Improve assert (and fix bug - FI needs to advance)

OCHyams · OCHyams · commit 0d44dea999c9 · 2025-05-15T16:53:55.000+01:00
Covered by existings tests e.g.
test/CodeGen/ARM/aes-erratum-fix.ll
diff --git a/llvm/lib/CodeGen/BranchFolding.cpp b/llvm/lib/CodeGen/BranchFolding.cpp
@@ -2091,12 +2091,14 @@ bool BranchFolder::HoistCommonCodeInSuccs(MachineBasicBlock *MBB) {
 
       // Get the next non-meta instruction in FBB.
       FI = skipDebugInstructionsForward(FI, FE, false);
-      assert(FI != FE && "Expected non-debug lockstep");
+      assert(TI->isIdenticalTo(*FI, MachineInstr::CheckKillDead) &&
+             "Expected non-debug lockstep");
 
       // Merge debug locs on hoisted instructions.
       TI->setDebugLoc(
           DILocation::getMergedLocation(TI->getDebugLoc(), FI->getDebugLoc()));
       TI->moveBefore(&*Loc);
+      ++FI;
     }
   }
   FBB->erase(FBB->begin(), FIB);

Original file line number	Diff line number	Diff line change
`@@ -2091,12 +2091,14 @@ bool BranchFolder::HoistCommonCodeInSuccs(MachineBasicBlock *MBB) {`
`2091`	`2091`
`2092`	`2092`	`// Get the next non-meta instruction in FBB.`
`2093`	`2093`	`FI = skipDebugInstructionsForward(FI, FE, false);`
`2094`		`- assert(FI != FE && "Expected non-debug lockstep");`
	`2094`	`+ assert(TI->isIdenticalTo(*FI, MachineInstr::CheckKillDead) &&`
	`2095`	`+ "Expected non-debug lockstep");`
`2095`	`2096`
`2096`	`2097`	`// Merge debug locs on hoisted instructions.`
`2097`	`2098`	`TI->setDebugLoc(`
`2098`	`2099`	`DILocation::getMergedLocation(TI->getDebugLoc(), FI->getDebugLoc()));`
`2099`	`2100`	`TI->moveBefore(&*Loc);`
	`2101`	`+ ++FI;`
`2100`	`2102`	`}`
`2101`	`2103`	`}`
`2102`	`2104`	`FBB->erase(FBB->begin(), FIB);`