target/s390x: Fix the floating-point multiply-and-add NaN rules

Order the helper arguments to match the Principles of Operation.
Implement the "Results: MULTIPLY AND ADD" table in pickNaNMulAdd().

target/s390x: Fix the floating-point multiply-and-add NaN rules

Order the helper arguments to match the Principles of Operation.
Implement the "Results: MULTIPLY AND ADD" table in pickNaNMulAdd().

Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-ID: <20241023000147.34035-2-iii@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

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softfloat: Remove fallback rule from pickNaN()

Now that all targets have been converted to explicitly set a NaN
propagation rule, we can remove the set of target ifdefs (which now
list every target)

softfloat: Remove fallback rule from pickNaN()

Now that all targets have been converted to explicitly set a NaN
propagation rule, we can remove the set of target ifdefs (which now
list every target) and clean up the references to fallback behaviour
for float_2nan_prop_none.

The "default" case in the switch will catch any remaining places
where status->float_2nan_prop_rule was not set by the target.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241025141254.2141506-22-peter.maydell@linaro.org

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target/rx: Explicitly set 2-NaN propagation rule

Set the NaN propagation rule explicitly for the float_status word
used in the rx target.

This not the architecturally correct behaviour, but since t

target/rx: Explicitly set 2-NaN propagation rule

Set the NaN propagation rule explicitly for the float_status word
used in the rx target.

This not the architecturally correct behaviour, but since this is a
no-behaviour-change patch, we leave a TODO note to that effect.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241025141254.2141506-21-peter.maydell@linaro.org

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target/openrisc: Explicitly set 2-NaN propagation rule

Set the NaN propagation rule explicitly for the float_status word
used in the openrisc target.

Signed-off-by: Peter Maydell <peter.maydell@lin

target/openrisc: Explicitly set 2-NaN propagation rule

Set the NaN propagation rule explicitly for the float_status word
used in the openrisc target.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241025141254.2141506-20-peter.maydell@linaro.org

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target/microblaze: Explicitly set 2-NaN propagation rule

Set the NaN propagation rule explicitly for the float_status word
used in the microblaze target.

This is probably not the architecturally co

target/microblaze: Explicitly set 2-NaN propagation rule

Set the NaN propagation rule explicitly for the float_status word
used in the microblaze target.

This is probably not the architecturally correct behaviour,
but since this is a no-behaviour-change patch, we leave a
TODO note to that effect.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241025141254.2141506-19-peter.maydell@linaro.org

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target/alpha: Explicitly set 2-NaN propagation rule

Set the NaN propagation rule explicitly for the float_status word
used in this target.

This is a no-behaviour-change commit, so we retain the exi

target/alpha: Explicitly set 2-NaN propagation rule

Set the NaN propagation rule explicitly for the float_status word
used in this target.

This is a no-behaviour-change commit, so we retain the existing
behaviour of x87-style pick-largest-significand NaN propagation.
This is however not the architecturally correct handling, so we leave
a TODO note to that effect.

We also leave a TODO note pointing out that all this code in the cpu
initfn (including the existing setting up of env->flags and the FPCR)
should be in a currently non-existent CPU reset function.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241025141254.2141506-17-peter.maydell@linaro.org

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target/i386: Set 2-NaN propagation rule explicitly

Set the NaN propagation rule explicitly for the float_status words
used in the x86 target.

This is a no-behaviour-change commit, so we retain the

target/i386: Set 2-NaN propagation rule explicitly

Set the NaN propagation rule explicitly for the float_status words
used in the x86 target.

This is a no-behaviour-change commit, so we retain the existing
behaviour of using the x87-style "prefer QNaN over SNaN, then prefer
the NaN with the larger significand" for MMX and SSE. This is
however not the documented hardware behaviour, so we leave a TODO
note about what we should be doing instead.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241025141254.2141506-16-peter.maydell@linaro.org

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target/xtensa: Explicitly set 2-NaN propagation rule

Set the NaN propagation rule explicitly in xtensa_use_first_nan().

(When we convert the softfloat pickNaNMulAdd routine to also
select a NaN pro

target/xtensa: Explicitly set 2-NaN propagation rule

Set the NaN propagation rule explicitly in xtensa_use_first_nan().

(When we convert the softfloat pickNaNMulAdd routine to also
select a NaN propagation rule at runtime, we will be able to
remove the use_first_nan flag because the propagation rules
will handle everything.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241025141254.2141506-15-peter.maydell@linaro.org

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target/sparc: Explicitly set 2-NaN propagation rule

Set the NaN propagation rule explicitly in the float_status
words we use.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Mark

target/sparc: Explicitly set 2-NaN propagation rule

Set the NaN propagation rule explicitly in the float_status
words we use.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241025141254.2141506-13-peter.maydell@linaro.org

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target/m68k: Explicitly set 2-NaN propagation rule

Explicitly set the 2-NaN propagation rule on env->fp_status
and on the temporary fp_status that we use in frem (since
we pass that to a division op

target/m68k: Explicitly set 2-NaN propagation rule

Explicitly set the 2-NaN propagation rule on env->fp_status
and on the temporary fp_status that we use in frem (since
we pass that to a division operation function).

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

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target/ppc: Explicitly set 2-NaN propagation rule

Set the 2-NaN propagation rule explicitly in env->fp_status
and env->vec_status.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-b

target/ppc: Explicitly set 2-NaN propagation rule

Set the 2-NaN propagation rule explicitly in env->fp_status
and env->vec_status.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241025141254.2141506-9-peter.maydell@linaro.org

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target/s390x: Explicitly set 2-NaN propagation rule

Set the 2-NaN propagation rule explicitly in env->fpu_status.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Ilya Leoshkevi

target/s390x: Explicitly set 2-NaN propagation rule

Set the 2-NaN propagation rule explicitly in env->fpu_status.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241025141254.2141506-8-peter.maydell@linaro.org

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target/hppa: Explicitly set 2-NaN propagation rule

Set the 2-NaN propagation rule explicitly in env->fp_status.

Really we only need to do this at CPU reset (after reset has zeroed
out most of the C

target/hppa: Explicitly set 2-NaN propagation rule

Set the 2-NaN propagation rule explicitly in env->fp_status.

Really we only need to do this at CPU reset (after reset has zeroed
out most of the CPU state struct, which typically includes fp_status
fields). However target/hppa does not currently implement CPU reset
at all, so leave a TODO comment to note that this could be moved if
we ever do implement reset.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241025141254.2141506-7-peter.maydell@linaro.org

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target/loongarch: Explicitly set 2-NaN propagation rule

Set the 2-NaN propagation rule explicitly in the float_status word we
use.

(There are a couple of places in fpu_helper.c where we create a
du

target/loongarch: Explicitly set 2-NaN propagation rule

Set the 2-NaN propagation rule explicitly in the float_status word we
use.

(There are a couple of places in fpu_helper.c where we create a
dummy float_status word with "float_status *s = { };", but these
are only used for calling float*_is_quiet_nan() so it doesn't
matter that we don't set a 2-NaN propagation rule there.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241025141254.2141506-6-peter.maydell@linaro.org

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target/mips: Explicitly set 2-NaN propagation rule

Set the 2-NaN propagation rule explicitly in the float_status words
we use.

For active_fpu.fp_status, we do this in a new fp_reset() function
whic

target/mips: Explicitly set 2-NaN propagation rule

Set the 2-NaN propagation rule explicitly in the float_status words
we use.

For active_fpu.fp_status, we do this in a new fp_reset() function
which mirrors the existing msa_reset() function in doing "first call
restore to set the fp status parts that depend on CPU state, then set
the fp status parts that are constant".

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20241025141254.2141506-5-peter.maydell@linaro.org

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target/arm: Explicitly set 2-NaN propagation rule

Set the 2-NaN propagation rule explicitly in the float_status words
we use. We wrap this plus the pre-existing setting of the
tininess-before-round

target/arm: Explicitly set 2-NaN propagation rule

Set the 2-NaN propagation rule explicitly in the float_status words
we use. We wrap this plus the pre-existing setting of the
tininess-before-rounding flag in a new function
arm_set_default_fp_behaviours() to avoid repetition, since we have a
lot of float_status words at this point.

The situation with FPA11 emulation in linux-user is a little odd, and
arguably "correct" behaviour there would be to exactly match a real
Linux kernel's FPA11 emulation. However FPA11 emulation is
essentially dead at this point and so it seems better to continue
with QEMU's current behaviour and leave a comment describing the
situation.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241025141254.2141506-4-peter.maydell@linaro.org

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softfloat: Allow 2-operand NaN propagation rule to be set at runtime

IEEE 758 does not define a fixed rule for which NaN to pick as the
result if both operands of a 2-operand operation are NaNs. As

softfloat: Allow 2-operand NaN propagation rule to be set at runtime

IEEE 758 does not define a fixed rule for which NaN to pick as the
result if both operands of a 2-operand operation are NaNs. As a
result different architectures have ended up with different rules for
propagating NaNs.

QEMU currently hardcodes the NaN propagation logic into the binary
because pickNaN() has an ifdef ladder for different targets. We want
to make the propagation rule instead be selectable at runtime,
because:
* this will let us have multiple targets in one QEMU binary
* the Arm FEAT_AFP architectural feature includes letting
the guest select a NaN propagation rule at runtime
* x86 specifies different propagation rules for x87 FPU ops
and for SSE ops, and specifying the rule in the float_status
would let us emulate this, instead of wrongly using the
x87 rules everywhere

In this commit we add an enum for the propagation rule, the field in
float_status, and the corresponding getters and setters. We change
pickNaN to honour this, but because all targets still leave this
field at its default 0 value, the fallback logic will pick the rule
type with the old ifdef ladder.

It's valid not to set a propagation rule if default_nan_mode is
enabled, because in that case there's no need to pick a NaN; all the
callers of pickNaN() catch this case and skip calling it. So we can
already assert that we don't get into the "no rule defined" codepath
for our four targets which always set default_nan_mode: Hexagon,
RiscV, SH4 and Tricore, and for the one target which does not have FP
at all: avr. These targets will not need to be updated to call
set_float_2nan_prop_rule().

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241025141254.2141506-2-peter.maydell@linaro.org

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fpu: remove break after g_assert_not_reached()

This patch is part of a series that moves towards a consistent use of
g_assert_not_reached() rather than an ad hoc mix of different
assertion mechanism

fpu: remove break after g_assert_not_reached()

This patch is part of a series that moves towards a consistent use of
g_assert_not_reached() rather than an ad hoc mix of different
assertion mechanisms.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Message-ID: <20240919044641.386068-24-pierrick.bouvier@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>

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target/cris: Remove the deprecated CRIS target

The CRIS target is deprecated since v9.0 (commit c7bbef40234
"docs: mark CRIS support as deprecated").

Signed-off-by: Philippe Mathieu-Daudé <philmd@l

target/cris: Remove the deprecated CRIS target

The CRIS target is deprecated since v9.0 (commit c7bbef40234
"docs: mark CRIS support as deprecated").

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
Message-ID: <20240904143603.52934-14-philmd@linaro.org>

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target/sparc: Implement FMAf extension

Rearrange PDIST so that do_dddd is general purpose and may
be re-used for FMADDd etc. Add pickNaN and pickNaNMulAdd.

Signed-off-by: Richard Henderson <richar

target/sparc: Implement FMAf extension

Rearrange PDIST so that do_dddd is general purpose and may
be re-used for FMADDd etc. Add pickNaN and pickNaNMulAdd.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

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