qemu/include/tcg/tcg-gvec-desc.h
Richard Henderson e2e7168a21 tcg: Adjust simd_desc size encoding
With larger vector sizes, it turns out oprsz == maxsz, and we only
need to represent mismatch for oprsz <= 32.  We do, however, need
to represent larger oprsz and do so without reducing SIMD_DATA_BITS.

Reduce the size of the oprsz field and increase the maxsz field.
Steal the oprsz value of 24 to indicate equality with maxsz.

Tested-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2020-10-08 05:57:32 -05:00

66 lines
2.1 KiB
C

/*
* Generic vector operation descriptor
*
* Copyright (c) 2018 Linaro
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#ifndef TCG_TCG_GVEC_DESC_H
#define TCG_TCG_GVEC_DESC_H
/*
* This configuration allows MAXSZ to represent 2048 bytes, and
* OPRSZ to match MAXSZ, or represent the smaller values 8, 16, or 32.
*
* Encode this with:
* 0, 1, 3 -> 8, 16, 32
* 2 -> maxsz
*
* This steals the input that would otherwise map to 24 to match maxsz.
*/
#define SIMD_MAXSZ_SHIFT 0
#define SIMD_MAXSZ_BITS 8
#define SIMD_OPRSZ_SHIFT (SIMD_MAXSZ_SHIFT + SIMD_MAXSZ_BITS)
#define SIMD_OPRSZ_BITS 2
#define SIMD_DATA_SHIFT (SIMD_OPRSZ_SHIFT + SIMD_OPRSZ_BITS)
#define SIMD_DATA_BITS (32 - SIMD_DATA_SHIFT)
/* Create a descriptor from components. */
uint32_t simd_desc(uint32_t oprsz, uint32_t maxsz, int32_t data);
/* Extract the max vector size from a descriptor. */
static inline intptr_t simd_maxsz(uint32_t desc)
{
return extract32(desc, SIMD_MAXSZ_SHIFT, SIMD_MAXSZ_BITS) * 8 + 8;
}
/* Extract the operation size from a descriptor. */
static inline intptr_t simd_oprsz(uint32_t desc)
{
uint32_t f = extract32(desc, SIMD_OPRSZ_SHIFT, SIMD_OPRSZ_BITS);
intptr_t o = f * 8 + 8;
intptr_t m = simd_maxsz(desc);
return f == 2 ? m : o;
}
/* Extract the operation-specific data from a descriptor. */
static inline int32_t simd_data(uint32_t desc)
{
return sextract32(desc, SIMD_DATA_SHIFT, SIMD_DATA_BITS);
}
#endif