https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66665
Bug ID: 66665
Summary: Increment instruction is not propagated into address
operand
Product: gcc
Version: 6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: kyukhin at gcc dot gnu.org
Target Milestone: ---
Hello,
Running this:
make check-gcc RUNTESTFLAGS="CFLAGS='-mregparm=3'
--target_board='unix/-mregparm=3{-m32}' i386.exp=addr-sel-1.c"
If got fail since:
f:
.LFB0:
movsbl a+1(%eax), %edx
incl %eax ;; Not propagated ...
movsbl b(%eax), %eax ;; ... to here.
addl %edx, %eax
ret
Increment of %eax is not propagated into load of b.
This kind of propagation is occurred during postreload in `reload_cse_regs',
but increment is promoted to load of a.
