Hi,
this patch adds logic to propagate nondeterministic and side_effects
bits in modref when summary is updated after inlining.
Bootstrapped/regtested x86_64-linux, comitted.
gcc/ChangeLog:
2022-04-09 Jan Hubicka <hubi...@ucw.cz>
* ipa-modref.cc (ipa_merge_modref_summary_after_inlining): Propagate
nondeterministic and side_effects flags.
gcc/testsuite/ChangeLog:
2022-04-09 Jan Hubicka <hubi...@ucw.cz>
* gcc.dg/ipa/pr105160.c: New test.
diff --git a/gcc/ipa-modref.cc b/gcc/ipa-modref.cc
index acfd7d80ff8..556816ab429 100644
--- a/gcc/ipa-modref.cc
+++ b/gcc/ipa-modref.cc
@@ -5281,6 +5281,29 @@ ipa_merge_modref_summary_after_inlining (cgraph_edge
*edge)
if (!ignore_stores)
to_info_lto->stores->collapse ();
}
+ /* Merge side effects and non-determinism.
+ PURE/CONST flags makes functions deterministic and if there is
+ no LOOPING_CONST_OR_PURE they also have no side effects. */
+ if (!(flags & (ECF_CONST | ECF_NOVOPS | ECF_PURE))
+ || (flags & ECF_LOOPING_CONST_OR_PURE))
+ {
+ if (to_info)
+ {
+ if (!callee_info || callee_info->side_effects)
+ to_info->side_effects = true;
+ if ((!callee_info || callee_info->nondeterministic)
+ && !ignore_nondeterminism_p (edge->caller->decl, flags))
+ to_info->nondeterministic = true;
+ }
+ if (to_info_lto)
+ {
+ if (!callee_info_lto || callee_info_lto->side_effects)
+ to_info_lto->side_effects = true;
+ if ((!callee_info_lto || callee_info_lto->nondeterministic)
+ && !ignore_nondeterminism_p (edge->caller->decl, flags))
+ to_info_lto->nondeterministic = true;
+ }
+ }
if (callee_info || callee_info_lto)
{
auto_vec <modref_parm_map, 32> parm_map;
diff --git a/gcc/testsuite/gcc.dg/ipa/pr105160.c
b/gcc/testsuite/gcc.dg/ipa/pr105160.c
new file mode 100644
index 00000000000..ea80545b102
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/ipa/pr105160.c
@@ -0,0 +1,77 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-ipa-modref" } */
+#define sysreg_read(regname) \
+({ \
+ unsigned long __sr_val; \
+ asm volatile(""); \
+ \
+ __sr_val; \
+})
+
+#define sysreg_write(regname, __sw_val) \
+do { \
+ asm volatile(""); \
+} while (0)
+
+#define isb() \
+do { \
+ asm volatile( \
+ "isb" \
+ : \
+ : \
+ : "memory"); \
+} while (0)
+
+static unsigned long sctlr_read(void)
+{
+ return sysreg_read(sctlr_el1);
+}
+
+static void sctlr_write(unsigned long val)
+{
+ sysreg_write(sctlr_el1, val);
+}
+
+static void sctlr_rmw(void)
+{
+ unsigned long val;
+
+ val = sctlr_read();
+ val |= 1UL << 7;
+ sctlr_write(val);
+}
+
+void sctlr_read_multiple(void)
+{
+ sctlr_read();
+ sctlr_read();
+ sctlr_read();
+ sctlr_read();
+}
+
+void sctlr_write_multiple(void)
+{
+ sctlr_write(0);
+ sctlr_write(0);
+ sctlr_write(0);
+ sctlr_write(0);
+ sctlr_write(0);
+}
+
+void sctlr_rmw_multiple(void)
+{
+ sctlr_rmw();
+ sctlr_rmw();
+ sctlr_rmw();
+ sctlr_rmw();
+}
+
+void function(void)
+{
+ sctlr_read_multiple();
+ sctlr_write_multiple();
+ sctlr_rmw_multiple();
+
+ isb();
+}
+/* { dg-final { scan-ipa-dump-not "Function found to be const" "modref" } } */
