[libclc] [libclc] Remove -fno-builtin from compile options (PR #162075)

[Wenju He via cfe-commits]

https://github.com/wenju-he created https://github.com/llvm/llvm-project/pull/162075

The flag was added in commit 5631a959571c to suppress build warning and is no longer needed. It adds "no-builtins" attribute, which prevents libclc functions from being inlined into caller that don't have the attribute.

The flag is meant to prevent folding standard library calls into optimized implementations. For libclc device targets, however, such target‑driven folding is desirable.

llvm-diff shows no change to amdgcn--amdhsa.bc and nvptx--nvidiacl.bc.

>From 768e328302027a004dd5fab69eeae1152aa4a42c Mon Sep 17 00:00:00 2001
From: Wenju He <wenju.he at intel.com>
Date: Mon, 6 Oct 2025 13:31:46 +0200
Subject: [PATCH] [libclc] Remove -fno-builtin from compile options
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The flag was added in commit 5631a959571c to suppress build warning and
is no longer needed. It adds "no-builtins" attribute, which prevents
libclc functions from being inlined into caller that don't have the attribute.

The flag is meant to prevent folding standard library calls into
optimized implementations. For libclc device targets, however, such
target‑driven folding is desirable.

llvm-diff shows no change to amdgcn--amdhsa.bc and nvptx--nvidiacl.bc.

Co-authored-by: Mészáros Gergely <gergely.meszaros at intel.com>
---
 libclc/cmake/modules/AddLibclc.cmake | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libclc/cmake/modules/AddLibclc.cmake b/libclc/cmake/modules/AddLibclc.cmake
index 22dfaac9779a8..614f9e3790a3c 100644
--- a/libclc/cmake/modules/AddLibclc.cmake
+++ b/libclc/cmake/modules/AddLibclc.cmake
@@ -353,7 +353,7 @@ function(add_libclc_builtin_set)
       TRIPLE ${ARG_TRIPLE}
       INPUT ${input_file}
       OUTPUT ${output_file}
-      EXTRA_OPTS -fno-builtin -nostdlib "${ARG_COMPILE_FLAGS}"
+      EXTRA_OPTS -nostdlib "${ARG_COMPILE_FLAGS}"
         "${file_specific_compile_options}"
         -I${CMAKE_CURRENT_SOURCE_DIR}/${file_dir}
       DEPENDENCIES ${input_file_dep}