rs6000: mark clobber for registers changed by untpyed_call

As PR93047 said, __builtin_apply/__builtin_return does not work well with
-frename-registers.  This is caused by return register(e.g. r3) is used to
rename another register, before return register is stored to stack.
This patch fix this issue by emitting clobber for those egisters which
maybe changed by untyped call.

gcc/
2020-02-17  Jiufu Guo  <guojiufu@linux.ibm.com>

	PR target/93047
	* config/rs6000/rs6000.md (untyped_call): Add emit_clobber.

gcc/testsuite
2020-02-17  Jiufu Guo  <guojiufu@linux.ibm.com>

	PR target/93047
	* gcc.dg/torture/stackalign/builtin-return-2.c: New test case.

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c7a551b..5357acf 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2020-02-17  Jiufu Guo  <guojiufu@linux.ibm.com>
+
+       PR target/93047
+       * config/rs6000/rs6000.md (untyped_call): Add emit_clobber.
+
 2020-02-16  Uroš Bizjak  <ubizjak@gmail.com>
 
        PR target/93743

diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md
index 3da7b1e..ad88b67 100644 (file)
--- a/gcc/config/rs6000/rs6000.md
+++ b/gcc/config/rs6000/rs6000.md
@@ -10870,6 +10870,10 @@
 
   emit_call_insn (gen_call (operands[0], const0_rtx, const0_rtx));
 
+  for (int i = 0; i < XVECLEN (operands[2], 0); i++)
+    emit_clobber (SET_SRC (XVECEXP (operands[2], 0, i)));
+  emit_insn (gen_blockage ());
+
   for (i = 0; i < XVECLEN (operands[2], 0); i++)
     {
       rtx set = XVECEXP (operands[2], 0, i);

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index f2566ad..83c581c 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2020-02-17  Jiufu Guo  <guojiufu@linux.ibm.com>
+
+       PR target/93047
+       * gcc.dg/torture/stackalign/builtin-return-2.c: New test case.
+
 2020-02-16  Uroš Bizjak  <ubizjak@gmail.com>
 
        PR target/93743

diff --git a/gcc/testsuite/gcc.dg/torture/stackalign/builtin-return-2.c b/gcc/testsuite/gcc.dg/torture/stackalign/builtin-return-2.c
new file mode 100644 (file)
index 0000000..7719109
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/stackalign/builtin-return-2.c
@@ -0,0 +1,40 @@
+/* PR target/93047 */
+/* Originator: Andrew Church <gcczilla@achurch.org> */
+/* { dg-do run } */
+/* { dg-additional-options "-O3 -frename-registers" } */
+/* { dg-require-effective-target untyped_assembly } */
+
+#ifdef __MMIX__
+/* No parameters on stack for bar.  */
+#define STACK_ARGUMENTS_SIZE 0
+#else
+#define STACK_ARGUMENTS_SIZE 64
+#endif
+
+extern void abort(void);
+
+int foo(int n)
+{
+  return n+1;
+}
+
+int bar(int n)
+{
+  __builtin_return(__builtin_apply((void (*)(void))foo, __builtin_apply_args(),
+                                  STACK_ARGUMENTS_SIZE));
+}
+
+int main(void)
+{
+  /* Allocate 64 bytes on the stack to make sure that __builtin_apply
+     can read at least 64 bytes above the return address.  */
+  char dummy[64];
+
+  __asm__ ("" : : "" (dummy));
+
+  if (bar(1) != 2)
+    abort();
+
+  return 0;
+}
+