[Bug middle-end/32398] [4.3 Regression] checking for suffix of object files... configure: error: cannot compute suffix of f object files: cannot compile

["dave at hiauly1 dot hia dot nrc dot ca" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #5 from dave at hiauly1 dot hia dot nrc dot ca  2007-07-02 20:07 -------
Subject: Re:  [4.3 Regression] checking for suffix of object files...
configure: error: cannot compute suffix of f objeRO

> Can you send me, the dump produced by -fdump-rtl-expand with the trunk and also
> revision 125754.  I am 99% sure this was exposed by pointer plus.

The problem doesn't appear to be in expand.  This is the difference
between the assembly code generated with and without -fno-schedule-insns,
respectively:

--- pr32398.s1  Mon Jul  2 15:08:11 2007
+++ pr32398.s   Mon Jul  2 15:06:55 2007
@@ -9,24 +9,24 @@ f:
        .ENTRY
        std %r2,-16(%r30)
        ldo 144(%r30),%r30
+       extrd,s %r26,63,32,%r31
        std %r4,-128(%r30)
-       std %r26,-64(%r29)
-       extrd,s %r26,63,32,%r26
        std %r25,-56(%r29)
+       ldo -56(%r29),%r29
        std %r24,-48(%r29)
        std %r23,-40(%r29)
        std %r22,-32(%r29)
        std %r21,-24(%r29)
        std %r20,-16(%r29)
        std %r19,-8(%r29)
-       ldo -56(%r29),%r29
-       cmpib,>= 0,%r26,L$0002
+       std %r26,-64(%r29)
+       cmpib,>= 0,%r31,L$0002
        std %r29,-136(%r30)
        ldi 0,%r28
 L$0003:
        ldo 1(%r28),%r28
        extrd,s %r28,63,32,%r28
-       cmpb,< %r28,%r26,L$0003
+       cmpb,< %r28,%r31,L$0003
        ldo 8(%r29),%r29
        std %r29,-136(%r30)
 L$0002:

The problem is the "ldo -56(%r29),%r29" insn has been moved forward
before the argument saves to the stack.  r29 is the incoming argument
pointer.

This occurs in the sched1 pass where the following rtl is generated:

(insn 13 8 21 2 pr32398.c:7 (set (mem:DI (plus:DI (reg/f:DI 29 %r29)
                (const_int -56 [0xffffffffffffffc8])) [0 S8 A64])
        (reg:DI 25 %r25)) 124 {*pa.md:4572} (expr_list:REG_DEAD (reg:DI 25
%r25)
        (nil)))

(insn 21 13 7 2 pr32398.c:7 (set (reg/f:DI 78)
        (plus:DI (reg/f:DI 29 %r29)
            (const_int -56 [0xffffffffffffffc8]))) 164 {*pa.md:5412}
(expr_list:REG_DEAD (reg/f:DI 29 %r29)
        (nil)))

(insn 7 21 14 2 pr32398.c:2 (set (reg/v:DI 75 [ n ])
        (sign_extend:DI (reg:SI 26 %r26 [ n+-4 ]))) 143 {extendsidi2}
(expr_list:REG_DEAD (reg:SI 26 %r26 [ n+-4 ])
        (nil)))

(insn 14 7 15 2 pr32398.c:7 (set (mem:DI (plus:DI (reg/f:DI 29 %r29)
                (const_int -48 [0xffffffffffffffd0])) [0 S8 A64])
        (reg:DI 24 %r24)) 124 {*pa.md:4572} (expr_list:REG_DEAD (reg:DI 24
%r24)
        (nil)))

The problem is the REG_DEAD note for r29.  r19 isn't dead after insn 21.

Dave


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32398