https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115202
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
It's a missed PRE:
ANTIC_OUT[3] := { iftmp.0_6 (0006), {min_expr,iftmp.0_6,-1} (0011),
{nop_expr,pretmp_10} (0012) }
[changed] ANTIC_IN[3] := { {mem_ref<0B>,addr_expr<&m>}@.MEM_5(D) (0001),
{nop_expr,m.1_1} (0006), {min_expr,iftmp.0_6,-1} (0011), {nop_expr,pretmp_10}
(0012) }
<bb 3> [local count: 536870912]:
m.1_1 = m;
iftmp.0_6 = (int) m.1_1;
<bb 4> [local count: 1073741824]:
# iftmp.0_2 = PHI <iftmp.0_6(3), a_4(D)(5)>
_7 = MIN_EXPR <iftmp.0_2, -1>;
we fail to fully simplify MIN_EXPR <iftmp.0_6, -1> because we lack a pattern
for MIN ((int)ushrtvar, -1)
Adding a lame
(simplify
(min (convert @0) INTEGER_CST@1)
(if (TYPE_UNSIGNED (TREE_TYPE (@0))
&& TYPE_PRECISION (type) > TYPE_PRECISION (TREE_TYPE (@0))
&& tree_int_cst_sgn (@1) == -1)
@1))
makes us PRE the MIN to
<bb 2> [local count: 1073741824]:
if (f_3(D) != 0)
goto <bb 4>; [50.00%]
else
goto <bb 3>; [50.00%]
<bb 3> [local count: 536870912]:
_10 = MIN_EXPR <a_4(D), -1>;
_12 = (short unsigned int) _10;
goto <bb 5>; [100.00%]
<bb 4> [local count: 536870912]:
<bb 5> [local count: 1073741824]:
# prephitmp_13 = PHI <65535(4), _12(3)>
return prephitmp_13;
which produces
_Z4funcii:
.LFB1:
.cfi_startproc
testl %edi, %edi
movl $-1, %eax
cmovns %eax, %edi
testl %esi, %esi
movl $65535, %eax
cmove %edi, %eax
ret
which looks even worse.
