In this PR graphite scop detection ends up doing make_forwarder_block
on a block with incoming abnormal edges but doesn't want those
"stay" on the forwarder. In the end it is an implementation detail
of make_forwarder_block that fails (because what graphite wants
would be possible - just not using make_forwarder_block).
Rather than changing make_forwarder_block I chose to avoid the
situation from GRAPHITE (also makes backporting obvious).
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
Richard.
2014-04-28 Richard Biener <rguent...@suse.de>
PR tree-optimization/60979
* graphite-scop-detection.c (scopdet_basic_block_info): Reject
SCOPs that end in a block with a successor with abnormal
predecessors.
* gcc.dg/graphite/pr60979.c: New testcase.
Index: gcc/graphite-scop-detection.c
===================================================================
*** gcc/graphite-scop-detection.c (revision 209849)
--- gcc/graphite-scop-detection.c (working copy)
*************** scopdet_basic_block_info (basic_block bb
*** 474,481 ****
result.exits = false;
/* Mark bbs terminating a SESE region difficult, if they start
! a condition. */
! if (!single_succ_p (bb))
result.difficult = true;
else
result.exit = single_succ (bb);
--- 474,483 ----
result.exits = false;
/* Mark bbs terminating a SESE region difficult, if they start
! a condition or if the block it exits to cannot be split
! with make_forwarder_block. */
! if (!single_succ_p (bb)
! || bb_has_abnormal_pred (single_succ (bb)))
result.difficult = true;
else
result.exit = single_succ (bb);
Index: gcc/testsuite/gcc.dg/graphite/pr60979.c
===================================================================
*** gcc/testsuite/gcc.dg/graphite/pr60979.c (revision 0)
--- gcc/testsuite/gcc.dg/graphite/pr60979.c (working copy)
***************
*** 0 ****
--- 1,37 ----
+ /* { dg-options "-O -fgraphite-identity" } */
+
+ #include <setjmp.h>
+
+ struct x;
+
+ typedef struct x **(*a)(struct x *);
+
+ struct x {
+ union {
+ struct {
+ union {
+ a *i;
+ } l;
+ int s;
+ } y;
+ } e;
+ };
+
+ jmp_buf c;
+
+ void
+ b(struct x *r)
+ {
+ int f;
+ static int w = 0;
+ volatile jmp_buf m;
+ f = (*(((struct x *)r)->e.y.l.i[2]((struct x *)r)))->e.y.s;
+ if (w++ != 0)
+ __builtin_memcpy((char *)m, (const char *)c, sizeof(jmp_buf));
+ if (setjmp (c) == 0) {
+ int z;
+ for (z = 0; z < 0; ++z)
+ ;
+ }
+ d((const char *)m);
+ }
