Commit f897d087 authored by Rachel Craik's avatar Rachel Craik
Browse files

[LoopCacheAnalysis]: Fix assertion failure during cost computation 

Ensure the stride and trip count have the same type before multiplying them during reference cost calculation

Reviewed By: jdoefert

Differential Revision: https://reviews.llvm.org/D70192
parent 1cbe0038

llvm/lib/Analysis/LoopCacheAnalysis.cpp

+3 −0
Original line number Diff line number Diff line
@@ -284,6 +284,9 @@ CacheCostTy IndexedReference::computeRefCost(const Loop &L, 
    const SCEV *ElemSize = Sizes.back();

    const SCEV *Stride = SE.getMulExpr(Coeff, ElemSize);

    const SCEV *CacheLineSize = SE.getConstant(Stride->getType(), CLS);

    Type *WiderType = SE.getWiderType(Stride->getType(), TripCount->getType());

    Stride = SE.getNoopOrSignExtend(Stride, WiderType);

    TripCount = SE.getNoopOrAnyExtend(TripCount, WiderType);

    const SCEV *Numerator = SE.getMulExpr(Stride, TripCount);

    RefCost = SE.getUDivExpr(Numerator, CacheLineSize);

    LLVM_DEBUG(dbgs().indent(4)

llvm/test/Analysis/LoopCacheAnalysis/PowerPC/compute-cost.ll

0 → 100644
+35 −0
Original line number Diff line number Diff line 
; RUN: opt < %s -passes='print<loop-cache-cost>' -disable-output 2>&1 | FileCheck %s



target datalayout = "e-m:e-i64:64-n32:64"

target triple = "powerpc64le-unknown-linux-gnu"



; Check IndexedReference::computeRefCost can handle type differences between

; Stride and TripCount



; CHECK: Loop 'for.cond' has cost = 64



%struct._Handleitem = type { %struct._Handleitem* }



define void @handle_to_ptr(%struct._Handleitem** %blocks) {

; Preheader:

entry:

  br label %for.cond



; Loop:

for.cond:                                         ; preds = %for.body, %entry

  %i.0 = phi i32 [ 1, %entry ], [ %inc, %for.body ]

  %cmp = icmp ult i32 %i.0, 1024

  br i1 %cmp, label %for.body, label %for.end



for.body:                                         ; preds = %for.cond

  %idxprom = zext i32 %i.0 to i64

  %arrayidx = getelementptr inbounds %struct._Handleitem*, %struct._Handleitem** %blocks, i64 %idxprom

  store %struct._Handleitem* null, %struct._Handleitem** %arrayidx, align 8

  %inc = add nuw nsw i32 %i.0, 1

  br label %for.cond



; Exit blocks

for.end:                                          ; preds = %for.cond

  ret void



}