[llvm] r267430 - [ValueTracking] Improve isImpliedCondition when the dominating cond is false.
Chad Rosier via llvm-commits
llvm-commits at lists.llvm.org
Mon Apr 25 10:23:36 PDT 2016
Author: mcrosier
Date: Mon Apr 25 12:23:36 2016
New Revision: 267430
URL: http://llvm.org/viewvc/llvm-project?rev=267430&view=rev
Log:
[ValueTracking] Improve isImpliedCondition when the dominating cond is false.
Added:
llvm/trunk/test/Transforms/SimplifyCFG/implied-cond-matching-false-dest.ll
Modified:
llvm/trunk/include/llvm/Analysis/ValueTracking.h
llvm/trunk/lib/Analysis/ValueTracking.cpp
llvm/trunk/lib/Transforms/Scalar/JumpThreading.cpp
llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp
llvm/trunk/test/Transforms/JumpThreading/implied-cond.ll
Modified: llvm/trunk/include/llvm/Analysis/ValueTracking.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/ValueTracking.h?rev=267430&r1=267429&r2=267430&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Analysis/ValueTracking.h (original)
+++ llvm/trunk/include/llvm/Analysis/ValueTracking.h Mon Apr 25 12:23:36 2016
@@ -463,11 +463,10 @@ template <typename T> class ArrayRef;
/// T | T | F
/// F | T | T
/// (A)
- Optional<bool> isImpliedCondition(Value *LHS, Value *RHS,
- const DataLayout &DL, unsigned Depth = 0,
- AssumptionCache *AC = nullptr,
- const Instruction *CxtI = nullptr,
- const DominatorTree *DT = nullptr);
+ Optional<bool> isImpliedCondition(
+ Value *LHS, Value *RHS, const DataLayout &DL, bool InvertAPred = false,
+ unsigned Depth = 0, AssumptionCache *AC = nullptr,
+ const Instruction *CxtI = nullptr, const DominatorTree *DT = nullptr);
} // end namespace llvm
#endif
Modified: llvm/trunk/lib/Analysis/ValueTracking.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ValueTracking.cpp?rev=267430&r1=267429&r2=267430&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ValueTracking.cpp (original)
+++ llvm/trunk/lib/Analysis/ValueTracking.cpp Mon Apr 25 12:23:36 2016
@@ -3962,8 +3962,8 @@ static Optional<bool> isImpliedCondMatch
}
Optional<bool> llvm::isImpliedCondition(Value *LHS, Value *RHS,
- const DataLayout &DL, unsigned Depth,
- AssumptionCache *AC,
+ const DataLayout &DL, bool InvertAPred,
+ unsigned Depth, AssumptionCache *AC,
const Instruction *CxtI,
const DominatorTree *DT) {
assert(LHS->getType() == RHS->getType() && "mismatched type");
@@ -3971,7 +3971,7 @@ Optional<bool> llvm::isImpliedCondition(
assert(OpTy->getScalarType()->isIntegerTy(1));
// LHS ==> RHS by definition
- if (LHS == RHS)
+ if (!InvertAPred && LHS == RHS)
return true;
if (OpTy->isVectorTy())
@@ -3987,6 +3987,9 @@ Optional<bool> llvm::isImpliedCondition(
!match(RHS, m_ICmp(BPred, m_Value(BLHS), m_Value(BRHS))))
return None;
+ if (InvertAPred)
+ APred = CmpInst::getInversePredicate(APred);
+
Optional<bool> Implication =
isImpliedCondMatchingOperands(APred, ALHS, ARHS, BPred, BLHS, BRHS);
if (Implication)
Modified: llvm/trunk/lib/Transforms/Scalar/JumpThreading.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/JumpThreading.cpp?rev=267430&r1=267429&r2=267430&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/JumpThreading.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/JumpThreading.cpp Mon Apr 25 12:23:36 2016
@@ -925,11 +925,14 @@ bool JumpThreading::ProcessImpliedCondit
while (CurrentPred && Iter++ < ImplicationSearchThreshold) {
auto *PBI = dyn_cast<BranchInst>(CurrentPred->getTerminator());
- if (!PBI || !PBI->isConditional() || PBI->getSuccessor(0) != CurrentBB)
+ if (!PBI || !PBI->isConditional())
+ return false;
+ if (PBI->getSuccessor(0) != CurrentBB && PBI->getSuccessor(1) != CurrentBB)
return false;
+ bool FalseDest = PBI->getSuccessor(1) == CurrentBB;
Optional<bool> Implication =
- isImpliedCondition(PBI->getCondition(), Cond, DL);
+ isImpliedCondition(PBI->getCondition(), Cond, DL, FalseDest);
if (Implication) {
BI->getSuccessor(*Implication ? 1 : 0)->removePredecessor(BB);
BranchInst::Create(BI->getSuccessor(*Implication ? 0 : 1), BI);
Modified: llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp?rev=267430&r1=267429&r2=267430&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp Mon Apr 25 12:23:36 2016
@@ -2703,11 +2703,13 @@ static bool SimplifyCondBranchToCondBran
// If BI is reached from the true path of PBI and PBI's condition implies
// BI's condition, we know the direction of the BI branch.
- if (PBI->getSuccessor(0) == BI->getParent() &&
+ if ((PBI->getSuccessor(0) == BI->getParent() ||
+ PBI->getSuccessor(1) == BI->getParent()) &&
PBI->getSuccessor(0) != PBI->getSuccessor(1) &&
BB->getSinglePredecessor()) {
- Optional<bool> Implication =
- isImpliedCondition(PBI->getCondition(), BI->getCondition(), DL);
+ bool FalseDest = PBI->getSuccessor(1) == BI->getParent();
+ Optional<bool> Implication = isImpliedCondition(
+ PBI->getCondition(), BI->getCondition(), DL, FalseDest);
if (Implication) {
// Turn this into a branch on constant.
auto *OldCond = BI->getCondition();
Modified: llvm/trunk/test/Transforms/JumpThreading/implied-cond.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/JumpThreading/implied-cond.ll?rev=267430&r1=267429&r2=267430&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/JumpThreading/implied-cond.ll (original)
+++ llvm/trunk/test/Transforms/JumpThreading/implied-cond.ll Mon Apr 25 12:23:36 2016
@@ -125,3 +125,53 @@ if.end:
if.end3:
ret void
}
+
+declare void @is(i1)
+
+; If A >=s B is false then A <=s B is implied true.
+; CHECK-LABEL: @test_sge_sle
+; CHECK: call void @is(i1 true)
+; CHECK-NOT: call void @is(i1 false)
+define void @test_sge_sle(i32 %a, i32 %b) {
+ %cmp1 = icmp sge i32 %a, %b
+ br i1 %cmp1, label %untaken, label %taken
+
+taken:
+ %cmp2 = icmp sle i32 %a, %b
+ br i1 %cmp2, label %istrue, label %isfalse
+
+istrue:
+ call void @is(i1 true)
+ ret void
+
+isfalse:
+ call void @is(i1 false)
+ ret void
+
+untaken:
+ ret void
+}
+
+; If A <=s B is false then A <=s B is implied false.
+; CHECK-LABEL: @test_sle_sle
+; CHECK-NOT: call void @is(i1 true)
+; CHECK: call void @is(i1 false)
+define void @test_sle_sle(i32 %a, i32 %b) {
+ %cmp1 = icmp sle i32 %a, %b
+ br i1 %cmp1, label %untaken, label %taken
+
+taken:
+ %cmp2 = icmp sle i32 %a, %b
+ br i1 %cmp2, label %istrue, label %isfalse
+
+istrue:
+ call void @is(i1 true)
+ ret void
+
+isfalse:
+ call void @is(i1 false)
+ ret void
+
+untaken:
+ ret void
+}
Added: llvm/trunk/test/Transforms/SimplifyCFG/implied-cond-matching-false-dest.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SimplifyCFG/implied-cond-matching-false-dest.ll?rev=267430&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/SimplifyCFG/implied-cond-matching-false-dest.ll (added)
+++ llvm/trunk/test/Transforms/SimplifyCFG/implied-cond-matching-false-dest.ll Mon Apr 25 12:23:36 2016
@@ -0,0 +1,339 @@
+; RUN: opt %s -S -simplifycfg | FileCheck %s
+
+declare void @is(i1)
+
+; If A == B is false then A == B is implied false.
+; CHECK-LABEL: @test_eq_eq
+; CHECK-NOT: call void @is(i1 true)
+; CHECK: call void @is(i1 false)
+define void @test_eq_eq(i32 %a, i32 %b) {
+ %cmp1 = icmp eq i32 %a, %b
+ br i1 %cmp1, label %untaken, label %taken
+
+taken:
+ %cmp2 = icmp eq i32 %a, %b
+ br i1 %cmp2, label %istrue, label %isfalse
+
+istrue:
+ call void @is(i1 true)
+ ret void
+
+isfalse:
+ call void @is(i1 false)
+ ret void
+
+untaken:
+ ret void
+}
+
+; If A == B is false then A != B is implied true.
+; CHECK-LABEL: @test_eq_ne
+; CHECK: call void @is(i1 true)
+; CHECK-NOT: call void @is(i1 false)
+define void @test_eq_ne(i32 %a, i32 %b) {
+ %cmp1 = icmp eq i32 %a, %b
+ br i1 %cmp1, label %untaken, label %taken
+
+taken:
+ %cmp2 = icmp ne i32 %a, %b
+ br i1 %cmp2, label %istrue, label %isfalse
+
+istrue:
+ call void @is(i1 true)
+ ret void
+
+isfalse:
+ call void @is(i1 false)
+ ret void
+
+untaken:
+ ret void
+}
+
+; If A != B is false then A != B is implied false.
+; CHECK-LABEL: @test_ne_ne
+; CHECK-NOT: call void @is(i1 true)
+; CHECK: call void @is(i1 false)
+define void @test_ne_ne(i32 %a, i32 %b) {
+ %cmp1 = icmp ne i32 %a, %b
+ br i1 %cmp1, label %untaken, label %taken
+
+taken:
+ %cmp2 = icmp ne i32 %a, %b
+ br i1 %cmp2, label %istrue, label %isfalse
+
+istrue:
+ call void @is(i1 true)
+ ret void
+
+isfalse:
+ call void @is(i1 false)
+ ret void
+
+untaken:
+ ret void
+}
+
+; If A != B is false then A >u B is implied false.
+; CHECK-LABEL: @test_ne_ugt
+; CHECK-NOT: call void @is(i1 true)
+; CHECK: call void @is(i1 false)
+define void @test_ne_ugt(i32 %a, i32 %b) {
+ %cmp1 = icmp ne i32 %a, %b
+ br i1 %cmp1, label %untaken, label %taken
+
+taken:
+ %cmp2 = icmp ugt i32 %a, %b
+ br i1 %cmp2, label %istrue, label %isfalse
+
+istrue:
+ call void @is(i1 true)
+ ret void
+
+isfalse:
+ call void @is(i1 false)
+ ret void
+
+untaken:
+ ret void
+}
+
+; If A != B is false then A >=u B is implied true.
+; CHECK-LABEL: @test_ne_uge
+; CHECK: call void @is(i1 true)
+; CHECK-NOT: call void @is(i1 false)
+define void @test_ne_uge(i32 %a, i32 %b) {
+ %cmp1 = icmp ne i32 %a, %b
+ br i1 %cmp1, label %untaken, label %taken
+
+taken:
+ %cmp2 = icmp uge i32 %a, %b
+ br i1 %cmp2, label %istrue, label %isfalse
+
+istrue:
+ call void @is(i1 true)
+ ret void
+
+isfalse:
+ call void @is(i1 false)
+ ret void
+
+untaken:
+ ret void
+}
+
+; If A != B is false then A <u B is implied false.
+; CHECK-LABEL: @test_ne_ult
+; CHECK-NOT: call void @is(i1 true)
+; CHECK: call void @is(i1 false)
+define void @test_ne_ult(i32 %a, i32 %b) {
+ %cmp1 = icmp ne i32 %a, %b
+ br i1 %cmp1, label %untaken, label %taken
+
+taken:
+ %cmp2 = icmp ult i32 %a, %b
+ br i1 %cmp2, label %istrue, label %isfalse
+
+istrue:
+ call void @is(i1 true)
+ ret void
+
+isfalse:
+ call void @is(i1 false)
+ ret void
+
+untaken:
+ ret void
+}
+
+; If A != B is false then A <=u B is implied true.
+; CHECK-LABEL: @test_ne_ule
+; CHECK: call void @is(i1 true)
+; CHECK-NOT: call void @is(i1 false)
+define void @test_ne_ule(i32 %a, i32 %b) {
+ %cmp1 = icmp ne i32 %a, %b
+ br i1 %cmp1, label %untaken, label %taken
+
+taken:
+ %cmp2 = icmp ule i32 %a, %b
+ br i1 %cmp2, label %istrue, label %isfalse
+
+istrue:
+ call void @is(i1 true)
+ ret void
+
+isfalse:
+ call void @is(i1 false)
+ ret void
+
+untaken:
+ ret void
+}
+
+; If A >u B is false then A >u B is implied false.
+; CHECK-LABEL: @test_ugt_ugt
+; CHECK-NOT: call void @is(i1 true)
+; CHECK: call void @is(i1 false)
+define void @test_ugt_ugt(i32 %a, i32 %b) {
+ %cmp1 = icmp ugt i32 %a, %b
+ br i1 %cmp1, label %untaken, label %taken
+
+taken:
+ %cmp2 = icmp ugt i32 %a, %b
+ br i1 %cmp2, label %istrue, label %isfalse
+
+istrue:
+ call void @is(i1 true)
+ ret void
+
+isfalse:
+ call void @is(i1 false)
+ ret void
+
+untaken:
+ ret void
+}
+
+; If A >u B is false then A <=u B is implied true.
+; CHECK-LABEL: @test_ugt_ule
+; CHECK: call void @is(i1 true)
+; CHECK-NOT: call void @is(i1 false)
+define void @test_ugt_ule(i32 %a, i32 %b) {
+ %cmp1 = icmp ugt i32 %a, %b
+ br i1 %cmp1, label %untaken, label %taken
+
+taken:
+ %cmp2 = icmp ule i32 %a, %b
+ br i1 %cmp2, label %istrue, label %isfalse
+
+istrue:
+ call void @is(i1 true)
+ ret void
+
+isfalse:
+ call void @is(i1 false)
+ ret void
+
+untaken:
+ ret void
+}
+
+; If A >=u B is false then A >=u B is implied false.
+; CHECK-LABEL: @test_uge_uge
+; CHECK-NOT: call void @is(i1 true)
+; CHECK: call void @is(i1 false)
+define void @test_uge_uge(i32 %a, i32 %b) {
+ %cmp1 = icmp uge i32 %a, %b
+ br i1 %cmp1, label %untaken, label %taken
+
+taken:
+ %cmp2 = icmp uge i32 %a, %b
+ br i1 %cmp2, label %istrue, label %isfalse
+
+istrue:
+ call void @is(i1 true)
+ ret void
+
+isfalse:
+ call void @is(i1 false)
+ ret void
+
+untaken:
+ ret void
+}
+
+; If A >=u B is false then A <u B is implied true.
+; CHECK-LABEL: @test_uge_ult
+; CHECK: call void @is(i1 true)
+; CHECK-NOT: call void @is(i1 false)
+define void @test_uge_ult(i32 %a, i32 %b) {
+ %cmp1 = icmp uge i32 %a, %b
+ br i1 %cmp1, label %untaken, label %taken
+
+taken:
+ %cmp2 = icmp ult i32 %a, %b
+ br i1 %cmp2, label %istrue, label %isfalse
+
+istrue:
+ call void @is(i1 true)
+ ret void
+
+isfalse:
+ call void @is(i1 false)
+ ret void
+
+untaken:
+ ret void
+}
+
+; If A >=u B is false then A <=u B is implied true.
+; CHECK-LABEL: @test_uge_ule
+; CHECK: call void @is(i1 true)
+; CHECK-NOT: call void @is(i1 false)
+define void @test_uge_ule(i32 %a, i32 %b) {
+ %cmp1 = icmp uge i32 %a, %b
+ br i1 %cmp1, label %untaken, label %taken
+
+taken:
+ %cmp2 = icmp ule i32 %a, %b
+ br i1 %cmp2, label %istrue, label %isfalse
+
+istrue:
+ call void @is(i1 true)
+ ret void
+
+isfalse:
+ call void @is(i1 false)
+ ret void
+
+untaken:
+ ret void
+}
+
+; If A <u B is false then A <u B is implied false.
+; CHECK-LABEL: @test_ult_ult
+; CHECK-NOT: call void @is(i1 true)
+; CHECK: call void @is(i1 false)
+define void @test_ult_ult(i32 %a, i32 %b) {
+ %cmp1 = icmp ult i32 %a, %b
+ br i1 %cmp1, label %untaken, label %taken
+
+taken:
+ %cmp2 = icmp ult i32 %a, %b
+ br i1 %cmp2, label %istrue, label %isfalse
+
+istrue:
+ call void @is(i1 true)
+ ret void
+
+isfalse:
+ call void @is(i1 false)
+ ret void
+
+untaken:
+ ret void
+}
+
+; If A <=u B is false then A <=u B is implied false.
+; CHECK-LABEL: @test_ule_ule
+; CHECK-NOT: call void @is(i1 true)
+; CHECK: call void @is(i1 false)
+define void @test_ule_ule(i32 %a, i32 %b) {
+ %cmp1 = icmp ule i32 %a, %b
+ br i1 %cmp1, label %untaken, label %taken
+
+taken:
+ %cmp2 = icmp ule i32 %a, %b
+ br i1 %cmp2, label %istrue, label %isfalse
+
+istrue:
+ call void @is(i1 true)
+ ret void
+
+isfalse:
+ call void @is(i1 false)
+ ret void
+
+untaken:
+ ret void
+}
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