[PATCH, PR 49923] Check for misaligned accesses before doing SRA

[Martin Jambor]

Hi,

the patch below fixes PR 49923 by checking for misaligned accesses
before doing IPA-SRA (on strict alignment targets).  I have checked it
fixes the issue on compile farm sparc64 and I also included this in a
bootstrap and testsuite run on an x86_64-linux just to double check.

OK for trunk and the 4.6 branch?

Thanks,

Martin


2011-08-04  Martin Jambor  <mjam...@suse.cz>

        PR middle-end/49923
        * tree-sra.c (access_precludes_ipa_sra_p): Also check access
        memory alignment.

        * testsuite/gcc.dg/tree-ssa/pr49923.c: New test.


Index: src/gcc/tree-sra.c
===================================================================
--- src.orig/gcc/tree-sra.c
+++ src/gcc/tree-sra.c
@@ -3688,6 +3688,9 @@ access_precludes_ipa_sra_p (struct acces
          || gimple_code (access->stmt) == GIMPLE_ASM))
     return true;
 
+  if (tree_non_mode_aligned_mem_p (access->expr))
+    return true;
+
   return false;
 }
 
Index: src/gcc/testsuite/gcc.dg/tree-ssa/pr49923.c
===================================================================
--- /dev/null
+++ src/gcc/testsuite/gcc.dg/tree-ssa/pr49923.c
@@ -0,0 +1,55 @@
+/* { dg-do run } */
+/* { dg-options "-O3" } */
+
+#define PACKED __attribute__(( packed ))
+
+struct PACKED aostk_point_u8 {
+  unsigned char x;
+  unsigned char y;
+};
+
+struct PACKED aostk_size_u8 {
+  unsigned char width;
+  unsigned char height;
+};
+
+struct PACKED aostk_glyph {
+       unsigned short i;
+       struct aostk_size_u8 size;
+       char top;
+       struct aostk_point_u8 advance;
+       unsigned char pitch;
+       unsigned char* data;
+       char left;
+};
+
+
+struct PACKED aostk_font {
+       unsigned short numglyphs;
+       unsigned char height;
+       struct aostk_glyph* glyphs;
+};
+
+struct aostk_font glob_font;
+
+static struct aostk_glyph* aostk_get_glyph(struct aostk_font* f, unsigned int 
c) {
+       return f->glyphs;
+}
+
+int aostk_font_strwidth(struct aostk_font* font, const char* str) {
+       struct aostk_glyph* g = aostk_get_glyph(font, 0);
+       return (g != 0);
+}
+
+struct aostk_font*
+__attribute__ ((noinline, noclone))
+get_some_font (void)
+{
+  return &glob_font;
+}
+
+int main (int argc, char *argv[])
+{
+  return (int) aostk_font_strwidth (get_some_font (), "sth");
+  
+}