[PATCH] PR88777, Out-of-range offsets building glibc test-tgmath2.c
Alan Modra
amodra@gmail.com
Fri Jan 11 23:45:00 GMT 2019
On Fri, Jan 11, 2019 at 11:42:31AM -0700, Jeff Law wrote:
> On 1/10/19 12:19 AM, Alan Modra wrote:
> > bb-reorder is quite seriously broken if get_attr_min_length should
> > return INT_MAX, which it does for hppa on branches with r267666.
> Presumably you're referring to the overflows and such?
Yes. Even get_uncond_jump_length would have been INT_MAX. All of
the predicates deciding on whether to copy or reorder blocks were
therefore broken.
The following is fairly obvious and would stop some of the silliness,
but I guess now is not the time to propose this sort of patch.
* bb-reorder.c (copy_bb_p): Don't overflow size calculation.
(get_uncond_jump_length): Assert length less than INT_MAX and
non-negative.
diff --git a/gcc/bb-reorder.c b/gcc/bb-reorder.c
index e4ae8b89c09..c21d204627e 100644
--- a/gcc/bb-reorder.c
+++ b/gcc/bb-reorder.c
@@ -1357,8 +1357,8 @@ connect_traces (int n_traces, struct trace *traces)
static bool
copy_bb_p (const_basic_block bb, int code_may_grow)
{
- int size = 0;
- int max_size = uncond_jump_length;
+ unsigned int size = 0;
+ unsigned int max_size = uncond_jump_length;
rtx_insn *insn;
if (EDGE_COUNT (bb->preds) < 2)
@@ -1376,7 +1376,11 @@ copy_bb_p (const_basic_block bb, int code_may_grow)
FOR_BB_INSNS (bb, insn)
{
if (INSN_P (insn))
- size += get_attr_min_length (insn);
+ {
+ size += get_attr_min_length (insn);
+ if (size > max_size)
+ break;
+ }
}
if (size <= max_size)
@@ -1385,7 +1389,7 @@ copy_bb_p (const_basic_block bb, int code_may_grow)
if (dump_file)
{
fprintf (dump_file,
- "Block %d can't be copied because its size = %d.\n",
+ "Block %d can't be copied because its size = %u.\n",
bb->index, size);
}
@@ -1397,7 +1401,7 @@ copy_bb_p (const_basic_block bb, int code_may_grow)
int
get_uncond_jump_length (void)
{
- int length;
+ unsigned int length;
start_sequence ();
rtx_code_label *label = emit_label (gen_label_rtx ());
@@ -1405,6 +1409,7 @@ get_uncond_jump_length (void)
length = get_attr_min_length (jump);
end_sequence ();
+ gcc_assert (length < INT_MAX);
return length;
}
--
Alan Modra
Australia Development Lab, IBM
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