https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62173
--- Comment #7 from Jiong Wang jiwang at gcc dot gnu.org ---
(In reply to bin.cheng from comment #6)
Em, is offset valid for [reg+offset] addressing mode? if it is, why don't we
transform reg+reg+offset into regX - reg + reg; [regX + offset];?
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62173
--- Comment #8 from Jiong Wang jiwang at gcc dot gnu.org ---
while above associate virtual_stack_var_rtx with constant offset actually cause
another hidding issue.
I assume after the association, we are generating cleaner insn sequences.
given
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62173
--- Comment #9 from Jiong Wang jiwang at gcc dot gnu.org ---
To summary, given the following testcases:
case A.C
===
void bar(int i)
{
char A[10];
g(A);
f(A[i]);
}
case B.c
===
void bar(int i)
{
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62173
Richard Biener rguenth at gcc dot gnu.org changed:
What|Removed |Added
Priority|P3 |P1
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62173
--- Comment #10 from Jiong Wang jiwang at gcc dot gnu.org ---
Finished a further investigation, looks like the simplest fix to genrate
optimized code for case A is to add one more optimization case in
eliminate_regs_in_insn.
currently we only
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62173
bin.cheng amker.cheng at gmail dot com changed:
What|Removed |Added
CC||amker.cheng at
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62173
--- Comment #5 from Jiong Wang jiwang at gcc dot gnu.org ---
The root cause is AArch64's TARGET_LEGITIMIZE_ADDRESS are not doing well when
the input is ((reg + reg) + offset).
looks like currently we have considered reg + non_normal_offset, and
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62173
Ramana Radhakrishnan ramana at gcc dot gnu.org changed:
What|Removed |Added
Status|NEW |ASSIGNED
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62173
--- Comment #4 from Jiong Wang jiwang at gcc dot gnu.org ---
interesting.
r213488 was doing something right, and I guess it exposed some other hidding
issues which need our investigations.
