[InstSimplify] allow integer vector types to use computeKnownBits
Note that the non-splat lshr+lshr test folded, but that does not
work in general. Something is missing or wrong in computeKnownBits
as the non-splat shl+shl test still shows.
llvm-svn: 288005
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
index 398ac52..0969e7a 100644
--- a/llvm/lib/Analysis/InstructionSimplify.cpp
+++ b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -4380,13 +4380,13 @@
// In general, it is possible for computeKnownBits to determine all bits in a
// value even when the operands are not all constants.
- if (!Result && I->getType()->isIntegerTy()) {
+ if (!Result && I->getType()->isIntOrIntVectorTy()) {
unsigned BitWidth = I->getType()->getScalarSizeInBits();
APInt KnownZero(BitWidth, 0);
APInt KnownOne(BitWidth, 0);
computeKnownBits(I, KnownZero, KnownOne, DL, /*Depth*/0, AC, I, DT);
if ((KnownZero | KnownOne).isAllOnesValue())
- Result = ConstantInt::get(I->getContext(), KnownOne);
+ Result = ConstantInt::get(I->getType(), KnownOne);
}
/// If called on unreachable code, the above logic may report that the
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp b/llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp
index 5181d23..95f06f2 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp
@@ -580,13 +580,13 @@
// Check for (X << c1) << c2 and (X >> c1) >> c2
if (I.getOpcode() == ShiftOp->getOpcode()) {
- uint32_t AmtSum = ShiftAmt1+ShiftAmt2; // Fold into one big shift.
- // If this is oversized composite shift, then unsigned shifts get 0, ashr
- // saturates.
+ uint32_t AmtSum = ShiftAmt1 + ShiftAmt2; // Fold into one big shift.
+ // If this is an oversized composite shift, then unsigned shifts become
+ // zero (handled in InstSimplify) and ashr saturates.
if (AmtSum >= TypeBits) {
if (I.getOpcode() != Instruction::AShr)
- return replaceInstUsesWith(I, Constant::getNullValue(I.getType()));
- AmtSum = TypeBits-1; // Saturate to 31 for i32 ashr.
+ return nullptr;
+ AmtSum = TypeBits - 1; // Saturate to 31 for i32 ashr.
}
return BinaryOperator::Create(I.getOpcode(), X,