------- Comment #7 from steven at gcc dot gnu dot org 2006-01-02 21:30 -------
With an even more modified test case, load PRE does happen:
unsigned long outcnt;
extern void flush_outbuf(void);
void
bi_windup(unsigned int *outbuf, unsigned int bi_buf, unsigned long *outcnt)
{
unsigned long t1 = *outcnt;
outbuf[t1] = bi_buf;
unsigned long t2 = *outcnt;
if (t2 == 16384)
flush_outbuf();
unsigned long t3 = *outcnt;
outbuf[t3] = bi_buf;
}
--> .pre tree dump
bi_windup (outbufD.1866, bi_bufD.1867, outcntD.1868)
{
unsigned intD.3 * prephitmp.26D.1925;
unsigned intD.3 * pretmp.25D.1924;
long unsigned intD.4 prephitmp.24D.1923;
long unsigned intD.4 pretmp.23D.1922;
unsigned intD.3 storetmp.22D.1921;
long unsigned intD.4 t3D.1873;
long unsigned intD.4 t2D.1872;
long unsigned intD.4 t1D.1871;
unsigned intD.3 * D.1879;
unsigned intD.3 * D.1878;
long unsigned intD.4 D.1877;
unsigned intD.3 * D.1876;
unsigned intD.3 * D.1875;
long unsigned intD.4 D.1874;
# BLOCK 2 freq:10000
# PRED: ENTRY [100.0%] (fallthru,exec)
# VUSE <TMT.4D.1902_15>;
t1D.1871_2 = *outcntD.1868_1;
D.1874_3 = t1D.1871_2 * 4;
D.1875_4 = (unsigned intD.3 *) D.1874_3;
D.1876_6 = D.1875_4 + outbufD.1866_5;
# TMT.5D.1903_17 = V_MAY_DEF <TMT.5D.1903_16>;
*D.1876_6 = bi_bufD.1867_7;
if (t1D.1871_2 == 16384) goto <L0>; else goto <L2>;
# SUCC: 3 [26.2%] (true,exec) 5 [73.8%] (false,exec)
# BLOCK 5 freq:7378
# PRED: 2 [73.8%] (false,exec)
<L2>:;
goto <bb 4> (<L1>);
# SUCC: 4 [100.0%] (fallthru)
# BLOCK 3 freq:2622
# PRED: 2 [26.2%] (true,exec)
<L0>:;
# TMT.4D.1902_19 = V_MAY_DEF <TMT.4D.1902_15>;
# TMT.5D.1903_20 = V_MAY_DEF <TMT.5D.1903_17>;
flush_outbuf ();
# VUSE <TMT.4D.1902_19>;
pretmp.23D.1922_23 = *outcntD.1868_1;
pretmp.23D.1922_25 = pretmp.23D.1922_23 * 4;
pretmp.25D.1924_27 = (unsigned intD.3 *) pretmp.23D.1922_25;
pretmp.25D.1924_29 = outbufD.1866_5 + pretmp.25D.1924_27;
# SUCC: 4 [100.0%] (fallthru,exec)
# BLOCK 4 freq:10000
# PRED: 5 [100.0%] (fallthru) 3 [100.0%] (fallthru,exec)
# prephitmp.26D.1925_30 = PHI <D.1876_6(5), pretmp.25D.1924_29(3)>;
# prephitmp.26D.1925_28 = PHI <D.1875_4(5), pretmp.25D.1924_27(3)>;
# prephitmp.24D.1923_26 = PHI <D.1874_3(5), pretmp.23D.1922_25(3)>;
# prephitmp.24D.1923_24 = PHI <t1D.1871_2(5), pretmp.23D.1922_23(3)>;
# TMT.5D.1903_14 = PHI <TMT.5D.1903_17(5), TMT.5D.1903_20(3)>;
# TMT.4D.1902_13 = PHI <TMT.4D.1902_15(5), TMT.4D.1902_19(3)>;
<L1>:;
t3D.1873_9 = prephitmp.24D.1923_24;
D.1877_10 = prephitmp.24D.1923_26;
D.1878_11 = prephitmp.26D.1925_28;
D.1879_12 = prephitmp.26D.1925_30;
# TMT.5D.1903_18 = V_MAY_DEF <TMT.5D.1903_14>;
*D.1879_12 = bi_bufD.1867_7;
return;
# SUCC: EXIT [100.0%]
}
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23455
