anybody using RTEMS on SH4?

[Nickolay Kolchin]

Hi,

We have a performance problem on SH4 with gcc4.x.

SciMark2 Numeric Benchmark, see http://math.nist.gov/scimark
================================================================
           GCC: 3.4.6   4.2.1   4.3.0 (20070907)
     Composite:  6.05    5.01    4.82
           FFT:  4.90    4.15    4.21
           SOR: 10.10    8.36    7.64
    MonteCarlo:  3.68    3.06    3.04
Sparse matmult:  5.45    4.45    4.03
            LU:  6.10    5.03    5.18
================================================================

BYTEmark* Native Mode Benchmark ver. 2 (10/95)
================================================================
             GCC:      3.4.6      4.2.1  4.3.0 (20070907)
    NUMERIC SORT:     35.459       32.2      29.327
     STRING SORT:     0.5943    0.57604      0.8603
        BITFIELD: 1.0585e+07  9.269e+06  9.4138e+06
    FP EMULATION:     4.4944     4.6012       5.364
         FOURIER:     272.28     241.34      259.12
      ASSIGNMENT:    0.35997    0.38373     0.39683
            IDEA:     124.11     95.057      100.07
         HUFFMAN:     45.593     52.083      56.391
      NEURAL NET:    0.36153    0.30922     0.31348
LU DECOMPOSITION:     11.331     9.4938       8.255
================================================================

The "real world application" has 20%-200% performance regression with GCC
4.x.

This effectively prevents us from moving to RTEMS 4.7 from 4.6.

I've reported this issue to gcc bugzilla:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33431

But SH4 backend maintainer Kazumoto Kojima, was unable to reproduce it under
linux-sh:
================================================================
                        gcc-3.4.6    gcc-4.2.1    gcc-4.3.0(20070910)
Composite Score:            16.76        16.86        16.99
FFT              Mflops:    12.92        13.36        13.36
SOR              Mflops:    27.88        26.76        28.01
MonteCarlo:      Mflops:     9.96         9.73         9.67
Sparse matmult   Mflops:    14.95        16.06        14.84
LU               Mflops:    18.08        18.39        19.05
================================================================

Maybe, somebody is also using RTEMS on SH4 and can confirm my or Kojima
results?

----
Nickolay
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