[llvm] r303710 - Revert "Disable coverage opt-out for strong postdominator blocks."

[George Karpenkov via llvm-commits]

Author: george.karpenkov
Date: Tue May 23 19:29:12 2017
New Revision: 303710

URL: http://llvm.org/viewvc/llvm-project?rev=303710&view=rev
Log:
Revert "Disable coverage opt-out for strong postdominator blocks."

This reverts commit 2ed06f05fc10869dd1239cff96fcdea2ee8bf4ef.
Buildbots do not like this on Linux.

Removed:
    llvm/trunk/test/Instrumentation/SanitizerCoverage/chains.ll
Modified:
    llvm/trunk/lib/Transforms/Instrumentation/SanitizerCoverage.cpp

Modified: llvm/trunk/lib/Transforms/Instrumentation/SanitizerCoverage.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/SanitizerCoverage.cpp?rev=303710&r1=303709&r2=303710&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/SanitizerCoverage.cpp (original)
+++ llvm/trunk/lib/Transforms/Instrumentation/SanitizerCoverage.cpp Tue May 23 19:29:12 2017
@@ -31,6 +31,7 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Analysis/EHPersonalities.h"
+#include "llvm/Analysis/PostDominators.h"
 #include "llvm/IR/CFG.h"
 #include "llvm/IR/CallSite.h"
 #include "llvm/IR/DataLayout.h"
@@ -168,6 +169,7 @@ public:
 
   void getAnalysisUsage(AnalysisUsage &AU) const override {
     AU.addRequired<DominatorTreeWrapperPass>();
+    AU.addRequired<PostDominatorTreeWrapperPass>();
   }
 
 private:
@@ -365,8 +367,23 @@ static bool isFullDominator(const BasicB
   return true;
 }
 
+// True if block has predecessors and it postdominates all of them.
+static bool isFullPostDominator(const BasicBlock *BB,
+                                const PostDominatorTree *PDT) {
+  if (pred_begin(BB) == pred_end(BB))
+    return false;
+
+  for (const BasicBlock *PRED : make_range(pred_begin(BB), pred_end(BB))) {
+    if (!PDT->dominates(BB, PRED))
+      return false;
+  }
+
+  return true;
+}
+
 static bool shouldInstrumentBlock(const Function &F, const BasicBlock *BB,
                                   const DominatorTree *DT,
+                                  const PostDominatorTree *PDT,
                                   const SanitizerCoverageOptions &Options) {
   // Don't insert coverage for unreachable blocks: we will never call
   // __sanitizer_cov() for them, so counting them in
@@ -384,7 +401,7 @@ static bool shouldInstrumentBlock(const
   if (Options.NoPrune || &F.getEntryBlock() == BB)
     return true;
 
-  return !isFullDominator(BB, DT);
+  return !(isFullDominator(BB, DT) || isFullPostDominator(BB, PDT));
 }
 
 bool SanitizerCoverageModule::runOnFunction(Function &F) {
@@ -416,9 +433,11 @@ bool SanitizerCoverageModule::runOnFunct
 
   const DominatorTree *DT =
       &getAnalysis<DominatorTreeWrapperPass>(F).getDomTree();
+  const PostDominatorTree *PDT =
+      &getAnalysis<PostDominatorTreeWrapperPass>(F).getPostDomTree();
 
   for (auto &BB : F) {
-    if (shouldInstrumentBlock(F, &BB, DT, Options))
+    if (shouldInstrumentBlock(F, &BB, DT, PDT, Options))
       BlocksToInstrument.push_back(&BB);
     for (auto &Inst : BB) {
       if (Options.IndirectCalls) {
@@ -700,6 +719,7 @@ INITIALIZE_PASS_BEGIN(SanitizerCoverageM
                       "ModulePass",
                       false, false)
 INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(PostDominatorTreeWrapperPass)
 INITIALIZE_PASS_END(SanitizerCoverageModule, "sancov",
                     "SanitizerCoverage: TODO."
                     "ModulePass",

Removed: llvm/trunk/test/Instrumentation/SanitizerCoverage/chains.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Instrumentation/SanitizerCoverage/chains.ll?rev=303709&view=auto
==============================================================================
--- llvm/trunk/test/Instrumentation/SanitizerCoverage/chains.ll (original)
+++ llvm/trunk/test/Instrumentation/SanitizerCoverage/chains.ll (removed)
@@ -1,27 +0,0 @@
-; RUN: opt < %s -sancov -sanitizer-coverage-level=4 -sanitizer-coverage-trace-pc -sanitizer-coverage-prune-blocks=1  -S | FileCheck %s
-
-define i32 @blah(i32) #0 {
-  %2 = icmp sgt i32 %0, 1
-  br i1 %2, label %branch, label %exit
-; CHECK: call void @__sanitizer_cov_trace_pc()
-branch:
-  br label %pos2
-; CHECK-LABEL: branch:
-; CHECK-NOT: call void @__sanitizer_cov_trace_pc()
-pos2:
-  br label %pos3
-; CHECK-LABEL: pos2:
-; CHECK-NOT: call void @__sanitizer_cov_trace_pc()
-pos3:
-  br label %pos4
-; CHECK-LABEL: pos3:
-; CHECK-NOT: call void @__sanitizer_cov_trace_pc()
-pos4:
-  ret i32 0
-; CHECK-LABEL: pos4:
-; CHECK: call void @__sanitizer_cov_trace_pc()
-exit:
-  ret i32 0
-; CHECK-LABEL: exit:
-; CHECK: call void @__sanitizer_cov_trace_pc()
-}