Align compiler flags of SOF Zephyr build with the build SOF XTOS
and use -fstrict-overflow.
With -fno-strict-overflow, some versions of XCC compiler (e.g. xt-xcc
12.0.8) always emit a "bltu" instruction to check for overflow in loops
like:
unsigned int n;
for(n = 0; n < 1024; n++)
do_arithmetic();
With "-fno-strict-overflow", you'll have:
18: 068076 loop a0, 22 <dummy_dspload+0x22>
1b: 445a add.n a4, a4, a5
1d: 551b addi.n a5, a5, 1
1f: 023657 bltu a6, a5, 25 <dummy_dspload+0x25>
22: fffc86 j 18 <dummy_dspload+0x18>
With "-fstrict-overflow":
16: 038476 loop a4, 1d <dummy_dspload+0x1d>
19: 223a add.n a2, a2, a3
1b: 331b addi.n a3, a3, 1
As this is a common pattern in audio DSP code, change the default
for SOF builds to -fstrict-overflow.
Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>