l2_pool_2d.cpp doesn't compile on esp32 at the -O2 compiler optimization level

[mocleiri]

There is a compiler bug that doesn't allow compiling l2_pool_2d.cpp at the -O2 optimization level on esp32.

jcmvbkbc/gcc-xtensa#14

The work around is to compile this file at the -O3 optimization level.

mocleiri/tensorflow-micropython-examples@0967b90

I'm restructuring how I build tflm to use the generator and then compile as part of the micropython build.

Micropython just turned on -O2 for all of the esp32 port: micropython/micropython@549448e

I don't think this is a blocker for me. I just hit it again and decided to report here in case it can be fixed.

I have plans to write some optimized esp32 kernels using the https://github.com/espressif/esp-dsp library so this might just be something that is better fixed that way.

/home/runner/work/tensorflow-micropython-examples/tensorflow-micropython-examples/micropython-modules/microlite/tflm/tensorflow/lite/micro/kernels/l2_pool_2d.cpp: In function 'TfLiteStatus tflite::{anonymous}::L2Eval(TfLiteContext*, TfLiteNode*)':
/home/runner/work/tensorflow-micropython-examples/tensorflow-micropython-examples/micropython-modules/microlite/tflm/tensorflow/lite/micro/kernels/l2_pool_2d.cpp:128:1: error: insn does not satisfy its constraints:
 }
 ^
(insn 753 18 593 28 (set (reg/v:SF 20 f1 [orig:77 sum_squares ] [77])
        (mem/u/c:SF (symbol_ref/u:SI ("*.LC28") [flags 0x2]) [0  S4 A32])) "/home/runner/work/tensorflow-micropython-examples/tensorflow-micropython-examples/micropython-modules/microlite/tflm/tensorflow/lite/kernels/internal/reference/pooling.h":169 47 {movsf_internal}
     (expr_list:REG_EQUAL (const_double:SF 0.0 [0x0.0p+0])
        (nil)))
during RTL pass: postreload
/home/runner/work/tensorflow-micropython-examples/tensorflow-micropython-examples/micropython-modules/microlite/tflm/tensorflow/lite/micro/kernels/l2_pool_2d.cpp:128:1: internal compiler error: in extract_constrain_insn, at recog.c:2210
Please submit a full bug report,
with preprocessed source if appropriate.

[mocleiri]

I don't think this is IDF version dependant but I'm compiling using the most recent version 4.4:
142bb32c50fa9875b8b69fa539a2d59559460d72

Pinned in micropython here:
micropython/micropython@64e4bae

[mocleiri]

I'm going to close this issue. Currently I plan to try and add an optimized version or at least a different implementation for esp32 that will not trigger the compiler bug.