add PhaseOrdering test

Author: hassnaaHamdi

llvm/lib/Passes/PassBuilderPipelines.cpp

@@ -305,6 +305,13 @@ static cl::opt<std::string> InstrumentColdFuncOnlyPath(
              "with --pgo-instrument-cold-function-only)"),
     cl::Hidden);
 
+// TODO: There is a similar flag in WPD pass, we should consolidate them by
+// parsing the option only once in PassBuilder and share it across both places.
+static cl::opt<bool> EnableDevirtualizeSpeculatively(
+    "enable-devirtualize-speculatively",
+    cl::desc("Enable speculative devirtualization optimization"),
+    cl::init(false));
+
 extern cl::opt<std::string> UseCtxProfile;
 extern cl::opt<bool> PGOInstrumentColdFunctionOnly;
 
@@ -326,7 +333,7 @@ PipelineTuningOptions::PipelineTuningOptions() {
   MergeFunctions = EnableMergeFunctions;
   InlinerThreshold = -1;
   EagerlyInvalidateAnalyses = EnableEagerlyInvalidateAnalyses;
-  DevirtualizeSpeculatively = false;
+  DevirtualizeSpeculatively = EnableDevirtualizeSpeculatively;
 }
 
 namespace llvm {

llvm/test/Transforms/PhaseOrdering/speculative-devirt-then-inliner.ll

@@ -0,0 +1,60 @@
+; RUN: opt -S -O3 -enable-devirtualize-speculatively %s 2>&1 | FileCheck %s
+
+; Test that the devirtualized calls are inlined.
+
+@vt1 = constant [1 x ptr] [ptr @vf], !type !0
+@vt2 = constant [1 x ptr] [ptr @vf2], !type !1
+
+
+define i1 @vf(ptr %this) {
+  ret i1 true
+}
+
+define i1 @vf2(ptr %this) {
+  ret i1 false
+}
+
+; CHECK: define i1 @call
+define i1 @call(ptr %obj) #1 {
+  %vtable = load ptr, ptr %obj
+  %p = call i1 @llvm.public.type.test(ptr %vtable, metadata !"typeid")
+  call void @llvm.assume(i1 %p)
+  %fptr = load ptr, ptr %vtable
+  ; if.true.direct_targ:                              ; preds = %0
+  ;   br label %if.end.icp
+  ; if.false.orig_indirect:                           ; preds = %0
+  ;   %res = tail call i1 %fptr(ptr nonnull %obj)
+  ;   br label %if.end.icp
+  ; if.end.icp:                                       ; preds = %if.false.orig_indirect, %if.true.direct_targ
+  ;   %2 = phi i1 [ %res, %if.false.orig_indirect ], [ true, %if.true.direct_targ ]
+  ;   ret i1 %2
+  %res = call i1 %fptr(ptr %obj)
+  ret i1 %res
+}
+
+
+; CHECK: define i1 @call1
+define i1 @call1(ptr %obj) #1 {
+  %vtable = load ptr, ptr %obj
+  %p = call i1 @llvm.type.test(ptr %vtable, metadata !"typeid1")
+  call void @llvm.assume(i1 %p)
+  %fptr = load ptr, ptr %vtable, align 8
+  ; if.true.direct_targ:                              ; preds = %0
+  ;   br label %if.end.icp
+  ; if.false.orig_indirect:                           ; preds = %0
+  ;   %res = tail call i1 %fptr(ptr nonnull %obj)
+  ;   br label %if.end.icp
+  ; if.end.icp:                                       ; preds = %if.false.orig_indirect, %if.true.direct_targ
+  ;   %2 = phi i1 [ %res, %if.false.orig_indirect ], [ false, %if.true.direct_targ ]
+  ;   ret i1 %2
+  %res = call i1 %fptr(ptr %obj)
+  ret i1 %res
+}
+
+
+declare i1 @llvm.type.test(ptr, metadata)
+declare i1 @llvm.public.type.test(ptr, metadata)
+declare void @llvm.assume(i1)
+
+!0 = !{i32 0, !"typeid"}
+!1 = !{i32 0, !"typeid1"}