[llvm] [AArch64][FEAT_CMPBR] Codegen for Armv9.6-a compare-and-branch (PR #116465)

[David Tellenbach via llvm-commits]

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@@ -543,6 +569,17 @@ bool AArch64InstrInfo::reverseBranchCondition(
     case AArch64::TBNZX:
       Cond[1].setImm(AArch64::TBZX);
       break;
+
+    // Cond is { -1, Opcode, CC, Op0, Op1 }
+    case AArch64::CBWPri:
+    case AArch64::CBXPri:
+    case AArch64::CBWPrr:
+    case AArch64::CBXPrr: {
+      // Pseudos using standard 4bit Arm condition codes
+      AArch64CC::CondCode CC =
+          static_cast<AArch64CC::CondCode>(Cond[2].getImm());
+      Cond[2].setImm(AArch64CC::getInvertedCondCode(CC));
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dtellenbach wrote:

Ah yes! Thanks, good catch! Changed the logic a bit to be more conservative with the check and left a comment explaining it.

https://github.com/llvm/llvm-project/pull/116465