[Bug target/19116] -fno-finite-math-only does not override -ffast-math

["Thomas dot Koenig at online dot de" <gcc-bugzilla@gcc.gnu.org>]

------- Additional Comments From Thomas dot Koenig at online dot de  2004-12-27 10:26 -------
(In reply to comment #6)
> Can you try just -funsafe-math-optimizations and see what happens I think you
will get the same 
> results as "-ffast-math -fno-finite-math-only" as I think an instruction in
the .md file checks the wrong 
> flag.

$ gcc -funsafe-math-optimizations nan-check2.c
$ ./a.out
nan compares equal to itself
$ gcc -S -funsafe-math-optimizations nan-check2.c
$ cat nan-check2.s
        .file   "nan-check2.c"
        .section        .rodata
.LC1:
        .string "%f compares equal to itself\n"
        .align 4
.LC2:
        .string "%f compares unequal to itself\n"
        .text
.globl main
        .type   main, @function
main:
        pushl   %ebp
        movl    %esp, %ebp
        subl    $56, %esp
        andl    $-16, %esp
        movl    $0, %eax
        addl    $15, %eax
        addl    $15, %eax
        shrl    $4, %eax
        sall    $4, %eax
        subl    %eax, %esp
        fldz
        fstpl   -16(%ebp)
        fldz
        fstpl   -8(%ebp)
        fldl    -16(%ebp)
        fdivl   -8(%ebp)
        fstpl   -24(%ebp)
        leal    -24(%ebp), %eax
        movl    %eax, 4(%esp)
        leal    -24(%ebp), %eax
        movl    %eax, (%esp)
        call    equality
        testl   %eax, %eax
        je      .L2
        fldl    -24(%ebp)
        fstpl   4(%esp)
        movl    $.LC1, (%esp)
        call    printf
        jmp     .L4
.L2:
        fldl    -24(%ebp)
        fstpl   4(%esp)
        movl    $.LC2, (%esp)
        call    printf
.L4:
        movl    $0, %eax
        leave
        ret
        .size   main, .-main
.globl equality
        .type   equality, @function
equality:
        pushl   %ebp
        movl    %esp, %ebp
        movl    8(%ebp), %eax
        fldl    (%eax)
        movl    12(%ebp), %eax
        fldl    (%eax)
        fcompp
        fnstsw  %ax
        sahf
        sete    %al
        movzbl  %al, %eax
        popl    %ebp
        ret
        .size   equality, .-equality
        .ident  "GCC: (GNU) 4.0.0 20041224 (experimental)"
        .section        .note.GNU-stack,"",@progbits
$                                                                       

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19116