ScalarEvolution: Derive element size from the type of the loaded element

Before, we where looking at the size of the pointer type that specifies the
location from which to load the element. This did not make any sense at all.

This change fixes a bug in the delinearization where we failed to delinerize
certain load instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210435 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index bc9f45b2043092219d31a2864172b36e5620d440..06dbde58c1084488ae087b9efbc0633394c0c11e 100644 (file)
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -7365,7 +7365,7 @@ const SCEV *ScalarEvolution::getElementSize(Instruction *Inst) {
   if (StoreInst *Store = dyn_cast<StoreInst>(Inst))
     Ty = Store->getValueOperand()->getType();
   else if (LoadInst *Load = dyn_cast<LoadInst>(Inst))
-    Ty = Load->getPointerOperand()->getType();
+    Ty = Load->getType();
   else
     return nullptr;
 

diff --git a/test/Analysis/Delinearization/multidim_only_ivs_2d.ll b/test/Analysis/Delinearization/multidim_only_ivs_2d.ll
index 48bec08190d9c2a3259f73c50f81c029fa5df955..5a88c4ce4eb1fc0baf2c461cd97aa1094bbbf2bd 100644 (file)
--- a/test/Analysis/Delinearization/multidim_only_ivs_2d.ll
+++ b/test/Analysis/Delinearization/multidim_only_ivs_2d.ll
@@ -8,6 +8,15 @@
 ;       A[i][j] = 1.0;
 ; }
 
+; Inst:  %val = load double* %arrayidx
+; In Loop with Header: for.j
+; AddRec: {{0,+,(%m * sizeof(double))}<%for.i>,+,sizeof(double)}<%for.j>
+; Base offset: %A
+; ArrayDecl[UnknownSize][%m] with elements of sizeof(double) bytes.
+; ArrayRef[{0,+,1}<nuw><nsw><%for.i>][{0,+,1}<nuw><nsw><%for.j>]
+
+; Inst:  store double %val, double* %arrayidx
+; In Loop with Header: for.j
 ; AddRec: {{%A,+,(8 * %m)}<%for.i>,+,8}<%for.j>
 ; CHECK: Base offset: %A
 ; CHECK: ArrayDecl[UnknownSize][%m] with elements of sizeof(double) bytes.
@@ -26,7 +35,8 @@ for.j:
   %j = phi i64 [ 0, %for.i ], [ %j.inc, %for.j ]
   %vlaarrayidx.sum = add i64 %j, %tmp
   %arrayidx = getelementptr inbounds double* %A, i64 %vlaarrayidx.sum
-  store double 1.0, double* %arrayidx
+  %val = load double* %arrayidx
+  store double %val, double* %arrayidx
   %j.inc = add nsw i64 %j, 1
   %j.exitcond = icmp eq i64 %j.inc, %m
   br i1 %j.exitcond, label %for.i.inc, label %for.j