From ac3b9cdf151264091bc92a87adeafc665bf183a4 Mon Sep 17 00:00:00 2001
From: Dan Gohman <gohman@apple.com>
Date: Mon, 12 Apr 2010 00:17:10 +0000
Subject: [PATCH] Revert 101000, which is breaking self-host builds.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101002 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Scalar/IndVarSimplify.cpp      | 38 ------------------
 .../IndVarSimplify/eliminate-comparison.ll    | 40 -------------------
 2 files changed, 78 deletions(-)
 delete mode 100644 test/Transforms/IndVarSimplify/eliminate-comparison.ll

diff --git a/lib/Transforms/Scalar/IndVarSimplify.cpp b/lib/Transforms/Scalar/IndVarSimplify.cpp
index 46fb5ecb95b..f87d69360c1 100644
--- a/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -97,7 +97,6 @@ namespace {
 
   private:
 
-    void EliminateIVComparisons();
     void RewriteNonIntegerIVs(Loop *L);
 
     ICmpInst *LinearFunctionTestReplace(Loop *L, const SCEV *BackedgeTakenCount,
@@ -337,40 +336,6 @@ void IndVarSimplify::RewriteNonIntegerIVs(Loop *L) {
     SE->forgetLoop(L);
 }
 
-void IndVarSimplify::EliminateIVComparisons() {
-  // Look for ICmp users.
-  for (IVUsers::iterator I = IU->begin(), E = IU->end(); I != E;) {
-    IVStrideUse &UI = *I++;
-    ICmpInst *ICmp = dyn_cast<ICmpInst>(UI.getUser());
-    if (!ICmp) continue;
-
-    bool Swapped = UI.getOperandValToReplace() == ICmp->getOperand(1);
-    ICmpInst::Predicate Pred = ICmp->getPredicate();
-    if (Swapped) Pred = ICmpInst::getSwappedPredicate(Pred);
-
-    // Get the SCEVs for the ICmp operands.
-    const SCEV *S = IU->getReplacementExpr(UI);
-    const SCEV *X = SE->getSCEV(ICmp->getOperand(!Swapped));
-
-    // Simplify unnecessary loops away.
-    const Loop *ICmpLoop = LI->getLoopFor(ICmp->getParent());
-    S = SE->getSCEVAtScope(S, ICmpLoop);
-    X = SE->getSCEVAtScope(X, ICmpLoop);
-
-    // If the condition is always true or always false, replace it with
-    // a constant value.
-    if (SE->isKnownPredicate(Pred, S, X))
-      ICmp->replaceAllUsesWith(ConstantInt::getTrue(ICmp->getContext()));
-    else if (SE->isKnownPredicate(ICmpInst::getInversePredicate(Pred), S, X))
-      ICmp->replaceAllUsesWith(ConstantInt::getFalse(ICmp->getContext()));
-    else
-      continue;
-
-    DEBUG(dbgs() << "INDVARS: Eliminated comparison: " << *ICmp << '\n');
-    ICmp->eraseFromParent();
-  }
-}
-
 bool IndVarSimplify::runOnLoop(Loop *L, LPPassManager &LPM) {
   IU = &getAnalysis<IVUsers>();
   LI = &getAnalysis<LoopInfo>();
@@ -397,9 +362,6 @@ bool IndVarSimplify::runOnLoop(Loop *L, LPPassManager &LPM) {
   if (!isa<SCEVCouldNotCompute>(BackedgeTakenCount))
     RewriteLoopExitValues(L, Rewriter);
 
-  // Simplify ICmp IV users.
-  EliminateIVComparisons();
-
   // Compute the type of the largest recurrence expression, and decide whether
   // a canonical induction variable should be inserted.
   const Type *LargestType = 0;
diff --git a/test/Transforms/IndVarSimplify/eliminate-comparison.ll b/test/Transforms/IndVarSimplify/eliminate-comparison.ll
deleted file mode 100644
index d15697497ff..00000000000
--- a/test/Transforms/IndVarSimplify/eliminate-comparison.ll
+++ /dev/null
@@ -1,40 +0,0 @@
-; RUN: opt -indvars -S < %s | FileCheck %s
-
-; Indvars should be able to simplify simple comparisons involving
-; induction variables.
-
-; CHECK: %cond = and i1 %tobool.not, true
-
-target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
-
-@X = external global [0 x double]
-
-define void @foo(i64 %n, i32* nocapture %p) nounwind {
-entry:
-  %cmp9 = icmp sgt i64 %n, 0
-  br i1 %cmp9, label %pre, label %return
-
-pre:
-  %t3 = load i32* %p
-  %tobool.not = icmp ne i32 %t3, 0
-  br label %loop
-
-loop:
-  %i = phi i64 [ 0, %pre ], [ %inc, %for.inc ]
-  %cmp6 = icmp slt i64 %i, %n
-  %cond = and i1 %tobool.not, %cmp6
-  br i1 %cond, label %if.then, label %for.inc
-
-if.then:
-  %arrayidx = getelementptr [0 x double]* @X, i64 0, i64 %i
-  store double 3.200000e+00, double* %arrayidx
-  br label %for.inc
-
-for.inc:
-  %inc = add nsw i64 %i, 1
-  %exitcond = icmp sge i64 %inc, %n
-  br i1 %exitcond, label %return, label %loop
-
-return:
-  ret void
-}