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authorVincent Chen <vincentc@andestech.com>2018-11-22 11:14:35 +0800
committerGreentime Hu <greentime@andestech.com>2018-11-22 18:13:21 +0800
commit1ac832509f2ea1b566f0c06f98f308f58b03d098 (patch)
tree080dcfd5832558823072d3fd4de51df32d96ef51 /arch/nds32/math-emu/fcmps.c
parentnds32: nds32 FPU port (diff)
downloadlinux-dev-1ac832509f2ea1b566f0c06f98f308f58b03d098.tar.xz
linux-dev-1ac832509f2ea1b566f0c06f98f308f58b03d098.zip
nds32: Support FP emulation
The Andes FPU coprocessor does not support denormalized number handling. According to the specification, FPU generates a denorm input exception that requires the kernel to deal with this instrution operation when it encounters denormalized operands. Hence an nds32 FPU ISA emulator in the kernel is required to meet requirement. Signed-off-by: Vincent Chen <vincentc@andestech.com> Signed-off-by: Nickhu <nickhu@andestech.com> Acked-by: Greentime Hu <greentime@andestech.com> Signed-off-by: Greentime Hu <greentime@andestech.com>
Diffstat (limited to 'arch/nds32/math-emu/fcmps.c')
-rw-r--r--arch/nds32/math-emu/fcmps.c24
1 files changed, 24 insertions, 0 deletions
diff --git a/arch/nds32/math-emu/fcmps.c b/arch/nds32/math-emu/fcmps.c
new file mode 100644
index 000000000000..681480758213
--- /dev/null
+++ b/arch/nds32/math-emu/fcmps.c
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2018 Andes Technology Corporation
+#include <asm/sfp-machine.h>
+#include <math-emu/soft-fp.h>
+#include <math-emu/single.h>
+int fcmps(void *ft, void *fa, void *fb, int cmpop)
+{
+ FP_DECL_S(A);
+ FP_DECL_S(B);
+ FP_DECL_EX;
+ long cmp;
+
+ FP_UNPACK_SP(A, fa);
+ FP_UNPACK_SP(B, fb);
+
+ FP_CMP_S(cmp, A, B, SF_CUN);
+ cmp += 2;
+ if (cmp == SF_CGT)
+ *(int *)ft = 0x0;
+ else
+ *(int *)ft = (cmp & cmpop) ? 0x1 : 0x0;
+
+ return 0;
+}