[llvm] 0383253 - [InlineCost] Addressing a very strict assert check in CostAnnotationWriter::emitInstructionAnnot

[Kirill Naumov via llvm-commits]

Author: Kirill Naumov
Date: 2020-04-30T15:38:36Z
New Revision: 0383253cdfe705c83fff60a15fc6b3b71c41ee89

URL: https://github.com/llvm/llvm-project/commit/0383253cdfe705c83fff60a15fc6b3b71c41ee89
DIFF: https://github.com/llvm/llvm-project/commit/0383253cdfe705c83fff60a15fc6b3b71c41ee89.diff

LOG: [InlineCost] Addressing a very strict assert check in CostAnnotationWriter::emitInstructionAnnot

The assert checks that every instruction must be annotated by this point while it is not
necessary. If the inlining process was interrupted because the threshold was reached, the rest
of the instructions would not be annotated which triggers the assert.
The added test shows the situation in which it can happen.
This is a recommit as the original commit fail due to the absence of REQUIRES: assert in the test.

Reviewed By: mtrofin
Differential Revision: https://reviews.llvm.org/D79107

Added: 
    llvm/test/Transforms/Inline/print-instructions-deltas-unfinished.ll

Modified: 
    llvm/lib/Analysis/InlineCost.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Analysis/InlineCost.cpp b/llvm/lib/Analysis/InlineCost.cpp
index 42f8fecb7783..ce9f030bf379 100644
--- a/llvm/lib/Analysis/InlineCost.cpp
+++ b/llvm/lib/Analysis/InlineCost.cpp
@@ -54,8 +54,8 @@ static cl::opt<int>
                      cl::ZeroOrMore,
                      cl::desc("Default amount of inlining to perform"));
 
-static cl::opt<bool> PrintDebugInstructionDeltas("print-instruction-deltas",
-    cl::Hidden, cl::init(false),
+static cl::opt<bool> PrintDebugInstructionDeltas(
+    "print-instruction-deltas", cl::Hidden, cl::init(false),
     cl::desc("Prints deltas of cost and threshold per instruction"));
 
 static cl::opt<int> InlineThreshold(
@@ -132,10 +132,10 @@ class CostAnnotationWriter : public AssemblyAnnotationWriter {
 public:
   // This DenseMap stores the delta change in cost and threshold after
   // accounting for the given instruction.
-  DenseMap <const Instruction *, InstructionCostDetail> CostThresholdMap;
+  DenseMap<const Instruction *, InstructionCostDetail> CostThresholdMap;
 
   virtual void emitInstructionAnnot(const Instruction *I,
-                                        formatted_raw_ostream &OS);
+                                    formatted_raw_ostream &OS);
 };
 
 class CallAnalyzer : public InstVisitor<CallAnalyzer, bool> {
@@ -590,7 +590,7 @@ class InlineCostCallAnalyzer final : public CallAnalyzer {
     // This function is called to store the initial cost of inlining before
     // the given instruction was assessed.
     if (!PrintDebugInstructionDeltas)
-        return ;
+      return;
     Writer.CostThresholdMap[I].CostBefore = Cost;
     Writer.CostThresholdMap[I].ThresholdBefore = Threshold;
   }
@@ -599,7 +599,7 @@ class InlineCostCallAnalyzer final : public CallAnalyzer {
     // This function is called to find new values of cost and threshold after
     // the instruction has been assessed.
     if (!PrintDebugInstructionDeltas)
-        return ;
+      return;
     Writer.CostThresholdMap[I].CostAfter = Cost;
     Writer.CostThresholdMap[I].ThresholdAfter = Threshold;
   }
@@ -727,22 +727,24 @@ void CallAnalyzer::disableSROAForArg(AllocaInst *SROAArg) {
   disableLoadElimination();
 }
 
-void CostAnnotationWriter::emitInstructionAnnot(
-    const Instruction *I, formatted_raw_ostream &OS) {
-    // The cost of inlining of the given instruction is printed always.
-    // The threshold delta is printed only when it is non-zero. It happens
-    // when we decided to give a bonus at a particular instruction.
-    assert(CostThresholdMap.count(I) > 0 &&
-           "Expected each instruction to have an instruction annotation");
-    const auto &Record = CostThresholdMap[I];
-    OS << "; cost before = " << Record.CostBefore
-       << ", cost after = " << Record.CostAfter
-       << ", threshold before = " << Record.ThresholdBefore
-       << ", threshold after = " << Record.ThresholdAfter << ", ";
-    OS << "cost delta = " << Record.getCostDelta();
-    if (Record.hasThresholdChanged())
-      OS << ", threshold delta = " << Record.getThresholdDelta();
-    OS << "\n";
+void CostAnnotationWriter::emitInstructionAnnot(const Instruction *I,
+                                                formatted_raw_ostream &OS) {
+  // The cost of inlining of the given instruction is printed always.
+  // The threshold delta is printed only when it is non-zero. It happens
+  // when we decided to give a bonus at a particular instruction.
+  if (CostThresholdMap.count(I) == 0) {
+    OS << "; No analysis for the instruction\n";
+    return;
+  }
+  const auto &Record = CostThresholdMap[I];
+  OS << "; cost before = " << Record.CostBefore
+     << ", cost after = " << Record.CostAfter
+     << ", threshold before = " << Record.ThresholdBefore
+     << ", threshold after = " << Record.ThresholdAfter << ", ";
+  OS << "cost delta = " << Record.getCostDelta();
+  if (Record.hasThresholdChanged())
+    OS << ", threshold delta = " << Record.getThresholdDelta();
+  OS << "\n";
 }
 
 /// If 'V' maps to a SROA candidate, disable SROA for it.
@@ -804,7 +806,8 @@ bool CallAnalyzer::isGEPFree(GetElementPtrInst &GEP) {
     else
       Operands.push_back(*I);
   return TargetTransformInfo::TCC_Free ==
-         TTI.getUserCost(&GEP, Operands, TargetTransformInfo::TCK_SizeAndLatency);
+         TTI.getUserCost(&GEP, Operands,
+                         TargetTransformInfo::TCK_SizeAndLatency);
 }
 
 bool CallAnalyzer::visitAlloca(AllocaInst &I) {

diff  --git a/llvm/test/Transforms/Inline/print-instructions-deltas-unfinished.ll b/llvm/test/Transforms/Inline/print-instructions-deltas-unfinished.ll
new file mode 100644
index 000000000000..cd7ef830460c
--- /dev/null
+++ b/llvm/test/Transforms/Inline/print-instructions-deltas-unfinished.ll
@@ -0,0 +1,22 @@
+; Require asserts for -debug-only
+; REQUIRES: asserts
+
+; This test ensures that the hadling of instructions which were not analyzed by
+; '-print-instruction-deltas' flag due to the early exit was done correctly.
+
+; RUN: opt < %s -inline -debug-only=inline-cost -disable-output -print-instruction-deltas -inline-threshold=0 2>&1 | FileCheck %s
+
+; CHECK: No analysis for the instruction
+; CHECK:   ret void
+
+declare void @callee1()
+
+define void @bar() {
+  call void @callee1()
+  ret void
+}
+
+define void @foo() {
+  call void @bar()
+  ret void
+}