Commit Graph

18 Commits

Author SHA1 Message Date
Joseph Myers 80b4008c80 target/i386: fix floating-point load-constant rounding
The implementations of the fldl2t, fldl2e, fldpi, fldlg2 and fldln2
instructions load fixed constants independent of the rounding mode.
Fix them to load a value correctly rounded for the current rounding
mode (but always rounded to 64-bit precision independent of the
precision control, and without setting "inexact") as specified.

Signed-off-by: Joseph Myers <joseph@codesourcery.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <alpine.DEB.2.21.2005132348310.11687@digraph.polyomino.org.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-10 12:10:24 -04:00
Joseph Myers c535d68755 target/i386: fix fscale handling of rounding precision
The fscale implementation uses floatx80_scalbn for the final scaling
operation.  floatx80_scalbn ends up rounding the result using the
dynamic rounding precision configured for the FPU.  But only a limited
set of x87 floating-point instructions are supposed to respect the
dynamic rounding precision, and fscale is not in that set.  Fix the
implementation to save and restore the rounding precision around the
call to floatx80_scalbn.

Signed-off-by: Joseph Myers <joseph@codesourcery.com>
Message-Id: <alpine.DEB.2.21.2005070045430.18350@digraph.polyomino.org.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-10 12:10:21 -04:00
Joseph Myers c1c5fb8f90 target/i386: fix fscale handling of infinite exponents
The fscale implementation passes infinite exponents through to generic
code that rounds the exponent to a 32-bit integer before using
floatx80_scalbn.  In round-to-nearest mode, and ignoring exceptions,
this works in many cases.  But it fails to handle the special cases of
scaling 0 by a +Inf exponent or an infinity by a -Inf exponent, which
should produce a NaN, and because it produces an inexact result for
finite nonzero numbers being scaled, the result is sometimes incorrect
in other rounding modes.  Add appropriate handling of infinite
exponents to produce a NaN or an appropriately signed exact zero or
infinity as a result.

Signed-off-by: Joseph Myers <joseph@codesourcery.com>
Message-Id: <alpine.DEB.2.21.2005070045010.18350@digraph.polyomino.org.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-10 12:10:18 -04:00
Joseph Myers b40eec96b2 target/i386: fix fscale handling of invalid exponent encodings
The fscale implementation does not check for invalid encodings in the
exponent operand, thus treating them like INT_MIN (the value returned
for invalid encodings by floatx80_to_int32_round_to_zero).  Fix it to
treat them similarly to signaling NaN exponents, thus generating a
quiet NaN result.

Signed-off-by: Joseph Myers <joseph@codesourcery.com>
Message-Id: <alpine.DEB.2.21.2005070044190.18350@digraph.polyomino.org.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-10 12:10:17 -04:00
Joseph Myers 0d48b43632 target/i386: fix fscale handling of signaling NaN
The implementation of the fscale instruction returns a NaN exponent
unchanged.  Fix it to return a quiet NaN when the provided exponent is
a signaling NaN.

Signed-off-by: Joseph Myers <joseph@codesourcery.com>
Message-Id: <alpine.DEB.2.21.2005070043330.18350@digraph.polyomino.org.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-10 12:10:17 -04:00
Joseph Myers c415f2c582 target/i386: implement special cases for fxtract
The implementation of the fxtract instruction treats all nonzero
operands as normal numbers, so yielding incorrect results for invalid
formats, infinities, NaNs and subnormal and pseudo-denormal operands.
Implement appropriate handling of all those cases.

Signed-off-by: Joseph Myers <joseph@codesourcery.com>
Acked-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <alpine.DEB.2.21.2005070042360.18350@digraph.polyomino.org.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-10 12:10:16 -04:00
Richard Henderson 71bfd65c5f softfloat: Name compare relation enum
Give the previously unnamed enum a typedef name.  Use it in the
prototypes of compare functions.  Use it to hold the results
of the compare functions.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2020-05-19 08:41:45 -07:00
Paolo Bonzini 93c3593ad0 target/i386: check for empty register in FXAM
The fxam instruction returns the wrong result after fdecstp or after
an underflow.  Check fptags to handle this.

Reported-by: <chengang@emindsoft.com.cn>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-25 09:18:01 +01:00
Paolo Bonzini bf13bfab08 i386: implement IGNNE
Change the handling of port F0h writes and FPU exceptions to implement IGNNE.

The implementation mixes a bit what the chipset and processor do in real
hardware, but the effect is the same as what happens with actual FERR#
and IGNNE# pins: writing to port F0h asserts IGNNE# in addition to lowering
FP_IRQ; while clearing the SE bit in the FPU status word deasserts IGNNE#.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-10-26 15:38:07 +02:00
Paolo Bonzini 5caa1833d2 target/i386: introduce cpu_set_fpus
In the next patch, this will provide a hook to detect clearing of
FSW.ES.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-10-26 15:38:07 +02:00
Paolo Bonzini 6f529b7534 target/i386: move FERR handling to target/i386
Move it out of pc.c since it is strictly tied to TCG.  This is
almost exclusively code movement, the next patch will implement
IGNNE.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-10-26 15:38:07 +02:00
Richard Henderson 6aa9e42f27 target/i386: Use env_cpu, env_archcpu
Cleanup in the boilerplate that each target must define.
Replace x86_env_get_cpu with env_archcpu.  The combination
CPU(x86_env_get_cpu) should have used ENV_GET_CPU to begin;
use env_cpu now.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-06-10 07:03:42 -07:00
Alex Bennée 24f91e81b6 target/*/cpu.h: remove softfloat.h
As cpu.h is another typically widely included file which doesn't need
full access to the softfloat API we can remove the includes from here
as well. Where they do need types it's typically for float_status and
the rounding modes so we move that to softfloat-types.h as well.

As a result of not having softfloat in every cpu.h call we now need to
add it to various helpers that do need the full softfloat.h
definitions.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
[For PPC parts]
Acked-by: David Gibson <david@gibson.dropbear.id.au>
2018-02-21 10:20:24 +00:00
Yang Zhong 1d8ad165b6 target/i386: split cpu_set_mxcsr() and make cpu_set_fpuc() inline
Split the cpu_set_mxcsr() and make cpu_set_fpuc() inline with specific
tcg code.

Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-07-05 09:12:44 +02:00
Yang Zhong db573d2cf7 target/i386: make cpu_get_fp80()/cpu_set_fp80() static
Move cpu_get_fp80()/cpu_set_fp80() from fpu_helper.c to
machine.c because fpu_helper.c will be disabled if tcg is
disabled in the build.

Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-07-05 09:12:44 +02:00
Pranith Kumar 1c1df0198b linux-user: Add signal handling support for x86_64
Note that x86_64 has only _rt signal handlers. This implementation
attempts to share code with the x86_32 implementation.

CC: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Allan Wirth <awirth@akamai.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20170226165345.8757-1-bobby.prani@gmail.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2017-02-27 23:10:02 +01:00
Alex Bennée d10eb08f5d cputlb: drop flush_global flag from tlb_flush
We have never has the concept of global TLB entries which would avoid
the flush so we never actually use this flag. Drop it and make clear
that tlb_flush is the sledge-hammer it has always been.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
[DG: ppc portions]
Acked-by: David Gibson <david@gibson.dropbear.id.au>
2017-01-13 14:24:37 +00:00
Thomas Huth fcf5ef2ab5 Move target-* CPU file into a target/ folder
We've currently got 18 architectures in QEMU, and thus 18 target-xxx
folders in the root folder of the QEMU source tree. More architectures
(e.g. RISC-V, AVR) are likely to be included soon, too, so the main
folder of the QEMU sources slowly gets quite overcrowded with the
target-xxx folders.
To disburden the main folder a little bit, let's move the target-xxx
folders into a dedicated target/ folder, so that target-xxx/ simply
becomes target/xxx/ instead.

Acked-by: Laurent Vivier <laurent@vivier.eu> [m68k part]
Acked-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de> [tricore part]
Acked-by: Michael Walle <michael@walle.cc> [lm32 part]
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> [s390x part]
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> [s390x part]
Acked-by: Eduardo Habkost <ehabkost@redhat.com> [i386 part]
Acked-by: Artyom Tarasenko <atar4qemu@gmail.com> [sparc part]
Acked-by: Richard Henderson <rth@twiddle.net> [alpha part]
Acked-by: Max Filippov <jcmvbkbc@gmail.com> [xtensa part]
Reviewed-by: David Gibson <david@gibson.dropbear.id.au> [ppc part]
Acked-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com> [cris&microblaze part]
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn> [unicore32 part]
Signed-off-by: Thomas Huth <thuth@redhat.com>
2016-12-20 21:52:12 +01:00