[LowerAllowCheckPass] allow to specify runtime.check hotness (#145998)

Author: fmayer

llvm/include/llvm/Transforms/Instrumentation/LowerAllowCheckPass.h

@@ -27,6 +27,7 @@ class LowerAllowCheckPass : public PassInfoMixin<LowerAllowCheckPass> {
 public:
   struct Options {
     std::vector<unsigned int> cutoffs;
+    unsigned int runtime_check = 0;
   };
 
   explicit LowerAllowCheckPass(LowerAllowCheckPass::Options Opts)

llvm/lib/Passes/PassBuilder.cpp

@@ -938,6 +938,19 @@ parseLowerAllowCheckPassOptions(StringRef Params) {
 
         Result.cutoffs[index] = cutoff;
       }
+    } else if (ParamName.starts_with("runtime_check")) {
+      StringRef ValueString;
+      std::tie(std::ignore, ValueString) = ParamName.split("=");
+      int runtime_check;
+      if (ValueString.getAsInteger(0, runtime_check)) {
+        return make_error<StringError>(
+            formatv("invalid LowerAllowCheck pass runtime_check parameter '{}' "
+                    "({})",
+                    ValueString, Params)
+                .str(),
+            inconvertibleErrorCode());
+      }
+      Result.runtime_check = runtime_check;
     } else {
       return make_error<StringError>(
           formatv("invalid LowerAllowCheck pass parameter '{}'", ParamName)

llvm/lib/Transforms/Instrumentation/LowerAllowCheckPass.cpp

@@ -74,7 +74,7 @@ static void emitRemark(IntrinsicInst *II, OptimizationRemarkEmitter &ORE,
 static bool removeUbsanTraps(Function &F, const BlockFrequencyInfo &BFI,
                              const ProfileSummaryInfo *PSI,
                              OptimizationRemarkEmitter &ORE,
-                             const std::vector<unsigned int> &cutoffs) {
+                             const LowerAllowCheckPass::Options &Opts) {
   SmallVector<std::pair<IntrinsicInst *, bool>, 16> ReplaceWithValue;
   std::unique_ptr<RandomNumberGenerator> Rng;
 
@@ -89,8 +89,10 @@ static bool removeUbsanTraps(Function &F, const BlockFrequencyInfo &BFI,
       return HotPercentileCutoff;
     else if (II->getIntrinsicID() == Intrinsic::allow_ubsan_check) {
       auto *Kind = cast<ConstantInt>(II->getArgOperand(0));
-      if (Kind->getZExtValue() < cutoffs.size())
-        return cutoffs[Kind->getZExtValue()];
+      if (Kind->getZExtValue() < Opts.cutoffs.size())
+        return Opts.cutoffs[Kind->getZExtValue()];
+    } else if (II->getIntrinsicID() == Intrinsic::allow_runtime_check) {
+      return Opts.runtime_check;
     }
 
     return 0;
@@ -157,7 +159,7 @@ PreservedAnalyses LowerAllowCheckPass::run(Function &F,
   OptimizationRemarkEmitter &ORE =
       AM.getResult<OptimizationRemarkEmitterAnalysis>(F);
 
-  return removeUbsanTraps(F, BFI, PSI, ORE, Opts.cutoffs)
+  return removeUbsanTraps(F, BFI, PSI, ORE, Opts)
              // We do not change the CFG, we only replace the intrinsics with
              // true or false.
              ? PreservedAnalyses::none().preserveSet<CFGAnalyses>()
@@ -193,5 +195,11 @@ void LowerAllowCheckPass::printPipeline(
 
     i++;
   }
+  if (Opts.runtime_check) {
+    if (printed)
+      OS << ";";
+    OS << "runtime_check=" << Opts.runtime_check;
+  }
+
   OS << '>';
 }

llvm/test/Transforms/lower-builtin-allow-check-remarks.ll

@@ -4,12 +4,21 @@
 ; RUN: opt < %s -passes='require<profile-summary>,function(lower-allow-check)' -lower-allow-check-percentile-cutoff-hot=0 -pass-remarks=lower-allow-check -pass-remarks-missed=lower-allow-check -S 2>&1 | FileCheck %s
 ; RUN: opt < %s -passes='require<profile-summary>,function(lower-allow-check)' -lower-allow-check-percentile-cutoff-hot=1000000 -pass-remarks=lower-allow-check -pass-remarks-missed=lower-allow-check -S 2>&1 | FileCheck %s --check-prefixes=REMOVE
 
+; RUN: opt < %s -passes='require<profile-summary>,function(lower-allow-check<cutoffs[7]=0;runtime_check=1000000>)' -pass-remarks=lower-allow-check -pass-remarks-missed=lower-allow-check -S 2>&1 | FileCheck %s --check-prefixes=MIXED
+; RUN: opt < %s -passes='require<profile-summary>,function(lower-allow-check<cutoffs[7]=1000000;runtime_check=0>)' -pass-remarks=lower-allow-check -pass-remarks-missed=lower-allow-check -S 2>&1 | FileCheck %s --check-prefixes=MIXED2
+
 ; CHECK: remark: <unknown>:0:0: Allowed check: Kind=test_check F=test_runtime BB=entry1
 ; CHECK: remark: <unknown>:0:0: Allowed check: Kind=7 F=test_ubsan BB=entry2
 
 ; REMOVE: remark: <unknown>:0:0: Removed check: Kind=test_check F=test_runtime BB=entry1
 ; REMOVE: remark: <unknown>:0:0: Removed check: Kind=7 F=test_ubsan BB=entry2
 
+; MIXED: remark: <unknown>:0:0: Removed check: Kind=test_check F=test_runtime BB=entry1
+; MIXED: remark: <unknown>:0:0: Allowed check: Kind=7 F=test_ubsan BB=entry2
+
+; MIXED2: remark: <unknown>:0:0: Allowed check: Kind=test_check F=test_runtime BB=entry1
+; MIXED2: remark: <unknown>:0:0: Removed check: Kind=7 F=test_ubsan BB=entry2
+
 target triple = "x86_64-pc-linux-gnu"
 
 define i1 @test_runtime() local_unnamed_addr {