[libc][NFC] Small abs related simplifications

[gchatelet]

No description provided.

[llvmbot]

@llvm/pr-subscribers-libc

Author: Guillaume Chatelet (gchatelet)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/79858.diff

3 Files Affected:

• (modified) libc/src/__support/FPUtil/BasicOperations.h (+1-3)
• (modified) libc/src/math/generic/acoshf.cpp (+1-5)
• (modified) libc/src/math/generic/asinhf.cpp (+1-3)

diff --git a/libc/src/__support/FPUtil/BasicOperations.h b/libc/src/__support/FPUtil/BasicOperations.h
index ccc61a89c5f831f..a19d6d0bef08ff0 100644
--- a/libc/src/__support/FPUtil/BasicOperations.h
+++ b/libc/src/__support/FPUtil/BasicOperations.h
@@ -19,9 +19,7 @@ namespace fputil {
 
 template <typename T, cpp::enable_if_t<cpp::is_floating_point_v<T>, int> = 0>
 LIBC_INLINE T abs(T x) {
-  FPBits<T> bits(x);
-  bits.set_sign(Sign::POS);
-  return bits.get_val();
+  return FPBits<T>(x).abs().get_val();
 }
 
 template <typename T, cpp::enable_if_t<cpp::is_floating_point_v<T>, int> = 0>
diff --git a/libc/src/math/generic/acoshf.cpp b/libc/src/math/generic/acoshf.cpp
index a546cc2268b049d..16328c7b07c3908 100644
--- a/libc/src/math/generic/acoshf.cpp
+++ b/libc/src/math/generic/acoshf.cpp
@@ -33,12 +33,8 @@ LLVM_LIBC_FUNCTION(float, acoshf, (float x)) {
   }
 
   if (LIBC_UNLIKELY(x_u >= 0x4f8ffb03)) {
-    // Check for exceptional values.
-    uint32_t x_abs = xbits.abs().uintval();
-    if (LIBC_UNLIKELY(x_abs >= 0x7f80'0000U)) {
-      // x is +inf or NaN.
+    if (LIBC_UNLIKELY(xbits.is_inf_or_nan()))
       return x;
-    }
 
     // Helper functions to set results for exceptional cases.
     auto round_result_slightly_down = [](float r) -> float {
diff --git a/libc/src/math/generic/asinhf.cpp b/libc/src/math/generic/asinhf.cpp
index ac059910b4ef2ac..6e351786e3eca1c 100644
--- a/libc/src/math/generic/asinhf.cpp
+++ b/libc/src/math/generic/asinhf.cpp
@@ -59,10 +59,8 @@ LLVM_LIBC_FUNCTION(float, asinhf, (float x)) {
   };
 
   if (LIBC_UNLIKELY(x_abs >= 0x4bdd'65a5U)) {
-    if (LIBC_UNLIKELY(x_abs >= 0x7f80'0000U)) {
-      // x is +-inf or nan
+    if (LIBC_UNLIKELY(xbits.is_inf_or_nan()))
       return x;
-    }
 
     // Exceptional cases when x > 2^24.
     switch (x_abs) {

[nickdesaulniers]

don't forget to land this

[jhuber6]

don't forget to land this

Can't other people merge PRs on the author's behalf?

[nickdesaulniers]

don't forget to land this

Can't other people merge PRs on the author's behalf?

Yes; I was hesitant in case there was a reason this hasn't been merged. There might not be, but just in case my personal preference is to defer to the patch author (when they have merge access). I also prefer to leave the dopamine hit for clicking merge to the author of the work. But if other people feel differently, I don't feel strongly about it either way.

[gchatelet]

I actually missed @lntue's approval, thx for the ping. Landing this now.