[CodeGen] Emit aliasing metadata for new arrays.

Ensure that all array base pointers are assigned before generating
aliasing metadata by allocating new arrays beforehand.

Before this patch, getBasePtr() returned nullptr for new arrays because
the arrays were created at a later point. Nullptr did not match to any
array after the created array base pointers have been assigned and when
the loads/stores are generated.

llvm-svn: 305675

polly/lib/CodeGen/CodeGeneration.cpp

@@ -162,7 +162,6 @@ static bool CodeGen(Scop &S, IslAstInfo &AI, LoopInfo &LI, DominatorTree &DT,
   assert(!R->isTopLevelRegion() && "Top level regions are not supported");
 
   ScopAnnotator Annotator;
-  Annotator.buildAliasScopes(S);
 
   simplifyRegion(R, &DT, &LI, &RI);
   assert(R->isSimple());
@@ -183,6 +182,11 @@ static bool CodeGen(Scop &S, IslAstInfo &AI, LoopInfo &LI, DominatorTree &DT,
 
   IslNodeBuilder NodeBuilder(Builder, Annotator, DL, LI, SE, DT, S, StartBlock);
 
+  // All arrays must have their base pointers known before
+  // ScopAnnotator::buildAliasScopes.
+  NodeBuilder.allocateNewArrays();
+  Annotator.buildAliasScopes(S);
+
   if (PerfMonitoring) {
     PerfMonitor P(S, EnteringBB->getParent()->getParent());
     P.initialize();
@@ -224,7 +228,6 @@ static bool CodeGen(Scop &S, IslAstInfo &AI, LoopInfo &LI, DominatorTree &DT,
 
     isl_ast_node_free(AstRoot);
   } else {
-    NodeBuilder.allocateNewArrays();
     NodeBuilder.addParameters(S.getContext());
     Value *RTC = NodeBuilder.createRTC(AI.getRunCondition());
 

polly/lib/CodeGen/IRBuilder.cpp

@@ -67,10 +67,12 @@ void ScopAnnotator::buildAliasScopes(Scop &S) {
     return;
 
   std::string AliasScopeStr = "polly.alias.scope.";
-  for (const ScopArrayInfo *Array : S.arrays())
+  for (const ScopArrayInfo *Array : S.arrays()) {
+    assert(Array->getBasePtr() && "Base pointer must be present");
     AliasScopeMap[Array->getBasePtr()] =
         getID(Ctx, AliasScopeDomain,
               MDString::get(Ctx, (AliasScopeStr + Array->getName()).c_str()));
+  }
 
   for (const ScopArrayInfo *Array : S.arrays()) {
     MDNode *AliasScopeList = MDNode::get(Ctx, {});

polly/test/Isl/CodeGen/MemAccess/create_arrays.ll

@@ -29,6 +29,18 @@
 ; CODEGEN:  %polly.access.cast.E = bitcast [270336 x [200000 x double]]* %E to double*
 ; CODEGEN:  %polly.access.mul.E = mul nsw i64 %polly.indvar33, 200000
 ; CODEGEN:  %polly.access.add.E = add nsw i64 %polly.access.mul.E, %polly.indvar
+; CODEGEN:  {{%.*}} = load double, double* %polly.access.E, align 8, !alias.scope [[TAG0:![0-9]+]], !noalias [[TAG2:![0-9]+]]
+; CODEGEN:  store double {{%.*}}, double* %scevgep36, align 8, !alias.scope [[TAG5:![0-9]+]], !noalias [[TAG8:![0-9]+]]
+;
+; CODEGEN-DAG: [[TAG0]] = distinct !{[[TAG0]], [[TAG1:![0-9]+]], !"polly.alias.scope.E"}
+; CODEGEN-DAG: [[TAG1]] = distinct !{[[TAG1]], !"polly.alias.scope.domain"}
+; CODEGEN-DAG: [[TAG2]] = !{[[TAG3:![0-9]+]], [[TAG4:![0-9]+]], [[TAG5:![0-9]+]], [[TAG6:![0-9]+]], [[TAG7:![0-9]+]]}
+; CODEGEN-DAG: [[TAG3]] = distinct !{[[TAG3]], [[TAG1]], !"polly.alias.scope.MemRef_B"}
+; CODEGEN-DAG: [[TAG4]] = distinct !{[[TAG4]], [[TAG1]], !"polly.alias.scope.MemRef_beta"}
+; CODEGEN-DAG: [[TAG5]] = distinct !{[[TAG5]], [[TAG1]], !"polly.alias.scope.MemRef_A"}
+; CODEGEN-DAG: [[TAG6]] = distinct !{[[TAG6]], [[TAG1]], !"polly.alias.scope.D"}
+; CODEGEN-DAG: [[TAG7]] = distinct !{[[TAG7]], [[TAG1]], !"polly.alias.scope.F"}
+; CODEGEN-DAG: [[TAG8]] = !{[[TAG3]], [[TAG4]], [[TAG6]], [[TAG0]], [[TAG7]]}
 ;
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-unknown"

polly/test/ScheduleOptimizer/pattern-matching-based-opts_10.ll

@@ -12,14 +12,14 @@
 ; This test case checks whether Polly generates second level alias metadata
 ; to distinguish the specific accesses in case of the ublas gemm kernel.
 ;
-; CHECK: %tmp22_p_scalar_{{[0-9]*}} = load double, double* %scevgep[[N0:[a-z_0-9]*]], align 8, !alias.scope !10, !noalias !2
+; CHECK: %tmp22_p_scalar_{{[0-9]*}} = load double, double* %scevgep[[N0:[a-z_0-9]*]], align 8
-; CHECK: store double %p_tmp23{{[0-9]*}}, double* %scevgep[[N0]], align 8, !alias.scope !10, !noalias !2
+; CHECK: store double %p_tmp23{{[0-9]*}}, double* %scevgep[[N0]], align 8
-; CHECK: %tmp22_p_scalar_{{[0-9]*}} = load double, double* %scevgep[[N1:[a-z_0-9]*]], align 8, !alias.scope !11, !noalias !12
+; CHECK: %tmp22_p_scalar_{{[0-9]*}} = load double, double* %scevgep[[N1:[a-z_0-9]*]], align 8
-; CHECK: store double %p_tmp23{{[0-9]*}}, double* %scevgep[[N1]], align 8, !alias.scope !11, !noalias !12
+; CHECK: store double %p_tmp23{{[0-9]*}}, double* %scevgep[[N1]], align 8
-; CHECK: %tmp22_p_scalar_{{[0-9]*}} = load double, double* %scevgep[[N2:[a-z_0-9]*]], align 8, !alias.scope !13, !noalias !14
+; CHECK: %tmp22_p_scalar_{{[0-9]*}} = load double, double* %scevgep[[N2:[a-z_0-9]*]], align 8
-; CHECK: store double %p_tmp23{{[0-9]*}}, double* %scevgep[[N2]], align 8, !alias.scope !13, !noalias !14
+; CHECK: store double %p_tmp23{{[0-9]*}}, double* %scevgep[[N2]], align 8
-; CHECK: %tmp22_p_scalar_{{[0-9]*}} = load double, double* %scevgep[[N3:[a-z_0-9]*]], align 8, !alias.scope !15, !noalias !16
+; CHECK: %tmp22_p_scalar_{{[0-9]*}} = load double, double* %scevgep[[N3:[a-z_0-9]*]], align 8
-; CHECK: store double %p_tmp23{{[0-9]*}}, double* %scevgep[[N3]], align 8, !alias.scope !15, !noalias !16
+; CHECK: store double %p_tmp23{{[0-9]*}}, double* %scevgep[[N3]], align 8
 ;
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-unknown"