qemu/target/arm/vfp.decode

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# AArch32 VFP instruction descriptions (conditional insns)
#
# Copyright (c) 2019 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/>.
#
# This file is processed by scripts/decodetree.py
#
# Encodings for the conditional VFP instructions are here:
# generally anything matching A32
# cccc 11.. .... .... .... 101. .... ....
# and T32
# 1110 110. .... .... .... 101. .... ....
# 1110 1110 .... .... .... 101. .... ....
# (but those patterns might also cover some Neon instructions,
# which do not live in this file.)
# VFP registers have an odd encoding with a four-bit field
# and a one-bit field which are assembled in different orders
# depending on whether the register is double or single precision.
# Each individual instruction function must do the checks for
# "double register selected but CPU does not have double support"
# and "double register number has bit 4 set but CPU does not
# support D16-D31" (which should UNDEF).
%vm_dp 5:1 0:4
%vm_sp 0:4 5:1
%vn_dp 7:1 16:4
%vn_sp 16:4 7:1
%vd_dp 22:1 12:4
%vd_sp 12:4 22:1
%vmov_idx_b 21:1 5:2
%vmov_idx_h 21:1 6:1
# VMOV scalar to general-purpose register; note that this does
# include some Neon cases.
VMOV_to_gp ---- 1110 u:1 1. 1 .... rt:4 1011 ... 1 0000 \
vn=%vn_dp size=0 index=%vmov_idx_b
VMOV_to_gp ---- 1110 u:1 0. 1 .... rt:4 1011 ..1 1 0000 \
vn=%vn_dp size=1 index=%vmov_idx_h
VMOV_to_gp ---- 1110 0 0 index:1 1 .... rt:4 1011 .00 1 0000 \
vn=%vn_dp size=2 u=0
VMOV_from_gp ---- 1110 0 1. 0 .... rt:4 1011 ... 1 0000 \
vn=%vn_dp size=0 index=%vmov_idx_b
VMOV_from_gp ---- 1110 0 0. 0 .... rt:4 1011 ..1 1 0000 \
vn=%vn_dp size=1 index=%vmov_idx_h
VMOV_from_gp ---- 1110 0 0 index:1 0 .... rt:4 1011 .00 1 0000 \
vn=%vn_dp size=2
VDUP ---- 1110 1 b:1 q:1 0 .... rt:4 1011 . 0 e:1 1 0000 \
vn=%vn_dp
VMSR_VMRS ---- 1110 111 l:1 reg:4 rt:4 1010 0001 0000
VMOV_single ---- 1110 000 l:1 .... rt:4 1010 . 001 0000 \
vn=%vn_sp
VMOV_64_sp ---- 1100 010 op:1 rt2:4 rt:4 1010 00.1 .... \
vm=%vm_sp
VMOV_64_dp ---- 1100 010 op:1 rt2:4 rt:4 1011 00.1 .... \
vm=%vm_dp
# Note that the half-precision variants of VLDR and VSTR are
# not part of this decodetree at all because they have bits [9:8] == 0b01
VLDR_VSTR_sp ---- 1101 u:1 .0 l:1 rn:4 .... 1010 imm:8 \
vd=%vd_sp
VLDR_VSTR_dp ---- 1101 u:1 .0 l:1 rn:4 .... 1011 imm:8 \
vd=%vd_dp
# We split the load/store multiple up into two patterns to avoid
# overlap with other insns in the "Advanced SIMD load/store and 64-bit move"
# grouping:
# P=0 U=0 W=0 is 64-bit VMOV
# P=1 W=0 is VLDR/VSTR
# P=U W=1 is UNDEF
# leaving P=0 U=1 W=x and P=1 U=0 W=1 for load/store multiple.
# These include FSTM/FLDM.
VLDM_VSTM_sp ---- 1100 1 . w:1 l:1 rn:4 .... 1010 imm:8 \
vd=%vd_sp p=0 u=1
VLDM_VSTM_dp ---- 1100 1 . w:1 l:1 rn:4 .... 1011 imm:8 \
vd=%vd_dp p=0 u=1
VLDM_VSTM_sp ---- 1101 0.1 l:1 rn:4 .... 1010 imm:8 \
vd=%vd_sp p=1 u=0 w=1
VLDM_VSTM_dp ---- 1101 0.1 l:1 rn:4 .... 1011 imm:8 \
vd=%vd_dp p=1 u=0 w=1
target/arm: Convert VFP VMLA to decodetree Convert the VFP VMLA instruction to decodetree. This is the first of the VFP 3-operand data processing instructions, so we include in this patch the code which loops over the elements for an old-style VFP vector operation. The existing code to do this looping uses the deprecated cpu_F0s/F0d/F1s/F1d TCG globals; since we are going to be converting instructions one at a time anyway we can take the opportunity to make the new loop use TCG temporaries, which means we can do that conversion one operation at a time rather than needing to do it all in one go. We include an UNDEF check which was missing in the old code: short-vector operations (with stride or length non-zero) were deprecated in v7A and must UNDEF in v8A, so if the MVFR0 FPShVec field does not indicate that support for short vectors is present we UNDEF the operations that would use them. (This is a change of behaviour for Cortex-A7, Cortex-A15 and the v8 CPUs, which previously were all incorrectly allowing short-vector operations.) Note that the conversion fixes a bug in the old code for the case of VFP short-vector "mixed scalar/vector operations". These happen where the destination register is in a vector bank but but the second operand is in a scalar bank. For example vmla.f64 d10, d1, d16 with length 2 stride 2 is equivalent to the pair of scalar operations vmla.f64 d10, d1, d16 vmla.f64 d8, d3, d16 where the destination and first input register cycle through their vector but the second input is scalar (d16). In the old decoder the gen_vfp_F1_mul() operation uses cpu_F1{s,d} as a temporary output for the multiply, which trashes the second input operand. For the fully-scalar case (where we never do a second iteration) and the fully-vector case (where the loop loads the new second input operand) this doesn't matter, but for the mixed scalar/vector case we will end up using the wrong value for later loop iterations. In the new code we use TCG temporaries and so avoid the bug. This bug is present for all the multiply-accumulate insns that operate on short vectors: VMLA, VMLS, VNMLA, VNMLS. Note 2: the expression used to calculate the next register number in the vector bank is not in fact correct; we leave this behaviour unchanged from the old decoder and will fix this bug later in the series. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
2019-06-11 23:39:46 +08:00
# 3-register VFP data-processing; bits [23,21:20,6] identify the operation.
VMLA_sp ---- 1110 0.00 .... .... 1010 .0.0 .... \
vm=%vm_sp vn=%vn_sp vd=%vd_sp
VMLA_dp ---- 1110 0.00 .... .... 1011 .0.0 .... \
vm=%vm_dp vn=%vn_dp vd=%vd_dp
VMLS_sp ---- 1110 0.00 .... .... 1010 .1.0 .... \
vm=%vm_sp vn=%vn_sp vd=%vd_sp
VMLS_dp ---- 1110 0.00 .... .... 1011 .1.0 .... \
vm=%vm_dp vn=%vn_dp vd=%vd_dp
VNMLS_sp ---- 1110 0.01 .... .... 1010 .0.0 .... \
vm=%vm_sp vn=%vn_sp vd=%vd_sp
VNMLS_dp ---- 1110 0.01 .... .... 1011 .0.0 .... \
vm=%vm_dp vn=%vn_dp vd=%vd_dp
VNMLA_sp ---- 1110 0.01 .... .... 1010 .1.0 .... \
vm=%vm_sp vn=%vn_sp vd=%vd_sp
VNMLA_dp ---- 1110 0.01 .... .... 1011 .1.0 .... \
vm=%vm_dp vn=%vn_dp vd=%vd_dp
VMUL_sp ---- 1110 0.10 .... .... 1010 .0.0 .... \
vm=%vm_sp vn=%vn_sp vd=%vd_sp
VMUL_dp ---- 1110 0.10 .... .... 1011 .0.0 .... \
vm=%vm_dp vn=%vn_dp vd=%vd_dp
VNMUL_sp ---- 1110 0.10 .... .... 1010 .1.0 .... \
vm=%vm_sp vn=%vn_sp vd=%vd_sp
VNMUL_dp ---- 1110 0.10 .... .... 1011 .1.0 .... \
vm=%vm_dp vn=%vn_dp vd=%vd_dp
VADD_sp ---- 1110 0.11 .... .... 1010 .0.0 .... \
vm=%vm_sp vn=%vn_sp vd=%vd_sp
VADD_dp ---- 1110 0.11 .... .... 1011 .0.0 .... \
vm=%vm_dp vn=%vn_dp vd=%vd_dp
VSUB_sp ---- 1110 0.11 .... .... 1010 .1.0 .... \
vm=%vm_sp vn=%vn_sp vd=%vd_sp
VSUB_dp ---- 1110 0.11 .... .... 1011 .1.0 .... \
vm=%vm_dp vn=%vn_dp vd=%vd_dp
VDIV_sp ---- 1110 1.00 .... .... 1010 .0.0 .... \
vm=%vm_sp vn=%vn_sp vd=%vd_sp
VDIV_dp ---- 1110 1.00 .... .... 1011 .0.0 .... \
vm=%vm_dp vn=%vn_dp vd=%vd_dp
VFM_sp ---- 1110 1.01 .... .... 1010 . o2:1 . 0 .... \
vm=%vm_sp vn=%vn_sp vd=%vd_sp o1=1
VFM_dp ---- 1110 1.01 .... .... 1011 . o2:1 . 0 .... \
vm=%vm_dp vn=%vn_dp vd=%vd_dp o1=1
VFM_sp ---- 1110 1.10 .... .... 1010 . o2:1 . 0 .... \
vm=%vm_sp vn=%vn_sp vd=%vd_sp o1=2
VFM_dp ---- 1110 1.10 .... .... 1011 . o2:1 . 0 .... \
vm=%vm_dp vn=%vn_dp vd=%vd_dp o1=2
VMOV_imm_sp ---- 1110 1.11 imm4h:4 .... 1010 0000 imm4l:4 \
vd=%vd_sp
VMOV_imm_dp ---- 1110 1.11 imm4h:4 .... 1011 0000 imm4l:4 \
vd=%vd_dp
VMOV_reg_sp ---- 1110 1.11 0000 .... 1010 01.0 .... \
vd=%vd_sp vm=%vm_sp
VMOV_reg_dp ---- 1110 1.11 0000 .... 1011 01.0 .... \
vd=%vd_dp vm=%vm_dp
VABS_sp ---- 1110 1.11 0000 .... 1010 11.0 .... \
vd=%vd_sp vm=%vm_sp
VABS_dp ---- 1110 1.11 0000 .... 1011 11.0 .... \
vd=%vd_dp vm=%vm_dp
VNEG_sp ---- 1110 1.11 0001 .... 1010 01.0 .... \
vd=%vd_sp vm=%vm_sp
VNEG_dp ---- 1110 1.11 0001 .... 1011 01.0 .... \
vd=%vd_dp vm=%vm_dp
VSQRT_sp ---- 1110 1.11 0001 .... 1010 11.0 .... \
vd=%vd_sp vm=%vm_sp
VSQRT_dp ---- 1110 1.11 0001 .... 1011 11.0 .... \
vd=%vd_dp vm=%vm_dp
VCMP_sp ---- 1110 1.11 010 z:1 .... 1010 e:1 1.0 .... \
vd=%vd_sp vm=%vm_sp
VCMP_dp ---- 1110 1.11 010 z:1 .... 1011 e:1 1.0 .... \
vd=%vd_dp vm=%vm_dp
# VCVTT and VCVTB from f16: Vd format depends on size bit; Vm is always vm_sp
VCVT_f32_f16 ---- 1110 1.11 0010 .... 1010 t:1 1.0 .... \
vd=%vd_sp vm=%vm_sp
VCVT_f64_f16 ---- 1110 1.11 0010 .... 1011 t:1 1.0 .... \
vd=%vd_dp vm=%vm_sp
# VCVTB and VCVTT to f16: Vd format is always vd_sp; Vm format depends on size bit
VCVT_f16_f32 ---- 1110 1.11 0011 .... 1010 t:1 1.0 .... \
vd=%vd_sp vm=%vm_sp
VCVT_f16_f64 ---- 1110 1.11 0011 .... 1011 t:1 1.0 .... \
vd=%vd_sp vm=%vm_dp
VRINTR_sp ---- 1110 1.11 0110 .... 1010 01.0 .... \
vd=%vd_sp vm=%vm_sp
VRINTR_dp ---- 1110 1.11 0110 .... 1011 01.0 .... \
vd=%vd_dp vm=%vm_dp
VRINTZ_sp ---- 1110 1.11 0110 .... 1010 11.0 .... \
vd=%vd_sp vm=%vm_sp
VRINTZ_dp ---- 1110 1.11 0110 .... 1011 11.0 .... \
vd=%vd_dp vm=%vm_dp
VRINTX_sp ---- 1110 1.11 0111 .... 1010 01.0 .... \
vd=%vd_sp vm=%vm_sp
VRINTX_dp ---- 1110 1.11 0111 .... 1011 01.0 .... \
vd=%vd_dp vm=%vm_dp
# VCVT between single and double: Vm precision depends on size; Vd is its reverse
VCVT_sp ---- 1110 1.11 0111 .... 1010 11.0 .... \
vd=%vd_dp vm=%vm_sp
VCVT_dp ---- 1110 1.11 0111 .... 1011 11.0 .... \
vd=%vd_sp vm=%vm_dp