src/compiler-rt/lib/builtins/i386/floatdixf.S

   1 // This file is dual licensed under the MIT and the University of Illinois Open
   2 // Source Licenses. See LICENSE.TXT for details.
   3
   4 #include "../assembly.h"
   5
   6 // float __floatdixf(di_int a);
   7
   8 #ifdef __i386__
   9
  10 // This routine has some extra memory traffic, loading the 64-bit input via two
  11 // 32-bit loads, then immediately storing it back to the stack via a single 64-bit
  12 // store.  This is to avoid a write-small, read-large stall.
  13 // However, if callers of this routine can be safely assumed to store the argument
  14 // via a 64-bt store, this is unnecessary memory traffic, and should be avoided.
  15 // It can be turned off by defining the TRUST_CALLERS_USE_64_BIT_STORES macro.
  16
  17 .text
  18 .balign 4
  19 DEFINE_COMPILERRT_FUNCTION(__floatdixf)
  20 #ifndef TRUST_CALLERS_USE_64_BIT_STORES
  21         movd            4(%esp),        %xmm0
  22         movd            8(%esp),        %xmm1
  23         punpckldq       %xmm1,          %xmm0
  24         movq            %xmm0,          4(%esp)
  25 #endif
  26         fildll          4(%esp)
  27         ret
  28 END_COMPILERRT_FUNCTION(__floatdixf)
  29
  30 #endif // __i386__