[Bug tree-optimization/14741] missing transformations lead to poorly optimized code

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-01-19 23:38 -------
We now get:
L33:
	lfd f13,0(r11)
	add r11,r11,r8
	lfd f0,0(r10)
	addi r10,r10,8
	fmadd f0,f13,f0,f12
	fmr f12,f0
	bdnz L33

Which is much better, thanks Zdenek.

The only problem left looks a coalescing problem with out of ssa
Before out of ssa:
  # ivtmp.89_54 = PHI <ivtmp.89_31(2), ivtmp.89_33(3)>;
  # lsm_tmp.85_52 = PHI <lsm_tmp.85_53(2), D.538_49(3)>;
  # k_3 = PHI <1(2), k_7(3)>;
<L4>:;
  D.529_38 = k_3 * stride.10_5;
  D.530_39 = i_2 + D.529_38;
  D.531_40 = offset.11_9 + D.530_39;
  D.532_42 = (*a_41)[D.531_40];
  b_30 = ivtmp.89_54;
  D.536_47 = *b_30;
  D.537_48 = D.532_42 * D.536_47;
  D.538_49 = D.537_48 + lsm_tmp.85_52;
  D.773_12 = (<unnamed type>) k_3;
  D.774_8 = D.773_12 + 1;
  k_7 = (int4) D.774_8;
  ivtmp.89_33 = ivtmp.89_54 + 8B;
  D.771_18 = (<unnamed type>) k_7;
  D.772_17 = D.771_18 + 4294967295;
  k_13 = (int4) D.772_17;
  if (stride.10_5 == k_13) goto <L25>; else goto <L4>;

After:
<L4>:;
  D.538 = (*a)[offset.11 + i + k * stride.10] * *ivtmp.89 + lsm_tmp.85;
  k = (int4) ((<unnamed type>) k + 1);
  ivtmp.89 = ivtmp.89 + 8B;
  lsm_tmp.85 = D.538;
  if (stride.10 == (int4) ((<unnamed type>) k + 4294967295)) goto <L25>; else goto <L4>;

We should have coalesced lsm_tmp.85 and D.538 together.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |enhancement


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14741