[Bug rtl-optimization/80791] [8 regression] test case gcc.dg/sms-1.c fail2 starting with r247885

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80791 --- Comment #18 from Bill Schmidt --- In the before case, it appears that later optimization is able to remove the i_12 add by adjusting the loop counter. After ivopts: i_12 = i_5 + 4; ivtmp.10_17 = ivtmp.10_18 + 32; Before SMS: r174 =

[Bug rtl-optimization/80791] [8 regression] test case gcc.dg/sms-1.c fail2 starting with r247885

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80791 --- Comment #17 from Bill Schmidt --- Sure. My point is that the modeling that's being done doesn't accurately predict the actual loop performance. What we need to do is figure out why.

[Bug rtl-optimization/80791] [8 regression] test case gcc.dg/sms-1.c fail2 starting with r247885

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80791 --- Comment #16 from amker at gcc dot gnu.org --- (In reply to Bill Schmidt from comment #15) > It's a bit shift, but the result is still that it is now in the loop instead > of outside the loop, and the total cost of the loop has increased. But

[Bug rtl-optimization/80791] [8 regression] test case gcc.dg/sms-1.c fail2 starting with r247885

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80791 --- Comment #15 from Bill Schmidt --- It's a bit shift, but the result is still that it is now in the loop instead of outside the loop, and the total cost of the loop has increased.

[Bug rtl-optimization/80791] [8 regression] test case gcc.dg/sms-1.c fail2 starting with r247885

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80791 --- Comment #14 from amker at gcc dot gnu.org --- (In reply to Bill Schmidt from comment #13) > Actually it appears that the IVOPTS change results in worse code going into > SMS, regardless of whether SMS can succeed on the loop. It comes down

[Bug rtl-optimization/80791] [8 regression] test case gcc.dg/sms-1.c fail2 starting with r247885

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80791 --- Comment #13 from Bill Schmidt --- Actually it appears that the IVOPTS change results in worse code going into SMS, regardless of whether SMS can succeed on the loop. It comes down to the fact that IVOPTS formerly pulled a multiply

[Bug rtl-optimization/80791] [8 regression] test case gcc.dg/sms-1.c fail2 starting with r247885

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80791 --- Comment #12 from Bill Schmidt --- It's not clear yet what we should do with this. It looks like SMS is able to figure out that the sign-extension is not needed in the pre-r247885 code, but can't sort this out with the IVOPTS change. The

[Bug rtl-optimization/80791] [8 regression] test case gcc.dg/sms-1.c fail2 starting with r247885

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80791 Richard Biener changed: What|Removed |Added Priority|P3 |P2

[Bug rtl-optimization/80791] [8 regression] test case gcc.dg/sms-1.c fail2 starting with r247885

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80791 --- Comment #11 from Segher Boessenkool --- In the 64-bit Power ABIs, an int is passed as a sign-extended 64-bit register. Take this trivial example: int f(int x) { return x*x; } which compiles to (on powerpc64-linux, BE): .L.f: mullw

[Bug rtl-optimization/80791] [8 regression] test case gcc.dg/sms-1.c fail2 starting with r247885

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80791 --- Comment #10 from amker at gcc dot gnu.org --- (In reply to Segher Boessenkool from comment #9) > Either r160 should be SImode, or we should copy it to a SImode pseudo > and use that instead throughout? Do we want to use it as DImode

[Bug rtl-optimization/80791] [8 regression] test case gcc.dg/sms-1.c fail2 starting with r247885

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80791 Segher Boessenkool changed: What|Removed |Added CC||segher at gcc dot gnu.org ---

[Bug rtl-optimization/80791] [8 regression] test case gcc.dg/sms-1.c fail2 starting with r247885

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80791 --- Comment #8 from amker at gcc dot gnu.org --- So whole expanded rtl is: ;; ;; Full RTL generated for this function: ;; 1: NOTE_INSN_DELETED 5: NOTE_INSN_BASIC_BLOCK 2 2: r160:DI=%3:DI 3: NOTE_INSN_FUNCTION_BEG 4:

[Bug rtl-optimization/80791] [8 regression] test case gcc.dg/sms-1.c fail2 starting with r247885

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80791 --- Comment #7 from amker at gcc dot gnu.org --- So dump of optimized pass is: ;; Function f (f, funcdef_no=0, decl_uid=2557, cgraph_uid=0, symbol_order=1) Removing basic block 5 __attribute__((noinline)) f (int m) { int sh; int i;

[Bug rtl-optimization/80791] [8 regression] test case gcc.dg/sms-1.c fail2 starting with r247885

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80791 --- Comment #6 from amker at gcc dot gnu.org --- So before the change, ivotps dump is like: [15.00%]: _15 = (unsigned int) m_8(D); ivtmp.10_16 = _15 * 8; [100.00%]: # i_5 = PHI # sh_6 = PHI <256(2), sh_10(4)>

[Bug rtl-optimization/80791] [8 regression] test case gcc.dg/sms-1.c fail2 starting with r247885

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80791 --- Comment #5 from seurer at gcc dot gnu.org --- FYI: I am testing on native powerpc64 hardware and tried this on both power7 and power8 systems.

[Bug rtl-optimization/80791] [8 regression] test case gcc.dg/sms-1.c fail2 starting with r247885

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80791 --- Comment #4 from seurer at gcc dot gnu.org --- I am using a very simple configuration: --enable-languages=c,fortran,c++ --with-cpu=power8 --disable-bootstrap I tried it without specifying a cpu as well and got the same results.

[Bug rtl-optimization/80791] [8 regression] test case gcc.dg/sms-1.c fail2 starting with r247885

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80791 --- Comment #3 from amker at gcc dot gnu.org --- (In reply to Aldy Hernandez from comment #2) > Confirmed. Any update on this amker? > > Started with: > > commit a9b41911523c1db8042f1f38d1ed814326ef > Author: amker

[Bug rtl-optimization/80791] [8 regression] test case gcc.dg/sms-1.c fail2 starting with r247885

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80791 Aldy Hernandez changed: What|Removed |Added Status|UNCONFIRMED |NEW Last reconfirmed|

[Bug rtl-optimization/80791] [8 regression] test case gcc.dg/sms-1.c fail2 starting with r247885

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80791 --- Comment #1 from amker at gcc dot gnu.org --- Sorry for causing this, I will investigate. Thanks,

[Bug rtl-optimization/80791] [8 regression] test case gcc.dg/sms-1.c fail2 starting with r247885

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80791 Richard Biener changed: What|Removed |Added Keywords||missed-optimization