[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=gccview=revrev=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


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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.


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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

[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.


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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=gccview=revrev=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


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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=0x83fffdff4a70,
dst=0x83fffdfb7540, orig_src=0x83fffdfacf30,
type=0x83fffdf9b750, ssize=16) at ../../gcc/gcc/expr.c:1779
1779  else if (CONSTANT_P (src))
(gdb) p debug_rtx (src)
(const_double 4919131751843889152 [0x] 1229782938533634594
[0x] 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.


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