Commit Graph

113 Commits

Author SHA1 Message Date
Matheus Ferst
caf6f9b568 target/ppc: move xscvqpdp to decodetree
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Message-Id: <20211213120958.24443-5-victor.colombo@eldorado.org.br>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:18 +01:00
Victor Colombo
201fc774e0 target/ppc: Fix xs{max, min}[cj]dp to use VSX registers
PPC instruction xsmaxcdp, xsmincdp, xsmaxjdp, and xsminjdp are using
vector registers when they should be using VSX ones. This happens
because the instructions are using GEN_VSX_HELPER_R3, which adds 32
to the register numbers, effectively making them vector registers.

This patch fixes it by changing these instructions to use
GEN_VSX_HELPER_X3.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Victor Colombo <victor.colombo@eldorado.org.br>
Message-Id: <20211213120958.24443-2-victor.colombo@eldorado.org.br>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:18 +01:00
Richard Henderson
a1f1c731c6 target/ppc: Use helper_todouble/tosingle in helper_xststdcsp
When computing the predicate "is this value currently formatted
for single precision", we do not want to round the value according
to the current rounding mode, nor perform a floating-point equality.
We want to see if the N bits that make up single-precision are the
only ones set within the register, and then a bitwise equality.

Fixes a bug in which a single-precision NaN is considered !SP,
because float64_eq(nan, nan) is always false.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-35-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:16 +01:00
Richard Henderson
7d82ea3484 target/ppc: Update fres to new flags and float64r32
There is no double-rounding bug here, because the result is
merely an estimate to within 1 part in 256, but perform the
operation with float64r32_div for consistency.

Use float_flag_invalid_snan instead of recomputing the
snan-ness of the operand.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-34-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:16 +01:00
Richard Henderson
dedbfda765 target/ppc: Add helper for frsqrtes
There is no double-rounding bug here, because the result is
merely an estimate to within 1 part in 32, but perform the
operation with float64r32_div for consistency.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-33-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:16 +01:00
Richard Henderson
7f87214e3b target/ppc: Add helper for fmuls
Use float64r32_mul.  Fixes a double-rounding issue with performing
the compuation in float64 and then rounding afterward.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-32-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:16 +01:00
Richard Henderson
d9e792a1c1 target/ppc: Add helpers for fadds, fsubs, fdivs
Use float64r32_{add,sub,div}.  Fixes a double-rounding issue with
performing the compuation in float64 and then rounding afterward.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-31-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:16 +01:00
Richard Henderson
41ae890d08 target/ppc: Add helper for fsqrts
Use float64r32_sqrt.  Fixes a double-rounding issue with performing
the compuation in float64 and then rounding afterward.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-30-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:16 +01:00
Richard Henderson
d04ca895dc target/ppc: Add helpers for fmadds et al
Use float64r32_muladd.  Fixes a double-rounding issue with performing
the compuation in float64 and then rounding afterward.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-29-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:16 +01:00
Richard Henderson
8ea0b1408e target/ppc: Update fre to new flags
Use float_flag_invalid_snan instead of recomputing
the snan-ness of the operand.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-27-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:15 +01:00
Richard Henderson
053e23a694 target/ppc: Update xsrqpi and xsrqpxp to new flags
Use float_flag_invalid_snan instead of recomputing
the snan-ness of the operand.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-26-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:15 +01:00
Richard Henderson
3d3050cc8d target/ppc: Update sqrt for new flags
Now that vxsqrt and vxsnan are computed directly by softfloat,
we don't need to recompute it.  Split out float_invalid_op_sqrt
to be used in several places.  This fixes VSX_SQRT, which did
not order its tests correctly to eliminate NaN with sign set.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-25-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:15 +01:00
Richard Henderson
58c7edef61 target/ppc: Use helper_todouble in do_frsp
We only needed one ieee arithmetic operation to raise
exceptions.  To convert back to register form, we can
use our simpler non-arithmetic function.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-24-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:15 +01:00
Richard Henderson
734cfbd84e target/ppc: Update do_frsp for new flags
Now that vxsnan is computed directly by softfloat,
we don't need to recompute it.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-23-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:15 +01:00
Richard Henderson
7238e55bd6 target/ppc: Split out do_frsp
Calling helper_frsp directly from other helpers generates
the incorrect retaddr.  Split out a helper that takes the
retaddr as a parameter.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-22-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:15 +01:00
Richard Henderson
2125ac18bf target/ppc: Do not call do_float_check_status from do_fmadd
We will process flags other than in valid in helper_float_check_status,
which is invoked after the writeback to FRT.
Fixes a bug in which FRT is not written when OE/UE/XE are enabled.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-21-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:15 +01:00
Richard Henderson
ffdaff8e9c target/ppc: Split out do_fmadd
Create a common function for all of the madd helpers.
Let the compiler tail call or inline as it chooses.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-20-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:15 +01:00
Richard Henderson
e4052bb773 target/ppc: Update fmadd for new flags
Now that vximz, vxisi, and vxsnan are computed directly by
softfloat, we don't need to recompute it.  This replaces the
separate float{32,64}_maddsub_update_excp functions with a
single float_invalid_op_madd function.

Fix VSX_MADD by passing sfprf to float_invalid_op_madd,
whereas the previous *_maddsub_update_excp assumed it true.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-19-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:15 +01:00
Richard Henderson
a496352736 target/ppc: Clean up do_fri
Let float64_round_to_int detect and silence snans.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-18-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:15 +01:00
Richard Henderson
1348d20b16 target/ppc: Tidy inexact handling in do_fri
In GEN_FLOAT_B, we called helper_reset_fpstatus immediately
before calling helper_fri*.  Therefore get_float_exception_flags
is known to be zero, and this code can be simplified.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-17-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:15 +01:00
Richard Henderson
6bce077777 target/ppc: Use FloatRoundMode in do_fri
This is the proper type for the enumeration.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20211119160502.17432-16-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:15 +01:00
Richard Henderson
b891757e44 target/ppc: Remove inline from do_fri
There's no reason the callers can't tail call to one function.
Leave it up to the compiler either way.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20211119160502.17432-15-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:15 +01:00
Richard Henderson
fed12f3b2d target/ppc: Fix VXCVI return value
We were returning nanval for any instance of invalid being set,
but that is an incorrect for VXCVI.  This failure can be seen
in the float_convs tests.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-14-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:14 +01:00
Richard Henderson
353464ea16 target/ppc: Update float_invalid_cvt for new flags
Now that vxsnan is computed directly by softfloat,
we don't need to recompute it via classes.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-13-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:14 +01:00
Richard Henderson
f2e2504676 target/ppc: Move float_check_status from FPU_FCTI to translate
Fixes a bug in which e.g XE enabled causes inexact to be raised
before the writeback to the architectural register.

All of the users of GEN_FLOAT_B either set set_fprf, or are one
of the convert-to-integer instructions that require this behaviour.
Split out the two gen_helper_* calls in gen_compute_fprf_float64
and protect only the first with set_fprf.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-12-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:14 +01:00
Richard Henderson
c07f82416c target/ppc: Update float_invalid_op_div for new flags
Now that vxidi, vxzdz, and vxsnan are computed directly by
softfloat, we don't need to recompute it via classes.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-11-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:14 +01:00
Richard Henderson
4edf55698f target/ppc: Update float_invalid_op_mul for new flags
Now that vximz and vxsnan are computed directly by
softfloat, we don't need to recompute it via classes.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-10-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:14 +01:00
Richard Henderson
941298ecd7 target/ppc: Update float_invalid_op_addsub for new flags
Now that vxisi and vxsnan are computed directly by
softfloat, we don't need to recompute it via classes.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-9-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:14 +01:00
Lucas Mateus Castro (alqotel)
c3a824b0cf target/ppc: Fixed call to deferred exception
mtfsf, mtfsfi and mtfsb1 instructions call helper_float_check_status
after updating the value of FPSCR, but helper_float_check_status
checks fp_status and fp_status isn't updated based on FPSCR and
since the value of fp_status is reset earlier in the instruction,
it's always 0.

Because of this helper_float_check_status would change the FI bit to 0
as this bit checks if the last operation was inexact and
float_flag_inexact is always 0.

These instructions also don't throw exceptions correctly since
helper_float_check_status throw exceptions based on fp_status.

This commit created a new helper, helper_fpscr_check_status that checks
FPSCR value instead of fp_status and checks for a larger variety of
exceptions than do_float_check_status.

Since fp_status isn't used, gen_reset_fpstatus() was removed.

The hardware used to compare QEMU's behavior to was a Power9.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Lucas Mateus Castro (alqotel) <lucas.araujo@eldorado.org.br>
Message-Id: <20211201163808.440385-2-lucas.araujo@eldorado.org.br>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:12 +01:00
Bruno Larsen (billionai)
fe43ba9721 target/ppc: overhauled and moved logic of storing fpscr
Followed the suggested overhaul to store_fpscr logic, and moved it to
cpu.c where it can be accessed in !TCG builds.

The overhaul was suggested because storing a value to fpscr should
never raise an exception, so we could remove all the mess that happened
with POWERPC_EXCP_FP.

We also moved fpscr_set_rounding_mode into cpu.c as it could now be moved
there, and it is needed when a value for the fpscr is being stored
directly.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Bruno Larsen (billionai) <bruno.larsen@eldorado.org.br>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210527163522.23019-1-bruno.larsen@eldorado.org.br>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2021-06-03 18:10:31 +10:00
Bruno Larsen (billionai)
63d06e90e6 target/ppc: reduce usage of fpscr_set_rounding_mode
It is preferable to store the current rounding mode and retore from that
than recalculating from fpscr, so we changed the behavior of do_fri and
VSX_ROUND to do it like that.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Bruno Larsen (billionai) <bruno.larsen@eldorado.org.br>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210521201759.85475-4-bruno.larsen@eldorado.org.br>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2021-06-03 13:22:06 +10:00
Giuseppe Musacchio
91699dbf30 ppc/translate: Raise exceptions after setting the cc
The PowerISA reference states that the comparison operators update the
FPCC, CR and FPSCR and, if VE=1, jump to the exception handler.

Moving the exception-triggering code after the CC update sequence solves
the problem.

Signed-off-by: Giuseppe Musacchio <thatlemon@gmail.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20201112230130.65262-5-thatlemon@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-12-14 15:53:59 +11:00
Giuseppe Musacchio
bc92c260f6 ppc/translate: Delay NaN checking after comparison
Since we always perform a comparison between the two operands avoid
checking for NaN unless the result states they're unordered.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Giuseppe Musacchio <thatlemon@gmail.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20201112230130.65262-4-thatlemon@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-12-14 15:53:52 +11:00
Giuseppe Musacchio
132954a830 ppc/translate: Turn the helper macros into functions
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Giuseppe Musacchio <thatlemon@gmail.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20201112230130.65262-3-thatlemon@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-12-14 15:53:41 +11:00
Giuseppe Musacchio
3278aa49d5 ppc/translate: Fix unordered f64/f128 comparisons
According to the PowerISA v3.1 reference, Table 68 "Actions for xscmpudp
- Part 1: Compare Unordered", whenever one of the two operands is a NaN
the SO bit is set while the other three bits are cleared.

Apply the same change to xscmpuqp.

The respective ordered counterparts are unaffected.

Signed-off-by: Giuseppe Musacchio <thatlemon@gmail.com>
Message-Id: <20201112230130.65262-2-thatlemon@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-12-14 15:53:26 +11:00
Chetan Pant
6bd039cdbe powerpc tcg: Fix Lesser GPL version number
There is no "version 2" of the "Lesser" General Public License.
It is either "GPL version 2.0" or "Lesser GPL version 2.1".
This patch replaces all occurrences of "Lesser GPL version 2" with
"Lesser GPL version 2.1" in comment section.

Signed-off-by: Chetan Pant <chetan4windows@gmail.com>
Message-Id: <20201019061126.3102-1-chetan4windows@gmail.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2020-11-15 16:38:50 +01:00
zhaolichang
136fbf654d ppc/: fix some comment spelling errors
I found that there are many spelling errors in the comments of qemu/target/ppc.
I used spellcheck to check the spelling errors and found some errors in the folder.

Signed-off-by: zhaolichang <zhaolichang@huawei.com>
Reviewed-by: David Edmondson <david.edmondson@oracle.com>
Message-Id: <20201009064449.2336-3-zhaolichang@huawei.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-10-28 01:08:53 +11:00
BALATON Zoltan
92eeb004e8 target/ppc: Fix typo in comments
"Deferred" was misspelled as "differed" in some comments, correct this
typo,

Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Message-Id: <20200214155748.0896B745953@zero.eik.bme.hu>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-02-21 09:15:04 +11:00
Paul A. Clarke
5c94dd3806 ppc: Use FPSCR defines instead of constants
There are FPSCR-related defines in target/ppc/cpu.h which can be used in
place of constants and explicit shifts which arguably improve the code a
bit in places.

Signed-off-by: Paul A. Clarke <pc@us.ibm.com>
Message-Id: <1568817169-1721-1-git-send-email-pc@us.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-10-04 10:25:23 +10:00
Richard Henderson
16ce2fffa6 target/ppc: Fix do_float_check_status vs inexact
The underflow and inexact exceptions are not mutually exclusive.
Check for both of them.  Tidy the reset of FPSCR[FI].

Fixes: https://bugs.launchpad.net/bugs/1841442
Reported-by: Paul Clarke <pc@us.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Paul Clarke <pc@us.ibm.com>
Message-Id: <20190826165434.18403-2-richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-08-29 09:46:07 +10:00
Paul A. Clarke
fa7d9cb960 ppc: Fix xscvdpspn for SNAN
The xscvdpspn instruction implements a non-arithmetic conversion.
In particular, NaNs are not silenced and rounding is not performed.

Rewrite to match the pseudocode for ConvertDPtoSP_NS() in the
Power 3.0B manual.

Signed-off-by: Paul A. Clarke <pc@us.ibm.com>
Message-Id: <1566321964-1447-1-git-send-email-pc@us.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
[dwg: Replaced description with clearer version from rth]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-08-29 09:46:07 +10:00
Paul A. Clarke
c0e6616b66 ppc: Fix emulated single to double denormalized conversions
helper_todouble() was not properly converting any denormalized 32 bit
float to 64 bit double.

Fix-suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paul A. Clarke <pc@us.ibm.com>

v2:
- Splitting patch "ppc: Three floating point fixes"; this is just one part.
- Original suggested "fix" was likely flawed.  v2 is rewritten by
  Richard Henderson (Thanks, Richard!); I reformatted the comments in a
  couple of places, compiled, and tested.
Message-Id: <1566250936-14538-1-git-send-email-pc@us.ibm.com>

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-08-21 17:17:39 +10:00
Paul A. Clarke
a7b7b98318 ppc: Fix emulated INFINITY and NAN conversions
helper_todouble() was not properly converting INFINITY from 32 bit
float to 64 bit double.

(Normalized operand conversion is unchanged, other than indentation.)

Signed-off-by: Paul A. Clarke <pc@us.ibm.com>
Message-Id: <1566242388-9244-1-git-send-email-pc@us.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-08-21 17:17:39 +10:00
Paul A. Clarke
e6f1bfb211 ppc: conform to processor User's Manual for xscvdpspn
The POWER8 and POWER9 User's Manuals specify the implementation
behavior for what the ISA leaves "undefined" behavior for the
xscvdpspn and xscvdpsp instructions.  This patch corrects the QEMU
implementation to match the hardware implementation for that case.

ISA 3.0B has xscvdpspn leaving its result in word 0 of the target register,
with the other words of the target register left "undefined".

The User's Manuals specify:
  VSX scalar convert from double-precision to single-precision (xscvdpsp,
  xscvdpspn).
  VSR[32:63] is set to VSR[0:31].
So, words 0 and 1 both contain the result.

Note: this is important because GCC as of version 8 or so, assumes and takes
advantage of this behavior to optimize the following sequence:
  xscvdpspn vs0,vs1
  mffprwz   r8,f0
ISA 3.0B has xscvdpspn leaving its result in word 0 of the target register,
and mffprwz expecting its input to come from word 1 of the source register.
This sequence fails with QEMU, as a shift is required between those two
instructions.  However, since the hardware splats the result to both words 0
and 1 of its output register, the shift is not necessary.

Expect a future revision of the ISA to specify this behavior.

Signed-off-by: Paul A. Clarke <pc@us.ibm.com>

v2
- Splitting patch "ppc: Three floating point fixes"; this is just one part.
- Updated commit message to clarify behavior is documented in User's Manuals.
- Updated commit message to correct which words are in output and source of
  xscvdpspn and mffprz.
- No source changes to this part of the original patch.

Message-Id: <1566236601-22954-1-git-send-email-pc@us.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-08-21 17:17:39 +10:00
Paul A. Clarke
31eb7dddac ppc: Add support for 'mffsl' instruction
ISA 3.0B added a set of Floating-Point Status and Control Register (FPSCR)
instructions: mffsce, mffscdrn, mffscdrni, mffscrn, mffscrni, mffsl.
This patch adds support for 'mffsl'.

'mffsl' is identical to 'mffs', except it only returns mode, status, and enable
bits from the FPSCR.

On CPUs without support for 'mffsl' (below ISA 3.0), the 'mffsl' instruction
will execute identically to 'mffs'.

Note: I renamed FPSCR_RN to FPSCR_RN0 so I could create an FPSCR_RN mask which
is both bits of the FPSCR rounding mode, as defined in the ISA.

I also fixed a typo in the definition of FPSCR_FR.

Signed-off-by: Paul A. Clarke <pc@us.ibm.com>

v4:
- nit: added some braces to resolve a checkpatch complaint.

v3:
- Changed tcg_gen_and_i64 to tcg_gen_andi_i64, eliminating the need for a
  temporary, per review from Richard Henderson.

v2:
- I found that I copied too much of the 'mffs' implementation.
  The 'Rc' condition code bits are not needed for 'mffsl'.  Removed.
- I now free the (renamed) 'tmask' temporary.
- I now bail early for older ISA to the original 'mffs' implementation.

Message-Id: <1565982203-11048-1-git-send-email-pc@us.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-08-21 17:17:39 +10:00
Mark Cave-Ayland
c9f4e4d8b6 target/ppc: improve VSX_FMADD with new GEN_VSX_HELPER_VSX_MADD macro
Introduce a new GEN_VSX_HELPER_VSX_MADD macro for the generator function which
enables the source and destination registers to be decoded at translation time.

This enables the determination of a or m form to be made at translation time so
that a single helper function can now be used for both variants.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20190616123751.781-16-mark.cave-ayland@ilande.co.uk>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-07-02 09:43:58 +10:00
Mark Cave-Ayland
6ae4a57ab0 target/ppc: introduce GEN_VSX_HELPER_R2_AB macro to fpu_helper.c
Rather than perform the VSR register decoding within the helper itself,
introduce a new GEN_VSX_HELPER_R2_AB macro which performs the decode based
upon rA and rB at translation time.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20190616123751.781-13-mark.cave-ayland@ilande.co.uk>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-07-02 09:43:58 +10:00
Mark Cave-Ayland
9922962011 target/ppc: introduce GEN_VSX_HELPER_R2 macro to fpu_helper.c
Rather than perform the VSR register decoding within the helper itself,
introduce a new GEN_VSX_HELPER_R2 macro which performs the decode based
upon rD and rB at translation time.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20190616123751.781-12-mark.cave-ayland@ilande.co.uk>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-07-02 09:43:58 +10:00
Mark Cave-Ayland
23d0766bd9 target/ppc: introduce GEN_VSX_HELPER_R3 macro to fpu_helper.c
Rather than perform the VSR register decoding within the helper itself,
introduce a new GEN_VSX_HELPER_R3 macro which performs the decode based
upon rD, rA and rB at translation time.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20190616123751.781-11-mark.cave-ayland@ilande.co.uk>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-07-02 09:43:58 +10:00
Mark Cave-Ayland
8d830485fc target/ppc: introduce GEN_VSX_HELPER_X1 macro to fpu_helper.c
Rather than perform the VSR register decoding within the helper itself,
introduce a new GEN_VSX_HELPER_X1 macro which performs the decode based
upon xB at translation time.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20190616123751.781-10-mark.cave-ayland@ilande.co.uk>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-07-02 09:43:58 +10:00