[Bug dynamic-link/18402] FPU use in application before main()

["dave at sr71 dot net" <sourceware-bugzilla at sourceware dot org>]

https://sourceware.org/bugzilla/show_bug.cgi?id=18402

--- Comment #4 from Dave Hansen <dave at sr71 dot net> ---
For a statically-linked app, things are a bit different.  I set a breakpoint
*at* strlen and then waited to see the FPU get used.  When strlen() was called,
the FPU was not in use, but I single-stepped and saw it get used on the next
instruction.  So perhaps there are two separate issues here?

(gdb) r
Starting program: /root/hellodave 

Breakpoint 2, 0x00000000004191f0 in strlen ()
# Note, no FPU use here
(gdb) stepi
0x00000000004191f5 in strlen ()
# FPU has been used
(gdb) bt
#0  0x00000000004191f5 in strlen ()
#1  0x00000000004073a6 in getenv ()
#2  0x000000000043793e in _dl_non_dynamic_init ()
#3  0x00000000004386f8 in __libc_init_first ()
#4  0x0000000000401222 in __libc_start_main ()
#5  0x0000000000400f77 in _start ()

(gdb) disassemble strlen
Dump of assembler code for function strlen:
=> 0x00000000004191f0 <+0>:     pxor   %xmm8,%xmm8
   0x00000000004191f5 <+5>:     pxor   %xmm9,%xmm9
   0x00000000004191fa <+10>:    pxor   %xmm10,%xmm10
   0x00000000004191ff <+15>:    pxor   %xmm11,%xmm11
   0x0000000000419204 <+20>:    mov    %rdi,%rax

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