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<p class="MsoNormal">A handful of files in compiler-rt/builtins use the macro “__SOFT_FP__”. All the uses are along the same lines. Here’s a representative example from compiler-rt/lib/builtins/fixdfdi.c:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="Code">#ifndef __SOFT_FP__<o:p></o:p></p>
<p class="Code">// Support for systems that have hardware floating-point; can set the invalid<o:p></o:p></p>
<p class="Code">// flag as a side-effect of computation.<o:p></o:p></p>
<p class="Code">…<o:p></o:p></p>
<p class="Code">#else<o:p></o:p></p>
<p class="Code">// Support for systems that don't have hardware floating-point; there are no<o:p></o:p></p>
<p class="Code">// flags to set, and we don't want to code-gen to an unknown soft-float<o:p></o:p></p>
<p class="Code">// implementation.<o:p></o:p></p>
<p class="Code">…<o:p></o:p></p>
<p class="Code">#endif<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">My question is : when - if ever - should __SOFT_FP__ be defined?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">The obvious answer is “when compiling for a soft-float target”.
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">However: __SOFT_FP__ is never set by the compiler (neither clang nor GCC).
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Nor (as far as I can tell) does it appear in any compiler-rt header file, build script, or Makefile. In fact the only occurrences of this macro anywhere in the llvm-project and GCC source trees are the aforementioned uses under compiler-rt/builtins.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">On the other hand both clang and GCC *do* set an alarmingly similar looking macro - “__SOFTFP__” (no middle underscore) - when compiling for soft-float.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Since we need to build compiler-rt libraries for a couple of our soft-float targets at Wind River, we want to make sure we’re building them in the “right” way. Currently we do *<b>not</b>* define __SOFT_FP__ for soft-float targets (and
our tests pass!).<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Regards,<br>
Salim<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Salim Nasser | Compilers | Wind River<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
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