Address Duncan's CR request:

1. Cleanup the tests in ConstantFolding.cpp
2. Implement isAllOnes for Constant, ConstantFP, ConstantVector





git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138340 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Nadav Rotem 2011-08-23 17:48:43 +00:00
parent 6153a036f5
commit 20a05be15e
4 changed files with 52 additions and 12 deletions

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@ -51,6 +51,9 @@ public:
/// isNullValue - Return true if this is the value that would be returned by
/// getNullValue.
bool isNullValue() const;
/// isAllOnesValue - Return true if this is the value that would be returned by
/// getAllOnesValue.
bool isAllOnesValue() const;
/// isNegativeZeroValue - Return true if the value is what would be returned
/// by getZeroValueForNegation.

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@ -45,15 +45,9 @@ using namespace llvm;
/// ConstantExpr if unfoldable.
static Constant *FoldBitCast(Constant *C, Type *DestTy,
const TargetData &TD) {
ConstantVector *CV = dyn_cast<ConstantVector>(C);
IntegerType *IntVTy = dyn_cast<IntegerType>(DestTy);
// When casting vectors to scalar integers, catch the
// obvious splat cases.
if (IntVTy && CV) {
if (CV->isNullValue()) return ConstantInt::getNullValue(IntVTy);
if (CV->isAllOnesValue()) return ConstantInt::getAllOnesValue(IntVTy);
}
// Catch the obvious splat cases.
if (C->isNullValue()) return Constant::getNullValue(DestTy);
if (C->isAllOnesValue()) return Constant::getAllOnesValue(DestTy);
// The code below only handles casts to vectors currently.
VectorType *DestVTy = dyn_cast<VectorType>(DestTy);
@ -68,6 +62,7 @@ static Constant *FoldBitCast(Constant *C, Type *DestTy,
}
// If this is a bitcast from constant vector -> vector, fold it.
ConstantVector *CV = dyn_cast<ConstantVector>(C);
if (CV == 0)
return ConstantExpr::getBitCast(C, DestTy);

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@ -62,6 +62,21 @@ bool Constant::isNullValue() const {
return isa<ConstantAggregateZero>(this) || isa<ConstantPointerNull>(this);
}
bool Constant::isAllOnesValue() const {
// Check for -1 integers
if (const ConstantInt *CI = dyn_cast<ConstantInt>(this))
return CI->isAllOnesValue();
// +0.0 is null.
if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this))
return CFP->getValueAPF().bitcastToAPInt().isAllOnesValue();
// Check for constant vectors
if (const ConstantVector *CV = dyn_cast<ConstantVector>(this))
return CV->isAllOnesValue();
return false;
}
// Constructor to create a '0' constant of arbitrary type...
Constant *Constant::getNullValue(Type *Ty) {
switch (Ty->getTypeID()) {
@ -126,7 +141,7 @@ Constant *Constant::getAllOnesValue(Type *Ty) {
SmallVector<Constant*, 16> Elts;
VectorType *VTy = cast<VectorType>(Ty);
Elts.resize(VTy->getNumElements(), getAllOnesValue(VTy->getElementType()));
assert(Elts[0] && "Not a vector integer type!");
assert(Elts[0] && "Invalid AllOnes value!");
return cast<ConstantVector>(ConstantVector::get(Elts));
}
@ -1064,13 +1079,16 @@ bool ConstantVector::isAllOnesValue() const {
// Check out first element.
const Constant *Elt = getOperand(0);
const ConstantInt *CI = dyn_cast<ConstantInt>(Elt);
if (!CI || !CI->isAllOnesValue()) return false;
const ConstantFP *CF = dyn_cast<ConstantFP>(Elt);
// Then make sure all remaining elements point to the same value.
for (unsigned I = 1, E = getNumOperands(); I < E; ++I)
if (getOperand(I) != Elt)
return false;
return true;
// First value is all-ones.
return (CI && CI->isAllOnesValue()) ||
(CF && CF->isAllOnesValue());
}
/// getSplatValue - If this is a splat constant, where all of the

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@ -113,3 +113,27 @@ define i64 @ISPC0(i64 %in) {
; CHECK: @ISPC0
; CHECK: ret i64 0
}
define i64 @Vec2(i64 %in) {
%out = and i64 %in, xor (i64 bitcast (<4 x i16> <i16 0, i16 0, i16 0, i16 0> to i64), i64 0)
ret i64 %out
; CHECK: @Vec2
; CHECK: ret i64 0
}
define i64 @All11(i64 %in) {
%out = and i64 %in, xor (i64 bitcast (<2 x float> bitcast (i64 -1 to <2 x float>) to i64), i64 -1)
ret i64 %out
; CHECK: @All11
; CHECK: ret i64 0
}
define i64 @All111(i32 %in) {
%out = and i32 %in, xor (i64 bitcast (<1 x float> bitcast (i32 -1 to <1 x float>) to i32), i32 -1)
ret i32 %out
; CHECK: @All11
; CHECK: ret i32 0
}