On Mon, Oct 11, 2021 at 09:38:36AM +0200, Richard Biener wrote:
> On Fri, Oct 8, 2021 at 1:31 PM Stefan Schulze Frielinghaus via
> Gcc-patches <gcc-patches@gcc.gnu.org> wrote:
> >
> > gcc/ChangeLog:
> >
> > * regcprop.c (maybe_mode_change): Determine offset relative to
> > high or low part depending on endianness.
> >
> > Bootstrapped and regtested on IBM Z. Ok for mainline and gcc-{11,10,9}?
>
> Is there a testcase to add?
I've updated the patch and added the testcase from the PR.
>
> > ---
> > gcc/regcprop.c | 11 ++++++++---
> > 1 file changed, 8 insertions(+), 3 deletions(-)
> >
> > diff --git a/gcc/regcprop.c b/gcc/regcprop.c
> > index d2a01130fe1..0e1ac12458a 100644
> > --- a/gcc/regcprop.c
> > +++ b/gcc/regcprop.c
> > @@ -414,9 +414,14 @@ maybe_mode_change (machine_mode orig_mode,
> > machine_mode copy_mode,
> > copy_nregs, &bytes_per_reg))
> > return NULL_RTX;
> > poly_uint64 copy_offset = bytes_per_reg * (copy_nregs - use_nregs);
> > - poly_uint64 offset
> > - = subreg_size_lowpart_offset (GET_MODE_SIZE (new_mode) +
> > copy_offset,
> > - GET_MODE_SIZE (orig_mode));
> > + poly_uint64 offset =
> > +#if WORDS_BIG_ENDIAN
> > + subreg_size_highpart_offset
> > +#else
> > + subreg_size_lowpart_offset
> > +#endif
> > + (GET_MODE_SIZE (new_mode) + copy_offset,
> > + GET_MODE_SIZE (orig_mode));
> > regno += subreg_regno_offset (regno, orig_mode, offset, new_mode);
> > if (targetm.hard_regno_mode_ok (regno, new_mode))
> > return gen_raw_REG (new_mode, regno);
> > --
> > 2.31.1
> >
>From 299959788321e21c27f0d4a6d437a586c5f6c92e Mon Sep 17 00:00:00 2001
From: Stefan Schulze Frielinghaus <stefa...@linux.ibm.com>
Date: Mon, 4 Oct 2021 09:36:21 +0200
Subject: [PATCH] regcprop: Determine subreg offset depending on endianness
[PR101260]
gcc/ChangeLog:
* regcprop.c (maybe_mode_change): Determine offset relative to
high or low part depending on endianness.
gcc/testsuite/ChangeLog:
* gcc.dg/pr101260.c: New test.
---
gcc/regcprop.c | 11 ++++++--
gcc/testsuite/gcc.dg/pr101260.c | 49 +++++++++++++++++++++++++++++++++
2 files changed, 57 insertions(+), 3 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/pr101260.c
diff --git a/gcc/regcprop.c b/gcc/regcprop.c
index d2a01130fe1..0e1ac12458a 100644
--- a/gcc/regcprop.c
+++ b/gcc/regcprop.c
@@ -414,9 +414,14 @@ maybe_mode_change (machine_mode orig_mode, machine_mode
copy_mode,
copy_nregs, &bytes_per_reg))
return NULL_RTX;
poly_uint64 copy_offset = bytes_per_reg * (copy_nregs - use_nregs);
- poly_uint64 offset
- = subreg_size_lowpart_offset (GET_MODE_SIZE (new_mode) + copy_offset,
- GET_MODE_SIZE (orig_mode));
+ poly_uint64 offset =
+#if WORDS_BIG_ENDIAN
+ subreg_size_highpart_offset
+#else
+ subreg_size_lowpart_offset
+#endif
+ (GET_MODE_SIZE (new_mode) + copy_offset,
+ GET_MODE_SIZE (orig_mode));
regno += subreg_regno_offset (regno, orig_mode, offset, new_mode);
if (targetm.hard_regno_mode_ok (regno, new_mode))
return gen_raw_REG (new_mode, regno);
diff --git a/gcc/testsuite/gcc.dg/pr101260.c b/gcc/testsuite/gcc.dg/pr101260.c
new file mode 100644
index 00000000000..0e9ec4e203a
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr101260.c
@@ -0,0 +1,49 @@
+/* PR rtl-optimization/101260 */
+/* { dg-do run } */
+/* { dg-options -O1 } */
+struct a {
+ unsigned b : 7;
+ int c;
+ int d;
+ short e;
+} p, *q = &p;
+int f, g, h, i, r, s;
+static short j[8][1][6] = {0};
+char k[7];
+short l, m;
+int *n;
+int **o = &n;
+void t() {
+ for (; f;)
+ ;
+}
+static struct a u(int x) {
+ struct a a = {4, 8, 5, 4};
+ for (; i <= 6; i++) {
+ struct a v = {0};
+ for (; l; l++)
+ h = 0;
+ for (; h >= 0; h--) {
+ struct a *w;
+ j[i];
+ w = &p;
+ s = 0;
+ for (; s < 3; s++) {
+ r ^= x;
+ m = j[i][g][h] == (k[g] = g);
+ *w = v;
+ }
+ r = 2;
+ for (; r; r--)
+ *o = &r;
+ }
+ }
+ t();
+ return a;
+}
+int main() {
+ *q = u(636);
+ if (p.b != 4)
+ __builtin_abort ();
+ return 0;
+}
--
2.31.1
