[llvm-commits] [llvm] r59398 - /llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp
Chris Lattner
sabre at nondot.org
Sat Nov 15 21:06:21 PST 2008
Author: lattner
Date: Sat Nov 15 23:06:21 2008
New Revision: 59398
URL: http://llvm.org/viewvc/llvm-project?rev=59398&view=rev
Log:
factor a whole bunch of code out into a helper function.
Modified:
llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp
Modified: llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp?rev=59398&r1=59397&r2=59398&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp Sat Nov 15 23:06:21 2008
@@ -180,6 +180,7 @@
Instruction *visitUDiv(BinaryOperator &I);
Instruction *visitSDiv(BinaryOperator &I);
Instruction *visitFDiv(BinaryOperator &I);
+ Instruction *FoldAndOfICmps(Instruction &I, ICmpInst *LHS, ICmpInst *RHS);
Instruction *visitAnd(BinaryOperator &I);
Instruction *visitOr (BinaryOperator &I);
Instruction *visitXor(BinaryOperator &I);
@@ -3552,6 +3553,168 @@
return InsertNewInstBefore(New, I);
}
+/// FoldAndOfICmps - Fold (icmp)&(icmp) if possible.
+Instruction *InstCombiner::FoldAndOfICmps(Instruction &I,
+ ICmpInst *LHS, ICmpInst *RHS) {
+ Value *Val;
+ ConstantInt *LHSCst, *RHSCst;
+ ICmpInst::Predicate LHSCC, RHSCC;
+
+ // (icmp1 A, C1) & (icmp2 A, C2) --> something simpler.
+ if (!match(LHS, m_ICmp(LHSCC, m_Value(Val), m_ConstantInt(LHSCst))) ||
+ !match(RHS, m_ICmp(RHSCC, m_Specific(Val), m_ConstantInt(RHSCst))))
+ return 0;
+
+ // ICMP_[US][GL]E X, CST is folded to ICMP_[US][GL]T elsewhere.
+ if (LHSCC == ICmpInst::ICMP_UGE || LHSCC == ICmpInst::ICMP_ULE ||
+ RHSCC == ICmpInst::ICMP_UGE || RHSCC == ICmpInst::ICMP_ULE ||
+ LHSCC == ICmpInst::ICMP_SGE || LHSCC == ICmpInst::ICMP_SLE ||
+ RHSCC == ICmpInst::ICMP_SGE || RHSCC == ICmpInst::ICMP_SLE)
+ return 0;
+
+ // We can't fold (ugt x, C) & (sgt x, C2).
+ if (!PredicatesFoldable(LHSCC, RHSCC))
+ return 0;
+
+ // Ensure that the larger constant is on the RHS.
+ ICmpInst::Predicate GT;
+ if (ICmpInst::isSignedPredicate(LHSCC) ||
+ (ICmpInst::isEquality(LHSCC) &&
+ ICmpInst::isSignedPredicate(RHSCC)))
+ GT = ICmpInst::ICMP_SGT;
+ else
+ GT = ICmpInst::ICMP_UGT;
+
+ Constant *Cmp = ConstantExpr::getICmp(GT, LHSCst, RHSCst);
+ if (cast<ConstantInt>(Cmp)->getZExtValue()) {
+ std::swap(LHS, RHS);
+ std::swap(LHSCst, RHSCst);
+ std::swap(LHSCC, RHSCC);
+ }
+
+ // At this point, we know we have have two icmp instructions
+ // comparing a value against two constants and and'ing the result
+ // together. Because of the above check, we know that we only have
+ // icmp eq, icmp ne, icmp [su]lt, and icmp [SU]gt here. We also know
+ // (from the FoldICmpLogical check above), that the two constants
+ // are not equal and that the larger constant is on the RHS
+ assert(LHSCst != RHSCst && "Compares not folded above?");
+
+ switch (LHSCC) {
+ default: assert(0 && "Unknown integer condition code!");
+ case ICmpInst::ICMP_EQ:
+ switch (RHSCC) {
+ default: assert(0 && "Unknown integer condition code!");
+ case ICmpInst::ICMP_EQ: // (X == 13 & X == 15) -> false
+ case ICmpInst::ICMP_UGT: // (X == 13 & X > 15) -> false
+ case ICmpInst::ICMP_SGT: // (X == 13 & X > 15) -> false
+ return ReplaceInstUsesWith(I, ConstantInt::getFalse());
+ case ICmpInst::ICMP_NE: // (X == 13 & X != 15) -> X == 13
+ case ICmpInst::ICMP_ULT: // (X == 13 & X < 15) -> X == 13
+ case ICmpInst::ICMP_SLT: // (X == 13 & X < 15) -> X == 13
+ return ReplaceInstUsesWith(I, LHS);
+ }
+ case ICmpInst::ICMP_NE:
+ switch (RHSCC) {
+ default: assert(0 && "Unknown integer condition code!");
+ case ICmpInst::ICMP_ULT:
+ if (LHSCst == SubOne(RHSCst)) // (X != 13 & X u< 14) -> X < 13
+ return new ICmpInst(ICmpInst::ICMP_ULT, Val, LHSCst);
+ break; // (X != 13 & X u< 15) -> no change
+ case ICmpInst::ICMP_SLT:
+ if (LHSCst == SubOne(RHSCst)) // (X != 13 & X s< 14) -> X < 13
+ return new ICmpInst(ICmpInst::ICMP_SLT, Val, LHSCst);
+ break; // (X != 13 & X s< 15) -> no change
+ case ICmpInst::ICMP_EQ: // (X != 13 & X == 15) -> X == 15
+ case ICmpInst::ICMP_UGT: // (X != 13 & X u> 15) -> X u> 15
+ case ICmpInst::ICMP_SGT: // (X != 13 & X s> 15) -> X s> 15
+ return ReplaceInstUsesWith(I, RHS);
+ case ICmpInst::ICMP_NE:
+ if (LHSCst == SubOne(RHSCst)){// (X != 13 & X != 14) -> X-13 >u 1
+ Constant *AddCST = ConstantExpr::getNeg(LHSCst);
+ Instruction *Add = BinaryOperator::CreateAdd(Val, AddCST,
+ Val->getName()+".off");
+ InsertNewInstBefore(Add, I);
+ return new ICmpInst(ICmpInst::ICMP_UGT, Add,
+ ConstantInt::get(Add->getType(), 1));
+ }
+ break; // (X != 13 & X != 15) -> no change
+ }
+ break;
+ case ICmpInst::ICMP_ULT:
+ switch (RHSCC) {
+ default: assert(0 && "Unknown integer condition code!");
+ case ICmpInst::ICMP_EQ: // (X u< 13 & X == 15) -> false
+ case ICmpInst::ICMP_UGT: // (X u< 13 & X u> 15) -> false
+ return ReplaceInstUsesWith(I, ConstantInt::getFalse());
+ case ICmpInst::ICMP_SGT: // (X u< 13 & X s> 15) -> no change
+ break;
+ case ICmpInst::ICMP_NE: // (X u< 13 & X != 15) -> X u< 13
+ case ICmpInst::ICMP_ULT: // (X u< 13 & X u< 15) -> X u< 13
+ return ReplaceInstUsesWith(I, LHS);
+ case ICmpInst::ICMP_SLT: // (X u< 13 & X s< 15) -> no change
+ break;
+ }
+ break;
+ case ICmpInst::ICMP_SLT:
+ switch (RHSCC) {
+ default: assert(0 && "Unknown integer condition code!");
+ case ICmpInst::ICMP_EQ: // (X s< 13 & X == 15) -> false
+ case ICmpInst::ICMP_SGT: // (X s< 13 & X s> 15) -> false
+ return ReplaceInstUsesWith(I, ConstantInt::getFalse());
+ case ICmpInst::ICMP_UGT: // (X s< 13 & X u> 15) -> no change
+ break;
+ case ICmpInst::ICMP_NE: // (X s< 13 & X != 15) -> X < 13
+ case ICmpInst::ICMP_SLT: // (X s< 13 & X s< 15) -> X < 13
+ return ReplaceInstUsesWith(I, LHS);
+ case ICmpInst::ICMP_ULT: // (X s< 13 & X u< 15) -> no change
+ break;
+ }
+ break;
+ case ICmpInst::ICMP_UGT:
+ switch (RHSCC) {
+ default: assert(0 && "Unknown integer condition code!");
+ case ICmpInst::ICMP_EQ: // (X u> 13 & X == 15) -> X == 15
+ case ICmpInst::ICMP_UGT: // (X u> 13 & X u> 15) -> X u> 15
+ return ReplaceInstUsesWith(I, RHS);
+ case ICmpInst::ICMP_SGT: // (X u> 13 & X s> 15) -> no change
+ break;
+ case ICmpInst::ICMP_NE:
+ if (RHSCst == AddOne(LHSCst)) // (X u> 13 & X != 14) -> X u> 14
+ return new ICmpInst(LHSCC, Val, RHSCst);
+ break; // (X u> 13 & X != 15) -> no change
+ case ICmpInst::ICMP_ULT: // (X u> 13 & X u< 15) ->(X-14) <u 1
+ return InsertRangeTest(Val, AddOne(LHSCst), RHSCst, false, true, I);
+ case ICmpInst::ICMP_SLT: // (X u> 13 & X s< 15) -> no change
+ break;
+ }
+ break;
+ case ICmpInst::ICMP_SGT:
+ switch (RHSCC) {
+ default: assert(0 && "Unknown integer condition code!");
+ case ICmpInst::ICMP_EQ: // (X s> 13 & X == 15) -> X == 15
+ case ICmpInst::ICMP_SGT: // (X s> 13 & X s> 15) -> X s> 15
+ return ReplaceInstUsesWith(I, RHS);
+ case ICmpInst::ICMP_UGT: // (X s> 13 & X u> 15) -> no change
+ break;
+ case ICmpInst::ICMP_NE:
+ if (RHSCst == AddOne(LHSCst)) // (X s> 13 & X != 14) -> X s> 14
+ return new ICmpInst(LHSCC, Val, RHSCst);
+ break; // (X s> 13 & X != 15) -> no change
+ case ICmpInst::ICMP_SLT: // (X s> 13 & X s< 15) ->(X-14) s< 1
+ return InsertRangeTest(Val, AddOne(LHSCst), RHSCst, true, true, I);
+ case ICmpInst::ICMP_ULT: // (X s> 13 & X u< 15) -> no change
+ break;
+ }
+ break;
+ }
+
+
+
+ return 0;
+}
+
+
Instruction *InstCombiner::visitAnd(BinaryOperator &I) {
bool Changed = SimplifyCommutative(I);
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
@@ -3789,155 +3952,9 @@
if (Instruction *R = AssociativeOpt(I, FoldICmpLogical(*this, RHS)))
return R;
- Value *Val;
- ConstantInt *LHSCst, *RHSCst;
- ICmpInst::Predicate LHSCC, RHSCC;
- // (icmp1 A, C1) & (icmp2 A, C2) --> something simpler.
- if (match(Op0, m_ICmp(LHSCC, m_Value(Val), m_ConstantInt(LHSCst))) &&
- match(RHS, m_ICmp(RHSCC, m_Specific(Val), m_ConstantInt(RHSCst))) &&
-
- // ICMP_[US][GL]E X, CST is folded to ICMP_[US][GL]T elsewhere.
- LHSCC != ICmpInst::ICMP_UGE && LHSCC != ICmpInst::ICMP_ULE &&
- RHSCC != ICmpInst::ICMP_UGE && RHSCC != ICmpInst::ICMP_ULE &&
- LHSCC != ICmpInst::ICMP_SGE && LHSCC != ICmpInst::ICMP_SLE &&
- RHSCC != ICmpInst::ICMP_SGE && RHSCC != ICmpInst::ICMP_SLE &&
-
- // We can't fold (ugt x, C) & (sgt x, C2).
- PredicatesFoldable(LHSCC, RHSCC)) {
- // Ensure that the larger constant is on the RHS.
- ICmpInst::Predicate GT;
- if (ICmpInst::isSignedPredicate(LHSCC) ||
- (ICmpInst::isEquality(LHSCC) &&
- ICmpInst::isSignedPredicate(RHSCC)))
- GT = ICmpInst::ICMP_SGT;
- else
- GT = ICmpInst::ICMP_UGT;
-
- Constant *Cmp = ConstantExpr::getICmp(GT, LHSCst, RHSCst);
- ICmpInst *LHS = cast<ICmpInst>(Op0);
- if (cast<ConstantInt>(Cmp)->getZExtValue()) {
- std::swap(LHS, RHS);
- std::swap(LHSCst, RHSCst);
- std::swap(LHSCC, RHSCC);
- }
-
- // At this point, we know we have have two icmp instructions
- // comparing a value against two constants and and'ing the result
- // together. Because of the above check, we know that we only have
- // icmp eq, icmp ne, icmp [su]lt, and icmp [SU]gt here. We also know
- // (from the FoldICmpLogical check above), that the two constants
- // are not equal and that the larger constant is on the RHS
- assert(LHSCst != RHSCst && "Compares not folded above?");
-
- switch (LHSCC) {
- default: assert(0 && "Unknown integer condition code!");
- case ICmpInst::ICMP_EQ:
- switch (RHSCC) {
- default: assert(0 && "Unknown integer condition code!");
- case ICmpInst::ICMP_EQ: // (X == 13 & X == 15) -> false
- case ICmpInst::ICMP_UGT: // (X == 13 & X > 15) -> false
- case ICmpInst::ICMP_SGT: // (X == 13 & X > 15) -> false
- return ReplaceInstUsesWith(I, ConstantInt::getFalse());
- case ICmpInst::ICMP_NE: // (X == 13 & X != 15) -> X == 13
- case ICmpInst::ICMP_ULT: // (X == 13 & X < 15) -> X == 13
- case ICmpInst::ICMP_SLT: // (X == 13 & X < 15) -> X == 13
- return ReplaceInstUsesWith(I, LHS);
- }
- case ICmpInst::ICMP_NE:
- switch (RHSCC) {
- default: assert(0 && "Unknown integer condition code!");
- case ICmpInst::ICMP_ULT:
- if (LHSCst == SubOne(RHSCst)) // (X != 13 & X u< 14) -> X < 13
- return new ICmpInst(ICmpInst::ICMP_ULT, Val, LHSCst);
- break; // (X != 13 & X u< 15) -> no change
- case ICmpInst::ICMP_SLT:
- if (LHSCst == SubOne(RHSCst)) // (X != 13 & X s< 14) -> X < 13
- return new ICmpInst(ICmpInst::ICMP_SLT, Val, LHSCst);
- break; // (X != 13 & X s< 15) -> no change
- case ICmpInst::ICMP_EQ: // (X != 13 & X == 15) -> X == 15
- case ICmpInst::ICMP_UGT: // (X != 13 & X u> 15) -> X u> 15
- case ICmpInst::ICMP_SGT: // (X != 13 & X s> 15) -> X s> 15
- return ReplaceInstUsesWith(I, RHS);
- case ICmpInst::ICMP_NE:
- if (LHSCst == SubOne(RHSCst)){// (X != 13 & X != 14) -> X-13 >u 1
- Constant *AddCST = ConstantExpr::getNeg(LHSCst);
- Instruction *Add = BinaryOperator::CreateAdd(Val, AddCST,
- Val->getName()+".off");
- InsertNewInstBefore(Add, I);
- return new ICmpInst(ICmpInst::ICMP_UGT, Add,
- ConstantInt::get(Add->getType(), 1));
- }
- break; // (X != 13 & X != 15) -> no change
- }
- break;
- case ICmpInst::ICMP_ULT:
- switch (RHSCC) {
- default: assert(0 && "Unknown integer condition code!");
- case ICmpInst::ICMP_EQ: // (X u< 13 & X == 15) -> false
- case ICmpInst::ICMP_UGT: // (X u< 13 & X u> 15) -> false
- return ReplaceInstUsesWith(I, ConstantInt::getFalse());
- case ICmpInst::ICMP_SGT: // (X u< 13 & X s> 15) -> no change
- break;
- case ICmpInst::ICMP_NE: // (X u< 13 & X != 15) -> X u< 13
- case ICmpInst::ICMP_ULT: // (X u< 13 & X u< 15) -> X u< 13
- return ReplaceInstUsesWith(I, LHS);
- case ICmpInst::ICMP_SLT: // (X u< 13 & X s< 15) -> no change
- break;
- }
- break;
- case ICmpInst::ICMP_SLT:
- switch (RHSCC) {
- default: assert(0 && "Unknown integer condition code!");
- case ICmpInst::ICMP_EQ: // (X s< 13 & X == 15) -> false
- case ICmpInst::ICMP_SGT: // (X s< 13 & X s> 15) -> false
- return ReplaceInstUsesWith(I, ConstantInt::getFalse());
- case ICmpInst::ICMP_UGT: // (X s< 13 & X u> 15) -> no change
- break;
- case ICmpInst::ICMP_NE: // (X s< 13 & X != 15) -> X < 13
- case ICmpInst::ICMP_SLT: // (X s< 13 & X s< 15) -> X < 13
- return ReplaceInstUsesWith(I, LHS);
- case ICmpInst::ICMP_ULT: // (X s< 13 & X u< 15) -> no change
- break;
- }
- break;
- case ICmpInst::ICMP_UGT:
- switch (RHSCC) {
- default: assert(0 && "Unknown integer condition code!");
- case ICmpInst::ICMP_EQ: // (X u> 13 & X == 15) -> X == 15
- case ICmpInst::ICMP_UGT: // (X u> 13 & X u> 15) -> X u> 15
- return ReplaceInstUsesWith(I, RHS);
- case ICmpInst::ICMP_SGT: // (X u> 13 & X s> 15) -> no change
- break;
- case ICmpInst::ICMP_NE:
- if (RHSCst == AddOne(LHSCst)) // (X u> 13 & X != 14) -> X u> 14
- return new ICmpInst(LHSCC, Val, RHSCst);
- break; // (X u> 13 & X != 15) -> no change
- case ICmpInst::ICMP_ULT: // (X u> 13 & X u< 15) ->(X-14) <u 1
- return InsertRangeTest(Val, AddOne(LHSCst), RHSCst, false, true, I);
- case ICmpInst::ICMP_SLT: // (X u> 13 & X s< 15) -> no change
- break;
- }
- break;
- case ICmpInst::ICMP_SGT:
- switch (RHSCC) {
- default: assert(0 && "Unknown integer condition code!");
- case ICmpInst::ICMP_EQ: // (X s> 13 & X == 15) -> X == 15
- case ICmpInst::ICMP_SGT: // (X s> 13 & X s> 15) -> X s> 15
- return ReplaceInstUsesWith(I, RHS);
- case ICmpInst::ICMP_UGT: // (X s> 13 & X u> 15) -> no change
- break;
- case ICmpInst::ICMP_NE:
- if (RHSCst == AddOne(LHSCst)) // (X s> 13 & X != 14) -> X s> 14
- return new ICmpInst(LHSCC, Val, RHSCst);
- break; // (X s> 13 & X != 15) -> no change
- case ICmpInst::ICMP_SLT: // (X s> 13 & X s< 15) ->(X-14) s< 1
- return InsertRangeTest(Val, AddOne(LHSCst), RHSCst, true, true, I);
- case ICmpInst::ICMP_ULT: // (X s> 13 & X u< 15) -> no change
- break;
- }
- break;
- }
- }
+ if (ICmpInst *LHS = dyn_cast<ICmpInst>(Op0))
+ if (Instruction *Res = FoldAndOfICmps(I, LHS, RHS))
+ return Res;
}
// fold (and (cast A), (cast B)) -> (cast (and A, B))
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