6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-11-02 07:11:49 +00:00
Code Issues Projects Releases Wiki Activity

CSE simple binary expressions when they are inserted. This makes LSR produce

Browse Source 
less huge code that needs to be cleaned up by sdisel.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35959 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2007-04-13 05:04:18 +00:00
parent 849c9a28e1
commit 7fec90ebf4
2 changed files with 32 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
include/llvm/Analysis/ScalarEvolutionExpander.h
View File

@ -89,7 +89,10 @@ namespace llvm {
/// we can to share the casts.
static Value *InsertCastOfTo(Instruction::CastOps opcode, Value *V,
const Type *Ty);
/// InsertBinop - Insert the specified binary operator, doing a small amount
/// of work to avoid inserting an obviously redundant operation.
static Value *InsertBinop(Instruction::BinaryOps Opcode, Value *LHS,
Value *RHS, Instruction *InsertPt);
protected:
Value *expand(SCEV *S) {
// Check to see if we already expanded this.
@ -141,8 +144,8 @@ namespace llvm {
// Emit a bunch of add instructions
for (int i = S->getNumOperands()-2; i >= 0; --i)
V = BinaryOperator::createAdd(V, expandInTy(S->getOperand(i), Ty),
"tmp.", InsertPt);
V = InsertBinop(Instruction::Add, V, expandInTy(S->getOperand(i), Ty),
InsertPt);
return V;
}
@ -152,7 +155,7 @@ namespace llvm {
const Type *Ty = S->getType();
Value *LHS = expandInTy(S->getLHS(), Ty);
Value *RHS = expandInTy(S->getRHS(), Ty);
return BinaryOperator::createSDiv(LHS, RHS, "tmp.", InsertPt);
return InsertBinop(Instruction::SDiv, LHS, RHS, InsertPt);
}
Value *visitAddRecExpr(SCEVAddRecExpr *S);

30
lib/Analysis/ScalarEvolutionExpander.cpp
View File

@ -68,6 +68,25 @@ Value *SCEVExpander::InsertCastOfTo(Instruction::CastOps opcode, Value *V,
return CastInst::create(opcode, V, Ty, V->getName(), IP);
}
/// InsertBinop - Insert the specified binary operator, doing a small amount
/// of work to avoid inserting an obviously redundant operation.
Value *SCEVExpander::InsertBinop(Instruction::BinaryOps Opcode, Value *LHS,
Value *RHS, Instruction *InsertPt) {
// Do a quick scan to see if we have this binop nearby. If so, reuse it.
unsigned ScanLimit = 6;
for (BasicBlock::iterator IP = InsertPt, E = InsertPt->getParent()->begin();
ScanLimit; --IP, --ScanLimit) {
if (BinaryOperator *BinOp = dyn_cast<BinaryOperator>(IP))
if (BinOp->getOpcode() == Opcode && BinOp->getOperand(0) == LHS &&
BinOp->getOperand(1) == RHS)
return BinOp;
if (IP == E) break;
}
// If we don't have
return BinaryOperator::create(Opcode, LHS, RHS, "tmp.", InsertPt);
}
Value *SCEVExpander::visitMulExpr(SCEVMulExpr *S) {
const Type *Ty = S->getType();
int FirstOp = 0; // Set if we should emit a subtract.
@ -80,11 +99,12 @@ Value *SCEVExpander::visitMulExpr(SCEVMulExpr *S) {
// Emit a bunch of multiply instructions
for (; i >= FirstOp; --i)
V = BinaryOperator::createMul(V, expandInTy(S->getOperand(i), Ty),
"tmp.", InsertPt);
V = InsertBinop(Instruction::Mul, V, expandInTy(S->getOperand(i), Ty),
InsertPt);
// -1 * ... ---> 0 - ...
if (FirstOp == 1)
V = BinaryOperator::createNeg(V, "tmp.", InsertPt);
V = InsertBinop(Instruction::Sub, Constant::getNullValue(V->getType()), V,
InsertPt);
return V;
}
@ -103,7 +123,7 @@ Value *SCEVExpander::visitAddRecExpr(SCEVAddRecExpr *S) {
Value *Rest = expandInTy(SCEVAddRecExpr::get(NewOps, L), Ty);
// FIXME: look for an existing add to use.
return BinaryOperator::createAdd(Rest, Start, "tmp.", InsertPt);
return InsertBinop(Instruction::Add, Rest, Start, InsertPt);
}
// {0,+,1} --> Insert a canonical induction variable into the loop!
@ -164,7 +184,7 @@ Value *SCEVExpander::visitAddRecExpr(SCEVAddRecExpr *S) {
}
}
return BinaryOperator::createMul(I, F, "tmp.", MulInsertPt);
return InsertBinop(Instruction::Mul, I, F, MulInsertPt);
}
// If this is a chain of recurrences, turn it into a closed form, using the