Adhemerval Zanella c288715e95 [compiler-rt] [builtins] Use _Float16 on extendhfsf2, truncdfhf2 __truncsfhf2 if available
On AArch64 it allows use the native FP16 ABI (although libcalls are
not emitted for fptrunc/fpext lowering), while on other architectures
the expected current semantic is preserved (arm for instance).

For testing the _Float16 usage is enabled by architecture base,
currently only for arm, aarch64, and arm64.

This re-enabled revert done by https://reviews.llvm.org/rGb534beabeed3ba1777cd0ff9ce552d077e496726

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D92241
2020-12-03 16:08:55 -03:00

86 lines
2.1 KiB
C

//=== lib/fp_trunc.h - high precision -> low precision conversion *- C -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// Set source and destination precision setting
//
//===----------------------------------------------------------------------===//
#ifndef FP_TRUNC_HEADER
#define FP_TRUNC_HEADER
#include "int_lib.h"
#if defined SRC_SINGLE
typedef float src_t;
typedef uint32_t src_rep_t;
#define SRC_REP_C UINT32_C
static const int srcSigBits = 23;
#elif defined SRC_DOUBLE
typedef double src_t;
typedef uint64_t src_rep_t;
#define SRC_REP_C UINT64_C
static const int srcSigBits = 52;
#elif defined SRC_QUAD
typedef long double src_t;
typedef __uint128_t src_rep_t;
#define SRC_REP_C (__uint128_t)
static const int srcSigBits = 112;
#else
#error Source should be double precision or quad precision!
#endif // end source precision
#if defined DST_DOUBLE
typedef double dst_t;
typedef uint64_t dst_rep_t;
#define DST_REP_C UINT64_C
static const int dstSigBits = 52;
#elif defined DST_SINGLE
typedef float dst_t;
typedef uint32_t dst_rep_t;
#define DST_REP_C UINT32_C
static const int dstSigBits = 23;
#elif defined DST_HALF
#ifdef COMPILER_RT_HAS_FLOAT16
typedef _Float16 dst_t;
#else
typedef uint16_t dst_t;
#endif
typedef uint16_t dst_rep_t;
#define DST_REP_C UINT16_C
static const int dstSigBits = 10;
#else
#error Destination should be single precision or double precision!
#endif // end destination precision
// End of specialization parameters. Two helper routines for conversion to and
// from the representation of floating-point data as integer values follow.
static __inline src_rep_t srcToRep(src_t x) {
const union {
src_t f;
src_rep_t i;
} rep = {.f = x};
return rep.i;
}
static __inline dst_t dstFromRep(dst_rep_t x) {
const union {
dst_t f;
dst_rep_t i;
} rep = {.i = x};
return rep.f;
}
#endif // FP_TRUNC_HEADER