Hi!
This patch fixes a RTL sharing issue, if *reg_equiv[REGNO (loc)].src_p
is e.g. a MEM and the cleared reg would be used in more than one
DEBUG_INSN or more than once in a single one, we'd incorrectly share it,
which can result e.g. in DF verification issue - change of one DEBUG_INSN
with the shared MEM results in a df insn rescan, but on the other DEBUG_INSN
no changes would be performed and thus rescanning wouldn't be performed.
Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux,
committed to trunk as obvious.
2014-03-20 Jakub Jelinek <ja...@redhat.com>
PR middle-end/60597
* ira.c (adjust_cleared_regs): Call copy_rtx on
*reg_equiv[REGNO (loc)].src_p before passing it to
simplify_replace_fn_rtx.
* g++.dg/opt/pr60597.C: New test.
--- gcc/ira.c.jj 2014-01-25 00:16:53.000000000 +0100
+++ gcc/ira.c 2014-03-20 16:35:11.881516283 +0100
@@ -3428,7 +3428,7 @@ adjust_cleared_regs (rtx loc, const_rtx
{
bitmap cleared_regs = (bitmap) data;
if (bitmap_bit_p (cleared_regs, REGNO (loc)))
- return simplify_replace_fn_rtx (*reg_equiv[REGNO (loc)].src_p,
+ return simplify_replace_fn_rtx (copy_rtx (*reg_equiv[REGNO
(loc)].src_p),
NULL_RTX, adjust_cleared_regs, data);
}
return NULL_RTX;
--- gcc/testsuite/g++.dg/opt/pr60597.C.jj 2014-03-20 16:34:40.915677263
+0100
+++ gcc/testsuite/g++.dg/opt/pr60597.C 2014-03-20 16:34:21.000000000 +0100
@@ -0,0 +1,46 @@
+// PR middle-end/60597
+// { dg-do compile }
+// { dg-options "-O2 -g" }
+
+struct A
+{
+ int foo () const;
+ int bar () const;
+ int a;
+};
+
+struct B
+{
+ int foo ();
+ int bar ();
+};
+
+int *c, d;
+
+int
+A::foo () const
+{
+ int b = a >> 16;
+ return b;
+}
+
+int
+A::bar () const
+{
+ int b = a;
+ return b;
+}
+
+void
+baz (A &x, B h, int i, int j)
+{
+ for (; i < h.bar (); ++i)
+ for (; h.foo (); ++j)
+ {
+ int g = x.foo ();
+ int f = x.bar ();
+ int e = c[0] & 1;
+ d = (e << 1) | (g << 16) | (f & 1);
+ c[j] = 0;
+ }
+}
Jakub
