[libc] [llvm] [libc][math][c23] Add rsqrtf() function (PR #159615)

[via llvm-commits]

================
@@ -4510,6 +4502,21 @@ libc_math_function(name = "roundevenf128")
 
 libc_math_function(name = "roundevenf16")
 
+libc_math_function(
+    name = "rsqrtf",
+    additional_deps = [
+        ":__support_math_rsqrtf",
+    ],
+)
+
+libc_math_function(
+    name = "rsqrtf16",
+    additional_deps = [
+        ":__support_math_rsqrtf16",
+        ":errno",
+    ],
+)
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overmighty wrote:

Why does `rsqrtf16` depend on `:errno`?

https://github.com/llvm/llvm-project/pull/159615