[gcc(refs/vendors/ibm/heads/perf)] pdp11: Fix handling of common (local and global) vars [PR94134]

[Jiu Fu Guo]

https://gcc.gnu.org/g:d42ff1d3b62521829d90e5b972baba2a0339e2bf

commit d42ff1d3b62521829d90e5b972baba2a0339e2bf
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Wed Mar 11 18:35:13 2020 +0100

    pdp11: Fix handling of common (local and global) vars [PR94134]
    
    As mentioned in the PR, the generic code decides to put the a variable into
    lcomm_section, which is a NOSWITCH section and thus the generic code doesn't
    switch into a particular section before using
    ASM_OUTPUT{_ALIGNED{,_DECL}_}_LOCAL, on many targets that results just in
    .lcomm (or for non-local .comm) directives which don't need a switch to some
    section, other targets put switch_to_section (bss_section) at the start of
    that macro.
    pdp11 doesn't do that (and doesn't have bss_section), and so emits the
    lcomm/comm variables in whatever section is current (it has only .text/.data
    and for DEC assembler rodata).
    
    The following patch fixes that by putting it always into data section, and
    additionally avoids emitting an empty line in the assembly for the lcomm
    vars.
    
    2020-03-11  Jakub Jelinek  <jakub@redhat.com>
    
            PR target/94134
            * config/pdp11/pdp11.c (pdp11_asm_output_var): Call switch_to_section
            at the start to switch to data section.  Don't print extra newline if
            .globl directive has not been emitted.
    
            * gcc.c-torture/execute/pr94134.c: New test.

Diff:
---
 gcc/ChangeLog                                 |  7 +++++++
 gcc/config/pdp11/pdp11.c                      |  3 ++-
 gcc/testsuite/ChangeLog                       |  5 +++++
 gcc/testsuite/gcc.c-torture/execute/pr94134.c | 14 ++++++++++++++
 4 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 73339dc2c2c..818cf19e886 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2020-03-11  Jakub Jelinek  <jakub@redhat.com>
+
+	PR target/94134
+	* config/pdp11/pdp11.c (pdp11_asm_output_var): Call switch_to_section
+	at the start to switch to data section.  Don't print extra newline if
+	.globl directive has not been emitted.
+
 2020-03-11  Richard Biener  <rguenther@suse.de>
 
 	* match.pd ((T *)(ptr - ptr-cst) -> &MEM[ptr + -ptr-cst]):
diff --git a/gcc/config/pdp11/pdp11.c b/gcc/config/pdp11/pdp11.c
index c8612ad53d7..25590be2b5c 100644
--- a/gcc/config/pdp11/pdp11.c
+++ b/gcc/config/pdp11/pdp11.c
@@ -743,6 +743,7 @@ void
 pdp11_asm_output_var (FILE *file, const char *name, int size,
 		      int align, bool global)
 {
+  switch_to_section (data_section);
   if (align > 8)
     fprintf (file, "\t.even\n");
   if (TARGET_DEC_ASM)
@@ -763,8 +764,8 @@ pdp11_asm_output_var (FILE *file, const char *name, int size,
 	{
 	  fprintf (file, ".globl ");
 	  assemble_name (file, name);
+	  fprintf (file, "\n");
 	}
-      fprintf (file, "\n");
       assemble_name (file, name);
       fputs (":", file);
       ASM_OUTPUT_SKIP (file, size);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index e2442fba35a..ba4cd147d8c 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2020-03-11  Jakub Jelinek  <jakub@redhat.com>
+
+	PR target/94134
+	* gcc.c-torture/execute/pr94134.c: New test.
+
 2020-03-11  Kito Cheng  <kito.cheng@sifive.com>
 
 	* gcc.target/riscv/interrupt-2.c: Update testcase and expected output.
diff --git a/gcc/testsuite/gcc.c-torture/execute/pr94134.c b/gcc/testsuite/gcc.c-torture/execute/pr94134.c
new file mode 100644
index 00000000000..b1b44c3b184
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr94134.c
@@ -0,0 +1,14 @@
+/* PR target/94134 */
+
+static volatile int a = 0;
+static volatile int b = 1;
+
+int
+main ()
+{
+  a++;
+  b++;
+  if (a != 1 || b != 2)
+    __builtin_abort ();
+  return 0;
+}