Commit Graph

15 Commits

Author SHA1 Message Date
Alex Bennée
e025d799af tests/plugin: expand insn test to detect duplicate instructions
A duplicate insn is one that is appears to be executed twice in a row.
This is currently possible due to -icount and cpu_io_recompile()
causing a re-translation of a block. On it's own this won't trigger
any tests though.

The heuristics that the plugin use can't deal with the x86 rep
instruction which (validly) will look like executing the same
instruction several times. To avoid problems later we tweak the rules
for x86 to run the "inline" version of the plugin. This also has the
advantage of increasing coverage of the plugin code (see bugfix in
previous commit).

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210213130325.14781-15-alex.bennee@linaro.org>
2021-02-18 08:19:23 +00:00
Paolo Bonzini
75b208c283 target/i386: fix operand order for PDEP and PEXT
For PDEP and PEXT, the mask is provided in the memory (mod+r/m)
operand, and therefore is loaded in s->T0 by gen_ldst_modrm.
The source is provided in the second source operand (VEX.vvvv)
and therefore is loaded in s->T1.  Fix the order in which
they are passed to the helpers.

Reported-by: Lenard Szolnoki <blog@lenardszolnoki.com>
Analyzed-by: Lenard Szolnoki <blog@lenardszolnoki.com>
Fixes: https://bugs.launchpad.net/qemu/+bug/1605123
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-10 12:14:49 -05:00
Joseph Myers
418b0f93d1 target/i386: fix IEEE SSE floating-point exception raising
The SSE instruction implementations all fail to raise the expected
IEEE floating-point exceptions because they do nothing to convert the
exception state from the softfloat machinery into the exception flags
in MXCSR.

Fix this by adding such conversions.  Unlike for x87, emulated SSE
floating-point operations might be optimized using hardware floating
point on the host, and so a different approach is taken that is
compatible with such optimizations.  The required invariant is that
all exceptions set in env->sse_status (other than "denormal operand",
for which the SSE semantics are different from those in the softfloat
code) are ones that are set in the MXCSR; the emulated MXCSR is
updated lazily when code reads MXCSR, while when code sets MXCSR, the
exceptions in env->sse_status are set accordingly.

A few instructions do not raise all the exceptions that would be
raised by the softfloat code, and those instructions are made to save
and restore the softfloat exception state accordingly.

Nothing is done about "denormal operand"; setting that (only for the
case when input denormals are *not* flushed to zero, the opposite of
the logic in the softfloat code for such an exception) will require
custom code for relevant instructions, or else architecture-specific
conditionals in the softfloat code for when to set such an exception
together with custom code for various SSE conversion and rounding
instructions that do not set that exception.

Nothing is done about trapping exceptions (for which there is minimal
and largely broken support in QEMU's emulation in the x87 case and no
support at all in the SSE case).

Signed-off-by: Joseph Myers <joseph@codesourcery.com>
Message-Id: <alpine.DEB.2.21.2006252358000.3832@digraph.polyomino.org.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10 18:02:17 -04:00
Alex Bennée
d16242e524 tests/tcg: ensure -cpu max also used for plugin run
The check-tcg plugins build was failing because some special case
tests that needed -cpu max failed because the plugin variant hadn't
carried across the QEMU_OPTS tweak.

Guests which globally set QEMU_OPTS=-cpu FOO where unaffected.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20200615141922.18829-3-alex.bennee@linaro.org>
2020-06-16 14:49:05 +01:00
Joseph Myers
bc921b2711 target/i386: correct fix for pcmpxstrx substring search
This corrects a bug introduced in my previous fix for SSE4.2 pcmpestri
/ pcmpestrm / pcmpistri / pcmpistrm substring search, commit
ae35eea7e4.

That commit fixed a bug that showed up in four GCC tests with one libc
implementation.  The tests in question generate random inputs to the
intrinsics and compare results to a C implementation, but they only
test 1024 possible random inputs, and when the tests use the cases of
those instructions that work with word rather than byte inputs, it's
easy to have problematic cases that show up much less frequently than
that.  Thus, testing with a different libc implementation, and so a
different random number generator, showed up a problem with the
previous patch.

When investigating the previous test failures, I found the description
of these instructions in the Intel manuals (starting from computing a
16x16 or 8x8 set of comparison results) confusing and hard to match up
with the more optimized implementation in QEMU, and referred to AMD
manuals which described the instructions in a different way.  Those
AMD descriptions are very explicit that the whole of the string being
searched for must be found in the other operand, not running off the
end of that operand; they say "If the prototype and the SUT are equal
in length, the two strings must be identical for the comparison to be
TRUE.".  However, that statement is incorrect.

In my previous commit message, I noted:

  The operation in this case is a search for a string (argument d to
  the helper) in another string (argument s to the helper); if a copy
  of d at a particular position would run off the end of s, the
  resulting output bit should be 0 whether or not the strings match in
  the region where they overlap, but the QEMU implementation was
  wrongly comparing only up to the point where s ends and counting it
  as a match if an initial segment of d matched a terminal segment of
  s.  Here, "run off the end of s" means that some byte of d would
  overlap some byte outside of s; thus, if d has zero length, it is
  considered to match everywhere, including after the end of s.

The description "some byte of d would overlap some byte outside of s"
is accurate only when understood to refer to overlapping some byte
*within the 16-byte operand* but at or after the zero terminator; it
is valid to run over the end of s if the end of s is the end of the
16-byte operand.  So the fix in the previous patch for the case of d
being empty was correct, but the other part of that patch was not
correct (as it never allowed partial matches even at the end of the
16-byte operand).  Nor was the code before the previous patch correct
for the case of d nonempty, as it would always have allowed partial
matches at the end of s.

Fix with a partial revert of my previous change, combined with
inserting a check for the special case of s having maximum length to
determine where it is necessary to check for matches.

In the added test, test 1 is for the case of empty strings, which
failed before my 2017 patch, test 2 is for the bug introduced by my
2017 patch and test 3 deals with the case where a match of an initial
segment at the end of the string is not valid when the string ends
before the end of the 16-byte operand (that is, the case that would be
broken by a simple revert of the non-empty-string part of my 2017
patch).

Signed-off-by: Joseph Myers <joseph@codesourcery.com>
Message-Id: <alpine.DEB.2.21.2006121344290.9881@digraph.polyomino.org.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-12 11:10:39 -04:00
Alex Bennée
eba9ccf8f8 tests/tcg: drop test-i386-fprem from TESTS when not SLOW
This is a very slow running test which we only enable explicitly.
However having it in the TESTS lists would confuse additional tests
like the plugins test which want to run on all currently enabled
tests.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
2019-10-28 15:12:38 +00:00
Paolo Bonzini
fc76c56d3f tests/tcg: cleanup Makefile inclusions
Rename Makefile.probe to Makefile.prereqs and make it actually
define rules for the tests.

Rename Makefile to Makefile.target, since it is not a toplevel
makefile.

Rename Makefile.include to Makefile.qemu and disentangle it
from the QEMU Makefile.target, so that it is invoked recursively
by tests/Makefile.include.  Tests are now placed in
tests/tcg/$(TARGET).

Drop the usage of TARGET_BASE_ARCH, which is ignored by everything except
x86_64 and aarch64.  Fix x86 tests by using -cpu max and, while
at it, standardize on QEMU_OPTS for aarch64 tests too.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20190807143523.15917-3-pbonzini@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
2019-09-10 09:38:33 +01:00
Alex Bennée
bd2c0f67e1 tests/tcg: fix up test-i386-fprem.ref generation
We never shipped the reference data in the source tree because it's
quite big (64M). As a result the only option is to generate it
locally. Although we have a rule to generate the reference file we
missed the dependency and location changes, probably because it's only
run for SLOW test runs.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
2019-07-10 10:31:20 +01:00
Alex Bennée
1a3bdc6111 tests/tcg: remove runcom test
The combination of being rather esoteric and needing to support mmap @
0 means this only ever worked under translation. It has now regressed
even further and is no longer useful. Kill it.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
2018-07-24 11:45:25 +01:00
Alex Bennée
ab93256144 tests/tcg/i386: extend timeout for runcom test
The Travis hardware can be a little slow and the runcom test is fairly
heavy in calculating pi. Lets double the timeout so we don't trip up
during CI by mistake.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
2018-06-20 20:22:34 +01:00
Alex Bennée
607bf9b5a5 tests/tcg: add run, diff, and skip helper macros
As we aren't using the default runners for all the test cases it is
easy to miss out things like timeouts. To help with this we add some
helpers and use them so we only need to make core changes in one
place.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2018-06-20 20:22:34 +01:00
Alex Bennée
3a082ec01b tests/tcg/x86_64: add Makefile.target
The sources for x86_64 are shared in the i386 directory which will be
included thanks to TARGET_BASE_ARCH. However not all sources build so
we need to filter out the ones we can't build in the 64 bit world and
those that can't be built for 32 bit.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2018-06-20 20:22:34 +01:00
Alex Bennée
25f9e7e8d7 tests/tcg/i386: add runner for test-i386-fprem
The runner needs to compare against a reference run. We also only run
this test when SPEED=slow as it takes a while.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2018-06-20 20:22:34 +01:00
Alex Bennée
8b17219e7d tests/tcg: enable building for i386
While you can construct a compile command that does work using the
x86_64 host compiler that most people use this is flakey. Different
distros handle this is different ways so we default to using a known
good i386 compiler via docker.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2018-06-20 20:22:34 +01:00
Alex Bennée
4132431f24 tests/tcg: move i386 specific tests into subdir
These only need to be built for i386 guests. This includes a stub
tests/tcg/i386/Makfile.target which absorbs some of what was in
tests/tcg/Makefile.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
2018-06-20 20:22:34 +01:00