Revert r314886 "[X86] Improvement in CodeGen instruction selection for LEAs (re-applying post required revision changes.)"

It broke the Chromium / SQLite build; see PR34830.

> Summary:
>    1/  Operand folding during complex pattern matching for LEAs has been
>        extended, such that it promotes Scale to accommodate similar operand
>        appearing in the DAG.
>        e.g.
>          T1 = A + B
>          T2 = T1 + 10
>          T3 = T2 + A
>        For above DAG rooted at T3, X86AddressMode will no look like
>          Base = B , Index = A , Scale = 2 , Disp = 10
>
>    2/  During OptimizeLEAPass down the pipeline factorization is now performed over LEAs
>        so that if there is an opportunity then complex LEAs (having 3 operands)
>        could be factored out.
>        e.g.
>          leal 1(%rax,%rcx,1), %rdx
>          leal 1(%rax,%rcx,2), %rcx
>        will be factored as following
>          leal 1(%rax,%rcx,1), %rdx
>          leal (%rdx,%rcx)   , %edx
>
>    3/ Aggressive operand folding for AM based selection for LEAs is sensitive to loops,
>       thus avoiding creation of any complex LEAs within a loop.
>
> Reviewers: lsaba, RKSimon, craig.topper, qcolombet, jmolloy
>
> Reviewed By: lsaba
>
> Subscribers: jmolloy, spatel, igorb, llvm-commits
>
>     Differential Revision: https://reviews.llvm.org/D35014

llvm-svn: 314919

1 files changed, 0 insertions, 11 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index ff8c892c5f9..15d06871e70 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -26,7 +26,6 @@
 #include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/Analysis/BranchProbabilityInfo.h"
 #include "llvm/Analysis/CFG.h"
-#include "llvm/Analysis/LoopInfo.h"
 #include "llvm/Analysis/OptimizationDiagnosticInfo.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/CodeGen/FastISel.h"
@@ -326,8 +325,6 @@ void SelectionDAGISel::getAnalysisUsage(AnalysisUsage &AU) const {
   if (OptLevel != CodeGenOpt::None)
     AU.addRequired<AAResultsWrapperPass>();
   AU.addRequired<GCModuleInfo>();
-  if (OptLevel != CodeGenOpt::None)
-    AU.addRequired<LoopInfoWrapperPass>();
   AU.addRequired<StackProtector>();
   AU.addPreserved<StackProtector>();
   AU.addPreserved<GCModuleInfo>();
@@ -1419,7 +1416,6 @@ void SelectionDAGISel::SelectAllBasicBlocks(const Function &Fn) {
 
   // Iterate over all basic blocks in the function.
   for (const BasicBlock *LLVMBB : RPOT) {
-    CurDAG->IsDAGPartOfLoop = false;
     if (OptLevel != CodeGenOpt::None) {
       bool AllPredsVisited = true;
       for (const_pred_iterator PI = pred_begin(LLVMBB), PE = pred_end(LLVMBB);
@@ -1597,13 +1593,6 @@ void SelectionDAGISel::SelectAllBasicBlocks(const Function &Fn) {
                                    FunctionBasedInstrumentation);
     }
 
-    if (OptLevel != CodeGenOpt::None) {
-      auto &LIWP = getAnalysis<LoopInfoWrapperPass>();
-      LoopInfo &LI = LIWP.getLoopInfo();
-      if (LI.getLoopFor(LLVMBB))
-        CurDAG->IsDAGPartOfLoop = true;
-    }
-
     if (Begin != BI)
       ++NumDAGBlocks;
     else