mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-08-18 12:29:21 +00:00
While calculating upper loop bound for first loop and lower loop bound for second loop, take care of edge cases.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41387 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
parent
7df31dc89b
commit
4a69da9cb0
@ -58,7 +58,8 @@ namespace {
|
||||
class SplitInfo {
|
||||
public:
|
||||
SplitInfo() : SplitValue(NULL), SplitCondition(NULL),
|
||||
UseTrueBranchFirst(true) {}
|
||||
UseTrueBranchFirst(true), A_ExitValue(NULL),
|
||||
B_StartValue(NULL) {}
|
||||
|
||||
// Induction variable's range is split at this value.
|
||||
Value *SplitValue;
|
||||
@ -69,11 +70,20 @@ namespace {
|
||||
// True if after loop index split, first loop will execute split condition's
|
||||
// true branch.
|
||||
bool UseTrueBranchFirst;
|
||||
|
||||
// Exit value for first loop after loop split.
|
||||
Value *A_ExitValue;
|
||||
|
||||
// Start value for second loop after loop split.
|
||||
Value *B_StartValue;
|
||||
|
||||
// Clear split info.
|
||||
void clear() {
|
||||
SplitValue = NULL;
|
||||
SplitCondition = NULL;
|
||||
UseTrueBranchFirst = true;
|
||||
A_ExitValue = NULL;
|
||||
B_StartValue = NULL;
|
||||
}
|
||||
|
||||
};
|
||||
@ -112,6 +122,10 @@ namespace {
|
||||
/// split loop using given split condition.
|
||||
bool safeSplitCondition(SplitInfo &SD);
|
||||
|
||||
/// calculateLoopBounds - ALoop exit value and BLoop start values are calculated
|
||||
/// based on split value.
|
||||
void calculateLoopBounds(SplitInfo &SD);
|
||||
|
||||
/// splitLoop - Split current loop L in two loops using split information
|
||||
/// SD. Update dominator information. Maintain LCSSA form.
|
||||
bool splitLoop(SplitInfo &SD);
|
||||
@ -295,7 +309,14 @@ void LoopIndexSplit::findLoopConditionals() {
|
||||
ICmpInst *CI = dyn_cast<ICmpInst>(BR->getCondition());
|
||||
if (!CI)
|
||||
return;
|
||||
|
||||
|
||||
// FIXME
|
||||
if (CI->getPredicate() == ICmpInst::ICMP_SGT
|
||||
|| CI->getPredicate() == ICmpInst::ICMP_UGT
|
||||
|| CI->getPredicate() == ICmpInst::ICMP_SGE
|
||||
|| CI->getPredicate() == ICmpInst::ICMP_UGE)
|
||||
return;
|
||||
|
||||
ExitCondition = CI;
|
||||
|
||||
// Exit condition's one operand is loop invariant exit value and second
|
||||
@ -747,6 +768,207 @@ bool LoopIndexSplit::safeSplitCondition(SplitInfo &SD) {
|
||||
return false;
|
||||
}
|
||||
|
||||
/// calculateLoopBounds - ALoop exit value and BLoop start values are calculated
|
||||
/// based on split value.
|
||||
void LoopIndexSplit::calculateLoopBounds(SplitInfo &SD) {
|
||||
|
||||
ICmpInst::Predicate SP = SD.SplitCondition->getPredicate();
|
||||
const Type *Ty = SD.SplitValue->getType();
|
||||
bool Sign = ExitCondition->isSignedPredicate();
|
||||
BasicBlock *Preheader = L->getLoopPreheader();
|
||||
Instruction *PHTerminator = Preheader->getTerminator();
|
||||
|
||||
// Initially use split value as upper loop bound for first loop and lower loop
|
||||
// bound for second loop.
|
||||
Value *AEV = SD.SplitValue;
|
||||
Value *BSV = SD.SplitValue;
|
||||
|
||||
switch (ExitCondition->getPredicate()) {
|
||||
case ICmpInst::ICMP_SGT:
|
||||
case ICmpInst::ICMP_UGT:
|
||||
case ICmpInst::ICMP_SGE:
|
||||
case ICmpInst::ICMP_UGE:
|
||||
default:
|
||||
assert (0 && "Unexpected exit condition predicate");
|
||||
|
||||
case ICmpInst::ICMP_SLT:
|
||||
case ICmpInst::ICMP_ULT:
|
||||
{
|
||||
switch (SP) {
|
||||
case ICmpInst::ICMP_SLT:
|
||||
case ICmpInst::ICMP_ULT:
|
||||
//
|
||||
// for (i = LB; i < UB; ++i) { if (i < SV) A; else B; }
|
||||
//
|
||||
// is transformed into
|
||||
// AEV = BSV = SV
|
||||
// for (i = LB; i < min(UB, AEV); ++i)
|
||||
// A;
|
||||
// for (i = max(LB, BSV); i < UB; ++i);
|
||||
// B;
|
||||
break;
|
||||
case ICmpInst::ICMP_SLE:
|
||||
case ICmpInst::ICMP_ULE:
|
||||
{
|
||||
//
|
||||
// for (i = LB; i < UB; ++i) { if (i <= SV) A; else B; }
|
||||
//
|
||||
// is transformed into
|
||||
//
|
||||
// AEV = SV + 1
|
||||
// BSV = SV + 1
|
||||
// for (i = LB; i < min(UB, AEV); ++i)
|
||||
// A;
|
||||
// for (i = max(LB, BSV); i < UB; ++i)
|
||||
// B;
|
||||
BSV = BinaryOperator::createAdd(SD.SplitValue,
|
||||
ConstantInt::get(Ty, 1, Sign),
|
||||
"lsplit.add", PHTerminator);
|
||||
AEV = BSV;
|
||||
}
|
||||
break;
|
||||
case ICmpInst::ICMP_SGE:
|
||||
case ICmpInst::ICMP_UGE:
|
||||
//
|
||||
// for (i = LB; i < UB; ++i) { if (i >= SV) A; else B; }
|
||||
//
|
||||
// is transformed into
|
||||
// AEV = BSV = SV
|
||||
// for (i = LB; i < min(UB, AEV); ++i)
|
||||
// B;
|
||||
// for (i = max(BSV, LB); i < UB; ++i)
|
||||
// A;
|
||||
break;
|
||||
case ICmpInst::ICMP_SGT:
|
||||
case ICmpInst::ICMP_UGT:
|
||||
{
|
||||
//
|
||||
// for (i = LB; i < UB; ++i) { if (i > SV) A; else B; }
|
||||
//
|
||||
// is transformed into
|
||||
//
|
||||
// BSV = AEV = SV + 1
|
||||
// for (i = LB; i < min(UB, AEV); ++i)
|
||||
// B;
|
||||
// for (i = max(LB, BSV); i < UB; ++i)
|
||||
// A;
|
||||
BSV = BinaryOperator::createAdd(SD.SplitValue,
|
||||
ConstantInt::get(Ty, 1, Sign),
|
||||
"lsplit.add", PHTerminator);
|
||||
AEV = BSV;
|
||||
}
|
||||
break;
|
||||
default:
|
||||
assert (0 && "Unexpected split condition predicate");
|
||||
break;
|
||||
} // end switch (SP)
|
||||
}
|
||||
break;
|
||||
case ICmpInst::ICMP_SLE:
|
||||
case ICmpInst::ICMP_ULE:
|
||||
{
|
||||
switch (SP) {
|
||||
case ICmpInst::ICMP_SLT:
|
||||
case ICmpInst::ICMP_ULT:
|
||||
//
|
||||
// for (i = LB; i <= UB; ++i) { if (i < SV) A; else B; }
|
||||
//
|
||||
// is transformed into
|
||||
// AEV = SV - 1;
|
||||
// BSV = SV;
|
||||
// for (i = LB; i <= min(UB, AEV); ++i)
|
||||
// A;
|
||||
// for (i = max(LB, BSV); i <= UB; ++i)
|
||||
// B;
|
||||
AEV = BinaryOperator::createSub(SD.SplitValue,
|
||||
ConstantInt::get(Ty, 1, Sign),
|
||||
"lsplit.sub", PHTerminator);
|
||||
break;
|
||||
case ICmpInst::ICMP_SLE:
|
||||
case ICmpInst::ICMP_ULE:
|
||||
//
|
||||
// for (i = LB; i <= UB; ++i) { if (i <= SV) A; else B; }
|
||||
//
|
||||
// is transformed into
|
||||
// AEV = SV;
|
||||
// BSV = SV + 1;
|
||||
// for (i = LB; i <= min(UB, AEV); ++i)
|
||||
// A;
|
||||
// for (i = max(LB, BSV); i <= UB; ++i)
|
||||
// B;
|
||||
BSV = BinaryOperator::createAdd(SD.SplitValue,
|
||||
ConstantInt::get(Ty, 1, Sign),
|
||||
"lsplit.add", PHTerminator);
|
||||
break;
|
||||
case ICmpInst::ICMP_SGT:
|
||||
case ICmpInst::ICMP_UGT:
|
||||
//
|
||||
// for (i = LB; i <= UB; ++i) { if (i > SV) A; else B; }
|
||||
//
|
||||
// is transformed into
|
||||
// AEV = SV;
|
||||
// BSV = SV + 1;
|
||||
// for (i = LB; i <= min(AEV, UB); ++i)
|
||||
// B;
|
||||
// for (i = max(LB, BSV); i <= UB; ++i)
|
||||
// A;
|
||||
BSV = BinaryOperator::createAdd(SD.SplitValue,
|
||||
ConstantInt::get(Ty, 1, Sign),
|
||||
"lsplit.add", PHTerminator);
|
||||
break;
|
||||
case ICmpInst::ICMP_SGE:
|
||||
case ICmpInst::ICMP_UGE:
|
||||
// ** TODO **
|
||||
//
|
||||
// for (i = LB; i <= UB; ++i) { if (i >= SV) A; else B; }
|
||||
//
|
||||
// is transformed into
|
||||
// AEV = SV - 1;
|
||||
// BSV = SV;
|
||||
// for (i = LB; i <= min(AEV, UB); ++i)
|
||||
// B;
|
||||
// for (i = max(LB, BSV); i <= UB; ++i)
|
||||
// A;
|
||||
AEV = BinaryOperator::createSub(SD.SplitValue,
|
||||
ConstantInt::get(Ty, 1, Sign),
|
||||
"lsplit.sub", PHTerminator);
|
||||
break;
|
||||
default:
|
||||
assert (0 && "Unexpected split condition predicate");
|
||||
break;
|
||||
} // end switch (SP)
|
||||
}
|
||||
break;
|
||||
}
|
||||
|
||||
// Calculate ALoop induction variable's new exiting value and
|
||||
// BLoop induction variable's new starting value. Calculuate these
|
||||
// values in original loop's preheader.
|
||||
// A_ExitValue = min(SplitValue, OrignalLoopExitValue)
|
||||
// B_StartValue = max(SplitValue, OriginalLoopStartValue)
|
||||
if (isa<ConstantInt>(SD.SplitValue)) {
|
||||
SD.A_ExitValue = AEV;
|
||||
SD.B_StartValue = BSV;
|
||||
return;
|
||||
}
|
||||
|
||||
Value *C1 = new ICmpInst(Sign ?
|
||||
ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT,
|
||||
AEV,
|
||||
ExitCondition->getOperand(ExitValueNum),
|
||||
"lsplit.ev", PHTerminator);
|
||||
SD.A_ExitValue = new SelectInst(C1, AEV,
|
||||
ExitCondition->getOperand(ExitValueNum),
|
||||
"lsplit.ev", PHTerminator);
|
||||
|
||||
Value *C2 = new ICmpInst(Sign ?
|
||||
ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT,
|
||||
BSV, StartValue, "lsplit.sv",
|
||||
PHTerminator);
|
||||
SD.B_StartValue = new SelectInst(C2, StartValue, BSV,
|
||||
"lsplit.sv", PHTerminator);
|
||||
}
|
||||
|
||||
/// splitLoop - Split current loop L in two loops using split information
|
||||
/// SD. Update dominator information. Maintain LCSSA form.
|
||||
bool LoopIndexSplit::splitLoop(SplitInfo &SD) {
|
||||
@ -762,38 +984,11 @@ bool LoopIndexSplit::splitLoop(SplitInfo &SD) {
|
||||
//
|
||||
// ALoop's exit edge enters BLoop's header through a forwarding block which
|
||||
// acts as a BLoop's preheader.
|
||||
BasicBlock *Preheader = L->getLoopPreheader();
|
||||
|
||||
//[*] Calculate ALoop induction variable's new exiting value and
|
||||
// BLoop induction variable's new starting value. Calculuate these
|
||||
// values in original loop's preheader.
|
||||
// A_ExitValue = min(SplitValue, OrignalLoopExitValue)
|
||||
// B_StartValue = max(SplitValue, OriginalLoopStartValue)
|
||||
Value *A_ExitValue = NULL;
|
||||
Value *B_StartValue = NULL;
|
||||
if (isa<ConstantInt>(SD.SplitValue)) {
|
||||
A_ExitValue = SD.SplitValue;
|
||||
B_StartValue = SD.SplitValue;
|
||||
}
|
||||
else {
|
||||
BasicBlock *Preheader = L->getLoopPreheader();
|
||||
Instruction *PHTerminator = Preheader->getTerminator();
|
||||
bool SignedPredicate = ExitCondition->isSignedPredicate();
|
||||
Value *C1 = new ICmpInst(SignedPredicate ?
|
||||
ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT,
|
||||
SD.SplitValue,
|
||||
ExitCondition->getOperand(ExitValueNum),
|
||||
"lsplit.ev", PHTerminator);
|
||||
A_ExitValue = new SelectInst(C1, SD.SplitValue,
|
||||
ExitCondition->getOperand(ExitValueNum),
|
||||
"lsplit.ev", PHTerminator);
|
||||
|
||||
Value *C2 = new ICmpInst(SignedPredicate ?
|
||||
ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT,
|
||||
SD.SplitValue, StartValue, "lsplit.sv",
|
||||
PHTerminator);
|
||||
B_StartValue = new SelectInst(C2, StartValue, SD.SplitValue,
|
||||
"lsplit.sv", PHTerminator);
|
||||
}
|
||||
// Calculate ALoop induction variable's new exiting value and
|
||||
// BLoop induction variable's new starting value.
|
||||
calculateLoopBounds(SD);
|
||||
|
||||
//[*] Clone loop.
|
||||
DenseMap<const Value *, Value *> ValueMap;
|
||||
@ -815,7 +1010,7 @@ bool LoopIndexSplit::splitLoop(SplitInfo &SD) {
|
||||
A_ExitInsn->setSuccessor(1, B_Header);
|
||||
|
||||
//[*] Update ALoop's exit value using new exit value.
|
||||
ExitCondition->setOperand(ExitValueNum, A_ExitValue);
|
||||
ExitCondition->setOperand(ExitValueNum, SD.A_ExitValue);
|
||||
|
||||
// [*] Update BLoop's header phi nodes. Remove incoming PHINode's from
|
||||
// original loop's preheader. Add incoming PHINode values from
|
||||
@ -831,7 +1026,7 @@ bool LoopIndexSplit::splitLoop(SplitInfo &SD) {
|
||||
} else
|
||||
break;
|
||||
}
|
||||
BasicBlock *Preheader = L->getLoopPreheader();
|
||||
|
||||
for (BasicBlock::iterator BI = B_Header->begin(), BE = B_Header->end();
|
||||
BI != BE; ++BI) {
|
||||
if (PHINode *PN = dyn_cast<PHINode>(BI)) {
|
||||
@ -840,7 +1035,7 @@ bool LoopIndexSplit::splitLoop(SplitInfo &SD) {
|
||||
|
||||
// Add incoming value from A_ExitingBlock.
|
||||
if (PN == B_IndVar)
|
||||
PN->addIncoming(B_StartValue, A_ExitingBlock);
|
||||
PN->addIncoming(SD.B_StartValue, A_ExitingBlock);
|
||||
else {
|
||||
PHINode *OrigPN = cast<PHINode>(InverseMap[PN]);
|
||||
Value *V2 = OrigPN->getIncomingValueForBlock(A_ExitingBlock);
|
||||
|
52
test/Transforms/LoopIndexSplit/SplitValue-2007-08-24.ll
Normal file
52
test/Transforms/LoopIndexSplit/SplitValue-2007-08-24.ll
Normal file
@ -0,0 +1,52 @@
|
||||
; Split loop. Save last value. Split value is off by one in this example.
|
||||
; RUN: llvm-as < %s | opt -loop-index-split -disable-output -stats |& \
|
||||
; RUN: grep "loop-index-split" | count 1
|
||||
|
||||
@k = external global i32 ; <i32*> [#uses=2]
|
||||
|
||||
define void @foobar(i32 %a, i32 %b) {
|
||||
entry:
|
||||
br label %bb
|
||||
|
||||
bb: ; preds = %cond_next16, %entry
|
||||
%i.01.0 = phi i32 [ 0, %entry ], [ %tmp18, %cond_next16 ] ; <i32> [#uses=5]
|
||||
%tsum.18.0 = phi i32 [ 42, %entry ], [ %tsum.013.1, %cond_next16 ] ; <i32> [#uses=3]
|
||||
%tmp1 = icmp sgt i32 %i.01.0, 50 ; <i1> [#uses=1]
|
||||
br i1 %tmp1, label %cond_true, label %cond_false
|
||||
|
||||
cond_true: ; preds = %bb
|
||||
%tmp4 = tail call i32 @foo( i32 %i.01.0 ) ; <i32> [#uses=1]
|
||||
%tmp6 = add i32 %tmp4, %tsum.18.0 ; <i32> [#uses=2]
|
||||
%tmp914 = load i32* @k, align 4 ; <i32> [#uses=1]
|
||||
%tmp1015 = icmp eq i32 %tmp914, 0 ; <i1> [#uses=1]
|
||||
br i1 %tmp1015, label %cond_next16, label %cond_true13
|
||||
|
||||
cond_false: ; preds = %bb
|
||||
%tmp8 = tail call i32 @bar( i32 %i.01.0 ) ; <i32> [#uses=0]
|
||||
%tmp9 = load i32* @k, align 4 ; <i32> [#uses=1]
|
||||
%tmp10 = icmp eq i32 %tmp9, 0 ; <i1> [#uses=1]
|
||||
br i1 %tmp10, label %cond_next16, label %cond_true13
|
||||
|
||||
cond_true13: ; preds = %cond_false, %cond_true
|
||||
%tsum.013.0 = phi i32 [ %tmp6, %cond_true ], [ %tsum.18.0, %cond_false ] ; <i32> [#uses=1]
|
||||
%tmp15 = tail call i32 @bar( i32 %i.01.0 ) ; <i32> [#uses=0]
|
||||
br label %cond_next16
|
||||
|
||||
cond_next16: ; preds = %cond_false, %cond_true, %cond_true13
|
||||
%tsum.013.1 = phi i32 [ %tsum.013.0, %cond_true13 ], [ %tmp6, %cond_true ], [ %tsum.18.0, %cond_false ] ; <i32> [#uses=2]
|
||||
%tmp18 = add i32 %i.01.0, 1 ; <i32> [#uses=3]
|
||||
%tmp21 = icmp slt i32 %tmp18, 100 ; <i1> [#uses=1]
|
||||
br i1 %tmp21, label %bb, label %bb24
|
||||
|
||||
bb24: ; preds = %cond_next16
|
||||
%tmp18.lcssa = phi i32 [ %tmp18, %cond_next16 ] ; <i32> [#uses=1]
|
||||
%tsum.013.1.lcssa = phi i32 [ %tsum.013.1, %cond_next16 ] ; <i32> [#uses=1]
|
||||
%tmp27 = tail call i32 @t( i32 %tmp18.lcssa, i32 %tsum.013.1.lcssa ) ; <i32> [#uses=0]
|
||||
ret void
|
||||
}
|
||||
|
||||
declare i32 @foo(i32)
|
||||
|
||||
declare i32 @bar(i32)
|
||||
|
||||
declare i32 @t(i32, i32)
|
Loading…
Reference in New Issue
Block a user