Fix -membedded-data bug found by mips16 port.

	* mips/mips.h (ENCODE_SECTION_INFO): Handle TARGET_EMBEDDED_DATA.
	Add comment.
	* mips/mips.c (mips_select_section): Add comment.

From-SVN: r24158

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c2811fe1ad8bc64a5d5d382f454f05978ae84aa1..bb4d0e453a3045c2afc6e9a7d044f35d332b090a 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+Mon Dec  7 15:27:09 1998  DJ Delorie  <dj@cygnus.com>
+
+       * mips/mips.h (ENCODE_SECTION_INFO): Handle TARGET_EMBEDDED_DATA.
+       Add comment.
+       * mips/mips.c (mips_select_section): Add comment.
+
 Mon Dec  7 17:55:06 1998  Mike Stump  <mrs@wrs.com>
 
        * cccp.c (ignore_escape_flag): Add support for \ as `natural'

diff --git a/gcc/config/mips/mips.c b/gcc/config/mips/mips.c
index f8b30660703e3ea010504255836993c46c5db59b..cf6ec55967272fb75745eebb64c9a610e624eab9 100644 (file)
--- a/gcc/config/mips/mips.c
+++ b/gcc/config/mips/mips.c
@@ -6861,7 +6861,16 @@ mips_select_rtx_section (mode, x)
 }
 
 /* Choose the section to use for DECL.  RELOC is true if its value contains
-   any relocatable expression.  */
+   any relocatable expression.
+
+   Some of the logic used here needs to be replicated in
+   ENCODE_SECTION_INFO in mips.h so that references to these symbols
+   are done correctly.  Specifically, at least all symbols assigned
+   here to rom (.text and/or .rodata) must not be referenced via
+   ENCODE_SECTION_INFO with %gprel, as the rom might be too far away.
+
+   If you need to make a change here, you probably should check
+   ENCODE_SECTION_INFO to see if it needs a similar change.  */
 
 void
 mips_select_section (decl, reloc)

diff --git a/gcc/config/mips/mips.h b/gcc/config/mips/mips.h
index 13f1b7bd227db9a22cf8d8758f9527eee95b4134..edf6399f3bd4a9ea747b7071fde25b434a038a8b 100644 (file)
--- a/gcc/config/mips/mips.h
+++ b/gcc/config/mips/mips.h
@@ -3080,7 +3080,19 @@ typedef struct mips_args {
    gp addresable section, SYMBOL_REF_FLAG is set prevent gcc from
    splitting the reference so that gas can generate a gp relative
    reference.
- */
+
+   When TARGET_EMBEDDED_DATA is set, we assume that all const
+   variables will be stored in ROM, which is too far from %gp to use
+   %gprel addressing.  Note that (1) we include "extern const"
+   variables in this, which mips_select_section doesn't, and (2) we
+   can't always tell if they're really const (they might be const C++
+   objects with non-const constructors), so we err on the side of
+   caution and won't use %gprel anyway (otherwise we'd have to defer
+   this decision to the linker/loader).  The handling of extern consts
+   is why the DECL_INITIAL macros differ from mips_select_section.
+
+   If you are changing this macro, you should look at
+   mips_select_section and see if it needs a similar change.  */
 
 #define ENCODE_SECTION_INFO(DECL)                                      \
 do                                                                     \
@@ -3094,7 +3106,17 @@ do                                                                       \
            mips_string_length += TREE_STRING_LENGTH (DECL);            \
          }                                                             \
       }                                                                        \
-    if (TARGET_EMBEDDED_PIC)                                           \
+                                                                       \
+    if (TARGET_EMBEDDED_DATA                                           \
+       && (TREE_CODE (DECL) == VAR_DECL                                \
+           && TREE_READONLY (DECL) && !TREE_SIDE_EFFECTS (DECL))       \
+           && (!DECL_INITIAL (DECL)                                    \
+               || TREE_CONSTANT (DECL_INITIAL (DECL))))                \
+      {                                                                        \
+       SYMBOL_REF_FLAG (XEXP (DECL_RTL (DECL), 0)) = 0;                \
+      }                                                                        \
+                                                                       \
+    else if (TARGET_EMBEDDED_PIC)                                      \
       {                                                                        \
         if (TREE_CODE (DECL) == VAR_DECL)                              \
          SYMBOL_REF_FLAG (XEXP (DECL_RTL (DECL), 0)) = 1;              \