mirror of
https://github.com/capstone-engine/llvm-capstone.git
synced 2025-05-13 09:26:43 +00:00
c7ff5b38f2
Now compiler defines 5 sets of constants to represent rounding mode. These are: 1. `llvm::APFloatBase::roundingMode`. It specifies all 5 rounding modes defined by IEEE-754 and is used in `APFloat` implementation. 2. `clang::LangOptions::FPRoundingModeKind`. It specifies 4 of 5 IEEE-754 rounding modes and a special value for dynamic rounding mode. It is used in clang frontend. 3. `llvm::fp::RoundingMode`. Defines the same values as `clang::LangOptions::FPRoundingModeKind` but in different order. It is used to specify rounding mode in in IR and functions that operate IR. 4. Rounding mode representation used by `FLT_ROUNDS` (C11, 5.2.4.2.2p7). Besides constants for rounding mode it also uses a special value to indicate error. It is convenient to use in intrinsic functions, as it represents platform-independent representation for rounding mode. In this role it is used in some pending patches. 5. Values like `FE_DOWNWARD` and other, which specify rounding mode in library calls `fesetround` and `fegetround`. Often they represent bits of some control register, so they are target-dependent. The same names (not values) and a special name `FE_DYNAMIC` are used in `#pragma STDC FENV_ROUND`. The first 4 sets of constants are target independent and could have the same numerical representation. It would simplify conversion between the representations. Also now `clang::LangOptions::FPRoundingModeKind` and `llvm::fp::RoundingMode` do not contain the value for IEEE-754 rounding direction `roundTiesToAway`, although it is supported natively on some targets. This change defines all the rounding mode type via one `llvm::RoundingMode`, which also contains rounding mode for IEEE rounding direction `roundTiesToAway`. Differential Revision: https://reviews.llvm.org/D77379
84 lines
2.6 KiB
C++
84 lines
2.6 KiB
C++
//===-- FPEnv.cpp ---- FP Environment -------------------------------------===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
/// @file
|
|
/// This file contains the implementations of entities that describe floating
|
|
/// point environment.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/ADT/StringSwitch.h"
|
|
#include "llvm/IR/FPEnv.h"
|
|
|
|
namespace llvm {
|
|
|
|
Optional<RoundingMode> StrToRoundingMode(StringRef RoundingArg) {
|
|
// For dynamic rounding mode, we use round to nearest but we will set the
|
|
// 'exact' SDNodeFlag so that the value will not be rounded.
|
|
return StringSwitch<Optional<RoundingMode>>(RoundingArg)
|
|
.Case("round.dynamic", RoundingMode::Dynamic)
|
|
.Case("round.tonearest", RoundingMode::NearestTiesToEven)
|
|
.Case("round.tonearestaway", RoundingMode::NearestTiesToAway)
|
|
.Case("round.downward", RoundingMode::TowardNegative)
|
|
.Case("round.upward", RoundingMode::TowardPositive)
|
|
.Case("round.towardzero", RoundingMode::TowardZero)
|
|
.Default(None);
|
|
}
|
|
|
|
Optional<StringRef> RoundingModeToStr(RoundingMode UseRounding) {
|
|
Optional<StringRef> RoundingStr = None;
|
|
switch (UseRounding) {
|
|
case RoundingMode::Dynamic:
|
|
RoundingStr = "round.dynamic";
|
|
break;
|
|
case RoundingMode::NearestTiesToEven:
|
|
RoundingStr = "round.tonearest";
|
|
break;
|
|
case RoundingMode::NearestTiesToAway:
|
|
RoundingStr = "round.tonearestaway";
|
|
break;
|
|
case RoundingMode::TowardNegative:
|
|
RoundingStr = "round.downward";
|
|
break;
|
|
case RoundingMode::TowardPositive:
|
|
RoundingStr = "round.upward";
|
|
break;
|
|
case RoundingMode::TowardZero:
|
|
RoundingStr = "round.towardzero";
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
return RoundingStr;
|
|
}
|
|
|
|
Optional<fp::ExceptionBehavior> StrToExceptionBehavior(StringRef ExceptionArg) {
|
|
return StringSwitch<Optional<fp::ExceptionBehavior>>(ExceptionArg)
|
|
.Case("fpexcept.ignore", fp::ebIgnore)
|
|
.Case("fpexcept.maytrap", fp::ebMayTrap)
|
|
.Case("fpexcept.strict", fp::ebStrict)
|
|
.Default(None);
|
|
}
|
|
|
|
Optional<StringRef> ExceptionBehaviorToStr(fp::ExceptionBehavior UseExcept) {
|
|
Optional<StringRef> ExceptStr = None;
|
|
switch (UseExcept) {
|
|
case fp::ebStrict:
|
|
ExceptStr = "fpexcept.strict";
|
|
break;
|
|
case fp::ebIgnore:
|
|
ExceptStr = "fpexcept.ignore";
|
|
break;
|
|
case fp::ebMayTrap:
|
|
ExceptStr = "fpexcept.maytrap";
|
|
break;
|
|
}
|
|
return ExceptStr;
|
|
}
|
|
}
|