[Bug target/43741] sh-elf ICEs for libstdc++-v3/src/ios_init.cc with -m2a

["kkojima at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #1 from kkojima at gcc dot gnu dot org  2010-04-13 01:16 -------
Created an attachment (id=20374)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=20374&action=view)
a reduced test case

xxx.ii: In constructor 'std::ios_base::Init::Init()':
xxx.ii:161:3: error: insn does not satisfy its constraints:
(insn 284 282 285 6 xxx.ii:113 (set (reg:SI 1 r1)
        (reg/f:SI 319)) 176 {movsi_ie} (nil))
xxx.ii:161:3: internal compiler error: in reload_cse_simplify_operands, at
postreload.c:396

which shows that the pseudo register remains after reload.
The .ira rtl dump looks that sh_legitimize_reload_address makes
a too complex reload for this case.  I've confirmed the patch
below fix the above failure.  I'll apply it if it survives
the usual tests and doesn't make the code quality worse with
CSiBE tests.

--- ORIG/trunk/gcc/config/sh/sh.c       2010-04-12 09:52:36.000000000 +0900
+++ trunk/gcc/config/sh/sh.c    2010-04-13 08:55:31.000000000 +0900
@@ -9649,8 +9649,7 @@ sh_legitimize_reload_address (rtx *p, en
          || XEXP (*p, 0) == hard_frame_pointer_rtx))
     {
       rtx index_rtx = XEXP (*p, 1);
-      HOST_WIDE_INT offset = INTVAL (index_rtx), offset_base;
-      rtx sum;
+      HOST_WIDE_INT offset = INTVAL (index_rtx);

       if (TARGET_SH2A && mode == DFmode && (offset & 0x7))
        {
@@ -9665,24 +9664,6 @@ sh_legitimize_reload_address (rtx *p, en
                       BASE_REG_CLASS, Pmode, VOIDmode, 0, 0, opnum, type);
          goto win;
        }
-      /* Instead of offset_base 128..131 use 124..127, so that
-        simple add suffices.  */
-      if (offset > 127)
-       offset_base = ((offset + 4) & ~60) - 4;
-      else
-       offset_base = offset & ~60;
-      /* Sometimes the normal form does not suit DImode.  We could avoid
-        that by using smaller ranges, but that would give less optimized
-        code when SImode is prevalent.  */
-      if (offset_base != 0
-         && GET_MODE_SIZE (mode) + offset - offset_base <= 64)
-       {
-         sum = gen_rtx_PLUS (Pmode, XEXP (*p, 0), GEN_INT (offset_base));
-         *p = gen_rtx_PLUS (Pmode, sum, GEN_INT (offset - offset_base));
-         push_reload (sum, NULL_RTX, &XEXP (*p, 0), NULL,
-                      BASE_REG_CLASS, Pmode, VOIDmode, 0, 0, opnum, type);
-         goto win;
-       }
     }
   /* We must re-recognize what we created before.  */
   else if (GET_CODE (*p) == PLUS


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43741