[llvm] cf79773 - [SCCP] Replace new value's value state with removed value's
luxufanxport https_proxy=http via llvm-commits
llvm-commits at lists.llvm.org
Sun Jun 11 20:41:14 PDT 2023
Author: luxufan
Date: 2023-06-12T11:40:47+08:00
New Revision: cf79773a9006a7e22f3919268b7db381ddcb3abc
URL: https://github.com/llvm/llvm-project/commit/cf79773a9006a7e22f3919268b7db381ddcb3abc
DIFF: https://github.com/llvm/llvm-project/commit/cf79773a9006a7e22f3919268b7db381ddcb3abc.diff
LOG: [SCCP] Replace new value's value state with removed value's
In replaceSignedInst, if a signed instruction can be repalced with
unsigned instruction, we created a new instruction and removed the old
instruction's value state. If the following instructions has this new
instruction as a use operand, transformations like replaceSignedInst and
refineInstruction would be blocked. The reason is there is no value
state for the new instrution.
This patch set the new instruction's value state with the removed
instruction's value state. I believe it is correct bacause when we
repalce a signed instruction with unsigned instruction, the value state
is not changed.
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D152337
Added:
Modified:
llvm/include/llvm/Transforms/Utils/SCCPSolver.h
llvm/lib/Transforms/IPO/SCCP.cpp
llvm/lib/Transforms/Scalar/SCCP.cpp
llvm/lib/Transforms/Utils/SCCPSolver.cpp
llvm/test/Transforms/SCCP/add-nuw-nsw-flags.ll
llvm/test/Transforms/SCCP/ip-ranges-sext.ll
Removed:
################################################################################
diff --git a/llvm/include/llvm/Transforms/Utils/SCCPSolver.h b/llvm/include/llvm/Transforms/Utils/SCCPSolver.h
index 3754b51f4722d..09a61600d65f8 100644
--- a/llvm/include/llvm/Transforms/Utils/SCCPSolver.h
+++ b/llvm/include/llvm/Transforms/Utils/SCCPSolver.h
@@ -130,7 +130,7 @@ class SCCPSolver {
std::vector<ValueLatticeElement> getStructLatticeValueFor(Value *V) const;
- void removeLatticeValueFor(Value *V);
+ void moveLatticeValue(Value *From, Value *To);
/// Invalidate the Lattice Value of \p Call and its users after specializing
/// the call. Then recompute it.
@@ -184,7 +184,6 @@ class SCCPSolver {
void visitCall(CallInst &I);
bool simplifyInstsInBlock(BasicBlock &BB,
- SmallPtrSetImpl<Value *> &InsertedValues,
Statistic &InstRemovedStat,
Statistic &InstReplacedStat);
diff --git a/llvm/lib/Transforms/IPO/SCCP.cpp b/llvm/lib/Transforms/IPO/SCCP.cpp
index 658d596b4bda8..85295c7d5a821 100644
--- a/llvm/lib/Transforms/IPO/SCCP.cpp
+++ b/llvm/lib/Transforms/IPO/SCCP.cpp
@@ -209,7 +209,6 @@ static bool runIPSCCP(
MadeChanges |= ReplacedPointerArg;
}
- SmallPtrSet<Value *, 32> InsertedValues;
for (BasicBlock &BB : F) {
if (!Solver.isBlockExecutable(&BB)) {
LLVM_DEBUG(dbgs() << " BasicBlock Dead:" << BB);
@@ -223,7 +222,7 @@ static bool runIPSCCP(
}
MadeChanges |= Solver.simplifyInstsInBlock(
- BB, InsertedValues, NumInstRemoved, NumInstReplaced);
+ BB, NumInstRemoved, NumInstReplaced);
}
DominatorTree *DT = FAM->getCachedResult<DominatorTreeAnalysis>(F);
diff --git a/llvm/lib/Transforms/Scalar/SCCP.cpp b/llvm/lib/Transforms/Scalar/SCCP.cpp
index fcdc503c54a42..a5e8f2997b638 100644
--- a/llvm/lib/Transforms/Scalar/SCCP.cpp
+++ b/llvm/lib/Transforms/Scalar/SCCP.cpp
@@ -92,7 +92,6 @@ static bool runSCCP(Function &F, const DataLayout &DL,
// delete their contents now. Note that we cannot actually delete the blocks,
// as we cannot modify the CFG of the function.
- SmallPtrSet<Value *, 32> InsertedValues;
SmallVector<BasicBlock *, 8> BlocksToErase;
for (BasicBlock &BB : F) {
if (!Solver.isBlockExecutable(&BB)) {
@@ -103,8 +102,8 @@ static bool runSCCP(Function &F, const DataLayout &DL,
continue;
}
- MadeChanges |= Solver.simplifyInstsInBlock(BB, InsertedValues,
- NumInstRemoved, NumInstReplaced);
+ MadeChanges |=
+ Solver.simplifyInstsInBlock(BB, NumInstRemoved, NumInstReplaced);
}
// Remove unreachable blocks and non-feasible edges.
diff --git a/llvm/lib/Transforms/Utils/SCCPSolver.cpp b/llvm/lib/Transforms/Utils/SCCPSolver.cpp
index 902651ab84f68..04dfc1659684b 100644
--- a/llvm/lib/Transforms/Utils/SCCPSolver.cpp
+++ b/llvm/lib/Transforms/Utils/SCCPSolver.cpp
@@ -105,15 +105,14 @@ bool SCCPSolver::tryToReplaceWithConstant(Value *V) {
/// Try to use \p Inst's value range from \p Solver to infer the NUW flag.
static bool refineInstruction(SCCPSolver &Solver,
- const SmallPtrSetImpl<Value *> &InsertedValues,
Instruction &Inst) {
if (!isa<OverflowingBinaryOperator>(Inst))
return false;
- auto GetRange = [&Solver, &InsertedValues](Value *Op) {
+ auto GetRange = [&Solver](Value *Op) {
if (auto *Const = dyn_cast<ConstantInt>(Op))
return ConstantRange(Const->getValue());
- if (isa<Constant>(Op) || InsertedValues.contains(Op)) {
+ if (isa<Constant>(Op)) {
unsigned Bitwidth = Op->getType()->getScalarSizeInBits();
return ConstantRange::getFull(Bitwidth);
}
@@ -146,7 +145,6 @@ static bool refineInstruction(SCCPSolver &Solver,
/// Try to replace signed instructions with their unsigned equivalent.
static bool replaceSignedInst(SCCPSolver &Solver,
- SmallPtrSetImpl<Value *> &InsertedValues,
Instruction &Inst) {
// Determine if a signed value is known to be >= 0.
auto isNonNegative = [&Solver](Value *V) {
@@ -168,7 +166,7 @@ static bool replaceSignedInst(SCCPSolver &Solver,
case Instruction::SExt: {
// If the source value is not negative, this is a zext.
Value *Op0 = Inst.getOperand(0);
- if (InsertedValues.count(Op0) || !isNonNegative(Op0))
+ if (!isNonNegative(Op0))
return false;
NewInst = new ZExtInst(Op0, Inst.getType(), "", &Inst);
break;
@@ -176,7 +174,7 @@ static bool replaceSignedInst(SCCPSolver &Solver,
case Instruction::AShr: {
// If the shifted value is not negative, this is a logical shift right.
Value *Op0 = Inst.getOperand(0);
- if (InsertedValues.count(Op0) || !isNonNegative(Op0))
+ if (!isNonNegative(Op0))
return false;
NewInst = BinaryOperator::CreateLShr(Op0, Inst.getOperand(1), "", &Inst);
break;
@@ -185,8 +183,7 @@ static bool replaceSignedInst(SCCPSolver &Solver,
case Instruction::SRem: {
// If both operands are not negative, this is the same as udiv/urem.
Value *Op0 = Inst.getOperand(0), *Op1 = Inst.getOperand(1);
- if (InsertedValues.count(Op0) || InsertedValues.count(Op1) ||
- !isNonNegative(Op0) || !isNonNegative(Op1))
+ if (!isNonNegative(Op0) || !isNonNegative(Op1))
return false;
auto NewOpcode = Inst.getOpcode() == Instruction::SDiv ? Instruction::UDiv
: Instruction::URem;
@@ -200,15 +197,13 @@ static bool replaceSignedInst(SCCPSolver &Solver,
// Wire up the new instruction and update state.
assert(NewInst && "Expected replacement instruction");
NewInst->takeName(&Inst);
- InsertedValues.insert(NewInst);
Inst.replaceAllUsesWith(NewInst);
- Solver.removeLatticeValueFor(&Inst);
+ Solver.moveLatticeValue(&Inst, NewInst);
Inst.eraseFromParent();
return true;
}
bool SCCPSolver::simplifyInstsInBlock(BasicBlock &BB,
- SmallPtrSetImpl<Value *> &InsertedValues,
Statistic &InstRemovedStat,
Statistic &InstReplacedStat) {
bool MadeChanges = false;
@@ -221,10 +216,10 @@ bool SCCPSolver::simplifyInstsInBlock(BasicBlock &BB,
MadeChanges = true;
++InstRemovedStat;
- } else if (replaceSignedInst(*this, InsertedValues, Inst)) {
+ } else if (replaceSignedInst(*this, Inst)) {
MadeChanges = true;
++InstReplacedStat;
- } else if (refineInstruction(*this, InsertedValues, Inst)) {
+ } else if (refineInstruction(*this, Inst)) {
MadeChanges = true;
}
}
@@ -731,7 +726,11 @@ class SCCPInstVisitor : public InstVisitor<SCCPInstVisitor> {
return StructValues;
}
- void removeLatticeValueFor(Value *V) { ValueState.erase(V); }
+ void moveLatticeValue(Value *From, Value *To) {
+ assert(ValueState.count(From) && "From is not existed in ValueState");
+ ValueState[To] = ValueState[From];
+ ValueState.erase(From);
+ }
/// Invalidate the Lattice Value of \p Call and its users after specializing
/// the call. Then recompute it.
@@ -2035,8 +2034,8 @@ SCCPSolver::getStructLatticeValueFor(Value *V) const {
return Visitor->getStructLatticeValueFor(V);
}
-void SCCPSolver::removeLatticeValueFor(Value *V) {
- return Visitor->removeLatticeValueFor(V);
+void SCCPSolver::moveLatticeValue(Value *From, Value *To) {
+ return Visitor->moveLatticeValue(From, To);
}
void SCCPSolver::resetLatticeValueFor(CallBase *Call) {
diff --git a/llvm/test/Transforms/SCCP/add-nuw-nsw-flags.ll b/llvm/test/Transforms/SCCP/add-nuw-nsw-flags.ll
index 97b471d985410..02198a1faa909 100644
--- a/llvm/test/Transforms/SCCP/add-nuw-nsw-flags.ll
+++ b/llvm/test/Transforms/SCCP/add-nuw-nsw-flags.ll
@@ -125,9 +125,9 @@ define i16 @sge_with_sext_to_zext_conversion(i8 %a) {
; CHECK-NEXT: br i1 [[CMP]], label [[THEN:%.*]], label [[ELSE:%.*]]
; CHECK: then:
; CHECK-NEXT: [[SEXT:%.*]] = zext i8 [[A]] to i16
-; CHECK-NEXT: [[ADD_1:%.*]] = add i16 [[SEXT]], 1
-; CHECK-NEXT: [[ADD_2:%.*]] = add i16 [[SEXT]], -128
-; CHECK-NEXT: [[ADD_3:%.*]] = add i16 [[SEXT]], -127
+; CHECK-NEXT: [[ADD_1:%.*]] = add nuw nsw i16 [[SEXT]], 1
+; CHECK-NEXT: [[ADD_2:%.*]] = add nuw nsw i16 [[SEXT]], -128
+; CHECK-NEXT: [[ADD_3:%.*]] = add nsw i16 [[SEXT]], -127
; CHECK-NEXT: [[RES_1:%.*]] = xor i16 [[ADD_1]], [[ADD_2]]
; CHECK-NEXT: [[RES_2:%.*]] = xor i16 [[RES_1]], [[ADD_3]]
; CHECK-NEXT: ret i16 [[RES_2]]
@@ -222,7 +222,7 @@ define i16 @test_add_in_
diff erent_block(i1 %c, i8 %a) {
; CHECK-NEXT: [[CONV:%.*]] = zext i8 [[COND4]] to i16
; CHECK-NEXT: br i1 [[C:%.*]], label [[THEN:%.*]], label [[ELSE:%.*]]
; CHECK: then:
-; CHECK-NEXT: [[ADD:%.*]] = add i16 1, [[CONV]]
+; CHECK-NEXT: [[ADD:%.*]] = add nuw nsw i16 1, [[CONV]]
; CHECK-NEXT: ret i16 [[ADD]]
; CHECK: else:
; CHECK-NEXT: ret i16 0
diff --git a/llvm/test/Transforms/SCCP/ip-ranges-sext.ll b/llvm/test/Transforms/SCCP/ip-ranges-sext.ll
index 6fa74b379f4c8..5f8a6e5039ed7 100644
--- a/llvm/test/Transforms/SCCP/ip-ranges-sext.ll
+++ b/llvm/test/Transforms/SCCP/ip-ranges-sext.ll
@@ -127,7 +127,7 @@ define i64 @test7(i16 %x) {
; CHECK-LABEL: @test7(
; CHECK-NEXT: [[P:%.*]] = and i16 [[X:%.*]], 15
; CHECK-NEXT: [[EXT_1:%.*]] = zext i16 [[P]] to i32
-; CHECK-NEXT: [[EXT_2:%.*]] = sext i32 [[EXT_1]] to i64
+; CHECK-NEXT: [[EXT_2:%.*]] = zext i32 [[EXT_1]] to i64
; CHECK-NEXT: ret i64 [[EXT_2]]
;
%p = and i16 %x, 15
More information about the llvm-commits
mailing list