[llvm] r236333 - [ARM] Transfer the internal flag in thumb2 size reduction.

[Pete Cooper]

Author: pete
Date: Fri May  1 13:57:32 2015
New Revision: 236333

URL: http://llvm.org/viewvc/llvm-project?rev=236333&view=rev
Log:
[ARM] Transfer the internal flag in thumb2 size reduction.

Converting from t2LDRs to tLDRr caused the shift argument to drop the internal flag.  This would then throw machine verifier errors.

Unfortunately i'm having trouble reducing a test case.  I'm going to keep trying, but so far its a scary combination of machine sinking, an 'and i1', loads feeding loads, and a bunch of code which shouldn't change IT block formation, but does.  Its not useful to commit a test in that state as we have no way of knowing if it even hits this code reliably in future.

rdar://problem/20752113

Modified:
    llvm/trunk/lib/Target/ARM/Thumb2SizeReduction.cpp

Modified: llvm/trunk/lib/Target/ARM/Thumb2SizeReduction.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/Thumb2SizeReduction.cpp?rev=236333&r1=236332&r2=236333&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/Thumb2SizeReduction.cpp (original)
+++ llvm/trunk/lib/Target/ARM/Thumb2SizeReduction.cpp Fri May  1 13:57:32 2015
@@ -470,9 +470,11 @@ Thumb2SizeReduce::ReduceLoadStore(Machin
 
   unsigned OffsetReg = 0;
   bool OffsetKill = false;
+  bool OffsetInternal = false;
   if (HasShift) {
     OffsetReg  = MI->getOperand(2).getReg();
     OffsetKill = MI->getOperand(2).isKill();
+    OffsetInternal = MI->getOperand(2).isInternalRead();
 
     if (MI->getOperand(3).getImm())
       // Thumb1 addressing mode doesn't support shift.
@@ -502,7 +504,8 @@ Thumb2SizeReduce::ReduceLoadStore(Machin
     assert((!HasShift || OffsetReg) && "Invalid so_reg load / store address!");
 
     if (HasOffReg)
-      MIB.addReg(OffsetReg, getKillRegState(OffsetKill));
+      MIB.addReg(OffsetReg, getKillRegState(OffsetKill) |
+                            getInternalReadRegState(OffsetInternal));
   }
 
   // Transfer the rest of operands.