ipa: Force args obtined through pass-through maps to the expected type (PR 113964)

Interactions of IPA-CP and IPA-SRA on the same data is a rather big
source of issues, I'm afraid.  PR 113964 is a situation where IPA-CP
propagates an unsigned short in a union parameter into a function
which itself calls a different function which has a same union
parameter and both these union parameters are split with IPA-SRA.  The
leaf function however uses a signed short member of the union.

In the calling function, we get the unsigned constant as the
replacement for the union and it is then passed in the call without
any type compatibility checks.  Apparently on riscv64 it matters
whether the parameter is signed or unsigned short and so the leaf
function can see different values.

Fixed by using useless_type_conversion_p at the appropriate place and
if it fails, use force_value_to type as elsewhere in similar
situations.

gcc/ChangeLog:

2024-04-04  Martin Jambor  <mjambor@suse.cz>

	PR ipa/113964
	* ipa-param-manipulation.cc (ipa_param_adjustments::modify_call):
	Force values obtined through pass-through maps to the expected
	split type.

gcc/testsuite/ChangeLog:

2024-04-04  Patrick O'Neill  <patrick@rivosinc.com>
	    Martin Jambor  <mjambor@suse.cz>

	PR ipa/113964
	* gcc.dg/ipa/pr114247.c: New test.

diff --git a/gcc/ipa-param-manipulation.cc b/gcc/ipa-param-manipulation.cc
index f4b5e850c2b1fbf729b6e7a6e15de98ffe0b362c..ad36b8389c00ae5f9a593dcde3f353e0db36ba75 100644 (file)
--- a/gcc/ipa-param-manipulation.cc
+++ b/gcc/ipa-param-manipulation.cc
@@ -740,6 +740,12 @@ ipa_param_adjustments::modify_call (cgraph_edge *cs,
          }
       if (repl)
        {
+         if (!useless_type_conversion_p(apm->type, repl->typed.type))
+           {
+             repl = force_value_to_type (apm->type, repl);
+             repl = force_gimple_operand_gsi (&gsi, repl,
+                                              true, NULL, true, GSI_SAME_STMT);
+           }
          vargs.quick_push (repl);
          continue;
        }

diff --git a/gcc/testsuite/gcc.dg/ipa/pr114247.c b/gcc/testsuite/gcc.dg/ipa/pr114247.c
new file mode 100644 (file)
index 0000000..60aa2bc
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/ipa/pr114247.c
@@ -0,0 +1,31 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fsigned-char -fno-strict-aliasing -fwrapv" } */
+
+union a {
+  unsigned short b;
+  int c;
+  signed short d;
+};
+int e, f = 1, g;
+long h;
+const int **i;
+void j(union a k, int l, unsigned m) {
+  const int *a[100];
+  i = &a[0];
+  h = k.d;
+}
+static int o(union a k) {
+  k.d = -1;
+  while (1)
+    if (f)
+      break;
+  j(k, g, e);
+  return 0;
+}
+int main() {
+  union a n = {1};
+  o(n);
+  if (h != -1)
+    __builtin_abort();
+  return 0;
+}