[llvm] Reserve R9 on armv6 iOS before 3.0 (PR #150835)

[via llvm-commits]

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@@ -227,7 +227,10 @@ void ARMSubtarget::initSubtargetFeatures(StringRef CPU, StringRef FS) {
       (Options.UnsafeFPMath || isTargetDarwin()))
     HasNEONForFP = true;
 
-  if (isRWPI())
+  if (isRWPI() ||
+      (isTargetIOS() &&
+       ARM::parseArch(TargetTriple.getArchName()) == ARM::ArchKind::ARMV6K &&
+       TargetTriple.isOSVersionLT(3, 0)))
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Un1q32 wrote:

tests added

https://github.com/llvm/llvm-project/pull/150835