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Re: [PATCH] Fix two bugs in gimple-fold.c and/or folding (PR tree-optimization/46909)
- From: Paul Koning <paul_koning at dell dot com>
- To: Jakub Jelinek <jakub at redhat dot com>
- Cc: gcc-patches <gcc-patches at gcc dot gnu dot org>
- Date: Tue, 28 Dec 2010 14:27:14 -0500
- Subject: Re: [PATCH] Fix two bugs in gimple-fold.c and/or folding (PR tree-optimization/46909)
I ran into an oddity with one of the testcases.
The one that scans the tree dump (gcc.dg/pr46909.c) fails for pdp11 because the tree dump file says it's checking for != 6 (which should be != 4). But the generated code is correct.
Also curious is that the tree dump looks very different from the tree dump generated by the same rev compiler (give or take a few hours) on linux-x86. Any idea what's going on here?
pdp11-aout-gcc tree dump:
;; Function foo (foo)
optimizing two comparisons to x_2(D) != 6
Removing basic block 3
foo (unsigned int x)
{
int D.1953;
<bb 2>:
if (x_2(D) != 4)
goto <bb 3>;
else
goto <bb 4>;
<bb 3>:
Invalid sum of incoming frequencies 7200, should be 2723
if (x_2(D) != 6)
goto <bb 6>;
else
goto <bb 4>;
<bb 4>:
if (x_2(D) == 6)
goto <bb 6>;
else
goto <bb 5>;
<bb 5>:
<bb 6>:
Invalid sum of incoming frequencies 5523, should be 10000
# D.1953_1 = PHI <1(3), -1(5), 1(4)>
return D.1953_1;
}
linux-x86 treedump:
;; Function foo (foo)
optimizing two comparisons to x_2(D) != 4
Merging blocks 2 and 3
foo (unsigned int x)
{
int D.1960;
_Bool D.1959;
_Bool D.1958;
_Bool D.1957;
_Bool D.1955;
_Bool D.1954;
_Bool D.1953;
<bb 2>:
D.1953_3 = x_2(D) != 4;
D.1954_4 = x_2(D) != 6;
D.1955_5 = D.1953_3 & D.1954_4;
D.1957_6 = x_2(D) == 2;
D.1958_7 = x_2(D) == 6;
D.1959_8 = D.1957_6 | D.1958_7;
if (x_2(D) != 4)
goto <bb 4>;
else
goto <bb 3>;
<bb 3>:
Invalid sum of incoming frequencies 400, should be 244
<bb 4>:
Invalid sum of incoming frequencies 9844, should be 10000
# D.1960_1 = PHI <1(2), -1(3)>
return D.1960_1;
}
paul