[llvm] [llvm][ARM] Add a cortex-m4f alignment hazard recognizer (PR #126991)

[David Green via llvm-commits]

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@@ -5455,6 +5514,21 @@ bool ARMBaseInstrInfo::hasNOP() const {
   return Subtarget.hasFeature(ARM::HasV6KOps);
 }
 
+void ARMBaseInstrInfo::insertNoop(MachineBasicBlock &MBB,
+                                  MachineBasicBlock::iterator MI) const {
+  DebugLoc DL;
+  if (hasNOP()) {
+    BuildMI(MBB, MI, DL, get(ARM::tHINT)).addImm(0).addImm(ARMCC::AL).addImm(0);
+  } else {
+    BuildMI(MBB, MI, DL, get(ARM::MOVr))
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davemgreen wrote:

Can this add an assert that the this is !Thumb.

https://github.com/llvm/llvm-project/pull/126991