[clang] [compiler-rt] [llvm] [TypeProf][InstrFDO]Implement more efficient comparison sequence for indirect-call-promotion with vtable profiles. (PR #81442)

[Teresa Johnson via cfe-commits]

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@@ -103,30 +110,220 @@ static cl::opt<bool>
     ICPDUMPAFTER("icp-dumpafter", cl::init(false), cl::Hidden,
                  cl::desc("Dump IR after transformation happens"));
 
+// This option is meant to be used by LLVM regression test and test the
+// transformation that compares vtables.
+static cl::opt<bool> ICPEnableVTableCmp(
+    "icp-enable-vtable-cmp", cl::init(false), cl::Hidden,
+    cl::desc("If ThinLTO and WPD is enabled and this option is true, "
+             "indirect-call promotion pass will compare vtables rather than "
+             "functions for speculative devirtualization of virtual calls."
+             " If set to false, indirect-call promotion pass will always "
+             "compare functions."));
+
+static cl::opt<float>
+    ICPVTableCountPercentage("icp-vtable-count-percentage", cl::init(0.99),
+                             cl::Hidden,
+                             cl::desc("Percentage of vtable count to compare"));
+
+static cl::opt<int> ICPNumAdditionalVTableLast(
+    "icp-num-additional-vtable-last", cl::init(0), cl::Hidden,
+    cl::desc("The number of additional instruction for the last candidate"));
+
 namespace {
 
+using VTableAddressPointOffsetValMap =
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teresajohnson wrote:

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https://github.com/llvm/llvm-project/pull/81442