[llvm-branch-commits] [llvm] [MTE] add stack frame history buffer (PR #86356)

[Evgenii Stepanov via llvm-branch-commits]

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@@ -2497,7 +2497,8 @@ AArch64FrameLowering::getFrameIndexReference(const MachineFunction &MF, int FI,
   return resolveFrameIndexReference(
       MF, FI, FrameReg,
       /*PreferFP=*/
-      MF.getFunction().hasFnAttribute(Attribute::SanitizeHWAddress),
+      MF.getFunction().hasFnAttribute(Attribute::SanitizeHWAddress) ||
+          MF.getFunction().hasFnAttribute(Attribute::SanitizeMemTag),
       /*ForSimm=*/false);
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eugenis wrote:

So this will cause most of the local references to use FP, but our "base tagged pointer" is SP-based (see the aarch64_irg_sp intrinsic). Would not that pessimize the codegen a lot? Please check that nothing stupid is happening in the backend.

There is a bunch of relevant tests under test/CodeGen/AArch64/stack-tagging-*

https://github.com/llvm/llvm-project/pull/86356