Author: Timm Baeder Date: 2024-09-29T20:56:17+02:00 New Revision: 6f04e65c3c62060de18a47ec351d1eedd703126d
URL: https://github.com/llvm/llvm-project/commit/6f04e65c3c62060de18a47ec351d1eedd703126d DIFF: https://github.com/llvm/llvm-project/commit/6f04e65c3c62060de18a47ec351d1eedd703126d.diff LOG: [clang][bytecode] Implement fixed-point shifts (#110429) Added: Modified: clang/lib/AST/ByteCode/Compiler.cpp clang/lib/AST/ByteCode/FixedPoint.h clang/lib/AST/ByteCode/Interp.h clang/lib/AST/ByteCode/Opcodes.td clang/test/Frontend/fixed_point_errors.c Removed: ################################################################################ diff --git a/clang/lib/AST/ByteCode/Compiler.cpp b/clang/lib/AST/ByteCode/Compiler.cpp index 378a78fb1316e8..c24c4b6db2a5bf 100644 --- a/clang/lib/AST/ByteCode/Compiler.cpp +++ b/clang/lib/AST/ByteCode/Compiler.cpp @@ -1563,6 +1563,10 @@ bool Compiler<Emitter>::VisitFixedPointBinOp(const BinaryOperator *E) { return ConvertResult(this->emitMulFixedPoint(E)); case BO_Div: return ConvertResult(this->emitDivFixedPoint(E)); + case BO_Shl: + return ConvertResult(this->emitShiftFixedPoint(/*Left=*/true, E)); + case BO_Shr: + return ConvertResult(this->emitShiftFixedPoint(/*Left=*/false, E)); default: return this->emitInvalid(E); diff --git a/clang/lib/AST/ByteCode/FixedPoint.h b/clang/lib/AST/ByteCode/FixedPoint.h index b27ecfadd85146..ab8d6d7f02b52f 100644 --- a/clang/lib/AST/ByteCode/FixedPoint.h +++ b/clang/lib/AST/ByteCode/FixedPoint.h @@ -68,6 +68,7 @@ class FixedPoint final { bool *Overflow) const { return FixedPoint(V.convert(Sem, Overflow)); } + llvm::FixedPointSemantics getSemantics() const { return V.getSemantics(); } llvm::APFloat toFloat(const llvm::fltSemantics *Sem) const { return V.convertToFloat(*Sem); @@ -120,6 +121,22 @@ class FixedPoint final { *R = FixedPoint(A.V.div(B.V, &Overflow)); return Overflow; } + + static bool shiftLeft(const FixedPoint A, const FixedPoint B, unsigned OpBits, + FixedPoint *R) { + unsigned Amt = B.V.getValue().getLimitedValue(OpBits); + bool Overflow; + *R = FixedPoint(A.V.shl(Amt, &Overflow)); + return Overflow; + } + static bool shiftRight(const FixedPoint A, const FixedPoint B, + unsigned OpBits, FixedPoint *R) { + unsigned Amt = B.V.getValue().getLimitedValue(OpBits); + bool Overflow; + *R = FixedPoint(A.V.shr(Amt, &Overflow)); + return Overflow; + } + static bool rem(const FixedPoint A, const FixedPoint B, unsigned Bits, FixedPoint *R) { llvm_unreachable("Rem doesn't exist for fixed point values"); diff --git a/clang/lib/AST/ByteCode/Interp.h b/clang/lib/AST/ByteCode/Interp.h index 62e4917d72b4d1..68c04587a4919e 100644 --- a/clang/lib/AST/ByteCode/Interp.h +++ b/clang/lib/AST/ByteCode/Interp.h @@ -2579,6 +2579,42 @@ inline bool Shl(InterpState &S, CodePtr OpPC) { return DoShift<LT, RT, ShiftDir::Left>(S, OpPC, LHS, RHS); } +static inline bool ShiftFixedPoint(InterpState &S, CodePtr OpPC, bool Left) { + const auto &RHS = S.Stk.pop<FixedPoint>(); + const auto &LHS = S.Stk.pop<FixedPoint>(); + llvm::FixedPointSemantics LHSSema = LHS.getSemantics(); + + unsigned ShiftBitWidth = + LHSSema.getWidth() - (unsigned)LHSSema.hasUnsignedPadding() - 1; + + // Embedded-C 4.1.6.2.2: + // The right operand must be nonnegative and less than the total number + // of (nonpadding) bits of the fixed-point operand ... + if (RHS.isNegative()) { + S.CCEDiag(S.Current->getLocation(OpPC), diag::note_constexpr_negative_shift) + << RHS.toAPSInt(); + } else if (static_cast<unsigned>(RHS.toAPSInt().getLimitedValue( + ShiftBitWidth)) != RHS.toAPSInt()) { + const Expr *E = S.Current->getExpr(OpPC); + S.CCEDiag(E, diag::note_constexpr_large_shift) + << RHS.toAPSInt() << E->getType() << ShiftBitWidth; + } + + FixedPoint Result; + if (Left) { + if (FixedPoint::shiftLeft(LHS, RHS, ShiftBitWidth, &Result) && + !handleFixedPointOverflow(S, OpPC, Result)) + return false; + } else { + if (FixedPoint::shiftRight(LHS, RHS, ShiftBitWidth, &Result) && + !handleFixedPointOverflow(S, OpPC, Result)) + return false; + } + + S.Stk.push<FixedPoint>(Result); + return true; +} + //===----------------------------------------------------------------------===// // NoRet //===----------------------------------------------------------------------===// diff --git a/clang/lib/AST/ByteCode/Opcodes.td b/clang/lib/AST/ByteCode/Opcodes.td index e88335e67c19ff..61b6f2e8daa2fb 100644 --- a/clang/lib/AST/ByteCode/Opcodes.td +++ b/clang/lib/AST/ByteCode/Opcodes.td @@ -698,6 +698,9 @@ def CastFixedPointIntegral : Opcode { let Types = [FixedSizeIntegralTypes]; let HasGroup = 1; } +def ShiftFixedPoint : Opcode { + let Args = [ArgBool]; +} def PtrPtrCast : Opcode { let Args = [ArgBool]; diff --git a/clang/test/Frontend/fixed_point_errors.c b/clang/test/Frontend/fixed_point_errors.c index 6a711936f23975..3472f595089a14 100644 --- a/clang/test/Frontend/fixed_point_errors.c +++ b/clang/test/Frontend/fixed_point_errors.c @@ -1,4 +1,5 @@ // RUN: %clang_cc1 -verify -ffixed-point %s +// RUN: %clang_cc1 -verify -ffixed-point %s -fexperimental-new-constant-interpreter /* We do not yet support long long. No recommended bit widths are given for this * size. */ _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
