[llvm] AArch64: Fix outline atomic libcall names for arm64ec (PR #144378)

[Matt Arsenault via llvm-commits]

https://github.com/arsenm updated https://github.com/llvm/llvm-project/pull/144378

>From 9e0e0ee38e78a386f388ffb4fe4f6a598fa55dac Mon Sep 17 00:00:00 2001
From: Matt Arsenault <Matthew.Arsenault at amd.com>
Date: Tue, 17 Jun 2025 00:46:22 +0900
Subject: [PATCH] AArch64: Fix outline atomic libcall names for arm64ec

---
 llvm/lib/IR/RuntimeLibcalls.cpp               | 14 +++++++++++---
 llvm/test/CodeGen/AArch64/arm64ec-builtins.ll |  3 +--
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/llvm/lib/IR/RuntimeLibcalls.cpp b/llvm/lib/IR/RuntimeLibcalls.cpp
index cb64426a111de..5d22b41e28aad 100644
--- a/llvm/lib/IR/RuntimeLibcalls.cpp
+++ b/llvm/lib/IR/RuntimeLibcalls.cpp
@@ -36,9 +36,6 @@ static void setAArch64LibcallNames(RuntimeLibcallsInfo &Info,
   LCALLNAME4(RTLIB::OUTLINE_ATOMIC_LDSET, __aarch64_ldset)
   LCALLNAME4(RTLIB::OUTLINE_ATOMIC_LDCLR, __aarch64_ldclr)
   LCALLNAME4(RTLIB::OUTLINE_ATOMIC_LDEOR, __aarch64_ldeor)
-#undef LCALLNAMES
-#undef LCALLNAME4
-#undef LCALLNAME5
 
   if (TT.isWindowsArm64EC()) {
     // FIXME: are there calls we need to exclude from this?
@@ -54,7 +51,18 @@ static void setAArch64LibcallNames(RuntimeLibcallsInfo &Info,
 #include "llvm/IR/RuntimeLibcalls.def"
 #undef HANDLE_LIBCALL
 #undef LIBCALL_NO_NAME
+
+    LCALLNAME5(RTLIB::OUTLINE_ATOMIC_CAS, #__aarch64_cas)
+    LCALLNAME4(RTLIB::OUTLINE_ATOMIC_SWP, #__aarch64_swp)
+    LCALLNAME4(RTLIB::OUTLINE_ATOMIC_LDADD, #__aarch64_ldadd)
+    LCALLNAME4(RTLIB::OUTLINE_ATOMIC_LDSET, #__aarch64_ldset)
+    LCALLNAME4(RTLIB::OUTLINE_ATOMIC_LDCLR, #__aarch64_ldclr)
+    LCALLNAME4(RTLIB::OUTLINE_ATOMIC_LDEOR, #__aarch64_ldeor)
   }
+
+#undef LCALLNAMES
+#undef LCALLNAME4
+#undef LCALLNAME5
 }
 
 static void setARMLibcallNames(RuntimeLibcallsInfo &Info, const Triple &TT) {
diff --git a/llvm/test/CodeGen/AArch64/arm64ec-builtins.ll b/llvm/test/CodeGen/AArch64/arm64ec-builtins.ll
index 92b95a90d89a0..cc4ec9c2eebd6 100644
--- a/llvm/test/CodeGen/AArch64/arm64ec-builtins.ll
+++ b/llvm/test/CodeGen/AArch64/arm64ec-builtins.ll
@@ -28,10 +28,9 @@ define i128 @f4(i128 %x, i128 %y) {
   ret i128 %r
 }
 
-; FIXME: This is wrong; should be "#__aarch64_cas1_relax"
 define i8 @f5(i8 %expected, i8 %new, ptr %ptr) "target-features"="+outline-atomics" {
 ; CHECK-LABEL: "#f5":
-; CHECK: bl __aarch64_cas1_relax
+; CHECK: bl "#__aarch64_cas1_relax"
     %pair = cmpxchg ptr %ptr, i8 %expected, i8 %new monotonic monotonic, align 1
    %r = extractvalue { i8, i1 } %pair, 0
     ret i8 %r