[llvm] Spill/restore FP/BP around instructions in which they are clobbered (PR #81048)

[Reid Kleckner via llvm-commits]

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@@ -228,17 +232,23 @@ void CFIInstrInserter::calculateOutgoingCFAInfo(MBBCFAInfo &MBBInfo) {
       case MCCFIInstruction::OpRememberState:
         // TODO: Add support for handling cfi_remember_state.
 #ifndef NDEBUG
-        report_fatal_error(
-            "Support for cfi_remember_state not implemented! Value of CFA "
-            "may be incorrect!\n");
+        // Currently we need cfi_remember_state and cfi_restore_state to be in
+        // the same BB, so it will not impact outgoing CFA.
+        ++RememberState;
+        if (RememberState != 1)
+          report_fatal_error(
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rnk wrote:

This is existing code, but I generally try to recommend `MCContext::reportError` over `report_fatal_error`. We do have actual non-fatal error handling facilities during CodeGen.

https://github.com/llvm/llvm-project/pull/81048