Initial import

libc/tinymath/roundf.S

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+/*-*- mode:asm; indent-tabs-mode:t; tab-width:8; coding:utf-8               -*-│
+│vi: set et ft=asm ts=8 tw=8 fenc=utf-8                                     :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ This program is free software; you can redistribute it and/or modify         │
+│ it under the terms of the GNU General Public License as published by         │
+│ the Free Software Foundation; version 2 of the License.                      │
+│                                                                              │
+│ This program is distributed in the hope that it will be useful, but          │
+│ WITHOUT ANY WARRANTY; without even the implied warranty of                   │
+│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU             │
+│ General Public License for more details.                                     │
+│                                                                              │
+│ You should have received a copy of the GNU General Public License            │
+│ along with this program; if not, write to the Free Software                  │
+│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA                │
+│ 02110-1301 USA                                                               │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/macros.h"
+#include "libc/bits/smmintrin.h"
+#include "libc/nexgen32e/x86feature.h"
+.yoink	__FILE__
+
+/	Rounds to nearest integer, away from zero.
+/
+/	@param	𝑥 is float scalar in low quarter of %xmm0
+/	@return	float scalar in low quarter of %xmm0
+tinymath_roundf:
+#if !X86_NEED(SSE4_2)
+	testb	X86_HAVE(SSE4_2)+kCpuids(%rip)
+	jz	tinymath_roundf$k8
+	.text.antiquity
+tinymath_roundf$k8:
+	.leafprologue
+	.profilable
+	movaps	%xmm0,%xmm1
+	movss	D(%rip),%xmm2
+	movss	C(%rip),%xmm3
+	andps	%xmm2,%xmm1
+	ucomiss	%xmm1,%xmm3
+	jbe	2f
+	addss	A(%rip),%xmm1
+	cvttss2sil %xmm1,%eax
+	pxor	%xmm1,%xmm1
+	cvtsi2ssl %eax,%xmm1
+	andnps	%xmm0,%xmm2
+	movaps	%xmm2,%xmm0
+	orps	%xmm1,%xmm0
+2:	.leafepilogue
+	.endfn	tinymath_roundf$k8,globl,hidden
+	.previous
+	.rodata.cst16
+C:	.long	0x4b000000,0,0,0
+D:	.long	0x7fffffff,0,0,0
+	.previous
+#endif
+	movaps	%xmm0,%xmm1
+	andps	B(%rip),%xmm0
+	orps	A(%rip),%xmm0
+	addss	%xmm1,%xmm0
+	roundss $_MM_FROUND_TO_ZERO,%xmm0,%xmm0
+	ret
+	.endfn	tinymath_roundf,globl
+	.alias	tinymath_roundf,roundf
+
+	.rodata.cst16
+A:	.long	0x3effffff,0,0,0
+B:	.long	0x80000000,0,0,0