[FFmpeg-cvslog] riscv: set fast half-precision conversion

[Rémi Denis-Courmont]

ffmpeg | branch: master | Rémi Denis-Courmont <remi at remlab.net> | Thu Nov 16 20:36:05 2023 +0200| [954d50e2ae1b2619af9bb5c0adb272eae6058499] | committer: Rémi Denis-Courmont

riscv: set fast half-precision conversion

This is only supported at compilation time. If Zfhmin is supported, then
conversions are fast, which is what the flag is used for. At this time,
run-tiem detection is not possible, as in not supported by Linux. But even
if it were, the current FFmpeg approach seems unable to deal with it (same
problem as on x86, really).

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=954d50e2ae1b2619af9bb5c0adb272eae6058499
---

 configure | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/configure b/configure
index d6e4a1e7df..6be849fc08 100755
--- a/configure
+++ b/configure
@@ -5413,6 +5413,9 @@ elif enabled riscv; then
     if test_cpp_condition stddef.h "__riscv_zbb"; then
         enable fast_clz
     fi
+    if test_cpp_condition stddef.h "__riscv_zfhmin"; then
+        enable fast_float16
+    fi
 
 elif enabled sparc; then