https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96031
Andrew Pinski changed:
What|Removed |Added
Severity|normal |enhancement
See Also|
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96031
--- Comment #4 from zhongyunde at tom dot com ---
> As for ivopt, I can see a minor improvement by replacing != exit condition
> with <=, thus saving add 2 instruction computing _22, which happens to
> "disable" the wrong PRE transformation.
>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96031
--- Comment #3 from zhongyunde at tom dot com ---
I find there is some different between the two cases during in ivopts.
For the 2nd case, a UINT32 type iv sum is choosed
[local count: 955630224]:
# sum_15 = PHI <0(5), sum_9(6)>
#
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96031
--- Comment #2 from bin cheng ---
Interesting case, I see two issues in generated asm. One is the unnecessary
bitwise and, the other is allocating different registers for induction variable
and the base address. However, looks like neither
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96031
--- Comment #1 from zhongyunde at tom dot com ---
this may can be enhance by ivopts.
If the case adjusted as following, then the 'and w2, w2, 65535 ' will
disappear.
typedef unsigned int UINT32;
typedef unsigned short UINT16;
UINT16
