zhizhouy updated this revision to Diff 158828.
zhizhouy added a comment.
Add `REQUIRES` to test.
Repository:
rL LLVM
https://reviews.llvm.org/D50092
Files:
lib/Transforms/Scalar/DCE.cpp
test/Other/debugcounter-dce.ll
Index: test/Other/debugcounter-dce.ll
===================================================================
--- /dev/null
+++ test/Other/debugcounter-dce.ll
@@ -0,0 +1,20 @@
+; REQUIRES: asserts
+; RUN: opt -dce -S -debug-counter=dce-transform-skip=1,dce-transform-count=2 < %s | FileCheck %s
+;; Test that, with debug counters on, we will skip the first DCE opportunity, perform next 2,
+;; and ignore all the others left.
+
+; CHECK-LABEL: @test
+; CHECK-NEXT: %add1 = add i32 1, 2
+; CHECK-NEXT: %sub1 = sub i32 %add1, 1
+; CHECK-NEXT: %add2 = add i32 1, 2
+; CHECK-NEXT: %add3 = add i32 1, 2
+; CHECK-NEXT: ret void
+define void @test() {
+ %add1 = add i32 1, 2
+ %sub1 = sub i32 %add1, 1
+ %add2 = add i32 1, 2
+ %sub2 = sub i32 %add2, 1
+ %add3 = add i32 1, 2
+ %sub3 = sub i32 %add3, 1
+ ret void
+}
Index: lib/Transforms/Scalar/DCE.cpp
===================================================================
--- lib/Transforms/Scalar/DCE.cpp
+++ lib/Transforms/Scalar/DCE.cpp
@@ -24,13 +24,16 @@
#include "llvm/IR/InstIterator.h"
#include "llvm/IR/Instruction.h"
#include "llvm/Pass.h"
+#include "llvm/Support/DebugCounter.h"
#include "llvm/Transforms/Scalar.h"
using namespace llvm;
#define DEBUG_TYPE "dce"
STATISTIC(DIEEliminated, "Number of insts removed by DIE pass");
STATISTIC(DCEEliminated, "Number of insts removed");
+DEBUG_COUNTER(DCECounter, "dce-transform",
+ "Controls which instructions are eliminated");
namespace {
//===--------------------------------------------------------------------===//
@@ -50,6 +53,8 @@
for (BasicBlock::iterator DI = BB.begin(); DI != BB.end(); ) {
Instruction *Inst = &*DI++;
if (isInstructionTriviallyDead(Inst, TLI)) {
+ if (!DebugCounter::shouldExecute(DCECounter))
+ continue;
salvageDebugInfo(*Inst);
Inst->eraseFromParent();
Changed = true;
@@ -77,6 +82,9 @@
SmallSetVector<Instruction *, 16> &WorkList,
const TargetLibraryInfo *TLI) {
if (isInstructionTriviallyDead(I, TLI)) {
+ if (!DebugCounter::shouldExecute(DCECounter))
+ return false;
+
salvageDebugInfo(*I);
// Null out all of the instruction's operands to see if any operand becomes
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