[llvm] [llvm] Allow Fast and Tail CC in UEFI (PR #138361)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-x86

Author: Prabhu Rajasekaran (Prabhuk)

<details>
<summary>Changes</summary>

Allow tail call and fastcc optimizations for UEFI X86_64 targets.


---
Full diff: https://github.com/llvm/llvm-project/pull/138361.diff


1 Files Affected:

- (modified) llvm/lib/Target/X86/X86Subtarget.h (+1-1) 


``````````diff
diff --git a/llvm/lib/Target/X86/X86Subtarget.h b/llvm/lib/Target/X86/X86Subtarget.h
index a0b182d3f4c9b..c2b7d3780a983 100644
--- a/llvm/lib/Target/X86/X86Subtarget.h
+++ b/llvm/lib/Target/X86/X86Subtarget.h
@@ -352,9 +352,9 @@ class X86Subtarget final : public X86GenSubtargetInfo {
     switch (CC) {
     // On Win64, all these conventions just use the default convention.
     case CallingConv::C:
-      return isTargetWin64() || isTargetUEFI64();
     case CallingConv::Fast:
     case CallingConv::Tail:
+      return isTargetWin64() || isTargetUEFI64();
     case CallingConv::Swift:
     case CallingConv::SwiftTail:
     case CallingConv::X86_FastCall:

``````````

</details>


https://github.com/llvm/llvm-project/pull/138361