[clang] [llvm] [X86] support reserve r8~r15 on X86_64 (PR #180242)

[Alexis Engelke via cfe-commits]

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@@ -65,6 +66,9 @@ class X86Subtarget final : public X86GenSubtargetInfo {
 #define GET_SUBTARGETINFO_MACRO(ATTRIBUTE, DEFAULT, GETTER)                    \
   bool ATTRIBUTE = DEFAULT;
 #include "X86GenSubtargetInfo.inc"
+  /// ReservedRReg R#i is not available as a general purpose register.
+  BitVector ReservedRReg;
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aengelke wrote:

Could be a bitset<>, max size is known at compile time.

https://github.com/llvm/llvm-project/pull/180242