commit 47c65cf62d06add9f55a77c9d45390fa3b986fc5
author David Green <david.green@arm.com> Sat Feb 17 08:57:14 2024 +0000
committer GitHub <noreply@github.com> Sat Feb 17 08:57:14 2024 +0000
tree 1ee4ba01e4bbb3d27688481ef7642fd2205ebfd6
parent f847c72be02e5b41e8139bf16de02dfd79476a52

[AArch64][GlobalISel] Fail legalization for unknown libcalls. (#81873)

If, like powi on windows, the libcall is unavailable we should fall back
to SDAG. Currently we try and generate a call to "".

llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp

diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index e4a5515..3870e66 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -596,6 +596,8 @@
                     LostDebugLocObserver &LocObserver, MachineInstr *MI) {
   auto &TLI = *MIRBuilder.getMF().getSubtarget().getTargetLowering();
   const char *Name = TLI.getLibcallName(Libcall);
+  if (!Name)
+    return LegalizerHelper::UnableToLegalize;
   const CallingConv::ID CC = TLI.getLibcallCallingConv(Libcall);
   return createLibcall(MIRBuilder, Name, Result, Args, CC, LocObserver, MI);
 }