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:
#ifndef SOFT_FP
// Support for systems that have hardware floating-point; can set the invalid
// flag as a side-effect of computation.
…
#else
// Support for systems that don’t have hardware floating-point; there are no
// flags to set, and we don’t want to code-gen to an unknown soft-float
// implementation.
…
#endif
My question is : when - if ever - should SOFT_FP be defined?
The obvious answer is “when compiling for a soft-float target”.
However: SOFT_FP is never set by the compiler (neither clang nor GCC).
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.
On the other hand both clang and GCC do set an alarmingly similar looking macro - “SOFTFP” (no middle underscore) - when compiling for soft-float.
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 not define SOFT_FP for soft-float targets (and our tests pass!).
Regards,
Salim
Salim Nasser | Compilers | Wind River
+Renato Golin
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:
#ifndef SOFT_FP
// Support for systems that have hardware floating-point; can set the invalid
// flag as a side-effect of computation.
…
#else
// Support for systems that don’t have hardware floating-point; there are no
// flags to set, and we don’t want to code-gen to an unknown soft-float
// implementation.
…
#endif
My question is : when - if ever - should SOFT_FP be defined?
The obvious answer is “when compiling for a soft-float target”.
However: SOFT_FP is never set by the compiler (neither clang nor GCC).
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.
On the other hand both clang and GCC do set an alarmingly similar looking macro - “SOFTFP” (no middle underscore) - when compiling for soft-float.
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 not define SOFT_FP for soft-float targets (and our tests pass!).
I believe that this is an accidental misspelling and went unnoticed. This should be __SOFTFP__ instead.
I believe that this is an accidental misspelling and went unnoticed. This should be __SOFTFP__ instead.
Thanks Saleem. I’ve filed the following PR:
https://bugs.llvm.org/show_bug.cgi?id=46294
Regards,
Salim.