Propagate nondeterministic and side_effects flags in modref summary after inlining

gcc/ChangeLog:

2022-04-09  Jan Hubicka  <hubicka@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  <hubicka@ucw.cz>

	* gcc.dg/ipa/pr105160.c: New test.

diff --git a/gcc/ipa-modref.cc b/gcc/ipa-modref.cc
index acfd7d8..556816a 100644 (file)
--- 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 (file)
index 0000000..ea80545
--- /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"  } } */