foo.cc: In function 'int main()':
foo.cc:54:9: warning: unused variable 'l' [-Wunused-variable]
   54 |     int l=1;
      |         ^
foo.cc:102:17: warning: 'r4' may be used uninitialized in this function [-Wmaybe-uninitialized]
  102 |     r4=gethalf_1(r4);
      |        ~~~~~~~~~^~~~
foo.cc:90:17: warning: 'r3' may be used uninitialized in this function [-Wmaybe-uninitialized]
   90 |     r3=gethalf_1(r3);
      |        ~~~~~~~~~^~~~
foo.cc:77:17: warning: 'r2' may be used uninitialized in this function [-Wmaybe-uninitialized]
   77 |     r2=gethalf_1(r2);
      |        ~~~~~~~~~^~~~
foo.cc:66:17: warning: 'r1' may be used uninitialized in this function [-Wmaybe-uninitialized]
   66 |     r1=gethalf_1(r1);
      |        ~~~~~~~~~^~~~

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