private:
- void EliminateIVComparisons();
void RewriteNonIntegerIVs(Loop *L);
ICmpInst *LinearFunctionTestReplace(Loop *L, const SCEV *BackedgeTakenCount,
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>();
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;
+++ /dev/null
-; 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
-}