forked from OSchip/llvm-project
Follow-up patch of http://reviews.llvm.org/D19948 to handle missing profiles when simplifying CFG.
Summary: Set default branch weight to 1:1 if one of the branch has profile missing when simplifying CFG. Reviewers: spatel, davidxl Subscribers: danielcdh, llvm-commits Differential Revision: http://reviews.llvm.org/D20307 llvm-svn: 269995
This commit is contained in:
Dehao Chen
parent
c01919e796
commit
f16376b505
|
|
@ -2094,6 +2094,29 @@ static bool checkCSEInPredecessor(Instruction *Inst, BasicBlock *PB) {
|
|||
return false;
|
||||
}
|
||||
|
||||
/// Return true if either PBI or BI has branch weight available, and store
|
||||
/// the weights in {Pred|Succ}{True|False}Weight. If one of PBI and BI does
|
||||
/// not have branch weight, use 1:1 as its weight.
|
||||
static bool extractPredSuccWeights(BranchInst *PBI, BranchInst *BI,
|
||||
uint64_t &PredTrueWeight,
|
||||
uint64_t &PredFalseWeight,
|
||||
uint64_t &SuccTrueWeight,
|
||||
uint64_t &SuccFalseWeight) {
|
||||
bool PredHasWeights =
|
||||
PBI->extractProfMetadata(PredTrueWeight, PredFalseWeight);
|
||||
bool SuccHasWeights =
|
||||
BI->extractProfMetadata(SuccTrueWeight, SuccFalseWeight);
|
||||
if (PredHasWeights || SuccHasWeights) {
|
||||
if (!PredHasWeights)
|
||||
PredTrueWeight = PredFalseWeight = 1;
|
||||
if (!SuccHasWeights)
|
||||
SuccTrueWeight = SuccFalseWeight = 1;
|
||||
return true;
|
||||
} else {
|
||||
return false;
|
||||
}
|
||||
}
|
||||
|
||||
/// If this basic block is simple enough, and if a predecessor branches to us
|
||||
/// and one of our successors, fold the block into the predecessor and use
|
||||
/// logical operations to pick the right destination.
|
||||
|
|
@ -2281,14 +2304,13 @@ bool llvm::FoldBranchToCommonDest(BranchInst *BI, unsigned BonusInstThreshold) {
|
|||
PBI->setCondition(NewCond);
|
||||
|
||||
uint64_t PredTrueWeight, PredFalseWeight, SuccTrueWeight, SuccFalseWeight;
|
||||
bool PredHasWeights =
|
||||
PBI->extractProfMetadata(PredTrueWeight, PredFalseWeight);
|
||||
bool SuccHasWeights =
|
||||
BI->extractProfMetadata(SuccTrueWeight, SuccFalseWeight);
|
||||
bool HasWeights =
|
||||
extractPredSuccWeights(PBI, BI, PredTrueWeight, PredFalseWeight,
|
||||
SuccTrueWeight, SuccFalseWeight);
|
||||
SmallVector<uint64_t, 8> NewWeights;
|
||||
|
||||
if (PBI->getSuccessor(0) == BB) {
|
||||
if (PredHasWeights && SuccHasWeights) {
|
||||
if (HasWeights) {
|
||||
// PBI: br i1 %x, BB, FalseDest
|
||||
// BI: br i1 %y, TrueDest, FalseDest
|
||||
// TrueWeight is TrueWeight for PBI * TrueWeight for BI.
|
||||
|
|
@ -2305,7 +2327,7 @@ bool llvm::FoldBranchToCommonDest(BranchInst *BI, unsigned BonusInstThreshold) {
|
|||
PBI->setSuccessor(0, TrueDest);
|
||||
}
|
||||
if (PBI->getSuccessor(1) == BB) {
|
||||
if (PredHasWeights && SuccHasWeights) {
|
||||
if (HasWeights) {
|
||||
// PBI: br i1 %x, TrueDest, BB
|
||||
// BI: br i1 %y, TrueDest, FalseDest
|
||||
// TrueWeight is TrueWeight for PBI * TotalWeight for BI +
|
||||
|
|
@ -2840,18 +2862,10 @@ static bool SimplifyCondBranchToCondBranch(BranchInst *PBI, BranchInst *BI,
|
|||
// Update branch weight for PBI.
|
||||
uint64_t PredTrueWeight, PredFalseWeight, SuccTrueWeight, SuccFalseWeight;
|
||||
uint64_t PredCommon, PredOther, SuccCommon, SuccOther;
|
||||
bool PredHasWeights =
|
||||
PBI->extractProfMetadata(PredTrueWeight, PredFalseWeight);
|
||||
bool SuccHasWeights =
|
||||
BI->extractProfMetadata(SuccTrueWeight, SuccFalseWeight);
|
||||
bool HasWeights = PredHasWeights || SuccHasWeights;
|
||||
bool HasWeights =
|
||||
extractPredSuccWeights(PBI, BI, PredTrueWeight, PredFalseWeight,
|
||||
SuccTrueWeight, SuccFalseWeight);
|
||||
if (HasWeights) {
|
||||
if (!PredHasWeights) {
|
||||
PredFalseWeight = PredTrueWeight = 1;
|
||||
}
|
||||
if (!SuccHasWeights) {
|
||||
SuccFalseWeight = SuccTrueWeight = 1;
|
||||
}
|
||||
PredCommon = PBIOp ? PredFalseWeight : PredTrueWeight;
|
||||
PredOther = PBIOp ? PredTrueWeight : PredFalseWeight;
|
||||
SuccCommon = BIOp ? SuccFalseWeight : SuccTrueWeight;
|
||||
|
|
@ -2893,7 +2907,7 @@ static bool SimplifyCondBranchToCondBranch(BranchInst *PBI, BranchInst *BI,
|
|||
// weights for PBI do not apply to the new select because the select's
|
||||
// 'logical' edges are incoming edges of the phi that is eliminated, not
|
||||
// the outgoing edges of PBI.
|
||||
if (PredHasWeights && SuccHasWeights) {
|
||||
if (HasWeights) {
|
||||
uint64_t PredCommon = PBIOp ? PredFalseWeight : PredTrueWeight;
|
||||
uint64_t PredOther = PBIOp ? PredTrueWeight : PredFalseWeight;
|
||||
uint64_t SuccCommon = BIOp ? SuccFalseWeight : SuccTrueWeight;
|
||||
|
|
|
|||
|
|
@ -29,8 +29,7 @@ define void @fake_weights(i1 %a, i1 %b) {
|
|||
entry:
|
||||
br i1 %a, label %Y, label %X, !prof !12
|
||||
; CHECK: %or.cond = and i1 %a.not, %c
|
||||
; CHECK-NEXT: br i1 %or.cond, label %Z, label %Y
|
||||
; CHECK-NOT: !prof !0
|
||||
; CHECK-NEXT: br i1 %or.cond, label %Z, label %Y, !prof !1
|
||||
; CHECK: Y:
|
||||
X:
|
||||
%c = or i1 %b, false
|
||||
|
|
@ -49,7 +48,7 @@ define void @test2(i1 %a, i1 %b) {
|
|||
; CHECK-LABEL: @test2(
|
||||
entry:
|
||||
br i1 %a, label %X, label %Y, !prof !1
|
||||
; CHECK: br i1 %or.cond, label %Z, label %Y, !prof !1
|
||||
; CHECK: br i1 %or.cond, label %Z, label %Y, !prof !2
|
||||
; CHECK-NOT: !prof
|
||||
|
||||
X:
|
||||
|
|
@ -67,7 +66,7 @@ Z:
|
|||
|
||||
define void @test3(i1 %a, i1 %b) {
|
||||
; CHECK-LABEL: @test3(
|
||||
; CHECK-NOT: !prof
|
||||
; CHECK: br i1 %or.cond, label %Z, label %Y, !prof !1
|
||||
entry:
|
||||
br i1 %a, label %X, label %Y, !prof !1
|
||||
|
||||
|
|
@ -86,7 +85,7 @@ Z:
|
|||
|
||||
define void @test4(i1 %a, i1 %b) {
|
||||
; CHECK-LABEL: @test4(
|
||||
; CHECK-NOT: !prof
|
||||
; CHECK: br i1 %or.cond, label %Z, label %Y, !prof !1
|
||||
entry:
|
||||
br i1 %a, label %X, label %Y
|
||||
|
||||
|
|
@ -115,7 +114,7 @@ entry:
|
|||
; CHECK: switch i32 %N, label %sw2 [
|
||||
; CHECK: i32 3, label %sw.bb1
|
||||
; CHECK: i32 2, label %sw.bb
|
||||
; CHECK: ], !prof !2
|
||||
; CHECK: ], !prof !3
|
||||
|
||||
sw.bb:
|
||||
call void @helper(i32 0)
|
||||
|
|
@ -148,7 +147,7 @@ entry:
|
|||
; CHECK: i32 3, label %sw.bb1
|
||||
; CHECK: i32 2, label %sw.bb
|
||||
; CHECK: i32 4, label %sw.bb5
|
||||
; CHECK: ], !prof !3
|
||||
; CHECK: ], !prof !4
|
||||
|
||||
sw.bb:
|
||||
call void @helper(i32 0)
|
||||
|
|
@ -183,7 +182,7 @@ define void @test1_swap(i1 %a, i1 %b) {
|
|||
; CHECK-LABEL: @test1_swap(
|
||||
entry:
|
||||
br i1 %a, label %Y, label %X, !prof !0
|
||||
; CHECK: br i1 %or.cond, label %Y, label %Z, !prof !4
|
||||
; CHECK: br i1 %or.cond, label %Y, label %Z, !prof !5
|
||||
|
||||
X:
|
||||
%c = or i1 %b, false
|
||||
|
|
@ -203,7 +202,7 @@ define void @test7(i1 %a, i1 %b) {
|
|||
entry:
|
||||
%c = or i1 %b, false
|
||||
br i1 %a, label %Y, label %X, !prof !0
|
||||
; CHECK: br i1 %brmerge, label %Y, label %Z, !prof !5
|
||||
; CHECK: br i1 %brmerge, label %Y, label %Z, !prof !6
|
||||
|
||||
X:
|
||||
br i1 %c, label %Y, label %Z, !prof !6
|
||||
|
|
@ -222,7 +221,7 @@ define void @test8(i64 %x, i64 %y) nounwind {
|
|||
; CHECK-LABEL: @test8(
|
||||
entry:
|
||||
%lt = icmp slt i64 %x, %y
|
||||
; CHECK: br i1 %lt, label %a, label %b, !prof !6
|
||||
; CHECK: br i1 %lt, label %a, label %b, !prof !7
|
||||
%qux = select i1 %lt, i32 0, i32 2
|
||||
switch i32 %qux, label %bees [
|
||||
i32 0, label %a
|
||||
|
|
@ -255,7 +254,7 @@ entry:
|
|||
; CHECK: i32 1, label %end
|
||||
; CHECK: i32 2, label %end
|
||||
; CHECK: i32 92, label %end
|
||||
; CHECK: ], !prof !7
|
||||
; CHECK: ], !prof !8
|
||||
|
||||
a:
|
||||
call void @helper(i32 0) nounwind
|
||||
|
|
@ -293,7 +292,7 @@ lor.end:
|
|||
; CHECK-LABEL: @test10(
|
||||
; CHECK: %x.off = add i32 %x, -1
|
||||
; CHECK: %switch = icmp ult i32 %x.off, 3
|
||||
; CHECK: br i1 %switch, label %lor.end, label %lor.rhs, !prof !8
|
||||
; CHECK: br i1 %switch, label %lor.end, label %lor.rhs, !prof !9
|
||||
}
|
||||
|
||||
; Remove dead cases from the switch.
|
||||
|
|
@ -305,7 +304,7 @@ define void @test11(i32 %x) nounwind {
|
|||
], !prof !8
|
||||
; CHECK-LABEL: @test11(
|
||||
; CHECK: %cond = icmp eq i32 %i, 24
|
||||
; CHECK: br i1 %cond, label %c, label %a, !prof !9
|
||||
; CHECK: br i1 %cond, label %c, label %a, !prof !10
|
||||
|
||||
a:
|
||||
call void @helper(i32 0) nounwind
|
||||
|
|
@ -368,7 +367,7 @@ c:
|
|||
@max_regno = common global i32 0, align 4
|
||||
define void @test14(i32* %old, i32 %final) {
|
||||
; CHECK-LABEL: @test14
|
||||
; CHECK: br i1 %or.cond, label %for.exit, label %for.inc, !prof !10
|
||||
; CHECK: br i1 %or.cond, label %for.exit, label %for.inc, !prof !11
|
||||
for.cond:
|
||||
br label %for.cond2
|
||||
for.cond2:
|
||||
|
|
@ -394,7 +393,7 @@ define i32 @HoistThenElseCodeToIf(i32 %n) {
|
|||
; CHECK-LABEL: @HoistThenElseCodeToIf(
|
||||
; CHECK-NEXT: entry:
|
||||
; CHECK-NEXT: [[TOBOOL:%.*]] = icmp eq i32 %n, 0
|
||||
; CHECK-NEXT: [[DOT:%.*]] = select i1 [[TOBOOL]], i32 1, i32 234, !prof !11
|
||||
; CHECK-NEXT: [[DOT:%.*]] = select i1 [[TOBOOL]], i32 1, i32 234, !prof !12
|
||||
; CHECK-NEXT: ret i32 [[DOT]]
|
||||
;
|
||||
entry:
|
||||
|
|
@ -418,8 +417,8 @@ define i32 @SimplifyCondBranchToCondBranch(i1 %cmpa, i1 %cmpb) {
|
|||
; CHECK-LABEL: @SimplifyCondBranchToCondBranch(
|
||||
; CHECK-NEXT: block1:
|
||||
; CHECK-NEXT: [[BRMERGE:%.*]] = or i1 %cmpa, %cmpb
|
||||
; CHECK-NEXT: [[DOTMUX:%.*]] = select i1 %cmpa, i32 0, i32 2, !prof !12
|
||||
; CHECK-NEXT: [[OUTVAL:%.*]] = select i1 [[BRMERGE]], i32 [[DOTMUX]], i32 1, !prof !13
|
||||
; CHECK-NEXT: [[DOTMUX:%.*]] = select i1 %cmpa, i32 0, i32 2, !prof !13
|
||||
; CHECK-NEXT: [[OUTVAL:%.*]] = select i1 [[BRMERGE]], i32 [[DOTMUX]], i32 1, !prof !14
|
||||
; CHECK-NEXT: ret i32 [[OUTVAL]]
|
||||
;
|
||||
block1:
|
||||
|
|
@ -445,8 +444,8 @@ define i32 @SimplifyCondBranchToCondBranchSwap(i1 %cmpa, i1 %cmpb) {
|
|||
; CHECK-NEXT: [[CMPA_NOT:%.*]] = xor i1 %cmpa, true
|
||||
; CHECK-NEXT: [[CMPB_NOT:%.*]] = xor i1 %cmpb, true
|
||||
; CHECK-NEXT: [[BRMERGE:%.*]] = or i1 [[CMPA_NOT]], [[CMPB_NOT]]
|
||||
; CHECK-NEXT: [[DOTMUX:%.*]] = select i1 [[CMPA_NOT]], i32 0, i32 2, !prof !14
|
||||
; CHECK-NEXT: [[OUTVAL:%.*]] = select i1 [[BRMERGE]], i32 [[DOTMUX]], i32 1, !prof !15
|
||||
; CHECK-NEXT: [[DOTMUX:%.*]] = select i1 [[CMPA_NOT]], i32 0, i32 2, !prof !15
|
||||
; CHECK-NEXT: [[OUTVAL:%.*]] = select i1 [[BRMERGE]], i32 [[DOTMUX]], i32 1, !prof !16
|
||||
; CHECK-NEXT: ret i32 [[OUTVAL]]
|
||||
;
|
||||
block1:
|
||||
|
|
@ -470,8 +469,8 @@ define i32 @SimplifyCondBranchToCondBranchSwapMissingWeight(i1 %cmpa, i1 %cmpb)
|
|||
; CHECK-NEXT: [[CMPA_NOT:%.*]] = xor i1 %cmpa, true
|
||||
; CHECK-NEXT: [[CMPB_NOT:%.*]] = xor i1 %cmpb, true
|
||||
; CHECK-NEXT: [[BRMERGE:%.*]] = or i1 [[CMPA_NOT]], [[CMPB_NOT]]
|
||||
; CHECK-NEXT: [[DOTMUX:%.*]] = select i1 [[CMPA_NOT]], i32 0, i32 2
|
||||
; CHECK-NEXT: [[OUTVAL:%.*]] = select i1 [[BRMERGE]], i32 [[DOTMUX]], i32 1, !prof !16
|
||||
; CHECK-NEXT: [[DOTMUX:%.*]] = select i1 [[CMPA_NOT]], i32 0, i32 2, !prof !17
|
||||
; CHECK-NEXT: [[OUTVAL:%.*]] = select i1 [[BRMERGE]], i32 [[DOTMUX]], i32 1, !prof !18
|
||||
; CHECK-NEXT: ret i32 [[OUTVAL]]
|
||||
;
|
||||
block1:
|
||||
|
|
@ -506,21 +505,23 @@ exit:
|
|||
!14 = !{!"branch_weights", i32 4, i32 7}
|
||||
|
||||
; CHECK: !0 = !{!"branch_weights", i32 5, i32 11}
|
||||
; CHECK: !1 = !{!"branch_weights", i32 1, i32 5}
|
||||
; CHECK: !2 = !{!"branch_weights", i32 7, i32 1, i32 2}
|
||||
; CHECK: !3 = !{!"branch_weights", i32 49, i32 12, i32 24, i32 35}
|
||||
; CHECK: !4 = !{!"branch_weights", i32 11, i32 5}
|
||||
; CHECK: !5 = !{!"branch_weights", i32 17, i32 15}
|
||||
; CHECK: !6 = !{!"branch_weights", i32 9, i32 7}
|
||||
; CHECK: !7 = !{!"branch_weights", i32 17, i32 9, i32 8, i32 7, i32 17}
|
||||
; CHECK: !8 = !{!"branch_weights", i32 24, i32 33}
|
||||
; CHECK: !9 = !{!"branch_weights", i32 8, i32 33}
|
||||
; CHECK: !1 = !{!"branch_weights", i32 1, i32 3}
|
||||
; CHECK: !2 = !{!"branch_weights", i32 1, i32 5}
|
||||
; CHECK: !3 = !{!"branch_weights", i32 7, i32 1, i32 2}
|
||||
; CHECK: !4 = !{!"branch_weights", i32 49, i32 12, i32 24, i32 35}
|
||||
; CHECK: !5 = !{!"branch_weights", i32 11, i32 5}
|
||||
; CHECK: !6 = !{!"branch_weights", i32 17, i32 15}
|
||||
; CHECK: !7 = !{!"branch_weights", i32 9, i32 7}
|
||||
; CHECK: !8 = !{!"branch_weights", i32 17, i32 9, i32 8, i32 7, i32 17}
|
||||
; CHECK: !9 = !{!"branch_weights", i32 24, i32 33}
|
||||
; CHECK: !10 = !{!"branch_weights", i32 8, i32 33}
|
||||
;; The false weight prints out as a negative integer here, but inside llvm, we
|
||||
;; treat the weight as an unsigned integer.
|
||||
; CHECK: !10 = !{!"branch_weights", i32 112017436, i32 -735157296}
|
||||
; CHECK: !11 = !{!"branch_weights", i32 3, i32 5}
|
||||
; CHECK: !12 = !{!"branch_weights", i32 22, i32 12}
|
||||
; CHECK: !13 = !{!"branch_weights", i32 34, i32 21}
|
||||
; CHECK: !14 = !{!"branch_weights", i32 33, i32 14}
|
||||
; CHECK: !15 = !{!"branch_weights", i32 47, i32 8}
|
||||
; CHECK: !16 = !{!"branch_weights", i32 8, i32 2}
|
||||
; CHECK: !11 = !{!"branch_weights", i32 112017436, i32 -735157296}
|
||||
; CHECK: !12 = !{!"branch_weights", i32 3, i32 5}
|
||||
; CHECK: !13 = !{!"branch_weights", i32 22, i32 12}
|
||||
; CHECK: !14 = !{!"branch_weights", i32 34, i32 21}
|
||||
; CHECK: !15 = !{!"branch_weights", i32 33, i32 14}
|
||||
; CHECK: !16 = !{!"branch_weights", i32 47, i32 8}
|
||||
; CHECK: !17 = !{!"branch_weights", i32 6, i32 2}
|
||||
; CHECK: !18 = !{!"branch_weights", i32 8, i32 2}
|
||||
|
|
|
|||
Loading…
Reference in New Issue