maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

Fix PR5421 by APInt'izing switch lowering. 

llvm-svn: 86354
This commit is contained in:
Chris Lattner 2009-11-07 07:50:34 +00:00
parent 9b669b3c4f
commit 8e1d7222a7
3 changed files with 36 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
View File

@ -1743,19 +1743,19 @@ bool SelectionDAGLowering::handleJTSwitchCase(CaseRec& CR,
Case& FrontCase = *CR.Range.first;
Case& BackCase = *(CR.Range.second-1);
const APInt& First = cast<ConstantInt>(FrontCase.Low)->getValue();
const APInt& Last = cast<ConstantInt>(BackCase.High)->getValue();
const APInt &First = cast<ConstantInt>(FrontCase.Low)->getValue();
const APInt &Last = cast<ConstantInt>(BackCase.High)->getValue();
size_t TSize = 0;
APInt TSize(First.getBitWidth(), 0);
for (CaseItr I = CR.Range.first, E = CR.Range.second;
I!=E; ++I)
TSize += I->size();
if (!areJTsAllowed(TLI) || TSize <= 3)
if (!areJTsAllowed(TLI) || TSize.ult(APInt(First.getBitWidth(), 4)))
return false;
APInt Range = ComputeRange(First, Last);
double Density = (double)TSize / Range.roundToDouble();
double Density = TSize.roundToDouble() / Range.roundToDouble();
if (Density < 0.4)
return false;
@ -1849,32 +1849,34 @@ bool SelectionDAGLowering::handleBTSplitSwitchCase(CaseRec& CR,
// Size is the number of Cases represented by this range.
unsigned Size = CR.Range.second - CR.Range.first;
const APInt& First = cast<ConstantInt>(FrontCase.Low)->getValue();
const APInt& Last = cast<ConstantInt>(BackCase.High)->getValue();
const APInt &First = cast<ConstantInt>(FrontCase.Low)->getValue();
const APInt &Last = cast<ConstantInt>(BackCase.High)->getValue();
double FMetric = 0;
CaseItr Pivot = CR.Range.first + Size/2;
// Select optimal pivot, maximizing sum density of LHS and RHS. This will
// (heuristically) allow us to emit JumpTable's later.
size_t TSize = 0;
APInt TSize(First.getBitWidth(), 0);
for (CaseItr I = CR.Range.first, E = CR.Range.second;
I!=E; ++I)
TSize += I->size();
size_t LSize = FrontCase.size();
size_t RSize = TSize-LSize;
APInt LSize = FrontCase.size();
APInt RSize = TSize-LSize;
DEBUG(errs() << "Selecting best pivot: \n"
<< "First: " << First << ", Last: " << Last <<'\n'
<< "LSize: " << LSize << ", RSize: " << RSize << '\n');
for (CaseItr I = CR.Range.first, J=I+1, E = CR.Range.second;
J!=E; ++I, ++J) {
const APInt& LEnd = cast<ConstantInt>(I->High)->getValue();
const APInt& RBegin = cast<ConstantInt>(J->Low)->getValue();
const APInt &LEnd = cast<ConstantInt>(I->High)->getValue();
const APInt &RBegin = cast<ConstantInt>(J->Low)->getValue();
APInt Range = ComputeRange(LEnd, RBegin);
assert((Range - 2ULL).isNonNegative() &&
"Invalid case distance");
double LDensity = (double)LSize / (LEnd - First + 1ULL).roundToDouble();
double RDensity = (double)RSize / (Last - RBegin + 1ULL).roundToDouble();
double LDensity = (double)LSize.roundToDouble() /
(LEnd - First + 1ULL).roundToDouble();
double RDensity = (double)RSize.roundToDouble() /
(Last - RBegin + 1ULL).roundToDouble();
double Metric = Range.logBase2()*(LDensity+RDensity);
// Should always split in some non-trivial place
DEBUG(errs() <<"=>Step\n"

6
llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuild.h
View File

@ -193,9 +193,9 @@ class SelectionDAGLowering {
Case() : Low(0), High(0), BB(0) { }
Case(Constant* low, Constant* high, MachineBasicBlock* bb) :
Low(low), High(high), BB(bb) { }
uint64_t size() const {
uint64_t rHigh = cast<ConstantInt>(High)->getSExtValue();
uint64_t rLow = cast<ConstantInt>(Low)->getSExtValue();
APInt size() const {
const APInt &rHigh = cast<ConstantInt>(High)->getValue();
const APInt &rLow = cast<ConstantInt>(Low)->getValue();
return (rHigh - rLow + 1ULL);
}
};

20
llvm/test/CodeGen/Generic/switch-lower.ll
View File

@ -1,8 +1,22 @@
; RUN: llc < %s
; PR5421
define void @test1() {
entry:
switch i128 undef, label %exit [
i128 55340232221128654848, label %exit
i128 92233720368547758080, label %exit
i128 73786976294838206464, label %exit
i128 147573952589676412928, label %exit
]
exit:
unreachable
}
; PR1197
define void @exp_attr__expand_n_attribute_reference() {
define void @test2() {
entry:
br i1 false, label %cond_next954, label %cond_true924