[PATCH v4 0/3] Add support for divde[.] and divdeu[.] instruction emulation

[Balamuruhan S]

Hi All,

This patchset adds support to emulate divde, divde., divdeu and divdeu.
instructions and testcases for it.

Resend v4: rebased on latest powerpc next branch

Changes in v4:
-------------
Fix review comments from Naveen,
* replace TEST_DIVDEU() instead of wrongly used TEST_DIVDEU_DOT() in
  divdeu testcase.
* Include `acked-by` tag from Naveen for the series.
* Rebase it on latest mpe's merge tree.

Changes in v3:
-------------
* Fix suggestion from Sandipan to remove `PPC_INST_DIVDE_DOT` and
  `PPC_INST_DIVDEU_DOT` opcode macros defined in ppc-opcode.h, reuse
  `PPC_INST_DIVDE` and `PPC_INST_DIVDEU` in test_emulate_step.c to
  derive them respectively.

Changes in v2:
-------------
* Fix review comments from Paul to make divde_dot and divdeu_dot simple
  by using divde and divdeu, then goto `arith_done` instead of
  `compute_done`.
* Include `Reviewed-by` tag from Sandipan Das.
* Rebase with recent mpe's merge tree.

I would request for your review and suggestions for making it better.

Boot Log:
--------
:: ::
:: ::
291494043: (291493996): [    0.352649][    T1] emulate_step_test: divde          : RA = LONG_MIN, RB = LONG_MIN                       PASS
291517665: (291517580): [    0.352695][    T1] emulate_step_test: divde          : RA = 1L, RB = 0                                    PASS
291541357: (291541234): [    0.352742][    T1] emulate_step_test: divde          : RA = LONG_MIN, RB = LONG_MAX                       PASS
291565107: (291564946): [    0.352788][    T1] emulate_step_test: divde.         : RA = LONG_MIN, RB = LONG_MIN                       PASS
291588757: (291588558): [    0.352834][    T1] emulate_step_test: divde.         : RA = 1L, RB = 0                                    PASS
291612477: (291612240): [    0.352881][    T1] emulate_step_test: divde.         : RA = LONG_MIN, RB = LONG_MAX                       PASS
291636201: (291635926): [    0.352927][    T1] emulate_step_test: divdeu         : RA = LONG_MIN, RB = LONG_MIN                       PASS
291659830: (291659517): [    0.352973][    T1] emulate_step_test: divdeu         : RA = 1L, RB = 0                                    PASS
291683529: (291683178): [    0.353019][    T1] emulate_step_test: divdeu         : RA = LONG_MIN, RB = LONG_MAX                       PASS
291707248: (291706859): [    0.353066][    T1] emulate_step_test: divdeu         : RA = LONG_MAX - 1, RB = LONG_MAX                   PASS
291730962: (291730535): [    0.353112][    T1] emulate_step_test: divdeu         : RA = LONG_MIN + 1, RB = LONG_MIN                   PASS
291754714: (291754249): [    0.353158][    T1] emulate_step_test: divdeu.        : RA = LONG_MIN, RB = LONG_MIN                       PASS
291778371: (291777868): [    0.353205][    T1] emulate_step_test: divdeu.        : RA = 1L, RB = 0                                    PASS
291802098: (291801557): [    0.353251][    T1] emulate_step_test: divdeu.        : RA = LONG_MIN, RB = LONG_MAX                       PASS
291825844: (291825265): [    0.353297][    T1] emulate_step_test: divdeu.        : RA = LONG_MAX - 1, RB = LONG_MAX                   PASS
291849586: (291848969): [    0.353344][    T1] emulate_step_test: divdeu.        : RA = LONG_MIN + 1, RB = LONG_MIN                   PASS
:: ::
:: ::
292520225: (292519608): [    0.354654][    T1] registered taskstats version 1
292584751: (292584134): [    0.354780][    T1] pstore: Using crash dump compression: deflate
296454422: (296453805): [    0.362338][    T1] Freeing unused kernel memory: 1408K
296467838: (296467221): [    0.362364][    T1] This architecture does not have kernel memory protection.
296485387: (296484770): [    0.362398][    T1] Run /init as init process
297987339: (297986761): [    0.365332][   T46] mount (46) used greatest stack depth: 12512 bytes left
298889548: (298888992): [    0.367094][   T47] mount (47) used greatest stack depth: 11824 bytes left

355356256: (355355821): Welcome to Buildroot
355376898: (355376463): buildroot login:

Balamuruhan S (3):
  powerpc ppc-opcode: add divde and divdeu opcodes
  powerpc sstep: add support for divde[.] and divdeu[.] instructions
  powerpc test_emulate_step: add testcases for divde[.] and divdeu[.]
    instructions

 arch/powerpc/include/asm/ppc-opcode.h |   6 +
 arch/powerpc/lib/sstep.c              |  13 ++-
 arch/powerpc/lib/test_emulate_step.c  | 156 ++++++++++++++++++++++++++
 3 files changed, 174 insertions(+), 1 deletion(-)


base-commit: 7a9912e4cf048b607c8fafcfbdca7566660f1d78
-- 
2.24.1