[MachineOutliner] Recommit r312194, missed optimization remarks

Before, this commit caused a buildbot failure:

http://bb.pgr.jp/builders/test-llvm-i686-linux-RA/builds/6026/steps/test_llvm/logs/LLVM%20%3A%3A%20CodeGen__AArch64__machine-outliner-remarks.ll

This was caused by the Key value in DiagnosticInfoOptimizationBase being
deallocated before emitting the remarks defined in MachineOutliner.cpp. As of
r312277 this should no longer be an issue.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312280 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/MachineOutliner.cpp b/lib/CodeGen/MachineOutliner.cpp
index 9a8eebff2b5547f2da7938a649b8bd31f25ad30c..c12035455aba362c5a48c9bdad0c3e492b0ce411 100644 (file)
--- a/lib/CodeGen/MachineOutliner.cpp
+++ b/lib/CodeGen/MachineOutliner.cpp
@@ -46,6 +46,7 @@
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h"
 #include "llvm/CodeGen/Passes.h"
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/Support/Allocator.h"
@@ -64,6 +65,7 @@
 #define DEBUG_TYPE "machine-outliner"
 
 using namespace llvm;
+using namespace ore;
 
 STATISTIC(NumOutlined, "Number of candidates outlined");
 STATISTIC(FunctionsCreated, "Number of functions created");
@@ -895,8 +897,41 @@ MachineOutliner::findCandidates(SuffixTree &ST, const TargetInstrInfo &TII,
     size_t OutliningCost = CallOverhead + FrameOverhead + SequenceOverhead;
     size_t NotOutliningCost = SequenceOverhead * Parent.OccurrenceCount;
 
-    if (NotOutliningCost <= OutliningCost)
+    // Is it better to outline this candidate than not?
+    if (NotOutliningCost <= OutliningCost) {
+      // Outlining this candidate would take more instructions than not
+      // outlining.
+      // Emit a remark explaining why we didn't outline this candidate.
+      std::pair<MachineBasicBlock::iterator, MachineBasicBlock::iterator> C =
+          CandidateClass[0];
+      MachineOptimizationRemarkEmitter MORE(
+          *(C.first->getParent()->getParent()), nullptr);
+      MachineOptimizationRemarkMissed R(DEBUG_TYPE, "NotOutliningCheaper",
+                                        C.first->getDebugLoc(),
+                                        C.first->getParent());
+      R << "Did not outline " << NV("Length", StringLen) << " instructions"
+        << " from " << NV("NumOccurrences", CandidateClass.size())
+        << " locations."
+        << " Instructions from outlining all occurrences ("
+        << NV("OutliningCost", OutliningCost) << ")"
+        << " >= Unoutlined instruction count ("
+        << NV("NotOutliningCost", NotOutliningCost) << ")"
+        << " (Also found at: ";
+
+      // Tell the user the other places the candidate was found.
+      for (size_t i = 1, e = CandidateClass.size(); i < e; i++) {
+        R << NV((Twine("OtherStartLoc") + Twine(i)).str(),
+                CandidateClass[i].first->getDebugLoc());
+        if (i != e - 1)
+          R << ", ";
+      }
+
+      R << ")";
+      MORE.emit(R);
+
+      // Move to the next candidate.
       continue;
+    }
 
     size_t Benefit = NotOutliningCost - OutliningCost;
 

diff --git a/test/CodeGen/AArch64/machine-outliner-remarks.ll b/test/CodeGen/AArch64/machine-outliner-remarks.ll
new file mode 100644 (file)
index 0000000..113f343
--- /dev/null
+++ b/test/CodeGen/AArch64/machine-outliner-remarks.ll
@@ -0,0 +1,73 @@
+; RUN: llc %s -enable-machine-outliner -mtriple=aarch64-unknown-unknown -pass-remarks-missed=machine-outliner -o /dev/null 2>&1 | FileCheck %s
+; CHECK: machine-outliner-remarks.ll:5:9:
+; CHECK-SAME: Did not outline 2 instructions from 2 locations.
+; CHECK-SAME: Instructions from outlining all occurrences (9) >=
+; CHECK-SAME: Unoutlined instruction count (4)
+; CHECK-SAME: (Also found at: machine-outliner-remarks.ll:13:9)
+; RUN: llc %s -enable-machine-outliner -mtriple=aarch64-unknown-unknown -o /dev/null -pass-remarks-missed=machine-outliner -pass-remarks-output=%t.yaml
+; RUN: cat %t.yaml | FileCheck %s -check-prefix=YAML
+; YAML: --- !Missed
+; YAML-NEXT: Pass:            machine-outliner
+; YAML-NEXT: Name:            NotOutliningCheaper
+; YAML-NEXT: DebugLoc:        { File: machine-outliner-remarks.ll, Line: 5, Column: 9 }
+; YAML-NEXT: Function:        dog
+; YAML-NEXT: Args:            
+; YAML-NEXT:   - String:          'Did not outline '
+; YAML-NEXT:   - Length:          '2'
+; YAML-NEXT:   - String:          ' instructions'
+; YAML-NEXT:   - String:          ' from '
+; YAML-NEXT:   - NumOccurrences:  '2'
+; YAML-NEXT:   - String:          ' locations.'
+; YAML-NEXT:   - String:          ' Instructions from outlining all occurrences ('
+; YAML-NEXT:   - OutliningCost:   '9'
+; YAML-NEXT:   - String:          ')'
+; YAML-NEXT:   - String:          ' >= Unoutlined instruction count ('
+; YAML-NEXT:   - NotOutliningCost: '4'
+; YAML-NEXT:   - String:          ')'
+; YAML-NEXT:   - String:          ' (Also found at: '
+; YAML-NEXT:   - OtherStartLoc1:  'machine-outliner-remarks.ll:13:9'
+; YAML-NEXT:     DebugLoc:        { File: machine-outliner-remarks.ll, Line: 13, Column: 9 }
+; YAML-NEXT:   - String:          ')'
+
+define void @dog() #0 !dbg !8 {
+entry:
+  %x = alloca i32, align 4
+  %y = alloca i32, align 4
+  store i32 0, i32* %x, align 4, !dbg !11
+  store i32 1, i32* %y, align 4, !dbg !12
+  ret void, !dbg !13
+}
+
+define void @cat() #0 !dbg !14 {
+entry:
+  %x = alloca i32, align 4
+  %y = alloca i32, align 4
+  store i32 0, i32* %x, align 4, !dbg !15
+  store i32 1, i32* %y, align 4, !dbg !16
+  ret void, !dbg !17
+}
+
+attributes #0 = { noredzone nounwind ssp uwtable "no-frame-pointer-elim"="false" "target-cpu"="cyclone" }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5, !6}
+!llvm.ident = !{!7}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
+!1 = !DIFile(filename: "machine-outliner-remarks.ll", directory: "/tmp")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{i32 7, !"PIC Level", i32 2}
+!7 = !{!""}
+!8 = distinct !DISubprogram(name: "dog", scope: !1, file: !1, line: 2, type: !9, isLocal: false, isDefinition: true, scopeLine: 3, flags: DIFlagPrototyped, isOptimized: false, unit: !0, variables: !2)
+!9 = !DISubroutineType(types: !10)
+!10 = !{null}
+!11 = !DILocation(line: 4, column: 9, scope: !8)
+!12 = !DILocation(line: 5, column: 9, scope: !8)
+!13 = !DILocation(line: 6, column: 1, scope: !8)
+!14 = distinct !DISubprogram(name: "cat", scope: !1, file: !1, line: 10, type: !9, isLocal: false, isDefinition: true, scopeLine: 11, flags: DIFlagPrototyped, isOptimized: false, unit: !0, variables: !2)
+!15 = !DILocation(line: 12, column: 9, scope: !14)
+!16 = !DILocation(line: 13, column: 9, scope: !14)
+!17 = !DILocation(line: 14, column: 1, scope: !14)