Index: lib/CodeGen/MachineBlockPlacement.cpp =================================================================== --- lib/CodeGen/MachineBlockPlacement.cpp +++ lib/CodeGen/MachineBlockPlacement.cpp @@ -60,17 +60,6 @@ "blocks in the function."), cl::init(0), cl::Hidden); -static cl::opt OnlyHotBadCFGConflictCheck( - "only-hot-bad-cfg-conflict-check", - cl::desc("Only check that a hot successor doesn't have a hot predecessor."), - cl::init(false), cl::Hidden); - -static cl::opt NoBadCFGConflictCheck( - "no-bad-cfg-conflict-check", - cl::desc("Don't check whether a hot successor has a more important " - "predecessor."), - cl::init(false), cl::Hidden); - // FIXME: Find a good default for this flag and remove the flag. static cl::opt ExitBlockBias("block-placement-exit-block-bias", @@ -385,33 +374,29 @@ continue; } - if (!NoBadCFGConflictCheck) { - // Make sure that a hot successor doesn't have a globally more - // important predecessor. - BlockFrequency CandidateEdgeFreq = - OnlyHotBadCFGConflictCheck - ? MBFI->getBlockFreq(BB) * SuccProb - : MBFI->getBlockFreq(BB) * SuccProb * HotProb.getCompl(); - bool BadCFGConflict = false; - for (MachineBasicBlock::pred_iterator PI = (*SI)->pred_begin(), - PE = (*SI)->pred_end(); - PI != PE; ++PI) { - if (*PI == *SI || (BlockFilter && !BlockFilter->count(*PI)) || - BlockToChain[*PI] == &Chain) - continue; - BlockFrequency PredEdgeFreq = - MBFI->getBlockFreq(*PI) * MBPI->getEdgeProbability(*PI, *SI); - if (PredEdgeFreq >= CandidateEdgeFreq) { - BadCFGConflict = true; - break; - } - } - if (BadCFGConflict) { - DEBUG(dbgs() << " " << getBlockName(*SI) << " -> " << SuccProb - << " (prob) (non-cold CFG conflict)\n"); + // Make sure that a hot successor doesn't have a globally more + // important predecessor. + BlockFrequency CandidateEdgeFreq = + MBFI->getBlockFreq(BB) * SuccProb * HotProb.getCompl(); + bool BadCFGConflict = false; + for (MachineBasicBlock::pred_iterator PI = (*SI)->pred_begin(), + PE = (*SI)->pred_end(); + PI != PE; ++PI) { + if (*PI == *SI || (BlockFilter && !BlockFilter->count(*PI)) || + BlockToChain[*PI] == &Chain) continue; + BlockFrequency PredEdgeFreq = + MBFI->getBlockFreq(*PI) * MBPI->getEdgeProbability(*PI, *SI); + if (PredEdgeFreq >= CandidateEdgeFreq) { + BadCFGConflict = true; + break; } } + if (BadCFGConflict) { + DEBUG(dbgs() << " " << getBlockName(*SI) << " -> " << SuccProb + << " (prob) (non-cold CFG conflict)\n"); + continue; + } } DEBUG(dbgs() << " " << getBlockName(*SI) << " -> " << SuccProb Index: test/CodeGen/X86/code_placement_bad_cfg_check.ll =================================================================== --- test/CodeGen/X86/code_placement_bad_cfg_check.ll +++ /dev/null @@ -1,112 +0,0 @@ -; RUN: llc -mcpu=corei7 -mtriple=x86_64-linux < %s | FileCheck %s -check-prefix=CHECK-BAD-CFG -; RUN: llc -mcpu=corei7 -mtriple=x86_64-linux -no-bad-cfg-conflict-check < %s | FileCheck %s -check-prefix=CHECK-NO-BAD-CFG -; RUN: llc -mcpu=corei7 -mtriple=x86_64-linux -only-hot-bad-cfg-conflict-check < %s | FileCheck %s -check-prefix=CHECK-HOT-BAD-CFG - -define void @foo(i32 %t) { -; Test that we lift the call to 'c' up to immediately follow the call to 'b' -; when we disable the cfg conflict check. -; -; CHECK-BAD-CFG-LABEL: foo: -; CHECK-BAD-CFG: callq b -; CHECK-BAD-CFG: callq a -; CHECK-BAD-CFG: callq c -; -; CHECK-NO-BAD-CFG-LABEL: foo: -; CHECK-NO-BAD-CFG: callq b -; CHECK-NO-BAD-CFG: callq c -; CHECK-NO-BAD-CFG: callq a -; -; CHECK-HOT-BAD-CFG-LABEL: foo: -; CHECK-HOT-BAD-CFG: callq b -; CHECK-HOT-BAD-CFG: callq c -; CHECK-HOT-BAD-CFG: callq a - -entry: - %cmp = icmp eq i32 %t, 0 - br i1 %cmp, label %if.then, label %if.else - -if.then: - call void @a() - br label %if.end - -if.else: - call void @b() - br label %if.end - -if.end: - call void @c() - ret void -} - -define void @bar(i32 %t1, i32 %t2, i32 %t3) { -; Test that we lift the call to 'c' up to immediately follow the call to 'b' -; when we disable the cfg conflict check. -; -; CHECK-BAD-CFG-LABEL: bar: -; CHECK-BAD-CFG: callq a -; CHECK-BAD-CFG: callq c -; CHECK-BAD-CFG: callq d -; CHECK-BAD-CFG: callq f -; CHECK-BAD-CFG: callq b -; CHECK-BAD-CFG: callq e -; CHECK-BAD-CFG: callq g -; -; CHECK-NO-BAD-CFG-LABEL: bar: -; CHECK-NO-BAD-CFG: callq a -; CHECK-NO-BAD-CFG: callq c -; CHECK-NO-BAD-CFG: callq g -; CHECK-NO-BAD-CFG: callq d -; CHECK-NO-BAD-CFG: callq f -; CHECK-NO-BAD-CFG: callq b -; CHECK-NO-BAD-CFG: callq e -; -; CHECK-HOT-BAD-CFG-LABEL: bar: -; CHECK-HOT-BAD-CFG: callq a -; CHECK-HOT-BAD-CFG: callq c -; CHECK-HOT-BAD-CFG: callq d -; CHECK-HOT-BAD-CFG: callq f -; CHECK-HOT-BAD-CFG: callq g -; CHECK-HOT-BAD-CFG: callq b -; CHECK-HOT-BAD-CFG: callq e - -entry: - br i1 undef, label %if1.then, label %if1.else - -if1.then: - call void @a() - %cmp2 = icmp eq i32 %t2, 0 - br i1 %cmp2, label %if2.then, label %if2.else - -if2.then: - call void @b() - br label %if.end - -if2.else: - call void @c() - br label %if.end - -if1.else: - call void @d() - %cmp3 = icmp eq i32 %t3, 0 - br i1 %cmp3, label %if3.then, label %if3.else - -if3.then: - call void @e() - br label %if.end - -if3.else: - call void @f() - br label %if.end - -if.end: - call void @g() - ret void -} - -declare void @a() -declare void @b() -declare void @c() -declare void @d() -declare void @e() -declare void @f() -declare void @g()