[PATCH] D70192: [LoopCacheAnalysis]: Fix assertion failure during cost computation

[Rachel Craik via Phabricator via llvm-commits]

rcraik updated this revision to Diff 229609.
rcraik added a comment.

Update Stride to use sign extension


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D70192/new/

https://reviews.llvm.org/D70192

Files:
  llvm/lib/Analysis/LoopCacheAnalysis.cpp
  llvm/test/Analysis/LoopCacheAnalysis/PowerPC/compute-cost.ll


Index: llvm/test/Analysis/LoopCacheAnalysis/PowerPC/compute-cost.ll
===================================================================
--- /dev/null
+++ llvm/test/Analysis/LoopCacheAnalysis/PowerPC/compute-cost.ll
@@ -0,0 +1,35 @@
+; 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
+
+}
Index: llvm/lib/Analysis/LoopCacheAnalysis.cpp
===================================================================
--- llvm/lib/Analysis/LoopCacheAnalysis.cpp
+++ llvm/lib/Analysis/LoopCacheAnalysis.cpp
@@ -284,6 +284,9 @@
     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)


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