[CodeGen] Allow undefined loads in statement instances outside context.

A check in assert-builds was meant to verify that a load provides a
value in all statement instances (i.e. its domain).  The domain is
commonly gist'ed within the parameter context to contain fewer
constraints.  However, statement instances outside the context are
no valid executions, hence the value provided can be undefined.

Refine the check for valid loads to only needed to be defined within
the SCoP context.

In addition, the JSONImporter had to be changed to allow importing
access relations that are broader than the current access relation,
but still defined over all statement instances.

This should fix the compiler crash in test-suite's oggenc of the
-polly-process-unprofitable buildbot.

llvm-svn: 329655

5 files changed, 209 insertions, 1 deletions

diff --git a/polly/lib/CodeGen/BlockGenerators.cpp b/polly/lib/CodeGen/BlockGenerators.cpp
index 1fe15e4fb28..9bff9d2a1b9 100644
--- a/polly/lib/CodeGen/BlockGenerators.cpp
+++ b/polly/lib/CodeGen/BlockGenerators.cpp
@@ -558,7 +558,8 @@ void BlockGenerator::generateScalarLoads(
       continue;
 
 #ifndef NDEBUG
-    auto StmtDom = Stmt.getDomain();
+    auto StmtDom =
+        Stmt.getDomain().intersect_params(Stmt.getParent()->getContext());
     auto AccDom = MA->getAccessRelation().domain();
     assert(!StmtDom.is_subset(AccDom).is_false() &&
            "Scalar must be loaded in all statement instances");
diff --git a/polly/lib/Exchange/JSONExporter.cpp b/polly/lib/Exchange/JSONExporter.cpp
index 512c51558c6..943d1b2d983 100644
--- a/polly/lib/Exchange/JSONExporter.cpp
+++ b/polly/lib/Exchange/JSONExporter.cpp
@@ -512,6 +512,8 @@ importAccesses(Scop &S, Json::Value &JScop, const DataLayout &DL,
           isl_set_intersect_params(NewAccessDomain, S.getContext().release());
       CurrentAccessDomain = isl_set_intersect_params(CurrentAccessDomain,
                                                      S.getContext().release());
+      CurrentAccessDomain =
+          isl_set_intersect(CurrentAccessDomain, Stmt.getDomain().release());
 
       if (MA->isRead() &&
           isl_set_is_subset(CurrentAccessDomain, NewAccessDomain) ==
diff --git a/polly/test/Isl/CodeGen/load_subset_with_context.ll b/polly/test/Isl/CodeGen/load_subset_with_context.ll
new file mode 100644
index 00000000000..10fb0f00586
--- /dev/null
+++ b/polly/test/Isl/CodeGen/load_subset_with_context.ll
@@ -0,0 +1,57 @@
+; RUN: opt %loadPolly -polly-import-jscop -polly-import-jscop-postfix=transformed -polly-codegen -S < %s | FileCheck %s
+;
+; A load must provide a value for every statement instance.
+; Statement instances not in the SCoP's context are irrelevant.
+;
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+@ATH = external dso_local unnamed_addr constant [88 x float], align 16
+
+define void @load_subset_with_context() {
+entry:
+  %ath = alloca [56 x float], align 16
+  br label %for.body
+
+for.cond176.preheader:                            ; preds = %for.cond33.preheader
+  ret void
+
+for.body:                                         ; preds = %for.cond33.preheader, %entry
+  %indvars.iv999 = phi i64 [ 0, %entry ], [ %indvars.iv.next1000, %for.cond33.preheader ]
+  %tmp5 = shl nsw i64 %indvars.iv999, 2
+  br label %for.cond7.preheader
+
+for.cond33.preheader:                             ; preds = %for.inc.3
+  %tmp175 = load float, float* undef, align 4
+  %indvars.iv.next1000 = add nuw nsw i64 %indvars.iv999, 1
+  %exitcond1002 = icmp eq i64 %indvars.iv.next1000, 17
+  br i1 %exitcond1002, label %for.cond176.preheader, label %for.body
+
+for.cond7.preheader:                              ; preds = %for.inc.3, %for.body
+  %indvars.iv958 = phi i64 [ 0, %for.body ], [ %indvars.iv.next959, %for.inc.3 ]
+  %tmp20 = add nuw nsw i64 %indvars.iv958, %tmp5
+  %arrayidx.2 = getelementptr inbounds [88 x float], [88 x float]* @ATH, i64 0, i64 0
+  %tmp157 = load float, float* %arrayidx.2, align 4
+  %tmp158 = add nuw nsw i64 %tmp20, 3
+  %cmp12.3 = icmp ult i64 %tmp158, 88
+  br i1 %cmp12.3, label %if.then.3, label %if.else.3
+
+if.else.3:                                        ; preds = %for.cond7.preheader
+  br label %for.inc.3
+
+if.then.3:                                        ; preds = %for.cond7.preheader
+  br label %for.inc.3
+
+for.inc.3:                                        ; preds = %if.then.3, %if.else.3
+  %min.1.3 = phi float [ undef, %if.then.3 ], [ %tmp157, %if.else.3 ]
+  %arrayidx29 = getelementptr inbounds [56 x float], [56 x float]* %ath, i64 0, i64 %indvars.iv958
+  store float %min.1.3, float* %arrayidx29, align 4
+  %indvars.iv.next959 = add nuw nsw i64 %indvars.iv958, 1
+  %exitcond961 = icmp eq i64 %indvars.iv.next959, 56
+  br i1 %exitcond961, label %for.cond33.preheader, label %for.cond7.preheader
+}
+
+
+; CHECK:      polly.stmt.if.else.3:
+; CHECK-NEXT:   %polly.access.cast.ath1 = bitcast [56 x float]* %ath to float*
+; CHECK-NEXT:   %polly.access.ath2 = getelementptr float, float* %polly.access.cast.ath1, i64 %polly.indvar
+; CHECK-NEXT:   %polly.access.ath2.reload = load float, float* %polly.access.ath2
diff --git a/polly/test/Isl/CodeGen/load_subset_with_context___%for.cond7.preheader---%for.cond33.preheader.jscop b/polly/test/Isl/CodeGen/load_subset_with_context___%for.cond7.preheader---%for.cond33.preheader.jscop
new file mode 100644
index 00000000000..6b137dda057
--- /dev/null
+++ b/polly/test/Isl/CodeGen/load_subset_with_context___%for.cond7.preheader---%for.cond33.preheader.jscop
@@ -0,0 +1,74 @@
+{
+   "arrays" : [
+      {
+         "name" : "MemRef_ATH",
+         "sizes" : [ "*" ],
+         "type" : "float"
+      },
+      {
+         "name" : "MemRef_ath",
+         "sizes" : [ "*" ],
+         "type" : "float"
+      }
+   ],
+   "context" : "[p_0] -> {  : 0 <= p_0 <= 16 }",
+   "name" : "%for.cond7.preheader---%for.cond33.preheader",
+   "statements" : [
+      {
+         "accesses" : [
+            {
+               "kind" : "read",
+               "relation" : "[p_0] -> { Stmt_for_cond7_preheader[i0] -> MemRef_ATH[0] }"
+            },
+            {
+               "kind" : "write",
+               "relation" : "[p_0] -> { Stmt_for_cond7_preheader[i0] -> MemRef_tmp157[] }"
+            }
+         ],
+         "domain" : "[p_0] -> { Stmt_for_cond7_preheader[i0] : 0 <= i0 <= 55 }",
+         "name" : "Stmt_for_cond7_preheader",
+         "schedule" : "[p_0] -> { Stmt_for_cond7_preheader[i0] -> [i0, 0] }"
+      },
+      {
+         "accesses" : [
+            {
+               "kind" : "write",
+               "relation" : "[p_0] -> { Stmt_if_then_3[i0] -> MemRef_min_1_3__phi[] }"
+            }
+         ],
+         "domain" : "[p_0] -> { Stmt_if_then_3[i0] : 0 <= i0 <= 84 - 4p_0 and i0 <= 55 }",
+         "name" : "Stmt_if_then_3",
+         "schedule" : "[p_0] -> { Stmt_if_then_3[i0] -> [i0, 2] }"
+      },
+      {
+         "accesses" : [
+            {
+               "kind" : "read",
+               "relation" : "[p_0] -> { Stmt_if_else_3[i0] -> MemRef_tmp157[] }"
+            },
+            {
+               "kind" : "write",
+               "relation" : "[p_0] -> { Stmt_if_else_3[i0] -> MemRef_min_1_3__phi[] }"
+            }
+         ],
+         "domain" : "[p_0] -> { Stmt_if_else_3[i0] : 85 - 4p_0 <= i0 <= 55 }",
+         "name" : "Stmt_if_else_3",
+         "schedule" : "[p_0] -> { Stmt_if_else_3[i0] -> [i0, 1] }"
+      },
+      {
+         "accesses" : [
+            {
+               "kind" : "read",
+               "relation" : "[p_0] -> { Stmt_for_inc_3[i0] -> MemRef_min_1_3__phi[] }"
+            },
+            {
+               "kind" : "write",
+               "relation" : "[p_0] -> { Stmt_for_inc_3[i0] -> MemRef_ath[i0] }"
+            }
+         ],
+         "domain" : "[p_0] -> { Stmt_for_inc_3[i0] : 0 <= i0 <= 55 }",
+         "name" : "Stmt_for_inc_3",
+         "schedule" : "[p_0] -> { Stmt_for_inc_3[i0] -> [i0, 3] }"
+      }
+   ]
+}
diff --git a/polly/test/Isl/CodeGen/load_subset_with_context___%for.cond7.preheader---%for.cond33.preheader.jscop.transformed b/polly/test/Isl/CodeGen/load_subset_with_context___%for.cond7.preheader---%for.cond33.preheader.jscop.transformed
new file mode 100644
index 00000000000..2bfd409961b
--- /dev/null
+++ b/polly/test/Isl/CodeGen/load_subset_with_context___%for.cond7.preheader---%for.cond33.preheader.jscop.transformed
@@ -0,0 +1,74 @@
+{
+   "arrays" : [
+      {
+         "name" : "MemRef_ATH",
+         "sizes" : [ "*" ],
+         "type" : "float"
+      },
+      {
+         "name" : "MemRef_ath",
+         "sizes" : [ "*" ],
+         "type" : "float"
+      }
+   ],
+   "context" : "[p_0] -> {  : 0 <= p_0 <= 16 }",
+   "name" : "%for.cond7.preheader---%for.cond33.preheader",
+   "statements" : [
+      {
+         "accesses" : [
+            {
+               "kind" : "read",
+               "relation" : "[p_0] -> { Stmt_for_cond7_preheader[i0] -> MemRef_ATH[0] }"
+            },
+            {
+               "kind" : "write",
+               "relation" : "[p_0] -> { Stmt_for_cond7_preheader[i0] -> MemRef_ath[i0] }"
+            }
+         ],
+         "domain" : "[p_0] -> { Stmt_for_cond7_preheader[i0] : 0 <= i0 <= 55 }",
+         "name" : "Stmt_for_cond7_preheader",
+         "schedule" : "[p_0] -> { Stmt_for_cond7_preheader[i0] -> [i0, 0] }"
+      },
+      {
+         "accesses" : [
+            {
+               "kind" : "write",
+               "relation" : "[p_0] -> { Stmt_if_then_3[i0] -> MemRef_ath[i0] }"
+            }
+         ],
+         "domain" : "[p_0] -> { Stmt_if_then_3[i0] : 0 <= i0 <= 84 - 4p_0 and i0 <= 55 }",
+         "name" : "Stmt_if_then_3",
+         "schedule" : "[p_0] -> { Stmt_if_then_3[i0] -> [i0, 2] }"
+      },
+      {
+         "accesses" : [
+            {
+               "kind" : "read",
+               "relation" : "[p_0] -> { Stmt_if_else_3[i0] -> MemRef_ath[i0] : i0 >= 0 }"
+            },
+            {
+               "kind" : "write",
+               "relation" : "[p_0] -> { Stmt_if_else_3[i0] -> MemRef_ath[i0] : i0 >= 0 }"
+            }
+         ],
+         "domain" : "[p_0] -> { Stmt_if_else_3[i0] : 85 - 4p_0 <= i0 <= 55 }",
+         "name" : "Stmt_if_else_3",
+         "schedule" : "[p_0] -> { Stmt_if_else_3[i0] -> [i0, 1] }"
+      },
+      {
+         "accesses" : [
+            {
+               "kind" : "read",
+               "relation" : "[p_0] -> { Stmt_for_inc_3[i0] -> MemRef_ath[i0] }"
+            },
+            {
+               "kind" : "write",
+               "relation" : "[p_0] -> { Stmt_for_inc_3[i0] -> MemRef_ath[i0] }"
+            }
+         ],
+         "domain" : "[p_0] -> { Stmt_for_inc_3[i0] : 0 <= i0 <= 55 }",
+         "name" : "Stmt_for_inc_3",
+         "schedule" : "[p_0] -> { Stmt_for_inc_3[i0] -> [i0, 3] }"
+      }
+   ]
+}