Because unallocated encodings generate different exception syndrome
information from traps due to FP being disabled, we can't do a single
"is fp access disabled" check at a high level in the decode tree.
To help in catching bugs where the access check was forgotten in some
code path, we set this flag when the access check is done, and assert
that it is set at the point where we actually touch the FP regs.

This requires us to pass the DisasContext to the vec_reg_offset
and fp_reg_offset functions.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>

For the A64 instruction set, the only FP/Neon disable trap
is the CPACR FPEN bits, which may indicate "enabled", "disabled"
or "disabled for EL0". Add a bit to the AArch64 tb flags indicating
whether FP/Neon access is currently enabled and make the decoder
emit code to raise exceptions on use of FP/Neon insns if it is not.

We use a new flag in DisasContext rather than borrowing the
existing vfp_enabled flag because the A32/T32 decoder is going
to need both.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Acked-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>
---
I'm aware this is a rather hard to review patch; sorry.
I have done an exhaustive check that we have fp access checks
in all code paths with the aid of the assertions added in the
next patch plus the code-coverage hack patch I posted to the
list earlier.

This patch is correct as of
09e03735 target-arm: A64: Add saturating accumulate ops (USQADD/SUQADD)
which was the last of the Neon insns to be added, so assuming
no refactoring of the code it should be fine.

Add new helpers exception_with_syndrome (for generating an exception
with syndrome information) and exception_uncategorized (for generating
an exception with "Unknown or Uncategorized Reason", which have a syndrome
register value of zero), and use them to generate the correct syndrome
information for exceptions which are raised directly from generated code.

This patch includes moving the A32/T32 gen_exception_insn functions
further up in the source file; they will be needed for "VFP/Neon disabled"
exception generation later.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>

For exceptions taken to AArch64, if a coprocessor/system register
access fails due to a trap or enable bit then the syndrome information
must include details of the failing instruction (crn/crm/opc1/opc2
fields, etc). Make the decoder construct the syndrome information
at translate time so it can be passed at runtime to the access-check
helper function and used as required.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>

Currently cpu.h defines a mixture of functions and types needed by
the rest of QEMU and those needed only by files within target-arm/.
Split the latter out into a new header so they aren't needlessly
exposed further than required.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>

The order of operands for the accumulate step in disas_simd_3same_int()
was reversed. This only affected the MLS instruction, since all the
other accumulating instructions in this category perform an addition
rather than a subtraction.
Reported-by: NLaurent Desnogues <laurent.desnogues@gmail.com>
Tested-by: NLaurent Desnogues <laurent.desnogues@gmail.com>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Add the saturating accumulate operations USQADD and SUQADD
to the A64 instruction set. This completes coverage of A64 Neon.
These operations (which are unsigned + signed -> signed and
signed + unsigned -> unsigned) don't exist in the A32/T32
instruction set, so require a complete new set of helper functions.
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>

This mostly re-uses the existing NEON helpers with an additional two for
the 64 bit case. I also took the opportunity to add TCG_CALL_NO_RWG
options to the helpers as they don't modify globals (saturation flags
are in the CPU Environment).
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>

This adds support for [UF]RSQRTE instructions. It utilises the existing
NEON helpers with some changes. The changes include an explicit passing
of fpstatus (so the correct one is used between arm32 and aarch64),
denormilzation, more correct error handling and also proper scaling of
the fraction going into the estimate.
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-25-git-send-email-peter.maydell@linaro.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Implement the FCVTXN operation, which does a narrowing fp precision
conversion using the "round to odd" (von Neumann) mode. This can
conveniently be implemented as "do operation using round to zero;
then set the LSB of the mantissa to 1 if the Inexact flag was set".
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-24-git-send-email-peter.maydell@linaro.org

This completes the set of integer narrowing saturating ops including:
     SQXTN, SQXTN2
     SQXTUN, SQXTUN2
     UQXTN, UQXTN2
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-23-git-send-email-peter.maydell@linaro.org

Move the handle_2misc_narrow() function up the file so that it can
be called from disas_simd_scalar_two_reg_misc().
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-22-git-send-email-peter.maydell@linaro.org

Implement URECPE and FRECPE instructions in both scalar and vector forms.
The actual reciprocal estimate function is shared with the A32/T32 Neon
code. However in A64 we aren't using the Neon "standard FPSCR value"
so extra checks are necessary to handle non-squashed denormal inputs
which can never happen for A32/T32. Calling conventions for the helpers
are thus modified to pass the fpst directly; we mark the helpers as
TCG_CALL_NO_RWG since we're changing the declarations anyway.
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-21-git-send-email-peter.maydell@linaro.org

Implement FCVTZS and FCVTZU in the shift-imm and scalar-shift-imm
categories; this completes the implementation of those two groups.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-19-git-send-email-peter.maydell@linaro.org

Implement the saturating left shift instructions SQSHL, SQSHLU
and UQSHL for the scalar-shift-imm and shift-imm categories.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-18-git-send-email-peter.maydell@linaro.org

Implement the FRINT* round-to-integral operations from
the 2-reg-misc category.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-16-git-send-email-peter.maydell@linaro.org

Implement SRI (shift right and insert).
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-15-git-send-email-peter.maydell@linaro.org

These are fairly simple exponent only estimation functions using helpers.
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-14-git-send-email-peter.maydell@linaro.org

Add the remaining unsupported opcodes to the decode switches
for the shift-imm and scalar shift-imm categories so we can
see what is still to be implemented.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-13-git-send-email-peter.maydell@linaro.org

Implement FCVTL, the only instruction in the 2-reg-misc group
which widens from size to 2*size elements.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-12-git-send-email-peter.maydell@linaro.org

Implement FCVTN (narrowing fp-to-fp conversions) from the SIMD
2-reg-misc category.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-11-git-send-email-peter.maydell@linaro.org

Implement the floating-point-to-integer conversion instructions
FCVT[NMAPZ][SU] in the 2-reg-misc and scalar-2-reg-misc
categories.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-10-git-send-email-peter.maydell@linaro.org

Implement the SHLL and SHLL2 instructions from the 2-reg-misc
category.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-9-git-send-email-peter.maydell@linaro.org

Implement the SADDLP, UADDLP, SADALP and UADALP instructions
in the SIMD 2-reg misc category.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-8-git-send-email-peter.maydell@linaro.org

This implements the remaining [US][Q][R]SHR[U][N][2] opcodes, which are
saturating and narrowing shift right operations. These are used in
things like libav. Note signed shifts can have an "unsigned" saturating
narrow operation which will floor negative values.
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Message-id: 1394822294-14837-7-git-send-email-peter.maydell@linaro.org
[PMM: Added the scalar encodings, style tweaks]
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Implement the CLS, CLZ operations in the 2-reg-misc category.
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-6-git-send-email-peter.maydell@linaro.org

Implement FSQRT in the two-reg-misc category.
GCC uses this instruction form.
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-5-git-send-email-peter.maydell@linaro.org

This adds the remaining [US]CVTF operations to the SIMD
shift-immediate, scalar-shift-immediate, two-reg-misc and
scalar-two-reg-misc groups of opcodes.
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Message-id: 1394822294-14837-4-git-send-email-peter.maydell@linaro.org
[PMM: added scalar 2-misc and scalar-shift-imm encodings]
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

rn == 31 always means SP (not XZR) whether an add_sub_ext
instruction is setting the flags or not; only rd has behaviour
dependent on whether we are setting flags.
Reported-by: NLaurent Desnogues <laurent.desnogues@gmail.com>
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-3-git-send-email-peter.maydell@linaro.org

Implement the PMULL instruction; this is the last unimplemented insn
in the three-reg-diff group.

Note that PMULL with size 3 is considered part of the AES part
of the crypto extensions (see the ID_AA64ISAR0_EL1 register definition
in the v8 ARM ARM), so it isn't necessary to burn an extra feature
bit on it, even though we're using more feature bits than a single
"crypto extension present/not present" toggle.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394822294-14837-2-git-send-email-peter.maydell@linaro.org

Most targets were using offsetof(CPUFooState, breakpoints) to determine
how much of CPUFooState to clear on reset. Use the next field after
CPU_COMMON instead, if any, or sizeof(CPUFooState) otherwise.
Signed-off-by: NAndreas Färber <afaerber@suse.de>

Fixes a build error when these are different, e.g. x32.
Signed-off-by: NRichard Henderson <rth@twiddle.net>
Message-id: 1394043257-4800-1-git-send-email-rth@twiddle.net
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Implement the MSR (immediate) instructions, which can update the
PSTATE SP and DAIF fields.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>

Implement the WFI instruction for A64; this just involves wiring
up the instruction, and adding a gen_a64_set_pc_im() which was
accidentally omitted from the A64 decoder top loop.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>

Emit the correct MMU index information for loads and stores from
A64 code, rather than hardwiring it to "always kernel mode",
by storing the exception level in the TB flags, and make
cpu_mmu_index() return the right answer when the CPU is in
AArch64 mode.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>

Implement the CurrentEL sysreg.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>

Implement the unprivileged load and store instructions.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>

Implement the narrowing three-reg-diff operations: ADDHN,
RADDHN, SUBHN and RSUBHN.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>

Implement the wide three-reg-different operations:
SADDW, UADDW, SSUBW and USUBW.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>

Add the remainder of the 64x64->128 operations in the three-reg-diff
category except for PMULL, PMULL2.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <rth@twiddle.net>