[PATCH] D17996: Add support for preserve_most/preserve_all calling conventions to the AArch64 backend.

[Tim Northover via llvm-commits]

t.p.northover added inline comments.

================
Comment at: lib/Target/AArch64/AArch64CallingConvention.td:314-315
@@ +313,4 @@
+
+def CSR_AArch64_RT_MostRegs :  CalleeSavedRegs<(add CSR_AArch64_AAPCS,
+                                                (sequence "X%u", 9, 14))>;
+
----------------
I think some more comments on the choices here would be useful. Obviously you can't preserve x16 or x17 because the linker may use them to resolve a PLT call, and x18 is the platform register on Darwin.

But you're excluding x15 too, which makes "RT_AllRegs" increasingly misnamed (it also excludes the high half of vector registers and the argument registers).


http://reviews.llvm.org/D17996