diff options
Diffstat (limited to 'compiler/semfold.nim')
| -rw-r--r-- | compiler/semfold.nim | 75 |
1 files changed, 47 insertions, 28 deletions
diff --git a/compiler/semfold.nim b/compiler/semfold.nim index 27a6af1f4..0018f0755 100644 --- a/compiler/semfold.nim +++ b/compiler/semfold.nim @@ -214,7 +214,24 @@ proc evalIs(n: PNode, lhs: PSym, g: ModuleGraph): PNode = result = newIntNode(nkIntLit, ord(res)) result.typ = n.typ +proc fitLiteral(c: ConfigRef, n: PNode): PNode = + # Trim the literal value in order to make it fit in the destination type + if n == nil: + # `n` may be nil if the overflow check kicks in + return + + doAssert n.kind in {nkIntLit, nkCharLit} + + result = n + + let typ = n.typ.skipTypes(abstractRange) + if typ.kind in tyUInt..tyUint32: + result.intVal = result.intVal and lastOrd(c, typ, fixedUnsigned=true) + proc evalOp(m: TMagic, n, a, b, c: PNode; g: ModuleGraph): PNode = + template doAndFit(op: untyped): untyped = + # Implements wrap-around behaviour for unsigned types + fitLiteral(g.config, op) # b and c may be nil result = nil case m @@ -224,12 +241,7 @@ proc evalOp(m: TMagic, n, a, b, c: PNode; g: ModuleGraph): PNode = of mUnaryMinusF64: result = newFloatNodeT(- getFloat(a), n, g) of mNot: result = newIntNodeT(1 - getInt(a), n, g) of mCard: result = newIntNodeT(nimsets.cardSet(g.config, a), n, g) - of mBitnotI: - case skipTypes(n.typ, abstractRange).kind - of tyUInt..tyUInt64: - result = newIntNodeT((not getInt(a)) and lastOrd(g.config, a.typ, fixedUnsigned=true), n, g) - else: - result = newIntNodeT(not getInt(a), n, g) + of mBitnotI: result = doAndFit(newIntNodeT(not getInt(a), n, g)) of mLengthArray: result = newIntNodeT(lengthOrd(g.config, a.typ), n, g) of mLengthSeq, mLengthOpenArray, mXLenSeq, mLengthStr, mXLenStr: if a.kind == nkNilLit: @@ -251,9 +263,9 @@ proc evalOp(m: TMagic, n, a, b, c: PNode; g: ModuleGraph): PNode = of mToU8: result = newIntNodeT(getInt(a) and 0x000000FF, n, g) of mToU16: result = newIntNodeT(getInt(a) and 0x0000FFFF, n, g) of mToU32: result = newIntNodeT(getInt(a) and 0x00000000FFFFFFFF'i64, n, g) - of mUnaryLt: result = foldSub(getOrdValue(a), 1, n, g) - of mSucc: result = foldAdd(getOrdValue(a), getInt(b), n, g) - of mPred: result = foldSub(getOrdValue(a), getInt(b), n, g) + of mUnaryLt: result = doAndFit(foldSub(getOrdValue(a), 1, n, g)) + of mSucc: result = doAndFit(foldAdd(getOrdValue(a), getInt(b), n, g)) + of mPred: result = doAndFit(foldSub(getOrdValue(a), getInt(b), n, g)) of mAddI: result = foldAdd(getInt(a), getInt(b), n, g) of mSubI: result = foldSub(getInt(a), getInt(b), n, g) of mMulI: result = foldMul(getInt(a), getInt(b), n, g) @@ -271,7 +283,7 @@ proc evalOp(m: TMagic, n, a, b, c: PNode; g: ModuleGraph): PNode = of tyInt64, tyInt: result = newIntNodeT(`shl`(getInt(a), getInt(b)), n, g) of tyUInt..tyUInt64: - result = newIntNodeT(`shl`(getInt(a), getInt(b)) and lastOrd(g.config, a.typ, fixedUnsigned=true), n, g) + result = doAndFit(newIntNodeT(`shl`(getInt(a), getInt(b)), n, g)) else: internalError(g.config, n.info, "constant folding for shl") of mShrI: case skipTypes(n.typ, abstractRange).kind @@ -324,14 +336,14 @@ proc evalOp(m: TMagic, n, a, b, c: PNode; g: ModuleGraph): PNode = result = newIntNodeT(ord(`<%`(getOrdValue(a), getOrdValue(b))), n, g) of mLeU, mLeU64: result = newIntNodeT(ord(`<=%`(getOrdValue(a), getOrdValue(b))), n, g) - of mBitandI, mAnd: result = newIntNodeT(a.getInt and b.getInt, n, g) - of mBitorI, mOr: result = newIntNodeT(getInt(a) or getInt(b), n, g) - of mBitxorI, mXor: result = newIntNodeT(a.getInt xor b.getInt, n, g) - of mAddU: result = newIntNodeT(`+%`(getInt(a), getInt(b)), n, g) - of mSubU: result = newIntNodeT(`-%`(getInt(a), getInt(b)), n, g) - of mMulU: result = newIntNodeT(`*%`(getInt(a), getInt(b)), n, g) - of mModU: result = foldModU(getInt(a), getInt(b), n, g) - of mDivU: result = foldDivU(getInt(a), getInt(b), n, g) + of mBitandI, mAnd: result = doAndFit(newIntNodeT(a.getInt and b.getInt, n, g)) + of mBitorI, mOr: result = doAndFit(newIntNodeT(getInt(a) or getInt(b), n, g)) + of mBitxorI, mXor: result = doAndFit(newIntNodeT(a.getInt xor b.getInt, n, g)) + of mAddU: result = doAndFit(newIntNodeT(`+%`(getInt(a), getInt(b)), n, g)) + of mSubU: result = doAndFit(newIntNodeT(`-%`(getInt(a), getInt(b)), n, g)) + of mMulU: result = doAndFit(newIntNodeT(`*%`(getInt(a), getInt(b)), n, g)) + of mModU: result = doAndFit(foldModU(getInt(a), getInt(b), n, g)) + of mDivU: result = doAndFit(foldDivU(getInt(a), getInt(b), n, g)) of mLeSet: result = newIntNodeT(ord(containsSets(g.config, a, b)), n, g) of mEqSet: result = newIntNodeT(ord(equalSets(g.config, a, b)), n, g) of mLtSet: @@ -462,17 +474,24 @@ proc foldConv(n, a: PNode; g: ModuleGraph; check = false): PNode = result = newIntNodeT(int(getFloat(a)), n, g) of tyChar: result = newIntNodeT(getOrdValue(a), n, g) - of tyUInt8..tyUInt32, tyInt8..tyInt32: - let fromSigned = srcTyp.kind in tyInt..tyInt64 + of tyUInt..tyUInt64, tyInt..tyInt64: let toSigned = dstTyp.kind in tyInt..tyInt64 - - let mask = lastOrd(g.config, dstTyp, fixedUnsigned=true) - - var val = - if toSigned: - a.getOrdValue mod mask - else: - a.getOrdValue and mask + var val = a.getOrdValue + + if dstTyp.kind in {tyInt, tyInt64, tyUint, tyUInt64}: + # No narrowing needed + discard + elif dstTyp.kind in {tyInt..tyInt64}: + # Signed type: Overflow check (if requested) and conversion + if check: rangeCheck(n, val, g) + let mask = (`shl`(1, getSize(g.config, dstTyp) * 8) - 1) + let valSign = val < 0 + val = abs(val) and mask + if valSign: val = -val + else: + # Unsigned type: Conversion + let mask = (`shl`(1, getSize(g.config, dstTyp) * 8) - 1) + val = val and mask result = newIntNodeT(val, n, g) else: |