Commit Graph

87 Commits

Author SHA1 Message Date
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
Mark Cave-Ayland
033e1fcd97 target/ppc: introduce GEN_VSX_HELPER_X2_AB macro to fpu_helper.c
Rather than perform the VSR register decoding within the helper itself,
introduce a new GEN_VSX_HELPER_X2_AB macro which performs the decode based
upon xA and 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: <20190616123751.781-9-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
75cf84cbee target/ppc: introduce GEN_VSX_HELPER_X2 macro to fpu_helper.c
Rather than perform the VSR register decoding within the helper itself,
introduce a new GEN_VSX_HELPER_X2 macro which performs the decode based
upon xT and xB at translation time.

With the previous change to the xscvqpdp generator and helper functions the
opcode parameter is no longer required in the common case and can be
removed.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20190616123751.781-8-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
e0d6a362be target/ppc: introduce separate generator and helper for xscvqpdp
Rather than perform the VSR register decoding within the helper itself,
introduce a new generator and helper function which perform the decode based
upon xT and xB at translation time.

The xscvqpdp helper is the only 2 parameter xT/xB implementation that requires
the opcode to be passed as an additional parameter, so handling this separately
allows us to optimise the conversion in the next commit.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20190616123751.781-7-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
99125c7499 target/ppc: introduce GEN_VSX_HELPER_X3 macro to fpu_helper.c
Rather than perform the VSR register decoding within the helper itself,
introduce a new GEN_VSX_HELPER_X3 macro which performs the decode based
upon xT, xA and xB at translation time.

With the previous changes to the VSX_CMP generator and helper macros the
opcode parameter is no longer required in the common case and can be
removed.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20190616123751.781-6-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
00084a25ad target/ppc: introduce separate VSX_CMP macro for xvcmp* instructions
Rather than perform the VSR register decoding within the helper itself,
introduce a new VSX_CMP macro which performs the decode based upon xT, xA
and xB at translation time.

Subsequent commits will make the same changes for other instructions however
the xvcmp* instructions are different in that they return a set of flags to be
optionally written back to the crf[6] register. Move this logic from the
helper function to the generator function, along with the float_status update.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20190616123751.781-5-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
cf3b0334f2 target/ppc: remove getVSR()/putVSR() from fpu_helper.c
Since commit 8a14d31b00 "target/ppc: switch fpr/vsrl registers so all VSX
registers are in host endian order" functions getVSR() and putVSR() which used
to convert the VSR registers into host endian order are no longer required.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Message-Id: <20190616123751.781-2-mark.cave-ayland@ilande.co.uk>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-07-02 09:43:58 +10:00
Richard Henderson
db70b31144 target/ppc: Use env_cpu, env_archcpu
Cleanup in the boilerplate that each target must define.
Replace ppc_env_get_cpu with env_archcpu.  The combination
CPU(ppc_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
David Gibson
fa9ebf8c3e target/ppc: Style fixes for fpu_helper.c
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
2019-04-26 10:42:38 +10:00
Richard Henderson
a3dec427e0 target/ppc: Split out float_invalid_cvt
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-11-08 12:04:40 +11:00
Richard Henderson
fec59ef30c target/ppc: Split out float_invalid_op_div
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-11-08 12:04:40 +11:00
Richard Henderson
4f0da706c2 target/ppc: Split out float_invalid_op_mul
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-11-08 12:04:40 +11:00
Richard Henderson
57483867e9 target/ppc: Split out float_invalid_op_addsub
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-11-08 12:04:40 +11:00
Richard Henderson
0394d7a684 target/ppc: Introduce fp number classification
Having a separate, logical classifiation of numbers will
unify more error paths for different formats.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-11-08 12:04:40 +11:00
Richard Henderson
6525aadc12 target/ppc: Remove float_check_status
Use do_float_check_status directly, so that we don't get confused
about which return address we're using.  And definitely don't use
helper_float_check_status.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-11-08 12:04:40 +11:00
Richard Henderson
13c9115fa9 target/ppc: Split up float_invalid_op_excp
The always_inline trick only works if the function is always
called from the outer-most helper.  But it isn't, so pass in
the outer-most return address.  There's no need for a switch
statement whose argument is always a constant.  Unravel the
switch and goto via more helpers.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-11-08 12:04:40 +11:00
Richard Henderson
86c0cab11a target/ppc: Use non-arithmetic conversions for fp load/store
Memory operations have no side effects on fp state.
The use of a "real" conversions between float64 and float32
would raise exceptions for SNaN and out-of-range inputs.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-08-21 14:28:45 +10:00
Richard Henderson
3843471755 target/ppc: Honor fpscr_ze semantics and tidy fre, fresqrt
Divide by zero, exception taken, leaves the destination register
unmodified.  Therefore we must raise the exception before returning
from the respective helpers.

>From helper_fre, divide by zero exception not taken, return the
documented +/- 0.5.

At the same time, tidy the invalid exception checking so that we
rely on softfloat for initial argument validation, and select the
kind of invalid operand exception only when we know we must.

At the same time, pass and return float64 values directly rather
than bounce through the CPU_DoubleU union.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-08-21 14:28:45 +10:00
Richard Henderson
49ab52ef69 target/ppc: Tidy helper_fsqrt
Tidy the invalid exception checking so that we rely on softfloat for
initial argument validation, and select the kind of invalid operand
exception only when we know we must.  Pass and return float64 values
directly rather than bounce through the CPU_DoubleU union.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-08-21 14:28:45 +10:00
Richard Henderson
ac43cec37e target/ppc: Tidy helper_fadd, helper_fsub
Tidy the invalid exception checking so that we rely on softfloat for
initial argument validation, and select the kind of invalid operand
exception only when we know we must.  Pass and return float64 values
directly rather than bounce through the CPU_DoubleU union.

Note that because we know float_flag_invalid was set, we do not have
to re-check the signs of the infinities.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-08-21 14:28:45 +10:00
Richard Henderson
79f916331d target/ppc: Tidy helper_fmul
Tidy the invalid exception checking so that we rely on softfloat for
initial argument validation, and select the kind of invalid operand
exception only when we know we must.  Pass and return float64 values
directly rather than bounce through the CPU_DoubleU union.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-08-21 14:28:45 +10:00
Richard Henderson
ae13018d79 target/ppc: Honor fpscr_ze semantics and tidy fdiv
Divide by zero, exception taken, leaves the destination register
unmodified.  Therefore we must raise the exception before returning
from helper_fdiv.  Move the check from do_float_check_status into
helper_fdiv.

At the same time, tidy the invalid exception checking so that we
rely on softfloat for initial argument validation, and select the
kind of invalid operand exception only when we know we must.

At the same time, pass and return float64 values directly rather
than bounce through the CPU_DoubleU union.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-08-21 14:28:45 +10:00
Richard Henderson
e82c42b7c5 target/ppc: Enable fp exceptions for user-only
While just setting the MSR bits is sufficient, we can tidy
the helper code by extracting the MSR test to a helper and
then forcing it true for user-only.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-08-21 14:28:45 +10:00
John Arbuckle
9e430ca3da fpu_helper.c: fix setting FPSCR[FI] bit
The FPSCR[FI] bit indicates if the last floating point instruction had a result that was rounded. Each consecutive floating point instruction is suppose to set this bit to the correct value. What currently happens is this bit is not set as often as it should be. I have verified that this is the behavior of a real PowerPC 950. This patch fixes that problem by deciding to set this bit after each floating point instruction.

https://www.pdfdrive.net/powerpc-microprocessor-family-the-programming-environments-for-32-e3087633.html
Page 63 in table 2-4 is where the description of this bit can be found.

Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-07-03 09:56:52 +10:00
John Arbuckle
88d8d5555d fpu_helper.c: fix helper_fpscr_clrbit() function
Fix the helper_fpscr_clrbit() function so it correctly sets the FEX
and VX bits.

Determining the value for the Floating Point Status and Control
Register's (FPSCR) FEX bit is suppose to be done like this:

FEX = (VX & VE) | (OX & OE) | (UX & UE) | (ZX & ZE) | (XX & XE))

It is described as "the logical OR of all the floating-point exception
bits masked by their respective enable bits". It was not implemented
correctly. The value of FEX would stay on even when all other bits
were set to off.

The VX bit is described as "the logical OR of all of the invalid
operation exceptions". This bit was also not implemented correctly. It
too would stay on when all the other bits were set to off.

My main source of information is an IBM document called:

PowerPC Microprocessor Family:
The Programming Environments for 32-Bit Microprocessors

Page 62 is where the FPSCR information is located.

This is an older copy than the one I use but it is still very useful:
https://www.pdfdrive.net/powerpc-microprocessor-family-the-programming-environments-for-32-e3087633.html

I use a G3 and G5 iMac to compare bit values with QEMU. This patch
fixed all the problems I was having with these bits.

Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
[dwg: Re-wrapped commit message]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-06-21 21:22:53 +10:00
Richard Henderson
03385dfdaa fpu/softfloat: Specialize on snan_bit_is_one
Only MIPS requires snan_bit_is_one to be variable.  While we are
specializing softfloat behaviour, allow other targets to eliminate
this runtime check.

Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Yongbok Kim <yongbok.kim@mips.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Alexander Graf <agraf@suse.de>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-05-17 15:27:15 -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