| // Copyright 2023 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| #include "textflag.h" |
| |
| #define PosInf 0x7FF0000000000000 |
| |
| // The rounding mode of RISC-V is different from Go spec. |
| |
| #define ROUNDFN(NAME, MODE) \ |
| TEXT NAME(SB),NOSPLIT,$0; \ |
| MOVD x+0(FP), F0; \ |
| /* whether x is NaN */; \ |
| FEQD F0, F0, X6; \ |
| BNEZ X6, 3(PC); \ |
| /* return NaN if x is NaN */; \ |
| MOVD F0, ret+8(FP); \ |
| RET; \ |
| MOV $PosInf, X6; \ |
| FMVDX X6, F1; \ |
| FABSD F0, F2; \ |
| /* if abs(x) > +Inf, return Inf instead of round(x) */; \ |
| FLTD F1, F2, X6; \ |
| /* Inf should keep same signed with x then return */; \ |
| BEQZ X6, 3(PC); \ |
| FCVTLD.MODE F0, X6; \ |
| FCVTDL X6, F1; \ |
| /* rounding will drop signed bit in RISCV, restore it */; \ |
| FSGNJD F0, F1, F0; \ |
| MOVD F0, ret+8(FP); \ |
| RET |
| |
| // func archFloor(x float64) float64 |
| ROUNDFN(·archFloor, RDN) |
| |
| // func archCeil(x float64) float64 |
| ROUNDFN(·archCeil, RUP) |
| |
| // func archTrunc(x float64) float64 |
| ROUNDFN(·archTrunc, RTZ) |
