY(x <= -0x1.e1a5e2p+2f)) {
+  if (LIBC_UNLIKELY(x_u >= 0xc0f0d2f1)) {
     // exp10m1(-inf) = -1
     if (xbits.is_inf())
       return -1.0f;
@@ -144,7 +144,7 @@ LLVM_LIBC_FUNCTION(float, exp10m1f, (float x)) {
 
     int rounding = fputil::quick_get_round();
     if (rounding == FE_UPWARD || rounding == FE_TOWARDZERO ||
-        (rounding == FE_TONEAREST && x == -0x1.e1a5e2p+2f))
+        (rounding == FE_TONEAREST && x_u == 0xc0f0d2f1))
       return -0x1.ffff'fep-1f; // -1.0f + 0x1.0p-24f
 
     fputil::set_errno_if_required(ERANGE);

libc/test/UnitTest/FPMatcher.h

@@ -68,7 +68,8 @@ template <typename T> struct FPTest : public Test {
       LIBC_NAMESPACE::cpp::numeric_limits<StorageType>::max();
   static constexpr T zero = FPBits::zero(Sign::POS).get_val();
   static constexpr T neg_zero = FPBits::zero(Sign::NEG).get_val();
-  static constexpr T aNaN = FPBits::quiet_nan().get_val();
+  static constexpr T aNaN = FPBits::quiet_nan(Sign::POS).get_val();
+  static constexpr T neg_aNaN = FPBits::quiet_nan(Sign::NEG).get_val();
   static constexpr T sNaN = FPBits::signaling_nan().get_val();
   static constexpr T inf = FPBits::inf(Sign::POS).get_val();
   static constexpr T neg_inf = FPBits::inf(Sign::NEG).get_val();

libc/test/src/math/exp10m1f_test.cpp

@@ -21,7 +21,7 @@ using LlvmLibcExp10m1fTest = LIBC_NAMESPACE::testing::FPTest<float>;
 namespace mpfr = LIBC_NAMESPACE::testing::mpfr;
 
 TEST_F(LlvmLibcExp10m1fTest, TrickyInputs) {
-  constexpr LIBC_NAMESPACE::cpp::array<float, 30> INPUTS = {
+  constexpr LIBC_NAMESPACE::cpp::array<float, 39> INPUTS = {
       // EXP10M1F_EXCEPTS_LO
       0x1.0fe54ep-11f,
       0x1.80e6eap-11f,
@@ -54,6 +54,18 @@ TEST_F(LlvmLibcExp10m1fTest, TrickyInputs) {
       -0x1.08e42p-6f,
       -0x1.0cdc44p-5f,
       -0x1.ca4322p-5f,
+      // Exceptional integers.
+      8.0f,
+      9.0f,
+      10.0f,
+      // Overflow boundaries.
+      0x1.344134p+5f,
+      0x1.344136p+5f,
+      0x1.344138p+5f,
+      // Underflow boundaries.
+      -0x1.e1a5e0p+2f,
+      -0x1.e1a5e2p+2f,
+      -0x1.e1a5e4p+2f,
   };
 
   for (float x : INPUTS) {

libc/test/src/math/smoke/exp10m1f_test.cpp

@@ -16,7 +16,10 @@ using LlvmLibcExp10m1fTest = LIBC_NAMESPACE::testing::FPTest<float>;
 TEST_F(LlvmLibcExp10m1fTest, SpecialNumbers) {
   LIBC_NAMESPACE::libc_errno = 0;
 
-  EXPECT_FP_EQ_ALL_ROUNDING(aNaN, LIBC_NAMESPACE::exp10m1f(aNaN));
+  EXPECT_EQ(FPBits(aNaN).uintval(),
+            FPBits(LIBC_NAMESPACE::exp10m1f(aNaN)).uintval());
+  EXPECT_EQ(FPBits(neg_aNaN).uintval(),
+            FPBits(LIBC_NAMESPACE::exp10m1f(neg_aNaN)).uintval());
   EXPECT_FP_EQ_ALL_ROUNDING(inf, LIBC_NAMESPACE::exp10m1f(inf));
   EXPECT_FP_EQ_ALL_ROUNDING(-1.0f, LIBC_NAMESPACE::exp10m1f(neg_inf));
   EXPECT_FP_EQ_ALL_ROUNDING(0.0f, LIBC_NAMESPACE::exp10m1f(0.0f));
@@ -34,20 +37,20 @@ TEST_F(LlvmLibcExp10m1fTest, Overflow) {
                               FE_OVERFLOW);
   EXPECT_MATH_ERRNO(ERANGE);
 
-  EXPECT_FP_EQ_WITH_EXCEPTION(inf, LIBC_NAMESPACE::exp10m1f(128.0f),
+  EXPECT_FP_EQ_WITH_EXCEPTION(inf, LIBC_NAMESPACE::exp10m1f(0x1.344136p+5),
                               FE_OVERFLOW);
   EXPECT_MATH_ERRNO(ERANGE);
 
-  EXPECT_FP_EQ_WITH_EXCEPTION(inf, LIBC_NAMESPACE::exp10m1f(0x1.000002p+7f),
+  EXPECT_FP_EQ_WITH_EXCEPTION(inf, LIBC_NAMESPACE::exp10m1f(0x1.344138p+5),
                               FE_OVERFLOW);
   EXPECT_MATH_ERRNO(ERANGE);
 }
 
 TEST_F(LlvmLibcExp10m1fTest, Underflow) {
   LIBC_NAMESPACE::libc_errno = 0;
 
-  EXPECT_FP_EQ_WITH_EXCEPTION(
-      -1.0f, LIBC_NAMESPACE::exp10m1f(-0x1.fffffep+127f), FE_UNDERFLOW);
+  EXPECT_FP_EQ_WITH_EXCEPTION(-1.0f, LIBC_NAMESPACE::exp10m1f(-max_normal),
+                              FE_UNDERFLOW);
   EXPECT_MATH_ERRNO(ERANGE);
 
   EXPECT_FP_EQ_WITH_EXCEPTION(-1.0f, LIBC_NAMESPACE::exp10m1f(-0x1.e1a5e4p+2f),