[llvm] 0e99562 - Revert "[JumpThreading] Preserve profile metadata during select unfolding"
Dmitri Gribenko via llvm-commits
llvm-commits at lists.llvm.org
Tue Jan 10 02:54:58 PST 2023
Author: Dmitri Gribenko
Date: 2023-01-10T11:54:50+01:00
New Revision: 0e9956204db3802ac94a7727bf2fe35c753cc8f5
URL: https://github.com/llvm/llvm-project/commit/0e9956204db3802ac94a7727bf2fe35c753cc8f5
DIFF: https://github.com/llvm/llvm-project/commit/0e9956204db3802ac94a7727bf2fe35c753cc8f5.diff
LOG: Revert "[JumpThreading] Preserve profile metadata during select unfolding"
This reverts commit 957952dbf2f34ed552e8e1f8c35eed17eee2ea38.
Addition in the newly added code can overflow. As a result, the
constructor of `BranchProbability()` can trigger an assertion. See
the discussion on https://reviews.llvm.org/D138132 for more details.
Added:
Modified:
llvm/lib/Transforms/Scalar/JumpThreading.cpp
llvm/test/Transforms/JumpThreading/select.ll
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/Scalar/JumpThreading.cpp b/llvm/lib/Transforms/Scalar/JumpThreading.cpp
index 19ed7e555dc59..e9bf66c4c6974 100644
--- a/llvm/lib/Transforms/Scalar/JumpThreading.cpp
+++ b/llvm/lib/Transforms/Scalar/JumpThreading.cpp
@@ -2785,24 +2785,8 @@ void JumpThreadingPass::unfoldSelectInstr(BasicBlock *Pred, BasicBlock *BB,
// Create a conditional branch and update PHI nodes.
auto *BI = BranchInst::Create(NewBB, BB, SI->getCondition(), Pred);
BI->applyMergedLocation(PredTerm->getDebugLoc(), SI->getDebugLoc());
- BI->copyMetadata(*SI, {LLVMContext::MD_prof});
SIUse->setIncomingValue(Idx, SI->getFalseValue());
SIUse->addIncoming(SI->getTrueValue(), NewBB);
- // Set the block frequency of NewBB.
- if (HasProfileData) {
- uint64_t TrueWeight, FalseWeight;
- if (extractBranchWeights(*SI, TrueWeight, FalseWeight) &&
- (TrueWeight + FalseWeight) != 0) {
- SmallVector<BranchProbability, 2> BP;
- BP.emplace_back(BranchProbability(TrueWeight, TrueWeight + FalseWeight));
- BP.emplace_back(BranchProbability(FalseWeight, TrueWeight + FalseWeight));
- BPI->setEdgeProbability(Pred, BP);
- }
-
- auto NewBBFreq =
- BFI->getBlockFreq(Pred) * BPI->getEdgeProbability(Pred, NewBB);
- BFI->setBlockFreq(NewBB, NewBBFreq.getFrequency());
- }
// The select is now dead.
SI->eraseFromParent();
diff --git a/llvm/test/Transforms/JumpThreading/select.ll b/llvm/test/Transforms/JumpThreading/select.ll
index d85fb45be5ff7..aedfab851d5d5 100644
--- a/llvm/test/Transforms/JumpThreading/select.ll
+++ b/llvm/test/Transforms/JumpThreading/select.ll
@@ -1,13 +1,5 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -S -passes=jump-threading -debug-only=branch-prob < %s 2>&1 | FileCheck %s
-; REQUIRES: asserts
-
-; CHECK-LABEL: ---- Branch Probability Info : unfold1 ----
-; CHECK: set edge cond.false -> 0 successor probability to 0x0ccccccd / 0x80000000 = 10.00%
-; CHECK: set edge cond.false -> 1 successor probability to 0x73333333 / 0x80000000 = 90.00%
-; CHECK-LABEL: ---- Branch Probability Info : unfold2 ----
-; CHECK: set edge cond.false -> 0 successor probability to 0x0ccccccd / 0x80000000 = 10.00%
-; CHECK: set edge cond.false -> 1 successor probability to 0x73333333 / 0x80000000 = 90.00%
+; RUN: opt -S -passes=jump-threading < %s | FileCheck %s
declare void @foo()
declare void @bar()
@@ -273,7 +265,7 @@ L4:
ret void
}
-define void @unfold1(double %x, double %y) nounwind !prof !1 {
+define void @unfold1(double %x, double %y) nounwind {
; CHECK-LABEL: @unfold1(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[SUB:%.*]] = fsub double [[X:%.*]], [[Y:%.*]]
@@ -282,7 +274,7 @@ define void @unfold1(double %x, double %y) nounwind !prof !1 {
; CHECK: cond.false:
; CHECK-NEXT: [[ADD:%.*]] = fadd double [[X]], [[Y]]
; CHECK-NEXT: [[CMP1:%.*]] = fcmp ogt double [[ADD]], 1.000000e+01
-; CHECK-NEXT: br i1 [[CMP1]], label [[COND_END4]], label [[IF_THEN:%.*]], !prof [[PROF1:![0-9]+]]
+; CHECK-NEXT: br i1 [[CMP1]], label [[COND_END4]], label [[IF_THEN:%.*]]
; CHECK: cond.end4:
; CHECK-NEXT: [[COND5:%.*]] = phi double [ [[SUB]], [[ENTRY:%.*]] ], [ [[ADD]], [[COND_FALSE]] ]
; CHECK-NEXT: [[CMP6:%.*]] = fcmp oeq double [[COND5]], 0.000000e+00
@@ -301,7 +293,7 @@ entry:
cond.false: ; preds = %entry
%add = fadd double %x, %y
%cmp1 = fcmp ogt double %add, 1.000000e+01
- %add. = select i1 %cmp1, double %add, double 0.000000e+00, !prof !0
+ %add. = select i1 %cmp1, double %add, double 0.000000e+00
br label %cond.end4
cond.end4: ; preds = %entry, %cond.false
@@ -319,7 +311,7 @@ if.end: ; preds = %if.then, %cond.end4
}
-define void @unfold2(i32 %x, i32 %y) nounwind !prof !1 {
+define void @unfold2(i32 %x, i32 %y) nounwind {
; CHECK-LABEL: @unfold2(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[SUB:%.*]] = sub nsw i32 [[X:%.*]], [[Y:%.*]]
@@ -328,7 +320,7 @@ define void @unfold2(i32 %x, i32 %y) nounwind !prof !1 {
; CHECK: cond.false:
; CHECK-NEXT: [[ADD:%.*]] = add nsw i32 [[X]], [[Y]]
; CHECK-NEXT: [[CMP1:%.*]] = icmp sgt i32 [[ADD]], 10
-; CHECK-NEXT: br i1 [[CMP1]], label [[IF_THEN:%.*]], label [[COND_END4:%.*]], !prof [[PROF1:![0-9]+]]
+; CHECK-NEXT: br i1 [[CMP1]], label [[IF_THEN:%.*]], label [[COND_END4:%.*]]
; CHECK: cond.end4:
; CHECK-NEXT: [[COND5:%.*]] = phi i32 [ [[ADD]], [[COND_FALSE]] ]
; CHECK-NEXT: [[CMP6:%.*]] = icmp eq i32 [[COND5]], 0
@@ -347,7 +339,7 @@ entry:
cond.false: ; preds = %entry
%add = add nsw i32 %x, %y
%cmp1 = icmp sgt i32 %add, 10
- %add. = select i1 %cmp1, i32 0, i32 %add, !prof !0
+ %add. = select i1 %cmp1, i32 0, i32 %add
br label %cond.end4
cond.end4: ; preds = %entry, %cond.false
@@ -660,6 +652,3 @@ if.end:
%v1 = select i1 %v, i32 %s, i32 42
ret i32 %v1
}
-
-!0 = !{!"branch_weights", i32 1, i32 9}
-!1 = !{!"function_entry_count", i64 1984}
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