Hello,
GCC code generator generates wrong code with -O2 optimization option for simple
statement like " x = -x;" where x is double type.
==Assembly code
# x = -x
movw r2, r0 # move r2 to r0
movw r3, r1 # move r3 to r1
addw $-32768, r1 # add 0x8000 to r1 ie negate
===
Note r0-r3 are 16 bit registers and above code is valid. But same code is
generated with 32 bit source register as:
==Assembly code
# x = -x
movw r13, r0 # move r13_L to r0
movw r13, r1 # move r13_L to r1
addw $-32768, r1 # add 0x8000 to r1 ie negate
===
In the above generated code, r13 higher bit never changed, which is not correct.
Expected code could be:
==Assembly code
# x = -x
movd r13, (r1,r0) # move r13 to r1-r0
addd $0x80000000, (r1-r0) # add 0x80000000 to r1 ie negate
===
Could please advise, if this issue could be fixed in gcc core or target port?
If its gcc core I will file PR on this.
Thank you very much for your suggestion.
PS: The above issues with cr16-elf target and its port submission is in review
(ie 3 reviews completed and review-4 pending).
Thanks
Swami
