[Bug target/79366] New: wrong result in cast to unsigned int

[bernd.edlinger at hotmail dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79366

            Bug ID: 79366
           Summary: wrong result in cast to unsigned int
           Product: gcc
           Version: 7.0.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: bernd.edlinger at hotmail dot de
  Target Milestone: ---

the following returns an unexpected result:

cat test.c
double f = -1.0;
int main()
{
  int g = (unsigned int)(f);
  __builtin_printf("%d\n", g);
}

gcc test.c
./a.out
0

that is only on arm-Linux-gnueabihf
other targets return -1 here.

Dump of assembler code for function main:
   0x000103c0 <+0>:     push    {r11, lr}
   0x000103c4 <+4>:     add     r11, sp, #4
   0x000103c8 <+8>:     sub     sp, sp, #8
=> 0x000103cc <+12>:    movw    r3, #1440       ; 0x5a0
   0x000103d0 <+16>:    movt    r3, #2
   0x000103d4 <+20>:    vldr    d7, [r3]
   0x000103d8 <+24>:    vcvt.u32.f64    s15, d7
   0x000103dc <+28>:    vmov    r3, s15
   0x000103e0 <+32>:    str     r3, [r11, #-8]
   0x000103e4 <+36>:    ldr     r1, [r11, #-8]
   0x000103e8 <+40>:    movw    r0, #1140       ; 0x474
   0x000103ec <+44>:    movt    r0, #1
   0x000103f0 <+48>:    bl      0x102a0 <printf@plt>
   0x000103f4 <+52>:    mov     r3, #0
   0x000103f8 <+56>:    mov     r0, r3
   0x000103fc <+60>:    sub     sp, r11, #4
   0x00010400 <+64>:    pop     {r11, pc}