[CodeGen] Fix for PR39094.

When using MachineInstr to get SlotIndex, the MI could not be a debug
instruction. mi2iMap does not contain debug instructions in it.

After enabling DBG_LABEL in the generated code, the first instruction in
the bundle may be a debug instruction. In this patch, I use the first
non-debug instruction in the bundle to query SlotIndex in mi2iMap.

Bugzilla report: https://bugs.llvm.org/show_bug.cgi?id=39094

Differential revision: https://reviews.llvm.org/D52927

llvm-svn: 344770

diff --git a/llvm/include/llvm/CodeGen/SlotIndexes.h b/llvm/include/llvm/CodeGen/SlotIndexes.h
index 5508222..b6e5088 100644 (file)
--- a/llvm/include/llvm/CodeGen/SlotIndexes.h
+++ b/llvm/include/llvm/CodeGen/SlotIndexes.h
@@ -413,10 +413,14 @@ class raw_ostream;
     /// Returns the base index for the given instruction.
     SlotIndex getInstructionIndex(const MachineInstr &MI) const {
       // Instructions inside a bundle have the same number as the bundle itself.
-      const MachineInstr &BundleStart = *getBundleStart(MI.getIterator());
-      assert(!BundleStart.isDebugInstr() &&
+      auto BundleStart = getBundleStart(MI.getIterator());
+      auto BundleEnd = getBundleEnd(MI.getIterator());
+      // Use the first non-debug instruction in the bundle to get SlotIndex.
+      const MachineInstr &BundleNonDebug =
+          *skipDebugInstructionsForward(BundleStart, BundleEnd);
+      assert(!BundleNonDebug.isDebugInstr() &&
              "Could not use a debug instruction to query mi2iMap.");
-      Mi2IndexMap::const_iterator itr = mi2iMap.find(&BundleStart);
+      Mi2IndexMap::const_iterator itr = mi2iMap.find(&BundleNonDebug);
       assert(itr != mi2iMap.end() && "Instruction not found in maps.");
       return itr->second;
     }