On Thu, 5 Sep 2019, Richard Biener wrote:
>
> I've made an error with the gcse-after-reload patch in disabling
> record_last_mem_set_info, but only for the first function so
> testing didn't reveal it.
>
> The following fixes this, avoding a few more allocations when
> not needing transp computation and checking a variable which
> is actually initialized at the point it is queried.
>
> Bootstrap & regtest running on x86_64-unknown-linux-gnu
> both with transp compute forced to be off and not.
>
> Will apply once testing succeeds.
Going with the following simpler change, the previous showed some
other issues.
Bootstrapped on x86_64-unknown-linux-gnu with -fgcse-after-reload
enabled and transp forced off sofar. More testing in progress.
(I realized -O2 doesn't enable -fgcse-after-reload)
Richard.
2019-09-05 Richard Biener <rguent...@suse.de>
PR rtl-optimization/91656
* postreload-gcse.c (record_last_mem_set_info): Revert addition
of early out.
* gcc.dg/torture/pr91656-1.c: New testcase.
* gcc.dg/torture/pr91656-2.c: Likewise.
* gcc.dg/torture/pr91656-3.c: Likewise.
Index: gcc/testsuite/gcc.dg/torture/pr91656-1.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/pr91656-1.c (nonexistent)
+++ gcc/testsuite/gcc.dg/torture/pr91656-1.c (working copy)
@@ -0,0 +1,24 @@
+/* { dg-do run } */
+/* { dg-additional-options "-fgcse-after-reload" } */
+
+int a, b, c, d, e;
+
+static __attribute__ ((__noipa__))
+int foo (int i)
+{
+ __builtin_memmove (&i, &e, 1);
+ if (a > 0)
+ i /= e;
+ e /= 5;
+ b = 0;
+ return i + c + d + 5;
+}
+
+int
+main (void)
+{
+ int x = foo (4);
+ if (x != 5)
+ __builtin_abort ();
+ return 0;
+}
Index: gcc/testsuite/gcc.dg/torture/pr91656-2.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/pr91656-2.c (nonexistent)
+++ gcc/testsuite/gcc.dg/torture/pr91656-2.c (working copy)
@@ -0,0 +1,27 @@
+/* { dg-do run { target int128 } } */
+/* { dg-additional-options "-fgcse-after-reload" } */
+
+typedef unsigned char u8;
+typedef unsigned short u16;
+typedef unsigned int u32;
+typedef unsigned long long u64;
+int a, b, c;
+__int128 e;
+int
+d (u16 g)
+{
+ u64 f = __builtin_bswap64 (c);
+ f = g == a;
+ __builtin_memmove (&f, &e, 1);
+ e >>= b;
+ return a + f;
+}
+
+int
+main (void)
+{
+ __int128 x = d (0);
+ if (x != 0)
+ __builtin_abort ();
+ return 0;
+}
Index: gcc/testsuite/gcc.dg/torture/pr91656-3.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/pr91656-3.c (nonexistent)
+++ gcc/testsuite/gcc.dg/torture/pr91656-3.c (working copy)
@@ -0,0 +1,25 @@
+/* { dg-do run { target int128 } } */
+/* { dg-additional-options "-fgcse-after-reload" } */
+
+typedef unsigned char u8;
+typedef unsigned short u16;
+typedef unsigned int u32;
+typedef unsigned long long u64;
+int a, b, c;
+int
+d (u16 e, u64 f)
+{
+ b |= e;
+ __builtin_memset (&f, e, 2);
+ a = (u16) - e >= 2 ? : __builtin_popcountll (f);
+ return a + c;
+}
+
+int
+main (void)
+{
+ __int128 x = d (~0, 0);
+ if (x != 16)
+ __builtin_abort ();
+ return 0;
+}
Index: gcc/postreload-gcse.c
===================================================================
--- gcc/postreload-gcse.c (revision 275399)
+++ gcc/postreload-gcse.c (working copy)
@@ -696,9 +696,6 @@ record_last_reg_set_info_regno (rtx_insn
static void
record_last_mem_set_info (rtx_insn *insn)
{
- if (!transp)
- return;
-
struct modifies_mem *list_entry;
list_entry = (struct modifies_mem *) obstack_alloc (&modifies_mem_obstack,
