https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63607
Bug ID: 63607
Summary: run fail with -flto -mfloat-abi=softfp for
armeb-linux-gnueabi-gcc
Product: gcc
Version: 4.7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: lto
Assignee: unassigned at gcc dot gnu.org
Reporter: fei.yang0953 at gmail dot com
testsuite/gcc.dg/torture/stackalign/builtin-apply-4.c:
/* PR tree-optimization/20076 */
/* { dg-do run } */
extern void abort (void);
double
foo (int arg)
{
if (arg != 116)
abort();
return arg + 1;
}
inline double
bar (int arg)
{
foo (arg);
__builtin_return (__builtin_apply ((void (*) ()) foo,
__builtin_apply_args (), 16));
}
int
main (int argc, char **argv)
{
if (bar (116) != 117.0)
abort ();
return 0;
}
Compile option: armeb-linux-gnueabi-gcc builtin-apply-4.c -static
-mfloat-abi=softfp -flto
Disassembly:
0000076c <main>:
76c: e92d4800 push {fp, lr}
770: e28db004 add fp, sp, #4
774: e3a02113 mov r2, #-1073741820 ; 0xc0000004
778: e30a3aaa movw r3, #43690 ; 0xaaaa
77c: e34a3aaa movt r3, #43690 ; 0xaaaa
780: e5823000 str r3, [r2]
784: e3a00074 mov r0, #116 ; 0x74
788: ebffffaa bl 638 <bar.4066>
78c: eeb06b40 vmov.f64 d6, d0
790: ed9f7b0a vldr d7, [pc, #40] ; 7c0 <main+0x54>
794: eeb46b47 vcmp.f64 d6, d7
Analysis: Return value is not passed correctly. As we can see from line 790,
main gets the return value from d0 register, which is wrong as we use
-mfloat-abi=softfp here.
