[Attributor] Stabilize llvm.assume output

Don't rely on the iteration order of DenseSet<StringRef>, which is not
guaranteed to be deterministic.

Author: MaskRay

llvm/lib/Transforms/IPO/AttributorAttributes.cpp

@@ -11739,11 +11739,14 @@ struct AAAssumptionInfoImpl : public AAAssumptionInfo {
       return ChangeStatus::UNCHANGED;
 
     const IRPosition &IRP = getIRPosition();
-    return A.manifestAttrs(
-        IRP,
-        Attribute::get(IRP.getAnchorValue().getContext(), AssumptionAttrKey,
-                       llvm::join(getAssumed().getSet(), ",")),
-        /* ForceReplace */ true);
+    SmallVector<StringRef, 0> Set(getAssumed().getSet().begin(),
+                                  getAssumed().getSet().end());
+    llvm::sort(Set);
+    return A.manifestAttrs(IRP,
+                           Attribute::get(IRP.getAnchorValue().getContext(),
+                                          AssumptionAttrKey,
+                                          llvm::join(Set, ",")),
+                           /*ForceReplace=*/true);
   }
 
   bool hasAssumption(const StringRef Assumption) const override {
@@ -11755,13 +11758,15 @@ struct AAAssumptionInfoImpl : public AAAssumptionInfo {
     const SetContents &Known = getKnown();
     const SetContents &Assumed = getAssumed();
 
-    const std::string KnownStr =
-        llvm::join(Known.getSet().begin(), Known.getSet().end(), ",");
-    const std::string AssumedStr =
-        (Assumed.isUniversal())
-            ? "Universal"
-            : llvm::join(Assumed.getSet().begin(), Assumed.getSet().end(), ",");
+    SmallVector<StringRef, 0> Set(Known.getSet().begin(), Known.getSet().end());
+    llvm::sort(Set);
+    const std::string KnownStr = llvm::join(Set, ",");
 
+    std::string AssumedStr = "Universal";
+    if (!Assumed.isUniversal()) {
+      Set.assign(Assumed.getSet().begin(), Assumed.getSet().end());
+      AssumedStr = llvm::join(Set, ",");
+    }
     return "Known [" + KnownStr + "]," + " Assumed [" + AssumedStr + "]";
   }
 };

llvm/test/Transforms/Attributor/assumes_info.ll

@@ -117,11 +117,11 @@ attributes #2 = { "llvm.assume"="B,C" }
 attributes #3 = { "llvm.assume"="B,C,A" }
 ;.
 ; TUNIT: attributes #[[ATTR0]] = { "llvm.assume"="A" }
-; TUNIT: attributes #[[ATTR1]] = { "llvm.assume"="B,A" }
-; TUNIT: attributes #[[ATTR2]] = { "llvm.assume"="B,C,A" }
+; TUNIT: attributes #[[ATTR1]] = { "llvm.assume"="A,B" }
+; TUNIT: attributes #[[ATTR2]] = { "llvm.assume"="A,B,C" }
 ;.
 ; CGSCC: attributes #[[ATTR0]] = { "llvm.assume"="A" }
-; CGSCC: attributes #[[ATTR1]] = { "llvm.assume"="B,A" }
-; CGSCC: attributes #[[ATTR2]] = { "llvm.assume"="B,C,A" }
+; CGSCC: attributes #[[ATTR1]] = { "llvm.assume"="A,B" }
+; CGSCC: attributes #[[ATTR2]] = { "llvm.assume"="A,B,C" }
 ; CGSCC: attributes #[[ATTR3]] = { "llvm.assume"="B" }
 ;.

llvm/test/Transforms/OpenMP/spmdization_guarding.ll

@@ -431,8 +431,8 @@ attributes #5 = { convergent nounwind "llvm.assume"="omp_no_openmp,ompx_spmd_ame
 ; CHECK: attributes #[[ATTR6]] = { nounwind }
 ; CHECK: attributes #[[ATTR7:[0-9]+]] = { nocallback nofree nosync nounwind willreturn memory(inaccessiblemem: readwrite) }
 ; CHECK: attributes #[[ATTR8:[0-9]+]] = { convergent nounwind }
-; CHECK: attributes #[[ATTR9]] = { nounwind willreturn "llvm.assume"="ompx_spmd_amenable,omp_no_openmp" }
-; CHECK: attributes #[[ATTR10]] = { convergent nounwind "llvm.assume"="ompx_spmd_amenable,omp_no_openmp" }
+; CHECK: attributes #[[ATTR9]] = { nounwind willreturn "llvm.assume"="omp_no_openmp,ompx_spmd_amenable" }
+; CHECK: attributes #[[ATTR10]] = { convergent nounwind "llvm.assume"="omp_no_openmp,ompx_spmd_amenable" }
 ;.
 ; CHECK-DISABLED: attributes #[[ATTR0]] = { convergent norecurse nounwind "frame-pointer"="all" "kernel" "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="sm_53" "target-features"="+ptx32,+sm_53" }
 ; CHECK-DISABLED: attributes #[[ATTR1:[0-9]+]] = { alwaysinline }
@@ -443,8 +443,8 @@ attributes #5 = { convergent nounwind "llvm.assume"="omp_no_openmp,ompx_spmd_ame
 ; CHECK-DISABLED: attributes #[[ATTR6]] = { nounwind }
 ; CHECK-DISABLED: attributes #[[ATTR7:[0-9]+]] = { nocallback nofree nosync nounwind willreturn memory(inaccessiblemem: readwrite) }
 ; CHECK-DISABLED: attributes #[[ATTR8:[0-9]+]] = { convergent nounwind }
-; CHECK-DISABLED: attributes #[[ATTR9]] = { nounwind willreturn "llvm.assume"="ompx_spmd_amenable,omp_no_openmp" }
-; CHECK-DISABLED: attributes #[[ATTR10]] = { convergent nounwind "llvm.assume"="ompx_spmd_amenable,omp_no_openmp" }
+; CHECK-DISABLED: attributes #[[ATTR9]] = { nounwind willreturn "llvm.assume"="omp_no_openmp,ompx_spmd_amenable" }
+; CHECK-DISABLED: attributes #[[ATTR10]] = { convergent nounwind "llvm.assume"="omp_no_openmp,ompx_spmd_amenable" }
 ;.
 ; CHECK: [[META0:![0-9]+]] = !{i32 0, i32 42, i32 16513658, !"sequential_loop", i32 6, i32 0}
 ; CHECK: [[META1:![0-9]+]] = !{ptr @__omp_offloading_2a_fbfa7a_sequential_loop_l6, !"kernel", i32 1}