This is another case where an optimization turns a trap_if
unconditional. We have to defer changing the CFG, since the rest of
cprop seems to blow up when we modify things while scanning.
Bootstrapped and tested on x86_64-linux, and reportedly fixes the
problem on ppc, ok?
Bernd
PR rtl-optimization/78626
* cprop.c (one_cprop_pass): Collect unconditional traps in the middle
of a block, and split such blocks after everything else is finished.
PR rtl-optimization/78626
* gcc.dg/torture/pr78626.c: New test.
Index: gcc/cprop.c
===================================================================
--- gcc/cprop.c (revision 243310)
+++ gcc/cprop.c (working copy)
@@ -1794,7 +1794,7 @@ one_cprop_pass (void)
if (set_hash_table.n_elems > 0)
{
basic_block bb;
- rtx_insn *insn;
+ auto_vec<rtx_insn *> uncond_traps;
alloc_cprop_mem (last_basic_block_for_fn (cfun),
set_hash_table.n_elems);
@@ -1810,6 +1810,9 @@ one_cprop_pass (void)
EXIT_BLOCK_PTR_FOR_FN (cfun),
next_bb)
{
+ rtx_insn *first_uncond_trap = NULL;
+ rtx_insn *insn;
+
/* Reset tables used to keep track of what's still valid [since
the start of the block]. */
reset_opr_set_tables ();
@@ -1825,11 +1828,26 @@ one_cprop_pass (void)
insn into a NOTE, or deleted the insn. */
if (! NOTE_P (insn) && ! insn->deleted ())
mark_oprs_set (insn);
+
+ if (first_uncond_trap == NULL
+ && GET_CODE (PATTERN (insn)) == TRAP_IF
+ && XEXP (PATTERN (insn), 0) == const1_rtx)
+ first_uncond_trap = insn;
}
+ if (first_uncond_trap != NULL && first_uncond_trap != BB_END (bb))
+ uncond_traps.safe_push (first_uncond_trap);
}
changed |= bypass_conditional_jumps ();
+ while (!uncond_traps.is_empty ())
+ {
+ rtx_insn *insn = uncond_traps.pop ();
+ basic_block to_split = BLOCK_FOR_INSN (insn);
+ remove_edge (split_block (to_split, insn));
+ emit_barrier_after_bb (to_split);
+ }
+
FREE_REG_SET (reg_set_bitmap);
free_cprop_mem ();
}
Index: gcc/testsuite/gcc.dg/torture/pr78626.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/pr78626.c (nonexistent)
+++ gcc/testsuite/gcc.dg/torture/pr78626.c (working copy)
@@ -0,0 +1,27 @@
+/* { dg-do compile } */
+
+int qs;
+
+void
+ms (int g1)
+{
+ int cy;
+ int *fr = &cy;
+
+ for (;;)
+ {
+ *fr = 1;
+ fr = &g1;
+
+ while (qs != 0)
+ {
+ if (qs | cy)
+ qs = g1 / 0; /* { dg-warning "division" } */
+ ++qs;
+ }
+
+ cy = 1;
+ while (cy != 0)
+ cy = 2;
+ }
+}
