kvx: add support for kvx arch to uClibc-ng

This commit adds support for Kalray VLIW family (kvx)

Kalray kv3 core is embedded in Kalray Coolidge SoC. This core which is the
third of the KV family has the following features:

    32/64 bits execution mode
    6-issue VLIW architecture
    64 x 64bits general purpose registers
    SIMD instructions
    little-endian

In order to build a usable toolchain, build scripts are provided at the
following address: https://github.com/kalray/build-scripts.

Kalray uses FOSS which is available at https://github.com/kalray
This includes Linux kernel, uClibc-ng, gcc, binutils, etc.

Signed-off-by: Clément Léger <cleger@kalray.eu>
Signed-off-by: Guillaume Thouvenin <gthouvenin@kalray.eu>
Signed-off-by: Laurent Thevenoux <lthevenoux@kalray.eu>
Signed-off-by: Marc Poulhies <mpoulhies@kalray.eu>
Signed-off-by: Marius Gligor <mgligor@kalray.eu>
Signed-off-by: Yann Sionneau <ysionneau@kalray.eu>

1 files changed, 26 insertions, 0 deletions

diff --git a/libm/kvx/feholdexcept.c b/libm/kvx/feholdexcept.c
new file mode 100644
index 000000000..e9dfc1862
--- /dev/null
+++ b/libm/kvx/feholdexcept.c
@@ -0,0 +1,26 @@
+/*
+  (C) Copyright 2019 Kalray S.A.
+  This file provides feholdexcept for the Coolidge processor.
+*/
+
+#include <fenv.h>
+
+int feholdexcept(fenv_t *envp)
+{
+  /* Get the current environment ($cs) */
+  fenv_t fe;
+  fe = __builtin_kvx_get(KVX_SFR_CS);
+
+  /* Mask $cs status to keep exception flags and rounding mode only. */
+  *envp = (fe & (FE_ALL_EXCEPT | FE_RND_MASK));
+
+  /* Set $cs with 'FE_ALL_EXCEPT' as a clear mask. */
+  __builtin_kvx_wfxl(KVX_SFR_CS, FE_ALL_EXCEPT);
+  
+  /* KVX does not raise FP traps so it is always in a "non-stop" mode */
+
+  /* The above insn cannot fail (while the OS allows access to the
+     floating-point exception flags of the $cs register). Return
+     success. */
+  return 0;
+}