Updated patch. This passed bootstrap and regtesting on powerpc64le-linux
with no regressions. Ok for trunk?
Changes from v1:
1. Moved the disabling of shrink-wrapping to rs6000_emit_prologue
and beefed up comment. Used a more accurate test.
2. Added comment to the test case on why rop_ok is needed.
Peter
rs6000: ROP - Do not disable shrink-wrapping for leaf functions [PR114759]
Only disable shrink-wrapping when using -mrop-protect when we know we
will be emitting the ROP-protect hash instructions (ie, non-leaf functions).
2024-06-17 Peter Bergner <berg...@linux.ibm.com>
gcc/
PR target/114759
* config/rs6000/rs6000.cc (rs6000_override_options_after_change): Move
the disabling of shrink-wrapping from here....
* config/rs6000/rs6000-logue.cc (rs6000_emit_prologue): ...to here.
gcc/testsuite/
PR target/114759
* gcc.target/powerpc/pr114759-1.c: New test.
---
gcc/config/rs6000/rs6000-logue.cc | 5 +++++
gcc/config/rs6000/rs6000.cc | 4 ----
gcc/testsuite/gcc.target/powerpc/pr114759-1.c | 16 ++++++++++++++++
3 files changed, 21 insertions(+), 4 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/powerpc/pr114759-1.c
diff --git a/gcc/config/rs6000/rs6000-logue.cc
b/gcc/config/rs6000/rs6000-logue.cc
index 193e2122c0f..c384e48e378 100644
--- a/gcc/config/rs6000/rs6000-logue.cc
+++ b/gcc/config/rs6000/rs6000-logue.cc
@@ -3018,6 +3018,11 @@ rs6000_emit_prologue (void)
&& (lookup_attribute ("no_split_stack",
DECL_ATTRIBUTES (cfun->decl))
== NULL));
+ /* If we are inserting ROP-protect hash instructions, disable shrink-wrap
+ until the bug where the hashst insn is emitted in the wrong location
+ is fixed. See PR101324 for details. */
+ if (info->rop_hash_size)
+ flag_shrink_wrap = 0;
frame_pointer_needed_indeed
= frame_pointer_needed && df_regs_ever_live_p (HARD_FRAME_POINTER_REGNUM);
diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
index e4dc629ddcc..fd6e013c346 100644
--- a/gcc/config/rs6000/rs6000.cc
+++ b/gcc/config/rs6000/rs6000.cc
@@ -3427,10 +3427,6 @@ rs6000_override_options_after_change (void)
}
else if (!OPTION_SET_P (flag_cunroll_grow_size))
flag_cunroll_grow_size = flag_peel_loops || optimize >= 3;
-
- /* If we are inserting ROP-protect instructions, disable shrink wrap. */
- if (rs6000_rop_protect)
- flag_shrink_wrap = 0;
}
#ifdef TARGET_USES_LINUX64_OPT
diff --git a/gcc/testsuite/gcc.target/powerpc/pr114759-1.c
b/gcc/testsuite/gcc.target/powerpc/pr114759-1.c
new file mode 100644
index 00000000000..579e08e920f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/pr114759-1.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mdejagnu-cpu=power10 -mrop-protect
-fdump-rtl-pro_and_epilogue" } */
+/* { dg-require-effective-target rop_ok } Only enable on supported ABIs. */
+
+/* Verify we still attempt shrink-wrapping when using -mrop-protect
+ and there are no function calls. */
+
+long
+foo (long arg)
+{
+ if (arg)
+ asm ("" ::: "r20");
+ return 0;
+}
+
+/* { dg-final { scan-rtl-dump-times "Performing shrink-wrapping" 1
"pro_and_epilogue" } } */
--
2.43.0
