Author: Timm Bäder Date: 2023-08-01T16:32:29+02:00 New Revision: 1684406e63b75d81707900c442a8c69c95640338
URL: https://github.com/llvm/llvm-project/commit/1684406e63b75d81707900c442a8c69c95640338 DIFF: https://github.com/llvm/llvm-project/commit/1684406e63b75d81707900c442a8c69c95640338.diff LOG: [clang][Interp] Implement __builtin_fabs() Differential Revision: https://reviews.llvm.org/D155400 Added: Modified: clang/lib/AST/Interp/Floating.h clang/lib/AST/Interp/InterpBuiltin.cpp clang/test/AST/Interp/builtin-functions.cpp Removed: ################################################################################ diff --git a/clang/lib/AST/Interp/Floating.h b/clang/lib/AST/Interp/Floating.h index 60e7ce2461aadc..b0fae4562b7830 100644 --- a/clang/lib/AST/Interp/Floating.h +++ b/clang/lib/AST/Interp/Floating.h @@ -119,6 +119,13 @@ class Floating final { return Status; } + static Floating abs(const Floating &F) { + APFloat V = F.F; + if (V.isNegative()) + V.changeSign(); + return Floating(V); + } + // ------- static APFloat::opStatus add(const Floating &A, const Floating &B, diff --git a/clang/lib/AST/Interp/InterpBuiltin.cpp b/clang/lib/AST/Interp/InterpBuiltin.cpp index 714fa9ee02ce13..0f269ae5a329df 100644 --- a/clang/lib/AST/Interp/InterpBuiltin.cpp +++ b/clang/lib/AST/Interp/InterpBuiltin.cpp @@ -266,6 +266,20 @@ static bool interp__builtin_fpclassify(InterpState &S, CodePtr OpPC, return true; } +// The C standard says "fabs raises no floating-point exceptions, +// even if x is a signaling NaN. The returned value is independent of +// the current rounding direction mode." Therefore constant folding can +// proceed without regard to the floating point settings. +// Reference, WG14 N2478 F.10.4.3 +static bool interp__builtin_fabs(InterpState &S, CodePtr OpPC, + const InterpFrame *Frame, + const Function *Func) { + const Floating &Val = getParam<Floating>(Frame, 0); + + S.Stk.push<Floating>(Floating::abs(Val)); + return true; +} + bool InterpretBuiltin(InterpState &S, CodePtr OpPC, const Function *F) { InterpFrame *Frame = S.Current; APValue Dummy; @@ -359,6 +373,14 @@ bool InterpretBuiltin(InterpState &S, CodePtr OpPC, const Function *F) { return Ret<PT_Sint32>(S, OpPC, Dummy); break; + case Builtin::BI__builtin_fabs: + case Builtin::BI__builtin_fabsf: + case Builtin::BI__builtin_fabsl: + case Builtin::BI__builtin_fabsf128: + if (interp__builtin_fabs(S, OpPC, Frame, F)) + return Ret<PT_Float>(S, OpPC, Dummy); + break; + default: return false; } diff --git a/clang/test/AST/Interp/builtin-functions.cpp b/clang/test/AST/Interp/builtin-functions.cpp index e3fabecf8c9378..5b8b2dbf09ce5e 100644 --- a/clang/test/AST/Interp/builtin-functions.cpp +++ b/clang/test/AST/Interp/builtin-functions.cpp @@ -140,3 +140,7 @@ namespace fpclassify { char classify_neg_zero[__builtin_fpclassify(-1, -1, -1, -1, +1, -0.0)]; char classify_subnorm [__builtin_fpclassify(-1, -1, -1, +1, -1, 1.0e-38f)]; } + +namespace fabs { + static_assert(__builtin_fabs(-14.0) == 14.0, ""); +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
