And, Constant::getNullValue(And->getType()));
}
- // FIXME: This check restricts all folds under here to scalar types.
- ConstantInt *RHS = dyn_cast<ConstantInt>(Cmp.getOperand(1));
- if (!RHS)
- return nullptr;
-
- // Transform (icmp pred iM (shl iM %v, N), CI)
- // -> (icmp pred i(M-N) (trunc %v iM to i(M-N)), (trunc (CI>>N))
- // Transform the shl to a trunc if (trunc (CI>>N)) has no loss and M-N.
- // This enables to get rid of the shift in favor of a trunc which can be
+ // Transform (icmp pred iM (shl iM %v, N), C)
+ // -> (icmp pred i(M-N) (trunc %v iM to i(M-N)), (trunc (C>>N))
+ // Transform the shl to a trunc if (trunc (C>>N)) has no loss and M-N.
+ // This enables us to get rid of the shift in favor of a trunc which can be
// free on the target. It has the additional benefit of comparing to a
// smaller constant, which will be target friendly.
unsigned Amt = ShiftAmt->getLimitedValue(TypeBits - 1);
if (Shl->hasOneUse() && Amt != 0 && C->countTrailingZeros() >= Amt) {
- Type *NTy = IntegerType::get(Cmp.getContext(), TypeBits - Amt);
- Constant *NCI = ConstantExpr::getTrunc(
- ConstantExpr::getAShr(RHS, ConstantInt::get(RHS->getType(), Amt)), NTy);
- return new ICmpInst(Pred, Builder->CreateTrunc(X, NTy), NCI);
+ Type *TruncTy = IntegerType::get(Cmp.getContext(), TypeBits - Amt);
+ if (X->getType()->isVectorTy())
+ TruncTy = VectorType::get(TruncTy, X->getType()->getVectorNumElements());
+ Constant *NewC =
+ ConstantInt::get(TruncTy, C->ashr(*ShiftAmt).trunc(TypeBits - Amt));
+ return new ICmpInst(Pred, Builder->CreateTrunc(X, TruncTy), NewC);
}
return nullptr;
ret i1 %cmp
}
-; FIXME: Vectors should fold the same way.
define <2 x i1> @icmp_shl16_vec(<2 x i32> %x) {
; CHECK-LABEL: @icmp_shl16_vec(
-; CHECK-NEXT: [[SHL:%.*]] = shl <2 x i32> %x, <i32 16, i32 16>
-; CHECK-NEXT: [[CMP:%.*]] = icmp slt <2 x i32> [[SHL]], <i32 2359296, i32 2359296>
+; CHECK-NEXT: [[TMP1:%.*]] = trunc <2 x i32> %x to <2 x i16>
+; CHECK-NEXT: [[CMP:%.*]] = icmp slt <2 x i16> [[TMP1]], <i16 36, i16 36>
; CHECK-NEXT: ret <2 x i1> [[CMP]]
;
%shl = shl <2 x i32> %x, <i32 16, i32 16>