[libc] Implement 'qsort' and 'bsearch' on the GPU

[jhuber6]

Summary:
This patch simply adds the necessary config to enable qsort and bsearch
on the GPU. It is highly unlikely that anyone will use these, as they
are single threaded, but we may as well support all entrypoints that we
can.

[llvmbot]

@llvm/pr-subscribers-backend-x86

Changes

Summary: This patch simply adds the necessary config to enable qsort and bsearch on the GPU. It is *highly* unlikely that anyone will use these, as they are single threaded, but we may as well support all entrypoints that we can.

--
Full diff: https://github.com/llvm/llvm-project/pull/66230.diff

4 Files Affected:

• (modified) clang/lib/Headers/llvm_libc_wrappers/stdlib.h (+4-1)
• (modified) libc/config/gpu/api.td (+3)
• (modified) libc/config/gpu/entrypoints.txt (+3)
• (modified) libc/docs/gpu/support.rst (+3)

diff --git a/clang/lib/Headers/llvm_libc_wrappers/stdlib.h b/clang/lib/Headers/llvm_libc_wrappers/stdlib.h
index 9cb2b4e64aa6824..7fce5a1a31d526b 100644
--- a/clang/lib/Headers/llvm_libc_wrappers/stdlib.h
+++ b/clang/lib/Headers/llvm_libc_wrappers/stdlib.h
@@ -23,8 +23,11 @@
 
 #pragma omp begin declare target
 
-// The LLVM C library uses this type so we forward declare it.
+// The LLVM C library uses these named types so we forward declare them.
 typedef void (*__atexithandler_t)(void);
+typedef int (*__bsearchcompare_t)(const void *, const void *);
+typedef int (*__qsortcompare_t)(const void *, const void *);
+typedef int (*__qsortrcompare_t)(const void *, const void *, void *);
 
 // Enforce ABI compatibility with the structs used by the LLVM C library.
 _Static_assert(__builtin_offsetof(div_t, quot) == 0, "ABI mismatch!");
diff --git a/libc/config/gpu/api.td b/libc/config/gpu/api.td
index f8db0742ac82926..dbd212be56a3f10 100644
--- a/libc/config/gpu/api.td
+++ b/libc/config/gpu/api.td
@@ -46,6 +46,9 @@ def StdlibAPI : PublicAPI<"stdlib.h"> {
     "ldiv_t",
     "lldiv_t",
     "size_t",
+    "__bsearchcompare_t",
+    "__qsortcompare_t",
+    "__qsortrcompare_t",
     "__atexithandler_t",
   ];
 }
diff --git a/libc/config/gpu/entrypoints.txt b/libc/config/gpu/entrypoints.txt
index 0e314c60870c6ae..b8d09c9bb8a8bde 100644
--- a/libc/config/gpu/entrypoints.txt
+++ b/libc/config/gpu/entrypoints.txt
@@ -58,9 +58,12 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.stdlib.atoll
     libc.src.stdlib.div
     libc.src.stdlib.labs
+    libc.src.stdlib.bsearch
     libc.src.stdlib.ldiv
     libc.src.stdlib.llabs
     libc.src.stdlib.lldiv
+    libc.src.stdlib.qsort
+    libc.src.stdlib.qsort_r
     libc.src.stdlib.strtod
     libc.src.stdlib.strtof
     libc.src.stdlib.strtol
diff --git a/libc/docs/gpu/support.rst b/libc/docs/gpu/support.rst
index fabdfb968a741ad..6d73addb28d0579 100644
--- a/libc/docs/gpu/support.rst
+++ b/libc/docs/gpu/support.rst
@@ -96,6 +96,9 @@ llabs          |check|
 div            |check|
 ldiv           |check|
 lldiv          |check|
+bsearch        |check|
+qsort          |check|
+qsort_r        |check|
 strtod         |check|
 strtof         |check|
 strtol         |check|

[sivachandra]

OK for libc changes.