Re: target/9929: [3.3/3.4 regression] Can't find spill register

[bangerth@dealii.org]

Old Synopsis: ICE when compiling innocent function
New Synopsis: [3.3/3.4 regression] Can't find spill register

State-Changed-From-To: open->analyzed
State-Changed-By: bangerth
State-Changed-When: Tue Mar  4 15:22:51 2003
State-Changed-Why:
    Confirmed. Here's a reduced example:
    ---------------------------
    typedef struct X {
        char * ptr;
        int    offset;
    } X_t;
    
    X_t foo(X_t *d1, char * A0);
    
    void bar() {
      X_t l1, l2, l3;
      l3 = foo(&l1, l2.ptr);
      (*(X_t *)(l2.ptr + l3.offset)) = l1;
    }
    -----------------------------
    
    It compiles cleanly with 3.2.2, but fails with 3.3 and
    present mainline when using -O2 -fPIC:
    g/x> /home/bangerth/bin/gcc-3.3-pre/bin/gcc -c -O2 -fPIC x.c
    x.c: In function `bar':
    x.c:12: error: unable to find a register to spill in class `GENERAL_REGS'
    x.c:12: error: this is the insn:
    (insn:HI 18 28 20 0 0x4014f2ec (set (mem/s:DI (plus:SI (subreg:SI (reg/v:DI 60) 0)
                    (subreg:SI (reg/v:DI 61) 4)) [2 S8 A32])
            (reg:DI 63)) 59 {*movdi_2} (insn_list 15 (insn_list 17 (nil)))
        (expr_list:REG_DEAD (reg:DI 63)
            (expr_list:REG_DEAD (reg/v:DI 60)
                (expr_list:REG_DEAD (reg/v:DI 61)
                    (nil)))))
    x.c:12: confused by earlier errors, bailing out
    g/x>
    g/x>
    g/x> /home/bangerth/bin/gcc-3.4-pre/bin/gcc -c -O2 -fPIC x.c
    x.c: In function `bar':
    x.c:12: error: unable to find a register to spill in class `GENERAL_REGS'
    x.c:12: error: this is the insn:
    (insn:HI 18 28 20 0 0x401532c0 (set (mem/s:DI (plus:SI (subreg:SI (reg/v:DI 60 [ l2 ]) 0)
                    (subreg:SI (reg/v:DI 61 [ l3 ]) 4)) [2 S8 A32])
            (reg:DI 63 [ l1 ])) 60 {*movdi_2} (insn_list 15 (insn_list 17 (nil)))
        (expr_list:REG_DEAD (reg:DI 63 [ l1 ])
            (expr_list:REG_DEAD (reg/v:DI 60 [ l2 ])
                (expr_list:REG_DEAD (reg/v:DI 61 [ l3 ])
                    (nil)))))
    x.c:12: internal compiler error: in spill_failure, at reload1.c:1919
    Please submit a full bug report,
    with preprocessed source if appropriate.
    See <URL:http://www.gnu.org/software/gcc/bugs.html> for instructions.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=9929