Avoids a wasted cycle loading up small constants.
Simplify the code assuming the tcg optimizer is going to work
and don't expect the first operand of the add to be constant.
Acked-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
When performing an operation with two input registers, we'd leave
the stop bit (and thus an extra cycle) that's only needed when one
or the other input is a constant.
Acked-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Since the move away from the global areg0, we're no longer globally
reserving areg0. Which means our use of R7 clobbers a call-saved
register. Shift areg0 into the windowed registers. Indeed, choose
the incoming parameter register that it comes to us by.
This requires moving the register holding the return address elsewhere.
Choose R33 for tidiness.
Acked-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
There was a misconception that a stop bit is required between a compare
and the branch that uses the predicate set by the compare. This lead to
the usage of an extra bundle in which to perform the compare. The extra
bundle left room for constants to be loaded for use with the compare insn.
If we pack the compare and the branch together in the same bundle, then
there's no longer any room for non-zero constants. At which point we
can eliminate half the function by not handling them.
Acked-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Using only indirect calls results in 3 bundles (one to load the
descriptor address), and 4 stop bits. By looking through the
descriptor to the constants, we can perform the call with 2
bundles and only 1 stop bit.
Acked-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
There's no need to go through the full opcode-to-insn function call
to generate nops. This makes the source a bit more readable.
Acked-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
If we pull the code to emit the actual load/store into a subroutine,
we can share the reg+reg addressing mode code between softmmu and
usermode. This lets us load GUEST_BASE into a temporary register
rather than attempting to add it piece-wise to the address.
Which lets us use movw+movt for armv7, rather than (up to) 4 adds.
Code size for pre-armv7 stays the same.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Once we form a combined qemu_st_i32 opcode, we won't be able to
have separate constraints based on size. This one is fairly easy
to work around, since eax is available as a scratch register.
When storing variable data, this tends to merely exchange one mov
for another. E.g.
-: mov %esi,%ecx
...
-: mov %cl,(%edx)
+: mov %esi,%eax
+: mov %al,(%edx)
Where we do have a regression is when storing constant data, in which
we may load the constant into edi, when only ecx/ebx ought to be used.
The proper way to recover this regression is to allow constants as
arguments to qemu_st_i32, so that we never load the constant data into
a register at all, must less the wrong register. TBD.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Pass two TCGReg to tcg_out_tlb_load, rather than idx+args.
Move ldst_optimization routines just below tcg_out_tlb_load to avoid
the need for forward declarations.
Use TCGReg enum in preference to int where apprpriate.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Step three in the transition: helpers not tied to the target
"default" endianness. To be used when the guest uses a memory
operation with non-default endianness.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Step two in the transition, adding the new ldst opcodes. Keep the old
opcodes around until all backends support the new opcodes.
Signed-off-by: Richard Henderson <rth@twiddle.net>
This is a no-op backend data implementation, for those targets that
are not currently using the load/store optimization path.
This is prepatory to always requiring these functions in all backends.
Signed-off-by: Richard Henderson <rth@twiddle.net>
A minimal update to use the new helpers with the return address argument.
Tested-by: Claudio Fontana <claudio.fontana@linaro.org>
Reviewed-by: Claudio Fontana <claudio.fontana@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
For the few targets that actually use these, we'd not report
them symbolicly in the tcg opcode logs.
Signed-off-by: Richard Henderson <rth@twiddle.net>
One call inside of a loop to tcg_register_helper instead of hundreds
of sequential calls.
Presumably more icache and branch prediction friendly; resulting binary
size mostly unchanged on x86_64, as we're trading 32-bit rip-relative
references in .text for full 64-bit pointers in .rodata.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Slightly changes the interface, in that we now return name
instead of a TCGHelperInfo structure, which goes away.
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Richard Henderson <rth@twiddle.net>
# By Richard Henderson
# Via Richard Henderson
* rth/tcg-arm-pull:
tcg-arm: Move the tlb addend load earlier
tcg-arm: Remove restriction on qemu_ld output register
tcg-arm: Return register containing tlb addend
tcg-arm: Move load of tlb addend into tcg_out_tlb_read
tcg-arm: Use QEMU_BUILD_BUG_ON to verify constraints on tlb
tcg-arm: Use strd for tcg_out_arg_reg64
tcg-arm: Rearrange slow-path qemu_ld/st
tcg-arm: Use ldrd/strd for appropriate qemu_ld/st64
Message-id: 1380663109-14434-1-git-send-email-rth@twiddle.net
Signed-off-by: Anthony Liguori <anthony@codemonkey.ws>
# By Stefan Weil
# Via Stefan Weil
* sweil/tci:
misc: Use new rotate functions
bitops: Add rotate functions (rol8, ror8, ...)
tci: Add implementation of rotl_i64, rotr_i64
Message-id: 1380137693-3729-1-git-send-email-sw@weilnetz.de
Signed-off-by: Anthony Liguori <anthony@codemonkey.ws>
There are free scheduling slots between the sequence of
comparison instructions. This requires changing the
register in use to avoid conflict with those compares.
Signed-off-by: Richard Henderson <rth@twiddle.net>
The main intent of the patch is to allow the tlb addend register
to be changed, without tying that change to the constraint. But
the most common side-effect seems to be to enable usage of ldrd
with the r0,r1 pair.
Signed-off-by: Richard Henderson <rth@twiddle.net>
This allows us to make more intelligent decisions about the relative
offsets of the tlb comparator and the addend, avoiding any need of
writeback addressing.
Signed-off-by: Richard Henderson <rth@twiddle.net>
One of the two constraints we already checked via #if, but
the tlb offset distance was only checked at runtime.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Use the new helper_ret_*_mmu routines. Use a conditional call
to arrange for a tail-call from the store path, and to load the
return address for the helper for the load path.
Signed-off-by: Richard Henderson <rth@twiddle.net>
It is used by qemu-ppc64 when running Debian's busybox-static.
Cc: qemu-stable <qemu-stable@nongnu.org>
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Less conditional compilation. Merge an add insn with the indexed
memory load insn. Load the tlb addend earlier. Avoid the address
update memory form.
Fix a bug in not allowing large enough tlb offsets for some guests.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Previously we'd only handle 16-bit offsets from memory operand without falling
back to indexed, but it's easy to use ADDIS to handle full 32-bit offsets.
This also lets us unify code that existed inline in tcg_out_op for handling
addition of large constants.
The new R2 temporary was marked reserved for the AIX calling convention, but
the register really is call-clobbered and since tcg generated code has no use
for a TOC, it's available for use.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Remove conditionalization from tcg_target_reg_alloc_order, relying on
reserved_regs to prevent register allocation that shouldn't happen.
So R11 is now present in reg_alloc_order for __APPLE__, but also now
reserved.
Sort reg_alloc_order into call-saved, call-clobbered, and parameters.
This reduces the effect of values getting spilled and reloaded before
function calls.
Whether or not it is reserved, R2 (TOC) is always call-clobbered.
Signed-off-by: Richard Henderson <rth@twiddle.net>
While these are rare from code that's been through the optimizer,
it's not uncommon within the tcg backend.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Instead of bare N, for clarity. The only (intentional) exception made
is for insns that encode R|0, i.e. when R0 encoded into the insn is
interpreted as zero not the contents of the register.
Signed-off-by: Richard Henderson <rth@twiddle.net>
The fix is that sparc has so many mmu modes that the last one overflowed
the 16-bit signed offset we assumed would fit. Handle this, and check
the new assumption at compile time.
Load the tlb addend earlier for the fast path.
Remove the explicit address + addend and make use of index addressing.
Adjust constraints for qemu_ld64 such that we don't clobber the address
register or tlb addend before loading both values.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Coding style fixes. Use TCGReg enumeration values instead of raw
numbers. Don't needlessly pull the whole TCGLabelQemuLdst struct
into local variables. Less conditional compilation.
No functional changes.
Signed-off-by: Richard Henderson <rth@twiddle.net>
While these are rare from code that's been through the optimizer,
it's not uncommon within the tcg backend.
Signed-off-by: Richard Henderson <rth@twiddle.net>
These use a 32-bit load-of-immediate to save a mflr+addi+mtlr sequence.
Tested with a Windows 98 guest (pretty much the most recent thing I
could run on my PPC machine) and kvm-unit-tests's sieve.flat. The
speed up for sieve.flat is as high as 10% for qemu-system-i386, 25%
(no kidding) for qemu-system-x86_64 on my PowerBook G4.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
For the AIX ABI, the function pointer and small area pointer need
to be loaded in the trampoline. The trampoline instead is called
with a normal BL instruction.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
error: suggest parentheses around comparison in operand of ‘&’ [-Werror=parentheses]
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
# By Stefan Weil (6) and others
# Via Michael Tokarev
* mjt/trivial-patches:
aio / timers: use g_usleep() not sleep()
adlib: sort offsets in portio registration
qmp: fix integer usage in examples
tci: Remove function tcg_out64 (fix broken build)
target-arm: Report unimplemented opcodes (LOG_UNIMP)
pflash_cfi02.c: fix debug macro
configure: Remove unneeded redirections of stderr (pkg-config --exists)
configure: Remove unneeded redirections of stderr (pkg-config --cflags, --libs)
configure: Don't write .pyc files by default (python -B)
curl: qemu_bh_new() can never return NULL
slirp/arp_table.c: Avoid shifting into sign bit of signed integers
configure: disable clang -Wstring-plus-int warning
rdma: silly ipv6 bugfix
misc: Fix some typos in names and comments
slirp: Port redirection option behave differently on Linux and Windows
Message-id: 1378119695-14568-1-git-send-email-mjt@msgid.tls.msk.ru
Signed-off-by: Anthony Liguori <anthony@codemonkey.ws>
* 'tcg-next' of git://github.com/rth7680/qemu: (29 commits)
tcg-i386: Make use of zero-extended memory helper routines
tcg: Introduce zero and sign-extended versions of load helpers
exec: Split softmmu_defs.h
target: Include softmmu_exec.h where forgotten
exec: Rename USUFFIX to LSUFFIX
tcg-i386: Don't perform GETPC adjustment in TCG code
exec: Reorganize the GETRA/GETPC macros
configure: Allow x32 as a host
tcg-i386: Adjust tcg_out_tlb_load for x32
tcg-i386: Use intptr_t appropriately
tcg: Fix jit debug for x32
tcg: Use appropriate types in tcg_reg_alloc_call
tcg: Change tcg_out_ld/st offset to intptr_t
tcg: Change tcg_gen_exit_tb argument to uintptr_t
tcg: Use uintptr_t in TCGHelperInfo
tcg: Change relocation offsets to intptr_t
tcg: Change memory offsets to intptr_t
tcg: Change frame pointer offsets to intptr_t
tcg: Define TCG_ptr properly
tcg: Define TCG_TYPE_PTR properly
...
On MIPS ext8s and ext16s ops are implemented with a dedicated
instruction only on MIPS32R2, otherwise the same kind of implementation
than at TCG level (shift left followed by shift right) is used.
Change that by only implementing the ext8s and ext16s ops on MIPS32R2 so
that optimizations can be done by the optimizer. Use an inline version to
avoid having to test again for MIPS32R2 instructions. Keep the shift
implementation for the ld/st routines.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Use an inline version for the bswap16 and bswap32 ops to avoid
testing for MIPS32R2 instructions availability, as these ops are
only available in that case.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Now that TCG supports enabling and disabling ops at runtime, it's
possible to detect the available host instructions at runtime, and
enable the corresponding ops accordingly.
Unfortunately it's not easy to probe for available instructions on
MIPS, the information is partially available in /proc/cpuinfo, and
not available in AUXV. This patch therefore probes for the instructions
by trying to execute them and by catching a possible SIGILL signal.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
For 8 and 16-bit unsigned loads, rely on the zero-extension
from the helper and use a smaller 32-bit move insn.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
The _cmmu helpers can be moved to exec-all.h. The helpers that are
used from TCG will shortly need access to tcg_target_long so move
their declarations into tcg.h.
This requires minor include adjustments to all TCG backends.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Since we now perform it inside the helper, no need to do it here.
This also lets us perform a tail-call from the store slow path to
the helper.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
There are several hosts for which it would be useful to use the
available 64-bit registers in a 32-bit pointer environment.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Using these instead of mulu2 and muls2 lets us avoid having to argument
overlap analysis in the backend. Normal register allocation will DTRT.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
With the optimization in tcg_liveness_analysis,
we can avoid the MFLO when it is unused.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Use them in places where mulu2 and muls2 are used.
Optimize mulx2 with dead low part to mulxh.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Commit ac26eb69a3 added tcg_out64 to tcg/tcg.c.
tcg/tci/tcg-target.c already had a nearly identical implementation which is
now removed to fix a compiler error.
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Discontinue the jump-around-jump-to-jump scheme, trading it for a single
immediate move instruction. The two extra jumps always consume 7 bytes,
whereas the immediate move is either 5 or 7 bytes depending on where the
code_gen_buffer gets located.
Signed-off-by: Richard Henderson <rth@twiddle.net>
No point in splitting the write into 32-bit pieces.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Aliasing was forcing s->code_ptr to be re-read after the store.
Keep the pointer in a local variable to help the compiler.
Signed-off-by: Richard Henderson <rth@twiddle.net>
tcg/mips/tcg-target.h defines various operations conditionally depending
upon the isa revision, however these operations are included in
mips_op_defs[] unconditionally resulting in the following runtime errors
if CONFIG_DEBUG_TCG is defined:
Invalid op definition for movcond_i32
Invalid op definition for rotl_i32
Invalid op definition for rotr_i32
Invalid op definition for deposit_i32
Invalid op definition for bswap16_i32
Invalid op definition for bswap32_i32
tcg/tcg.c:1196: tcg fatal error
Fix with ifdefs like the i386 backend does for movcond_i32.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
The definition of macro BIT in tci/tcg-target.c now conflicts with the
definition of the same macro in includes qemu/bitops.h.
This conflict was triggered by a recent change in the include chain of
tcg.c (probably commit 949fc82314).
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Message-id: 1375216883-23969-1-git-send-email-sw@weilnetz.de
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
We can check the condition at compile time, rather than run time.
Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Richard Henderson <rth@twiddle.net>
These will necessarily be the same layout for all hosts. This limits
the amount of boilerplate required to implement jit debug for a host.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
I don't think the debugger actually looks at this for anything,
using the correct .debug_frame contents, but might as well get
it all correct.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
With this we can generate armv7 insns even when the OS compiles for a
lower common denominator. The macros are arranged so that when we do
compile for a given ISA, all of the runtime checks for that ISA are
optimized away.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
GCC 4.8 defines a handy __ARM_ARCH symbol that we can use, which
will make us nicely forward compatible with ARMv8 AArch32.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
As it really controls the availability of a thumb interworking
instruction on armv5t.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
We can now detect and use divide instructions at runtime, rather than
having to restrict their availability to compile-time.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Expand the definition of "not present" to include "should not be present".
This means we can simplify the logic surrounding the generic tcg opcodes
for which the host backend ought not be providing definitions.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
This allows TCG_TARGET_HAS_* to be a variable rather than a constant,
which allows easier support for differing ISA levels for the host.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
There are several hosts with only a "div" insn. Remainder is computed
manually from the quotient and inputs. We can do this generically.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
implement the 12bit scaled unsigned immediate offset
variant of LDR/STR. This improves code size by avoiding
the movi + ldst_r for naturally aligned offsets in range.
Signed-off-by: Claudio Fontana <claudio.fontana@huawei.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
rotr_i32 calculates the amount to left shift and puts it into a
temporary, but then doesn't use it when doing the shift.
Cc: qemu-stable@nongnu.org
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
add2_i64 was adding the lower double word to the upper double word
of each input. Fix this so we add the lower double words, then the
upper double words with carry propagation.
Cc: qemu-stable@nongnu.org
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
If our input and output is in the same register, bswap64 tries to
undo a rotate of the input. This just ends up rotating the output.
Cc: qemu-stable@nongnu.org
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
The rldcl instruction doesn't have an sh field, so the minor opcode
is shifted 1 bit. We were using the XO30 macro which shifted the
minor opcode 2 bits.
Remove XO30 and add MD30 and MDS30 macros which match the
Power ISA categories.
Cc: qemu-stable@nongnu.org
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
# By Claudio Fontana (9) and others
# Via Peter Maydell
* pmaydell/tcg-aarch64.next:
MAINTAINERS: add tcg/aarch64 maintainer
configure: permit compilation on arm aarch64
tcg/aarch64: implement user mode qemu ld/st
user-exec.c: aarch64 initial implementation of cpu_signal_handler
tcg/aarch64: implement sign/zero extend operations
tcg/aarch64: implement byte swap operations
tcg/aarch64: implement AND/TEST immediate pattern
tcg/aarch64: improve arith shifted regs operations
tcg/aarch64: implement new TCG target for aarch64
include/elf.h: add aarch64 ELF machine and relocs
configure: Drop CONFIG_ATFILE test
linux-user: Drop direct use of openat etc syscalls
linux-user: Allow getdents to be provided by getdents64
Message-id: 1371052645-9006-1-git-send-email-peter.maydell@linaro.org
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
also put aarch64 in the list of archs that do not need an ldscript.
Signed-off-by: Jani Kokkoken <jani.kokkonen@huawei.com>
Signed-off-by: Claudio Fontana <claudio.fontana@huawei.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 51AF40EE.1000104@huawei.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
implement the optional sign/zero extend operations with the dedicated
aarch64 instructions.
Signed-off-by: Claudio Fontana <claudio.fontana@huawei.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-id: 51AC9A58.40502@huawei.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
implement the optional byte swap operations with the dedicated
aarch64 instructions.
Signed-off-by: Claudio Fontana <claudio.fontana@huawei.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-id: 51AC9A33.9050003@huawei.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
for arith operations, add SUBS, ANDS, ADDS and add a shift parameter
so that all arith instructions can make use of shifted registers.
Signed-off-by: Claudio Fontana <claudio.fontana@huawei.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-id: 51AC998B.7070506@huawei.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
add preliminary support for TCG target aarch64.
Signed-off-by: Claudio Fontana <claudio.fontana@huawei.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 51A5C596.3090108@huawei.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
We've got a compile-time check for the condition in exec/cpu-defs.h.
Reviewed-by: Andreas Färber <afaerber@suse.de>
Reviewed-by: liguang <lig.fnst@cn.fujitsu.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
When setcond2 is rewritten into setcond, the state of the destination
temp should be reset, so that a copy of the previous value is not
used instead of the result.
Reported-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Avoid the mini constant pool for armv7, and avoid replicating
the test for pre-v7.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Found by inspection, since the effect of the bug was simply to
send all memory ops through the slow path.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Move the slow path out of line, as the TODO's mention.
This allows the fast path to be unconditional, which can
speed up the fast path as well, depending on the core.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Work better with branch predition when we have movw+movt,
as the size of the code is the same. Perhaps re-evaluate
when we have a proper constant pool.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
The schedule was fully serial, with no possibility for dual issue.
The old schedule had a minimal issue of 7 cycles; the new schedule
has a minimal issue of 5 cycles.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Share code between qemu_ld and qemu_st to process the tlb.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Use even more primitive helper functions to avoid lots of duplicated code.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Make the code more readable by only having one copy of the magic
numbers, swapping registers as needed prior to that. Speed the
compiler by not applying the rd == rn avoidance for v6 or later.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
R12 is call clobbered, while R8 is call saved. This change
gives tcg one more call saved register for real data.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
We get to re-use the _rIN and _rIK subroutines to handle the various
combinations of add vs sub. Fold the << 21 into the opcode enum values
so that we can explicitly add TO_CPSR as desired.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
This greatly improves code generation for addition of small
negative constants.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
This greatly improves the code we can produce for deposit
without armv7 support.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
This makes it easier to verify changes to the code
generating the prologue.
[Aurelien: change the format from %i to %zu]
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
We were not allocating TCG_STATIC_CALL_ARGS_SIZE, so this meant that
any helper with more than 4 arguments would clobber the saved regs.
Realizing that we're supposed to have this memory pre-allocated means
we can clean up the tcg_out_arg functions, which were trying to do
more stack allocation.
Allocate stack memory for the TCG temporaries while we're at it.
Signed-off-by: Richard Henderson <rth@twiddle.net>
On 32-bit TCG targets, when emulating deposit_i64 with a mov_i32 +
deposit_i32, care should be taken to not overwrite the low part of
the second argument before the deposit when it is the same the
destination.
This fixes the shld instruction in qemu-system-x86_64, which in turns
fixes booting "system rescue CD version 2.8.0" on this target.
Reported-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
The TCG optimizer does great work when inserting constants, being able
to fold the open-coded deposit expansion to just an AND or an OR. Avoid
a bit the regression caused by having the deposit opcode by expanding
deposit of zero as an AND.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Glibc 2.16 includes an easy way to get feature bits previously
buried in /proc or the program startup auxiliary vector. Use it.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
There are a few simple special cases that should be handled first.
Break these out to subroutines to avoid code duplication.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
It takes half the cycles to read one CR register instead of all 8.
This is a backward compatible addition to the ISA, so chips prior
to Power 2.00 spec will simply continue to read the entire CR register.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Nothing else in the call chain ensures that these
constants don't have garbage in the high bits.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
The optimization/bug being fixed is that tcg_out_cmp was not applying the
right type to loading a constant, in the case it can't be implemented
directly. Rather than recomputing the TCGType enum from the arch64 bool,
pass around the original TCGType throughout.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
The mul_i32 pattern was loading non-16-bit constants into a register,
when we can get the middle-end to do that for us. The mul_i64 pattern
was not considering that MULLI takes 64-bit inputs.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Since we have special code to handle and/or/xor with a constant,
apply the same to andc/orc/eqv with a constant.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Using a table to look up insns of the right width and sign.
Include support for the Power 2.06 LDBRX and STDBRX insns.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Handle constants in common code; we'll want to reuse that later.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Improve constant addition -- previously we'd emit useless addi with 0.
Use new constraints to force the driver to pull full 64-bit constants
into a register.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
We'll need a zero, and Z makes more sense for that. Make sure we
have a full compliment of signed and unsigned 16 and 32-bit tests.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
The test for using movi32 was sub-optimal for TCG_TYPE_I32, comparing
a signed 32-bit quantity against an unsigned 32-bit quantity.
When possible, use addi+oris for 32-bit unsigned constants. Otherwise,
standardize on addi+oris+ori instead of addis+ori+rldicl.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
We weren't ignoring the high 32 bits during a NE comparison.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
* 'tci' of git://qemu.weilnetz.de/qemu:
tci: Make tcg temporaries local to tcg_qemu_tb_exec
tci: Delete unused tb_ret_addr
tci: Avoid code before declarations
tci: Use a local variable for env
tci: Use 32-bit signed offsets to loads/stores
We're moving away from the temporaries stored in env. Make sure we can
differentiate between temp stores and possibly bogus stores for extra
call arguments. Move TCG_AREG0 and TCG_REG_CALL_STACK out of the way
of the parameter passing registers.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off by: Stefan Weil <sw@weilnetz.de>
Since the change to tcg_exit_req, the first insn of every TB is
a load with a negative offset from env.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off by: Stefan Weil <sw@weilnetz.de>
When the TCG condition codes were re-organized last year,
we failed to update all of the "old-style" tests for unsigned.
Signed-off-by: Richard Henderson <rth@twiddle.net>
This can save one insn, if the constant has any bits in 32-63 set,
but no bits in 21-31 set. It never results in more insns.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Since we're always in 64-bit mode, load address performs a full
64-bit add. Use that for 3-address addition, as well as for
larger constant addends when we lack extended-immediates facility.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Since we have a free temporary and can always just load the constant, we
ought to do so, rather than spending the same effort constraining the const.
Signed-off-by: Richard Henderson <rth@twiddle.net>
We only support 64-bit code generation for s390x.
Don't clutter the code with ifdefs that suggest otherwise.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Set TCG_TARGET_CALL_STACK_OFFSET properly for the abi. Allocate the
standard TCG_STATIC_CALL_ARGS_SIZE. And while we're at it, allocate
space for CPU_TEMP_BUF_NLONGS.
Signed-off-by: Richard Henderson <rth@twiddle.net>
In TCG, "target" means the host architecture for which TCG generates
the code. Using "guest" rather than "target" to make the document more
consistent.
Signed-off-by: Chen Wei-Ren <chenwj@iis.sinica.edu.tw>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Fix some of the nasty TCG race conditions and crashes by implementing
cpu_exit() as setting a flag which is checked at the start of each TB.
This avoids crashes if a thread or signal handler calls cpu_exit()
while the execution thread is itself modifying the TB graph (which
may happen in system emulation mode as well as in linux-user mode
with a multithreaded guest binary).
This fixes the crashes seen in LP:668799; however there are another
class of crashes described in LP:1098729 which stem from the fact
that in linux-user with a multithreaded guest all threads will
use and modify the same global TCG date structures (including the
generated code buffer) without any kind of locking. This means that
multithreaded guest binaries are still in the "unsupported"
category.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Document tcg_qemu_tb_exec(). In particular, its return value is a
combination of a pointer to the next translation block and some
extra information in the low two bits. Provide some #defines for
the values passed in these bits to improve code clarity.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Fix build breakage by 803d805bcef4ea7b7d6ef0b4929263e1160d6b3c:
make tcg_out_addsub2() always available.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Switch the default for qemu_log logging output from "/tmp/qemu.log"
to stderr. This is an incompatible change in some sense, but logging
is mostly used for debugging purposes so it shouldn't affect production
use. The previous behaviour can be obtained by adding "-D /tmp/qemu.log"
to the command line.
This change requires us to:
* update all the documentation/help text (we take the opportunity
to smooth out minor inconsistencies between the phrasing in
linux-user/bsd-user/system help messages)
* make linux-user and bsd-user defer to qemu-log for the default
logging destination rather than overriding it themselves
* ensure that all logfile closing is done via qemu_log_close()
and that that function doesn't close stderr
as well as the obvious change to the behaviour of do_qemu_set_log()
when no logfile name has been specified.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-id: 1361901160-28729-1-git-send-email-peter.maydell@linaro.org
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
We even had the encoding of smull already handy...
Cc: Andrzej Zaborowski <balrogg@gmail.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
We're going to have use for this shortly in implementing other helpers.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Commit 0b0d3320db (TCG: Final globals
clean-up) moved code_gen_prologue but forgot to update ppc code.
This broke the build on 32-bit ppc. ppc64 is unaffected.
Cc: Evgeny Voevodin <evgenyvoevodin@gmail.com>
Cc: Blue Swirl <blauwirbel@gmail.com>
Signed-off-by: Andreas Färber <andreas.faerber@web.de>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Rename the public-facing function cpu_set_log to qemu_set_log. This
requires us to rename the internal-only qemu_set_log() to
do_qemu_set_log().
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
It's worth to clean-up translation blocks variables and move them
into one context as was suggested by Swirl.
Also if we use this context directly inside tcg_ctx, then it
speeds up code generation a bit.
Signed-off-by: Evgeny Voevodin <evgenyvoevodin@gmail.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Silence a (legitimate) complaint about missing parentheses:
tcg/arm/tcg-target.c: In function ‘tcg_out_qemu_ld’:
tcg/arm/tcg-target.c:1148:5: error: suggest parentheses around
comparison in operand of ‘&’ [-Werror=parentheses]
tcg/arm/tcg-target.c: In function ‘tcg_out_qemu_st’:
tcg/arm/tcg-target.c:1357:5: error: suggest parentheses around
comparison in operand of ‘&’ [-Werror=parentheses]
which meant that we would mistakenly always assert if running
a QEMU built with debug enabled on ARM.
Signed-off-by: Peter Maydell <peter.maydelL@linaro.org>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
This adds two optimizations using the non-zero bit mask. In some cases
involving shifts or ANDs the value can become zero, and can thus be
optimized to a move of zero. Second, useless zero-extension or an
AND with constant can be detected that would only zero bits that are
already zero.
The main advantage of this optimization is that it turns zero-extensions
into moves, thus enabling much better copy propagation (around 1% code
reduction). Here is for example a "test $0xff0000,%ecx + je" before
optimization:
mov_i64 tmp0,rcx
movi_i64 tmp1,$0xff0000
discard cc_src
and_i64 cc_dst,tmp0,tmp1
movi_i32 cc_op,$0x1c
ext32u_i64 tmp0,cc_dst
movi_i64 tmp12,$0x0
brcond_i64 tmp0,tmp12,eq,$0x0
and after (without patch on the left, with on the right):
movi_i64 tmp1,$0xff0000 movi_i64 tmp1,$0xff0000
discard cc_src discard cc_src
and_i64 cc_dst,rcx,tmp1 and_i64 cc_dst,rcx,tmp1
movi_i32 cc_op,$0x1c movi_i32 cc_op,$0x1c
ext32u_i64 tmp0,cc_dst
movi_i64 tmp12,$0x0 movi_i64 tmp12,$0x0
brcond_i64 tmp0,tmp12,eq,$0x0 brcond_i64 cc_dst,tmp12,eq,$0x0
Other similar cases: "test %eax, %eax + jne" where eax is already 32-bit
(after optimization, without patch on the left, with on the right):
discard cc_src discard cc_src
mov_i64 cc_dst,rax mov_i64 cc_dst,rax
movi_i32 cc_op,$0x1c movi_i32 cc_op,$0x1c
ext32u_i64 tmp0,cc_dst
movi_i64 tmp12,$0x0 movi_i64 tmp12,$0x0
brcond_i64 tmp0,tmp12,ne,$0x0 brcond_i64 rax,tmp12,ne,$0x0
"test $0x1, %dl + je":
movi_i64 tmp1,$0x1 movi_i64 tmp1,$0x1
discard cc_src discard cc_src
and_i64 cc_dst,rdx,tmp1 and_i64 cc_dst,rdx,tmp1
movi_i32 cc_op,$0x1a movi_i32 cc_op,$0x1a
ext8u_i64 tmp0,cc_dst
movi_i64 tmp12,$0x0 movi_i64 tmp12,$0x0
brcond_i64 tmp0,tmp12,eq,$0x0 brcond_i64 cc_dst,tmp12,eq,$0x0
In some cases TCG even outsmarts GCC. :) Here the input code has
"and $0x2,%eax + movslq %eax,%rbx + test %rbx, %rbx" and the optimizer,
thanks to copy propagation, does the following:
movi_i64 tmp12,$0x2 movi_i64 tmp12,$0x2
and_i64 rax,rax,tmp12 and_i64 rax,rax,tmp12
mov_i64 cc_dst,rax mov_i64 cc_dst,rax
ext32s_i64 tmp0,rax -> nop
mov_i64 rbx,tmp0 -> mov_i64 rbx,cc_dst
and_i64 cc_dst,rbx,rbx -> nop
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Add a "mask" field to the tcg_temp_info struct. A bit that is zero
in "mask" will always be zero in the corresponding temporary.
Zero bits in the mask can be produced from moves of immediates,
zero-extensions, ANDs with constants, shifts; they can then be
be propagated by logical operations, shifts, sign-extensions,
negations, deposit operations, and conditional moves. Other
operations will just reset the mask to all-ones, i.e. unknown.
[rth: s/target_ulong/tcg_target_ulong/]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
The next patch will add to the TCG optimizer a field that should be
non-zero in the default case. Thus, replace the memset of the
temps array with a loop. Only the state field has to be up-to-date,
because others are not used except if the state is TCG_TEMP_COPY
or TCG_TEMP_CONST.
[rth: Extracted the loop to a function.]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Commit 7f6f0ae5b9 added two assertions.
One of these assertions is not needed:
The pointer ts is never NULL because it is initialized with the
address of an array element.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Existing compile-time detection is spotty at best. Convert
it all to runtime detection instead.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
In dead_temp, local temps should always be marked as back to memory,
even if they have not been allocated (i.e. they are discared before
cross a basic block).
It fixes the following assertion in target-xtensa:
qemu-system-xtensa: tcg/tcg.c:1665: temp_save: Assertion `s->temps[temp].val_type == 2 || s->temps[temp].fixed_reg' failed.
Aborted
Reported-by: Max Filippov <jcmvbkbc@gmail.com>
Tested-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
The bswap16 TCG opcode assumes that the high bytes of the temp equal
to 0 before calling it. The ARM backend implementation takes this
assumption to slightly optimize the generated code.
The same implementation is called for implementing the cross-endian
qemu_st16 opcode, where this assumption is not true anymore. One way to
fix that would be to zero the high bytes before calling it. Given the
store instruction just ignore them, it is possible to provide a slightly
more optimized version. With ARMv6+ the rev16 instruction does the work
correctly. For lower ARM versions the patch provides a version which
behaves correctly with non-zero high bytes, but fill them with junk.
Cc: Andrzej Zaborowski <balrogg@gmail.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: qemu-stable@nongnu.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
The TCG arm backend considers likely that the offset to the TLB
entries does not exceed 12 bits for mem_index = 0. In practice this is
not true for at least the MIPS target.
The current patch fixes that by loading the bits 23-12 with a separate
instruction, and using loads with address writeback, independently of
the value of mem_idx. In total this allow a 24-bit offset, which is a
lot more than needed.
Cc: Andrzej Zaborowski <balrogg@gmail.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: qemu-stable@nongnu.org
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
The operations for INDEX_op_deposit_i32 and INDEX_op_deposit_i64
are now supported and enabled by default.
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
mmu access looks something like:
<check tlb>
if miss goto slow_path
<fast path>
done:
...
; end of the TB
slow_path:
<pre process>
mr r3, r27 ; move areg0 to r3
; (r3 holds the first argument for all the PPC32 ABIs)
<call mmu_helper>
b $+8
.long done
<post process>
b done
On ppc32 <call mmu_helper> is:
(SysV and Darwin)
mmu_helper is most likely not within direct branching distance from
the call site, necessitating
a. moving 32 bit offset of mmu_helper into a GPR ; 8 bytes
b. moving GPR to CTR/LR ; 4 bytes
c. (finally) branching to CTR/LR ; 4 bytes
r3 setting - 4 bytes
call - 16 bytes
dummy jump over retaddr - 4 bytes
embedded retaddr - 4 bytes
Total overhead - 28 bytes
(PowerOpen (AIX))
a. moving 32 bit offset of mmu_helper's TOC into a GPR1 ; 8 bytes
b. loading 32 bit function pointer into GPR2 ; 4 bytes
c. moving GPR2 to CTR/LR ; 4 bytes
d. loading 32 bit small area pointer into R2 ; 4 bytes
e. (finally) branching to CTR/LR ; 4 bytes
r3 setting - 4 bytes
call - 24 bytes
dummy jump over retaddr - 4 bytes
embedded retaddr - 4 bytes
Total overhead - 36 bytes
Following is done to trim the code size of slow path sections:
In tcg_target_qemu_prologue trampolines are emitted that look like this:
trampoline:
mfspr r3, LR
addi r3, 4
mtspr LR, r3 ; fixup LR to point over embedded retaddr
mr r3, r27
<jump mmu_helper> ; tail call of sorts
And slow path becomes:
slow_path:
<pre process>
<call trampoline>
.long done
<post process>
b done
call - 4 bytes (trampoline is within code gen buffer
and most likely accessible via
direct branch)
embedded retaddr - 4 bytes
Total overhead - 8 bytes
In the end the icache pressure is decreased by 20/28 bytes at the cost
of an extra jump to trampoline and adjusting LR (to skip over embedded
retaddr) once inside.
Signed-off-by: malc <av1474@comtv.ru>
Add optimized TCG qemu_ld/st generation which locates the code of TLB miss
cases at the end of a block after generating the other IRs.
Currently, this optimization supports only i386 and x86_64 hosts.
Signed-off-by: Yeongkyoon Lee <yeongkyoon.lee@samsung.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Commit 9c43b68de6 do not correctly check
for dead outputs when they need to be synced to memory in case of
half-dead operations.
Fix that by applying the same pattern than for the default case.
Tested-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
MIPS32 and later instruction sets have a multiplication instruction
directly operating on GPRs. It only produces a 32-bit result but
it is exactly what is needed by QEMU.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
When we allocate a reserved_va for the guest, the kernel will likely
choose an address well above 4G. At which point we must use a pair
of movabsq+addq to form the host address. If we have OS support,
set up a segment register to point to guest_base instead.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
The current helper flags, TCG_CALL_CONST and TCG_CALL_PURE might be
confusing and doesn't provide enough granularity for some helpers (FP
helpers for example).
This patch changes them into the following helpers flags:
- TCG_CALL_NO_READ_GLOBALS means that the helper does not read globals,
either directly or via an exception. They will not be saved to their
canonical location before calling the helper.
- TCG_CALL_NO_WRITE_GLOBALS means that the helper does not modify any
globals. They will only be saved to their canonical locations before
calling helpers, but they won't be reloaded afterwise.
- TCG_CALL_NO_SIDE_EFFECTS means that the call to the function is
removed if the return value is not used.
It provides convenience flags, to avoid helper definitions longer than
80 characters. It also provides compatibility flags, and updates the
documentation.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Operations with side effects (in practice qemu_ld/st ops), only need to
synchronize globals to make sure the CPU state is consistent in case of
exception.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Mapping a memory address using a global and accessing it through
ld/st operations is currently broken. As it doesn't make any sense
to do that performance wise, let's forbid that.
Update the TCG documentation, and remove partial support for that.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Some branch related ops are marked with TCG_OPF_SIDE_EFFECTS, some other
not. In practice they don't need to, as they are all marked with
TCG_OPF_BB_END, which is handled specifically in all the code.
The call op is marked as TCG_OPF_SIDE_EFFECTS, which might be not true
as there is are specific flags (TCG_CALL_CONST and TCG_CALL_PURE) for
specifying that. On the other hand it always clobber arguments, so mark
it as such even if the call op is handled in a different code path.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
The liveness analysis ensures that globals and temps are at the correct
state at a basic block end or with an op with side effects. Avoid
looping on all temps, this can be time consuming on targets with a lot
of globals. Keep an assert in debug mode.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Start with local temps in TEMP_VAL_MEM state, to make possible a later
check that all the temps are correctly saved back to memory.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Always mark dead input arguments as dead, even if the op is at the basic
block end. This will allow to check that all temps are correctly saved.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Now that the liveness analysis provides more information, rewrite
tcg_reg_alloc_mov(). This changes the behaviour about propagating
constants and memory accesses. We now take the assumption that once
a value is loaded into a register (from memory or from a constant),
it's better to keep it there than to reload it later. This assumption
is now always almost correct given that we are now sure the
corresponding temp is going to be used later (otherwise it would have
been synchronized and marked as dead already). The assumption is wrong
if one of the op after clobbers some registers including the one
of the holding the temp (this can be avoided by allocating clobbered
registers last, which is what most TCG target do), or in case of lack
of available register.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Now that the liveness analysis might mark some output temps as dead, call
temp_dead() if needed.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Rework the liveness analysis by tracking temps that need to go back to
memory in addition to dead temps tracking. This allows to mark output
arguments as "need sync", and to synchronize them back to memory as soon
as they are not written anymore. This way even arguments mapping to
globals can be marked as "dead", avoiding moves to a new register when
input and outputs are aliased.
In addition it means that registers are freed as soon as temps are not
used anymore, instead of waiting for a basic block end or an op with side
effects. This reduces register spilling especially on CPUs with few
registers, and spread the mov over all the TB, increasing the
performances on in-order CPUs.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Synchronize an output argument when requested by the liveness analysis.
This is needed so that the temp can be declared dead later.
For that, add a new op_sync_args table in which each bit tells if the
corresponding output argument needs to be synchronized with the memory.
Pass it to the tcg_reg_alloc_* functions, and honor this bit. We need to
synchronize the argument before marking it as dead, and we have to make
sure all the infos about the temp are correctly filled.
At the same time change some types from unsigned int to uint16_t when
passing op_dead_args.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Add a new function temp_sync() to synchronize the canonical location
of a temp with the value in the corresponding register, but without
freeing the associated register. Rewrite temp_save() to call
temp_sync() followed by temp_dead().
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Add a new function tcg_reg_sync() to synchronize the canonical location
of a temp with the value in the associated register, but without freeing
it. Rewrite tcg_reg_free() to first call tcg_reg_sync() and then to free
the register.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
A lot of code is duplicated to mark a temporary as dead. Replace it
by temp_dead(), which in addition marks the temp as saved in memory
for globals and local temps, instead of doing this a posteriori in
temp_save().
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
On x86_64, remove the constraint on the third argument register which
is not needed:
- For loads the helper arguments are env, addr, mem_idx. The addr
value should not be in the two first argument registers as they are
used in tcg_out_tlb_load().
- For stores the helper arguments are env, addr, data, mem_idx.
The addr and data values should not be in the two first argument
registers as they are used in tcg_out_tlb_load(). The data value
should also not be in the two first argument registers, but could
be in the third argument register in which case it would be already
loaded at the right location.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Now that CONFIG_TCG_PASS_AREG0 has been removed, it's easier to get
an optimal code for the load/store functions.
First swap the two registers used in tcg_out_tlb_load() so that the
address end-up in the second register instead of the first one. Adjust
tcg_out_qemu_ld() and tcg_out_qemu_st() to respectively call
tcg_out_qemu_ld_direct() and tcg_out_qemu_st_direct() with the correct
registers. Then replace the register shifting by direct load of the
arguments.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
We had a hack for arm and sparc, allocating code_gen_prologue to a
special section. Which, honestly does no good under certain cases.
We've already got limits on code_gen_buffer_size to ensure that all
TBs can use direct branches between themselves; reuse this limit to
ensure the prologue is also reachable.
As a bonus, we get to avoid marking a page of the main executable's
data segment as executable.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Like add2, do operand ordering, constant folding, and dead operand
elimination. The latter happens about 15% of all mulu2 during an
x86_64 bios boot.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
When x86_64 guest is not in 64-bit mode, the high-part of the 64-bit
add is dead. When the host is 32-bit, we can simplify to 32-bit
arithmetic.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
We can re-use these for implementing double-word folding.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
This saves a whole lot of repetitive code sequences.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Reduces code duplication and prefers
movcond d, c1, c2, const, s
to
movcond d, c1, c2, s, const
It also prefers
add r, r, c
over
add r, c, r
when both inputs are known constants. This doesn't matter for true add, as
we will fully constant fold that. But it matters for a follow-on patch using
this routine for add2 which may not be fully foldable.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Note that in the general reg=reg,reg case we're restricted
to 16-bit insertions. This makes it easy to allow "any"
constant as input, as post-truncation it will fit into the
constant load insn for which we have room in the bundle.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
It is possible to slightly optimize the TLB access code, by replacing
the movi + and instructions by a deposit instruction.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Remove suboptimal register shifting in qemu_ld/st ops, introduced at the
CONFIG_TCG_PASS_AREG0 time.
As mem_idx is now loaded in register R58/R59 for the slow path, we have
to make sure to do it last, to not add additional register constraints.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Implement movcond_i32/64 on ia64 hosts. It is not possible to have
immediate compare arguments without adding a new bundle, but it is
possible to have 22-bit immediate value arguments.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Use stack instead of temp_buf array in CPUState for TCG temps.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Implement movcond_i32 for ARM, as the sequence
mov dst, v2 (implicitly done by the tcg common code)
cmp c1, c2
movCC dst, v1
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
The code to emit either an immediate cmp or a register cmp insn is
duplicated in several places; factor it out into its own function.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Richard Henderson