This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
[PATCH] Fix find_call_stack_args in RTL DCE (PR rtl-optimization/47337, take 2)
On Wed, Jan 19, 2011 at 01:36:49AM +0100, Eric Botcazou wrote:
> > 2011-01-18 Jakub Jelinek <jakub@redhat.com>
> >
> > PR rtl-optimization/47337
> > * dce.c (find_call_stack_args): Ignore debug insns.
> > Stop on memory stores other than argument stores.
>
> Can you make an (inline) predicate out of the test and just do:
>
> if (predicate (xxx))
> break;
>
> instead?
So like this?
2011-01-19 Jakub Jelinek <jakub@redhat.com>
PR rtl-optimization/47337
* dce.c (check_argument_store): New function.
(find_call_stack_args): Ignore debug insns. Use check_argument_store.
* gcc.c-torture/execute/pr47337.c: New test.
--- gcc/dce.c.jj 2011-01-18 23:56:46.713420010 +0100
+++ gcc/dce.c 2011-01-19 09:51:15.756808297 +0100
@@ -220,6 +220,26 @@ mark_nonreg_stores (rtx body, rtx insn,
}
+/* Return true if store to MEM, starting OFF bytes from stack pointer,
+ is a call argument store, and clear corresponding bits from SP_BYTES
+ bitmap if it is. */
+
+static bool
+check_argument_store (rtx mem, HOST_WIDE_INT off, HOST_WIDE_INT min_sp_off,
+ HOST_WIDE_INT max_sp_off, bitmap sp_bytes)
+{
+ HOST_WIDE_INT byte;
+ for (byte = off; byte < off + GET_MODE_SIZE (GET_MODE (mem)); byte++)
+ {
+ if (byte < min_sp_off
+ || byte >= max_sp_off
+ || !bitmap_clear_bit (sp_bytes, byte - min_sp_off))
+ return false;
+ }
+ return true;
+}
+
+
/* Try to find all stack stores of CALL_INSN arguments if
ACCUMULATE_OUTGOING_ARGS. If all stack stores have been found
and it is therefore safe to eliminate the call, return true,
@@ -364,7 +384,7 @@ find_call_stack_args (rtx call_insn, boo
for (insn = PREV_INSN (call_insn); insn; insn = prev_insn)
{
rtx set, mem, addr;
- HOST_WIDE_INT off, byte;
+ HOST_WIDE_INT off;
if (insn == BB_HEAD (BLOCK_FOR_INSN (call_insn)))
prev_insn = NULL_RTX;
@@ -374,7 +394,7 @@ find_call_stack_args (rtx call_insn, boo
if (CALL_P (insn))
break;
- if (!INSN_P (insn))
+ if (!NONDEBUG_INSN_P (insn))
continue;
set = single_set (insn);
@@ -433,17 +453,11 @@ find_call_stack_args (rtx call_insn, boo
break;
}
- if (GET_MODE_SIZE (GET_MODE (mem)) == 0)
+ if (GET_MODE_SIZE (GET_MODE (mem)) == 0
+ || !check_argument_store (mem, off, min_sp_off,
+ max_sp_off, sp_bytes))
break;
- for (byte = off; byte < off + GET_MODE_SIZE (GET_MODE (mem)); byte++)
- {
- if (byte < min_sp_off
- || byte >= max_sp_off
- || !bitmap_clear_bit (sp_bytes, byte - min_sp_off))
- break;
- }
-
if (!deletable_insn_p (insn, fast, NULL))
break;
--- gcc/testsuite/gcc.c-torture/execute/pr47337.c.jj 2011-01-19 09:38:08.747806904 +0100
+++ gcc/testsuite/gcc.c-torture/execute/pr47337.c 2011-01-19 09:38:08.747806904 +0100
@@ -0,0 +1,86 @@
+/* PR rtl-optimization/47337 */
+
+static unsigned int a[256], b = 0;
+static char c = 0;
+static int d = 0, *f = &d;
+static long long e = 0;
+
+static short
+foo (long long x, long long y)
+{
+ return x / y;
+}
+
+static char
+bar (char x, char y)
+{
+ return x - y;
+}
+
+static int
+baz (int x, int y)
+{
+ *f = (y != (short) (y * 3));
+ for (c = 0; c < 2; c++)
+ {
+ lab:
+ if (d)
+ {
+ if (e)
+ e = 1;
+ else
+ return x;
+ }
+ else
+ {
+ d = 1;
+ goto lab;
+ }
+ f = &d;
+ }
+ return x;
+}
+
+static void
+fnx (unsigned long long x, int y)
+{
+ if (!y)
+ {
+ b = a[b & 1];
+ b = a[b & 1];
+ b = a[(b ^ (x & 1)) & 1];
+ b = a[(b ^ (x & 1)) & 1];
+ }
+}
+
+char *volatile w = "2";
+
+int
+main ()
+{
+ int h = 0;
+ unsigned int k = 0;
+ int l[8];
+ int i, j;
+
+ if (__builtin_strcmp (w, "1") == 0)
+ h = 1;
+
+ for (i = 0; i < 256; i++)
+ {
+ for (j = 8; j > 0; j--)
+ k = 1;
+ a[i] = k;
+ }
+ for (i = 0; i < 8; i++)
+ l[i] = 0;
+
+ d = bar (c, c);
+ d = baz (c, 1 | foo (l[0], 10));
+ fnx (d, h);
+ fnx (e, h);
+
+ if (d != 0)
+ __builtin_abort ();
+ return 0;
+}
Jakub