util: add softfloat functions to operate with doubles and floats

Implemented fadd, fsub, fmul and ffma for doubles and ffma for floats,
rounding to zero, using a modified implementation from Berkely
Softfloat 3e Library.

Their implementation correctness has been checked with the Berkeley
TestFloat Release 3e tool for x86_64.

v2:
- Reuse util_last_bit64() in _mesa_count_leading_zeros64()
  implementation (Connor).

v3:
- Add a specific ffma for floats version (Connor).
- Implement the ffma for doubles version (Andres).
- Lots of fixes in fadd, fsub and fmul (Andres).
- Improved documentation (Andres).

v4:
- Added f64 -> f32 conversion function (Andres).
- Added f32 -> f16 RTZ conversion function (Andres).

Signed-off-by: Samuel Iglesias Gonsálvez <[email protected]>
Signed-off-by: Andres Gomez <[email protected]>
Tested-by: Andres Gomez <[email protected]>
Acked-by: Caio Marcelo de Oliveira Filho <[email protected]>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/util/Makefile.sources b/src/util/Makefile.sources
index fdb9b6dd135..e4d9d73ce8a 100644
--- a/src/util/Makefile.sources
+++ b/src/util/Makefile.sources
@@ -56,6 +56,8 @@ MESA_UTIL_FILES := \
 	simple_mtx.h \
 	slab.c \
 	slab.h \
+	softfloat.c \
+	softfloat.h \
 	string_buffer.c \
 	string_buffer.h \
 	strndup.h \