[flang-commits] [compiler-rt] [flang] [llvm] [AArch64] fix trampoline implementation: use X15 (PR #126743)

[Eli Friedman via flang-commits]

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@@ -523,6 +537,7 @@ def CC_AArch64_Preserve_None : CallingConv<[
   // We can pass arguments in all general registers, except:
   // - X8, used for sret
   // - X16/X17, used by the linker as IP0/IP1
+  // - X15, the nest register and used by Windows for stack allocation
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efriedma-quic wrote:

Instead of reducing the utility preservenone/preservemost/etc., can we just forbid using "nest" arguments with them?  I can't see why you'd want to use them together.

https://github.com/llvm/llvm-project/pull/126743