[ARM] Remove EarlyCSE from backend

There is an issue with early CSE hitting an assert, so temporarily
remove the pass from the Arm backend.
    
Bug: https://bugs.llvm.org/show_bug.cgi?id=41081

Differential Revision: https://reviews.llvm.org/D59410

llvm-svn: 356259

lib/Target/ARM/ARMTargetMachine.cpp

@@ -403,11 +403,9 @@ void ARMPassConfig::addIRPasses() {
 
   TargetPassConfig::addIRPasses();
 
-  // Run the parallel DSP pass and its helpers.
-  if (getOptLevel() == CodeGenOpt::Aggressive) {
-    addPass(createEarlyCSEPass());
+  // Run the parallel DSP pass.
+  if (getOptLevel() == CodeGenOpt::Aggressive) 
     addPass(createARMParallelDSPPass());
-  }
 
   // Match interleaved memory accesses to ldN/stN intrinsics.
   if (TM->getOptLevel() != CodeGenOpt::None)

test/CodeGen/ARM/O3-pipeline.ll

@@ -33,7 +33,6 @@
 ; CHECK:      Scalarize Masked Memory Intrinsics
 ; CHECK:      Expand reduction intrinsics
 ; CHECK:      Dominator Tree Construction
-; CHECK:      Early CSE
 ; CHECK:      Natural Loop Information
 ; CHECK:      Scalar Evolution Analysis
 ; CHECK:      Basic Alias Analysis (stateless AA impl)

test/CodeGen/ARM/ParallelDSP/unroll-n-jam-smlad.ll

@@ -31,15 +31,11 @@ entry:
   %inc11.us.i.3.i = add i32 %idx, 4
   br label %for.body
 
+; TODO: CSE, or something similar, is required to remove the duplicate loads.
 ; CHECK: %for.body
 ; CHECK: smlad
 ; CHECK: smlad
-; CHECK: smlad
-; CHECK: smlad
-; CHECK: smlad
-; CHECK: smlad
-; CHECK: smlad
-; CHECK: smlad
+; CHECK-NOT: smlad r{{.*}}
 
 for.body:
   %A3 = phi i32 [ %add9.us.i.3361.i, %for.body ], [ 0, %entry ]

test/CodeGen/Thumb2/2010-06-21-TailMergeBug.ll

@@ -32,12 +32,13 @@
 
 define fastcc i32 @parse_percent_token() nounwind {
 entry:
-; CHECK: bx lr
-; CHECK: bx lr
-; CHECK: bx lr
-; CHECK: bx lr
-; CHECK: bx lr
-; CHECK: bx lr
+; CHECK: pop
+; CHECK: pop
+; CHECK: pop
+; CHECK: pop
+; CHECK: pop
+; CHECK: pop
+; CHECK: pop
 ; Do not convert into single stream code. BranchProbability Analysis assumes
 ; that branches which goes to "ret" instruction have lower probabilities.
   switch i32 undef, label %bb7 [