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re PR tree-optimization/71433 (-Warray-bounds false positive with -O2) 

2017-01-17  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/71433
	* tree-vrp.c (register_new_assert_for): Merge same asserts
	on all incoming edges.
	(process_assert_insertions_for): Handle insertions at the
	beginning of BBs.

	* gcc.dg/Warray-bounds-20.c: New testcase.

From-SVN: r244520
This commit is contained in:
Richard Biener 2017-01-17 08:38:59 +00:00 committed by Richard Biener
parent a23e48df45
commit 12314dc989
4 changed files with 54 additions and 0 deletions
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8
gcc/ChangeLog
View File

@ -1,3 +1,11 @@
2017-01-17 Richard Biener <rguenther@suse.de>
PR tree-optimization/71433
* tree-vrp.c (register_new_assert_for): Merge same asserts
on all incoming edges.
(process_assert_insertions_for): Handle insertions at the
beginning of BBs.
2017-01-17 Gerald Pfeifer <gerald@pfeifer.com>
* config/i386/cygwin.h (LIBGCJ_SONAME): Remove.

5
gcc/testsuite/ChangeLog
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@ -1,3 +1,8 @@
2017-01-17 Richard Biener <rguenther@suse.de>
PR tree-optimization/71433
* gcc.dg/Warray-bounds-20.c: New testcase.
2017-01-17 Richard Biener <rguenther@suse.de>
PR testsuite/52563

21
gcc/testsuite/gcc.dg/Warray-bounds-20.c Normal file
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@ -0,0 +1,21 @@
/* { dg-do compile } */
/* { dg-options "-O2 -Warray-bounds" } */
int t[1];
int fct (int r, long e)
{
int d = 0;
if (r == 4)
r = 1;
if (e < -52)
d = r == 0 ? 1 : 2;
else
{
int i, n = 53;
if (__builtin_expect (e < 0, 0))
n += e;
for (i = 1 ; i < n / 64 + 1 ; i++)
t[i] = 0; /* { dg-bogus "array bounds" } */
}
return d;
}

20
gcc/tree-vrp.c
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@ -5032,6 +5032,17 @@ register_new_assert_for (tree name, tree expr,
loc->si = si;
return;
}
/* If we have the same assertion on all incoming edges of a BB
instead insert it at the beginning of it. */
if (e && loc->e
&& dest_bb == loc->e->dest
&& EDGE_COUNT (dest_bb->preds) == 2)
{
loc->bb = dest_bb;
loc->e = NULL;
loc->si = gsi_none ();
return;
}
}
/* Update the last node of the list and move to the next one. */
@ -6429,6 +6440,15 @@ process_assert_insertions_for (tree name, assert_locus *loc)
return true;
}
/* If the stmt iterator points at the end then this is an insertion
at the beginning of a block. */
if (gsi_end_p (loc->si))
{
gimple_stmt_iterator si = gsi_after_labels (loc->bb);
gsi_insert_before (&si, assert_stmt, GSI_SAME_STMT);
return false;
}
/* Otherwise, we can insert right after LOC->SI iff the
statement must not be the last statement in the block. */
stmt = gsi_stmt (loc->si);