From: Mikael Pettersson <mikpelinux@gmail.com>
Date: Thu, 13 Jul 2023 20:06:39 +0000 (-0400)
Subject: pdp11: Fix epilogue generation [PR107841]
X-Git-Tag: basepoints/gcc-15~7630
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8f1a26ee259f72e42405b9c5f2b161042ec4014b;p=thirdparty%2Fgcc.git

pdp11: Fix epilogue generation [PR107841]

gcc/

	PR target/107841
	* config/pdp11/pdp11.cc (pdp11_expand_epilogue): Also
	deallocate alloca-only frame.

gcc/testsuite/

	PR target/107841
	* gcc.target/pdp11/pr107841.c: New test.
---

diff --git a/gcc/config/pdp11/pdp11.cc b/gcc/config/pdp11/pdp11.cc
index f6dd841f1847..311a1d225e05 100644
--- a/gcc/config/pdp11/pdp11.cc
+++ b/gcc/config/pdp11/pdp11.cc
@@ -393,7 +393,7 @@ pdp11_expand_epilogue (void)
   rtx x, reg, via_ac = NULL;
 
   /* Deallocate the local variables.  */
-  if (fsize)
+  if (fsize || cfun->calls_alloca)
     {
       if (frame_pointer_needed)
 	{
diff --git a/gcc/testsuite/gcc.target/pdp11/pr107841.c b/gcc/testsuite/gcc.target/pdp11/pr107841.c
new file mode 100644
index 000000000000..a363c468b0ba
--- /dev/null
+++ b/gcc/testsuite/gcc.target/pdp11/pr107841.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+/* Verify that the stack frame is deallocated using the frame pointer.  */
+
+void qq (int a)
+{
+    char *s = __builtin_alloca (128);
+    __builtin_sprintf (s, "qq %d", 3);
+}
+
+/* { dg-final { scan-assembler "mov\tr5,sp" } } */