target/arm: Implement SVE predicate test

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180516223007.10256-6-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Richard Henderson 2018-05-18 17:48:08 +01:00 committed by Peter Maydell
parent d1822297f6
commit 9e18d7a67f
6 changed files with 171 additions and 1 deletions

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@ -19,4 +19,4 @@ target/arm/decode-sve.inc.c: $(SRC_PATH)/target/arm/sve.decode $(DECODETREE)
"GEN", $(TARGET_DIR)$@)
target/arm/translate-sve.o: target/arm/decode-sve.inc.c
obj-$(TARGET_AARCH64) += translate-sve.o
obj-$(TARGET_AARCH64) += translate-sve.o sve_helper.o

21
target/arm/helper-sve.h Normal file
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@ -0,0 +1,21 @@
/*
* AArch64 SVE specific helper definitions
*
* Copyright (c) 2018 Linaro, Ltd
*
* 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 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/>.
*/
DEF_HELPER_FLAGS_2(sve_predtest1, TCG_CALL_NO_WG, i32, i64, i64)
DEF_HELPER_FLAGS_3(sve_predtest, TCG_CALL_NO_WG, i32, ptr, ptr, i32)

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@ -603,4 +603,5 @@ DEF_HELPER_FLAGS_5(gvec_fcmlad, TCG_CALL_NO_RWG,
#ifdef TARGET_AARCH64
#include "helper-a64.h"
#include "helper-sve.h"
#endif

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@ -56,6 +56,11 @@ ORR_zzz 00000100 01 1 ..... 001 100 ..... ..... @rd_rn_rm_e0
EOR_zzz 00000100 10 1 ..... 001 100 ..... ..... @rd_rn_rm_e0
BIC_zzz 00000100 11 1 ..... 001 100 ..... ..... @rd_rn_rm_e0
### SVE Predicate Misc Group
# SVE predicate test
PTEST 00100101 01 010000 11 pg:4 0 rn:4 0 0000
### SVE Memory - 32-bit Gather and Unsized Contiguous Group
# SVE load predicate register

78
target/arm/sve_helper.c Normal file
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@ -0,0 +1,78 @@
/*
* ARM SVE Operations
*
* Copyright (c) 2018 Linaro, Ltd.
*
* 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 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/>.
*/
#include "qemu/osdep.h"
#include "cpu.h"
#include "exec/exec-all.h"
#include "exec/cpu_ldst.h"
#include "exec/helper-proto.h"
#include "tcg/tcg-gvec-desc.h"
/* Return a value for NZCV as per the ARM PredTest pseudofunction.
*
* The return value has bit 31 set if N is set, bit 1 set if Z is clear,
* and bit 0 set if C is set. Compare the definitions of these variables
* within CPUARMState.
*/
/* For no G bits set, NZCV = C. */
#define PREDTEST_INIT 1
/* This is an iterative function, called for each Pd and Pg word
* moving forward.
*/
static uint32_t iter_predtest_fwd(uint64_t d, uint64_t g, uint32_t flags)
{
if (likely(g)) {
/* Compute N from first D & G.
Use bit 2 to signal first G bit seen. */
if (!(flags & 4)) {
flags |= ((d & (g & -g)) != 0) << 31;
flags |= 4;
}
/* Accumulate Z from each D & G. */
flags |= ((d & g) != 0) << 1;
/* Compute C from last !(D & G). Replace previous. */
flags = deposit32(flags, 0, 1, (d & pow2floor(g)) == 0);
}
return flags;
}
/* The same for a single word predicate. */
uint32_t HELPER(sve_predtest1)(uint64_t d, uint64_t g)
{
return iter_predtest_fwd(d, g, PREDTEST_INIT);
}
/* The same for a multi-word predicate. */
uint32_t HELPER(sve_predtest)(void *vd, void *vg, uint32_t words)
{
uint32_t flags = PREDTEST_INIT;
uint64_t *d = vd, *g = vg;
uintptr_t i = 0;
do {
flags = iter_predtest_fwd(d[i], g[i], flags);
} while (++i < words);
return flags;
}

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@ -87,6 +87,43 @@ static bool do_mov_z(DisasContext *s, int rd, int rn)
return do_vector2_z(s, tcg_gen_gvec_mov, 0, rd, rn);
}
/* Set the cpu flags as per a return from an SVE helper. */
static void do_pred_flags(TCGv_i32 t)
{
tcg_gen_mov_i32(cpu_NF, t);
tcg_gen_andi_i32(cpu_ZF, t, 2);
tcg_gen_andi_i32(cpu_CF, t, 1);
tcg_gen_movi_i32(cpu_VF, 0);
}
/* Subroutines computing the ARM PredTest psuedofunction. */
static void do_predtest1(TCGv_i64 d, TCGv_i64 g)
{
TCGv_i32 t = tcg_temp_new_i32();
gen_helper_sve_predtest1(t, d, g);
do_pred_flags(t);
tcg_temp_free_i32(t);
}
static void do_predtest(DisasContext *s, int dofs, int gofs, int words)
{
TCGv_ptr dptr = tcg_temp_new_ptr();
TCGv_ptr gptr = tcg_temp_new_ptr();
TCGv_i32 t;
tcg_gen_addi_ptr(dptr, cpu_env, dofs);
tcg_gen_addi_ptr(gptr, cpu_env, gofs);
t = tcg_const_i32(words);
gen_helper_sve_predtest(t, dptr, gptr, t);
tcg_temp_free_ptr(dptr);
tcg_temp_free_ptr(gptr);
do_pred_flags(t);
tcg_temp_free_i32(t);
}
/*
*** SVE Logical - Unpredicated Group
*/
@ -115,6 +152,34 @@ static bool trans_BIC_zzz(DisasContext *s, arg_rrr_esz *a, uint32_t insn)
return do_vector3_z(s, tcg_gen_gvec_andc, 0, a->rd, a->rn, a->rm);
}
/*
*** SVE Predicate Misc Group
*/
static bool trans_PTEST(DisasContext *s, arg_PTEST *a, uint32_t insn)
{
if (sve_access_check(s)) {
int nofs = pred_full_reg_offset(s, a->rn);
int gofs = pred_full_reg_offset(s, a->pg);
int words = DIV_ROUND_UP(pred_full_reg_size(s), 8);
if (words == 1) {
TCGv_i64 pn = tcg_temp_new_i64();
TCGv_i64 pg = tcg_temp_new_i64();
tcg_gen_ld_i64(pn, cpu_env, nofs);
tcg_gen_ld_i64(pg, cpu_env, gofs);
do_predtest1(pn, pg);
tcg_temp_free_i64(pn);
tcg_temp_free_i64(pg);
} else {
do_predtest(s, nofs, gofs, words);
}
}
return true;
}
/*
*** SVE Memory - 32-bit Gather and Unsized Contiguous Group
*/