[Bug target/63260] [SH] fabs, fneg do not need fp-mode setting and do not use fpscr

[olegendo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63260

Oleg Endo <olegendo at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |kkojima at gcc dot gnu.org

--- Comment #2 from Oleg Endo <olegendo at gcc dot gnu.org> ---
(In reply to Oleg Endo from comment #0)
> Created attachment 33490 [details]
> Proposed patch
> 
> The fabs and fneg insns do not require an FPSCR.PR or FPSCR.SZ mode setting
> as they operate on the high part of a double register pair.  Thus they are
> the same for single and double precision

I've tested the proposed patch on sh-sim, there are some new failures:

-m4 -mb:
FAIL: g++.dg/torture/type-generic-1.C   -O0  execution test
FAIL: gcc.c-torture/execute/builtins/complex-1.c execution,  -O0 
FAIL: gcc.c-torture/execute/builtins/complex-1.c execution,  -Og -g 
FAIL: gcc.c-torture/execute/complex-6.c   -O0  execution test
FAIL: gcc.c-torture/execute/gofast.c   -O0  execution test
FAIL: gcc.c-torture/execute/ieee/20010114-2.c execution,  -O0 
FAIL: gcc.c-torture/execute/ieee/20010114-2.c execution,  -O1 
FAIL: gcc.c-torture/execute/ieee/20010114-2.c execution,  -Og -g 
FAIL: gcc.c-torture/execute/ieee/20030331-1.c execution,  -O0 
FAIL: gcc.c-torture/execute/ieee/copysign1.c execution,  -O0 
FAIL: gcc.c-torture/execute/ieee/mzero3.c execution,  -O0 
FAIL: gcc.dg/torture/type-generic-1.c   -O0  execution test

-m4 -ml:
FAIL: g++.dg/torture/type-generic-1.C   -O0  execution test
FAIL: g++.dg/torture/type-generic-1.C   -O1  execution test
FAIL: g++.dg/torture/type-generic-1.C   -O2  execution test
FAIL: g++.dg/torture/type-generic-1.C   -O2 -flto -fno-use-linker-plugin
-flto-partition=none  execution test
FAIL: g++.dg/torture/type-generic-1.C   -O2 -flto -fuse-linker-plugin
-fno-fat-lto-objects  execution test
FAIL: g++.dg/torture/type-generic-1.C   -O3 -fomit-frame-pointer  execution
test
FAIL: g++.dg/torture/type-generic-1.C   -O3 -g  execution test
FAIL: g++.dg/torture/type-generic-1.C   -Os  execution test
FAIL: gcc.c-torture/execute/builtins/complex-1.c execution,  -O0 
FAIL: gcc.c-torture/execute/builtins/complex-1.c execution,  -Og -g 
FAIL: gcc.c-torture/execute/complex-6.c   -O0  execution test
FAIL: gcc.c-torture/execute/conversion.c   -O0  execution test
FAIL: gcc.c-torture/execute/gofast.c   -O0  execution test
FAIL: gcc.c-torture/execute/ieee/20010114-2.c execution,  -O0 
FAIL: gcc.c-torture/execute/ieee/20010114-2.c execution,  -O1 
FAIL: gcc.c-torture/execute/ieee/20010114-2.c execution,  -Og -g 
FAIL: gcc.c-torture/execute/ieee/20030331-1.c execution,  -O0 
FAIL: gcc.c-torture/execute/ieee/copysign1.c execution,  -O0 
FAIL: gcc.c-torture/execute/ieee/mzero3.c execution,  -O0 
FAIL: gcc.dg/pr28796-2.c execution test
FAIL: gcc.dg/torture/fp-int-convert-float.c   -O0  execution test
FAIL: gcc.dg/torture/fp-int-convert-float.c   -O1  execution test
FAIL: gcc.dg/torture/fp-int-convert-float.c   -O2  execution test
FAIL: gcc.dg/torture/fp-int-convert-float.c   -O2 -flto -fno-use-linker-plugin
-flto-partition=none  execution test
FAIL: gcc.dg/torture/fp-int-convert-float.c   -O2 -flto -fuse-linker-plugin
-fno-fat-lto-objects  execution test
FAIL: gcc.dg/torture/fp-int-convert-float.c   -O3 -fomit-frame-pointer 
execution test
FAIL: gcc.dg/torture/fp-int-convert-float.c   -O3 -g  execution test
FAIL: gcc.dg/torture/fp-int-convert-float.c   -Os  execution test
FAIL: gcc.dg/torture/type-generic-1.c   -O0  execution test
FAIL: gcc.dg/torture/type-generic-1.c   -O1  execution test
FAIL: gcc.dg/torture/type-generic-1.c   -O2  execution test
FAIL: gcc.dg/torture/type-generic-1.c   -O2 -flto -fno-use-linker-plugin
-flto-partition=none  execution test
FAIL: gcc.dg/torture/type-generic-1.c   -O2 -flto -fuse-linker-plugin
-fno-fat-lto-objects  execution test
FAIL: gcc.dg/torture/type-generic-1.c   -O3 -fomit-frame-pointer  execution
test
FAIL: gcc.dg/torture/type-generic-1.c   -O3 -g  execution test
FAIL: gcc.dg/torture/type-generic-1.c   -Os  execution test
FAIL: gcc.dg/torture/vec-cvt-1.c   -O0  execution test
FAIL: gcc.dg/torture/vec-cvt-1.c   -O1  execution test
FAIL: gcc.dg/torture/vec-cvt-1.c   -O2  execution test
FAIL: gcc.dg/torture/vec-cvt-1.c   -O2 -flto -fno-use-linker-plugin
-flto-partition=none  execution test
FAIL: gcc.dg/torture/vec-cvt-1.c   -O2 -flto -fuse-linker-plugin
-fno-fat-lto-objects  execution test
FAIL: gcc.dg/torture/vec-cvt-1.c   -O3 -fomit-frame-pointer  execution test
FAIL: gcc.dg/torture/vec-cvt-1.c   -O3 -fomit-frame-pointer -funroll-all-loops
-finline-functions  execution test
FAIL: gcc.dg/torture/vec-cvt-1.c   -O3 -fomit-frame-pointer -funroll-loops 
execution test
FAIL: gcc.dg/torture/vec-cvt-1.c   -O3 -g  execution test
FAIL: gcc.dg/torture/vec-cvt-1.c   -Os  execution test


This seems to be due to the implementation in GDB.

sim/sh/interp.c:

#define FP_UNARY(n, OP) \
{ \
  if (FPSCR_PR) \
    { \
      if ((n) & 1) \
    RAISE_EXCEPTION (SIGILL); \
      else \
    SET_DR (n, (OP (DR (n)))); \
    } \
  else \
    SET_FR (n, (OP (FR (n)))); \
} while (0)

sim/sh/gencode.c:

  /* sh2e */
  { "", "", "fabs <FREG_N>", "1111nnnn01011101",
    "FP_UNARY (n, fabs);",
    "/* FIXME: FR (n) &= 0x7fffffff; */",

  /* sh2e */
  { "", "", "fneg <FREG_N>", "1111nnnn01001101",
    "FP_UNARY (n, -);",
  },

As the FIXME in the fabs code above suggests, fabs and fneg there are treated
like a real unary FP operations, which seems not entirely accurate.  I think
GDB's sh-sim needs a patch for that.

Kaz, could you please add the proposed patch to your test run and let me know
of the result?  I'd like to sort this out before proceeding with PR 53513.