[libc] Simplify wcscmp (#143457)

michaelrj-google · web-flow · commit 06f6a771da10 · 2025-06-10T11:24:18.000-07:00
The implementation of wcscmp mimicked strcmp, but was more complicated
than necessary. This patch makes it simpler.
diff --git a/libc/src/wchar/wcscmp.cpp b/libc/src/wchar/wcscmp.cpp
@@ -19,12 +19,10 @@ LLVM_LIBC_FUNCTION(int, wcscmp, (const wchar_t *left, const wchar_t *right)) {
   LIBC_CRASH_ON_NULLPTR(left);
   LIBC_CRASH_ON_NULLPTR(right);
 
-  auto comp = [](wchar_t l, wchar_t r) -> int { return l - r; };
-
-  for (; *left && !comp(*left, *right); ++left, ++right)
+  for (; *left && (*left == *right); ++left, ++right)
     ;
 
-  return comp(*left, *right);
+  return *left - *right;
 }
 
 } // namespace LIBC_NAMESPACE_DECL

Original file line number	Diff line number	Diff line change
`@@ -19,12 +19,10 @@ LLVM_LIBC_FUNCTION(int, wcscmp, (const wchar_t left, const wchar_t right)) {`
`19`	`19`	`LIBC_CRASH_ON_NULLPTR(left);`
`20`	`20`	`LIBC_CRASH_ON_NULLPTR(right);`
`21`	`21`
`22`		`- auto comp = [](wchar_t l, wchar_t r) -> int { return l - r; };`
`23`		`-`
`24`		`- for (; left && !comp(left, *right); ++left, ++right)`
	`22`	`+ for (; left && (left == *right); ++left, ++right)`
`25`	`23`	`;`
`26`	`24`
`27`		`- return comp(left, right);`
	`25`	`+ return left - right;`
`28`	`26`	`}`
`29`	`27`
`30`	`28`	`} // namespace LIBC_NAMESPACE_DECL`