re PR target/81979 (Assembler messages: Error: can't resolve `.got2' {.got2 section} - `.LCF0' {.text.unlikely section})

	PR target/81979
	* output.h (switch_to_other_text_partition): New declaration.
	* varasm.c (switch_to_other_text_partition): New function.
	* config/rs6000/rs6000.c (uses_TOC): Return 2 if
	NOTE_INSN_SWITCH_TEXT_SECTIONS is seen before finding load_toc_* insn.
	(rs6000_elf_declare_function_name): If uses_TOC returned 2, switch
	to the other text partition before emitting LCL label and switch back
	after emitting the word after it.

	* gcc.dg/pr81979.c: New test.

From-SVN: r251843

6 files changed, 92 insertions, 19 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 8e614f6..4b6d9c2 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,14 @@
+2017-09-07  Jakub Jelinek  <jakub@redhat.com>
+
+	PR target/81979
+	* output.h (switch_to_other_text_partition): New declaration.
+	* varasm.c (switch_to_other_text_partition): New function.
+	* config/rs6000/rs6000.c (uses_TOC): Return 2 if
+	NOTE_INSN_SWITCH_TEXT_SECTIONS is seen before finding load_toc_* insn.
+	(rs6000_elf_declare_function_name): If uses_TOC returned 2, switch
+	to the other text partition before emitting LCL label and switch back
+	after emitting the word after it.
+
 2017-09-07  Richard Biener  <rguenther@suse.de>
 
 	* passes.def (pass_split_crit_edges): Remove instance before PRE.
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index fdc39d9..ecdf776 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -25277,32 +25277,41 @@ get_TOC_alias_set (void)
 
 /* This returns nonzero if the current function uses the TOC.  This is
    determined by the presence of (use (unspec ... UNSPEC_TOC)), which
-   is generated by the ABI_V4 load_toc_* patterns.  */
+   is generated by the ABI_V4 load_toc_* patterns.
+   Return 2 instead of 1 if the load_toc_* pattern is in the function
+   partition that doesn't start the function.  */
 #if TARGET_ELF
 static int
 uses_TOC (void)
 {
   rtx_insn *insn;
+  int ret = 1;
 
   for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
-    if (INSN_P (insn))
-      {
-	rtx pat = PATTERN (insn);
-	int i;
+    {
+      if (INSN_P (insn))
+	{
+	  rtx pat = PATTERN (insn);
+	  int i;
 
-	if (GET_CODE (pat) == PARALLEL)
-	  for (i = 0; i < XVECLEN (pat, 0); i++)
-	    {
-	      rtx sub = XVECEXP (pat, 0, i);
-	      if (GET_CODE (sub) == USE)
-		{
-		  sub = XEXP (sub, 0);
-		  if (GET_CODE (sub) == UNSPEC
-		      && XINT (sub, 1) == UNSPEC_TOC)
-		    return 1;
-		}
-	    }
-      }
+	  if (GET_CODE (pat) == PARALLEL)
+	    for (i = 0; i < XVECLEN (pat, 0); i++)
+	      {
+		rtx sub = XVECEXP (pat, 0, i);
+		if (GET_CODE (sub) == USE)
+		  {
+		    sub = XEXP (sub, 0);
+		    if (GET_CODE (sub) == UNSPEC
+			&& XINT (sub, 1) == UNSPEC_TOC)
+		      return ret;
+		  }
+	      }
+	}
+      else if (crtl->has_bb_partition
+	       && NOTE_P (insn)
+	       && NOTE_KIND (insn) == NOTE_INSN_SWITCH_TEXT_SECTIONS)
+	ret = 2;
+    }
   return 0;
 }
 #endif
@@ -33336,14 +33345,17 @@ rs6000_elf_declare_function_name (FILE *file, const char *name, tree decl)
       return;
     }
 
+  int uses_toc;
   if (DEFAULT_ABI == ABI_V4
       && (TARGET_RELOCATABLE || flag_pic > 1)
       && !TARGET_SECURE_PLT
       && (!constant_pool_empty_p () || crtl->profile)
-      && uses_TOC ())
+      && (uses_toc = uses_TOC ()))
     {
       char buf[256];
 
+      if (uses_toc == 2)
+	switch_to_other_text_partition ();
       (*targetm.asm_out.internal_label) (file, "LCL", rs6000_pic_labelno);
 
       fprintf (file, "\t.long ");
@@ -33353,6 +33365,8 @@ rs6000_elf_declare_function_name (FILE *file, const char *name, tree decl)
       ASM_GENERATE_INTERNAL_LABEL (buf, "LCF", rs6000_pic_labelno);
       assemble_name (file, buf);
       putc ('\n', file);
+      if (uses_toc == 2)
+	switch_to_other_text_partition ();
     }
 
   ASM_OUTPUT_TYPE_DIRECTIVE (file, name, "function");
diff --git a/gcc/output.h b/gcc/output.h
index e2d5503..e98a911 100644
--- a/gcc/output.h
+++ b/gcc/output.h
@@ -537,6 +537,7 @@ extern section *mergeable_constant_section (machine_mode,
 extern section *function_section (tree);
 extern section *unlikely_text_section (void);
 extern section *current_function_section (void);
+extern void switch_to_other_text_partition (void);
 
 /* Return the numbered .ctors.N (if CONSTRUCTOR_P) or .dtors.N (if
    not) section for PRIORITY.  */
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index d138514..1080030 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2017-09-07  Jakub Jelinek  <jakub@redhat.com>
+
+	PR target/81979
+	* gcc.dg/pr81979.c: New test.
+
 2017-09-07  Eric Botcazou  <ebotcazou@adacore.com>
 
 	PR ada/82126
diff --git a/gcc/testsuite/gcc.dg/pr81979.c b/gcc/testsuite/gcc.dg/pr81979.c
new file mode 100644
index 0000000..4ac9add
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr81979.c
@@ -0,0 +1,32 @@
+/* PR target/81979 */
+/* { dg-do link } */
+/* { dg-options "-O2 -w" } */
+/* { dg-additional-options "-fPIC" { target fpic } } */
+/* { dg-additional-options "-freorder-blocks-and-partition" { target freorder } } */
+
+int d;
+
+__attribute__((noinline, noclone)) void
+foo (int x)
+{
+  int c;
+  while (c < 1)
+    {
+      int o;
+      for (o = 0; o < 4; ++o)
+	c /= (x != 0) ? 2 : x;
+    }
+
+  d = 1;
+  for (;;)
+    ;
+}
+
+int
+main ()
+{
+  asm volatile ("" : : "r" (&d) : "memory");
+  foo (d);
+  asm volatile ("" : : "r" (&d) : "memory");
+  return 0;
+}
diff --git a/gcc/varasm.c b/gcc/varasm.c
index 6177eec..a7dca89 100644
--- a/gcc/varasm.c
+++ b/gcc/varasm.c
@@ -695,6 +695,16 @@ unlikely_text_section_p (section *sect)
   return sect == function_section_1 (current_function_decl, true);
 }
 
+/* Switch to the other function partition (if inside of hot section
+   into cold section, otherwise into the hot section).  */
+
+void
+switch_to_other_text_partition (void)
+{
+  in_cold_section_p = !in_cold_section_p;
+  switch_to_section (current_function_section ());
+}
+
 /* Return the read-only data section associated with function DECL.  */
 
 section *