[Bug middle-end/33436] New: Bad constant output with TARGET_ASM_ALIGNED_DI_OP

[Bug middle-end/33436] New: Bad constant output with TARGET_ASM_ALIGNED_DI_OP

[danglin at gcc dot gnu dot org]

Executing on host: /mnt/gnu/gcc/objdir/gcc/xgcc -B/mnt/gnu/gcc/objdir/gcc/
/mnt/
gnu/gcc/gcc/gcc/testsuite/gcc.dg/pr32912-2.c   -O2 -w -fno-show-column  -lm  
-o
 ./pr32912-2.exe    (timeout = 300)
/var/tmp//cclFD5RH.s: Assembler messages:
/var/tmp//cclFD5RH.s:5: Warning: bignum truncated to 8 bytes
output is:
/var/tmp//cclFD5RH.s: Assembler messages:
/var/tmp//cclFD5RH.s:5: Warning: bignum truncated to 8 bytes

FAIL: gcc.dg/pr32912-2.c (test for excess errors)
Excess errors:
/var/tmp//cclFD5RH.s:5: Warning: bignum truncated to 8 bytes

Setting LD_LIBRARY_PATH to :/mnt/gnu/gcc/objdir/gcc::/mnt/gnu/gcc/objdir/gcc
FAIL: gcc.dg/pr32912-2.c execution test

        .LEVEL 2.0w
        .section        .rodata
        .align 8
L$C0000:
        .dword  0x11111111222222224444444400000000
...

Mainline is ok.


-- 
           Summary: Bad constant output with TARGET_ASM_ALIGNED_DI_OP
           Product: gcc
           Version: 4.2.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: danglin at gcc dot gnu dot org
 GCC build triplet: hppa64-hp-hpux11.11
  GCC host triplet: hppa64-hp-hpux11.11
GCC target triplet: hppa64-hp-hpux11.11


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33436

[Bug middle-end/33436] Bad constant output with TARGET_ASM_ALIGNED_DI_OP

[danglin at gcc dot gnu dot org]

------- Comment #1 from danglin at gcc dot gnu dot org  2007-09-22 01:18 -------
Although it might be possible to fix this at an earlier point,
things go seriously wrong in emit_group_load_1.  We have:

Breakpoint 7, emit_group_load_1 (tmps=0x800003fffdff4a70,
    dst=0x800003fffdfb7540, orig_src=0x800003fffdfacf30,
    type=0x800003fffdf9b750, ssize=16) at ../../gcc/gcc/expr.c:1779
1779          else if (CONSTANT_P (src))
(gdb) p debug_rtx (src)
(const_double 4919131751843889152 [0x4444444400000000] 1229782938533634594
[0x1111111122222222] 0 [0x0] 0 [0x0])
$7 = void
(gdb) p debug_rtx (dst)
(parallel:BLK [
        (expr_list:REG_DEP_TRUE (reg:DI 66 [ <result> ])
            (const_int 0 [0x0]))
        (expr_list:REG_DEP_TRUE (reg:DI 67 [ <result>+8 ])
            (const_int 8 [0x8]))
    ])

As can be seen, dst is a parallel but src is a CONST_DOUBLE.  The code
as currently written assigns src to both parts of the parallel.

I believe this occurs because hppa64 doesn't support TImode.

The break above is in a modified version of expr.c which appears to
correct the problem.  Here's the diff:

Index: expr.c
===================================================================
--- expr.c      (revision 128642)
+++ expr.c      (working copy)
@@ -1776,8 +1776,23 @@
       else if (CONSTANT_P (src) && GET_MODE (dst) != BLKmode
                && XVECLEN (dst, 0) > 1)
         tmps[i] = simplify_gen_subreg (mode, src, GET_MODE(dst), bytepos);
-      else if (CONSTANT_P (src)
-              || (REG_P (src) && GET_MODE (src) == mode))
+      else if (CONSTANT_P (src))
+       {
+         if ((HOST_WIDE_INT) bytelen == ssize)
+           tmps[i] = src;
+         else
+           {
+             rtx first, second;
+
+             gcc_assert (i <= 1);
+             split_double (src, &first, &second);
+             if (i)
+               tmps[i] = second;
+             else
+               tmps[i] = first;
+           }
+       }
+      else if (REG_P (src) && GET_MODE (src) == mode)
        tmps[i] = src;
       else
        tmps[i] = extract_bit_field (src, bytelen * BITS_PER_UNIT,

I used split_double because neither simplify_subreg or extract_bit_field
handle this.

I'm a little unhappy about splitting the double but in some cases it is
possible to load the values without forcing them to memory.  In any event,
this is a rare situation.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33436

[Bug middle-end/33436] Bad constant output with TARGET_ASM_ALIGNED_DI_OP

[danglin at gcc dot gnu dot org]

------- Comment #2 from danglin at gcc dot gnu dot org  2007-09-28 00:54 -------
Subject: Bug 33436

Author: danglin
Date: Fri Sep 28 00:54:29 2007
New Revision: 128855

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=128855
Log:
        PR middle-end/33436
        * expr.c (emit_group_load_1): Split constant double when destination
        length is half source length.


Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/expr.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33436

[Bug middle-end/33436] Bad constant output with TARGET_ASM_ALIGNED_DI_OP

[danglin at gcc dot gnu dot org]

------- Comment #3 from danglin at gcc dot gnu dot org  2007-09-28 00:57 -------
Fixed on trunk.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33436

[Bug middle-end/33436] Bad constant output with TARGET_ASM_ALIGNED_DI_OP

[danglin at gcc dot gnu dot org]

------- Comment #4 from danglin at gcc dot gnu dot org  2008-01-22 19:40 -------
Subject: Bug 33436

Author: danglin
Date: Tue Jan 22 19:39:39 2008
New Revision: 131739

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=131739
Log:
        PR middle-end/33436
        * expr.c (emit_group_load_1): Split constant double when destination
        length is half source length.


Modified:
    branches/gcc-4_2-branch/gcc/ChangeLog
    branches/gcc-4_2-branch/gcc/expr.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33436

[Bug middle-end/33436] Bad constant output with TARGET_ASM_ALIGNED_DI_OP

[danglin at gcc dot gnu dot org]

------- Comment #5 from danglin at gcc dot gnu dot org  2008-01-22 19:50 -------
Fixed on 4.2.


-- 

danglin at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33436