From c7ff5b38f27f812dcd6e2e8732208a39232dc284 Mon Sep 17 00:00:00 2001 From: Serge Pavlov Date: Thu, 26 Mar 2020 14:51:09 +0700 Subject: [FPEnv] Use single enum to represent rounding mode 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 --- clang/lib/CodeGen/CodeGenFunction.cpp | 22 +++------------------- 1 file changed, 3 insertions(+), 19 deletions(-) (limited to 'clang/lib/CodeGen/CodeGenFunction.cpp') diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp index b01a5a4..05bf70e 100644 --- a/clang/lib/CodeGen/CodeGenFunction.cpp +++ b/clang/lib/CodeGen/CodeGenFunction.cpp @@ -115,21 +115,6 @@ CodeGenFunction::~CodeGenFunction() { OMPBuilder->finalize(); } -// Map the LangOption for rounding mode into -// the corresponding enum in the IR. -static llvm::fp::RoundingMode ToConstrainedRoundingMD( - LangOptions::FPRoundingModeKind Kind) { - - switch (Kind) { - case LangOptions::FPR_ToNearest: return llvm::fp::rmToNearest; - case LangOptions::FPR_Downward: return llvm::fp::rmDownward; - case LangOptions::FPR_Upward: return llvm::fp::rmUpward; - case LangOptions::FPR_TowardZero: return llvm::fp::rmTowardZero; - case LangOptions::FPR_Dynamic: return llvm::fp::rmDynamic; - } - llvm_unreachable("Unsupported FP RoundingMode"); -} - // Map the LangOption for exception behavior into // the corresponding enum in the IR. static llvm::fp::ExceptionBehavior ToConstrainedExceptMD( @@ -144,18 +129,17 @@ static llvm::fp::ExceptionBehavior ToConstrainedExceptMD( } void CodeGenFunction::SetFPModel() { - auto fpRoundingMode = ToConstrainedRoundingMD( - getLangOpts().getFPRoundingMode()); + llvm::RoundingMode RM = getLangOpts().getFPRoundingMode(); auto fpExceptionBehavior = ToConstrainedExceptMD( getLangOpts().getFPExceptionMode()); if (fpExceptionBehavior == llvm::fp::ebIgnore && - fpRoundingMode == llvm::fp::rmToNearest) + RM == llvm::RoundingMode::NearestTiesToEven) // Constrained intrinsics are not used. ; else { Builder.setIsFPConstrained(true); - Builder.setDefaultConstrainedRounding(fpRoundingMode); + Builder.setDefaultConstrainedRounding(RM); Builder.setDefaultConstrainedExcept(fpExceptionBehavior); } } -- cgit v1.1