re PR target/43961 ([ARM thumb] "branch out of range" with thumb1_output_casesi)

2013-01-15  Joseph Myers  <joseph@codesourcery.com>
	    Mikael Pettersson  <mikpe@it.uu.se>

	PR target/43961
	* config/arm/arm.h (ADDR_VEC_ALIGN): Align SImode jump tables for
	Thumb.
	(ASM_OUTPUT_CASE_LABEL): Remove.
	(ASM_OUTPUT_BEFORE_CASE_LABEL): Define to empty.
	* final.c (shorten_branches): Update alignment of labels before
	jump tables if CASE_VECTOR_SHORTEN_MODE.

Co-Authored-By: Mikael Pettersson <mikpe@it.uu.se>
From-SVN: r195208

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 1a44b17..f900422 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,14 @@
+2013-01-15  Joseph Myers  <joseph@codesourcery.com>
+           Mikael Pettersson  <mikpe@it.uu.se>
+
+       PR target/43961
+       * config/arm/arm.h (ADDR_VEC_ALIGN): Align SImode jump tables for
+       Thumb.
+       (ASM_OUTPUT_CASE_LABEL): Remove.
+       (ASM_OUTPUT_BEFORE_CASE_LABEL): Define to empty.
+       * final.c (shorten_branches): Update alignment of labels before
+       jump tables if CASE_VECTOR_SHORTEN_MODE.
+
 2013-01-15  Richard Biener  <rguenther@suse.de>
 
        PR bootstrap/55961

diff --git a/gcc/config/arm/arm.h b/gcc/config/arm/arm.h
index 4558621..6d336e8 100644 (file)
--- a/gcc/config/arm/arm.h
+++ b/gcc/config/arm/arm.h
@@ -2129,20 +2129,13 @@ extern int making_const_table;
        asm_fprintf (STREAM, "\tpop {%r}\n", REGNO);    \
     } while (0)
 
-/* Jump table alignment is explicit in ASM_OUTPUT_CASE_LABEL.  */
-#define ADDR_VEC_ALIGN(JUMPTABLE) 0
-
-/* This is how to output a label which precedes a jumptable.  Since
-   Thumb instructions are 2 bytes, we may need explicit alignment here.  */
-#undef  ASM_OUTPUT_CASE_LABEL
-#define ASM_OUTPUT_CASE_LABEL(FILE, PREFIX, NUM, JUMPTABLE)            \
-  do                                                                   \
-    {                                                                  \
-      if (TARGET_THUMB && GET_MODE (PATTERN (JUMPTABLE)) == SImode)    \
-        ASM_OUTPUT_ALIGN (FILE, 2);                                    \
-      (*targetm.asm_out.internal_label) (FILE, PREFIX, NUM);           \
-    }                                                                  \
-  while (0)
+#define ADDR_VEC_ALIGN(JUMPTABLE)      \
+  ((TARGET_THUMB && GET_MODE (PATTERN (JUMPTABLE)) == SImode) ? 2 : 0)
+
+/* Alignment for case labels comes from ADDR_VEC_ALIGN; avoid the
+   default alignment from elfos.h.  */
+#undef ASM_OUTPUT_BEFORE_CASE_LABEL
+#define ASM_OUTPUT_BEFORE_CASE_LABEL(FILE, PREFIX, NUM, TABLE) /* Empty.  */
 
 /* Make sure subsequent insns are aligned after a TBB.  */
 #define ASM_OUTPUT_CASE_END(FILE, NUM, JUMPTABLE)      \

diff --git a/gcc/final.c b/gcc/final.c
index 3da07ed..d5154db 100644 (file)
--- a/gcc/final.c
+++ b/gcc/final.c
@@ -1182,6 +1182,29 @@ shorten_branches (rtx first)
          if (LABEL_P (insn))
            {
              int log = LABEL_TO_ALIGNMENT (insn);
+
+#ifdef CASE_VECTOR_SHORTEN_MODE
+             /* If the mode of a following jump table was changed, we
+                may need to update the alignment of this label.  */
+             rtx next;
+             bool next_is_jumptable;
+
+             next = next_nonnote_insn (insn);
+             next_is_jumptable = next && JUMP_TABLE_DATA_P (next);
+             if ((JUMP_TABLES_IN_TEXT_SECTION
+                  || readonly_data_section == text_section)
+                 && next_is_jumptable)
+               {
+                 int newlog = ADDR_VEC_ALIGN (next);
+                 if (newlog != log)
+                   {
+                     log = newlog;
+                     LABEL_TO_ALIGNMENT (insn) = log;
+                     something_changed = 1;
+                   }
+               }
+#endif
+
              if (log > insn_current_align)
                {
                  int align = 1 << log;