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-rw-r--r--arch/mips/math-emu/sp_fdp.c73
1 files changed, 73 insertions, 0 deletions
diff --git a/arch/mips/math-emu/sp_fdp.c b/arch/mips/math-emu/sp_fdp.c
new file mode 100644
index 000000000..56417497c
--- /dev/null
+++ b/arch/mips/math-emu/sp_fdp.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* IEEE754 floating point arithmetic
+ * single precision
+ */
+/*
+ * MIPS floating point support
+ * Copyright (C) 1994-2000 Algorithmics Ltd.
+ */
+
+#include "ieee754sp.h"
+#include "ieee754dp.h"
+
+static inline union ieee754sp ieee754sp_nan_fdp(int xs, u64 xm)
+{
+ return buildsp(xs, SP_EMAX + 1 + SP_EBIAS,
+ xm >> (DP_FBITS - SP_FBITS));
+}
+
+union ieee754sp ieee754sp_fdp(union ieee754dp x)
+{
+ union ieee754sp y;
+ u32 rm;
+
+ COMPXDP;
+ COMPYSP;
+
+ EXPLODEXDP;
+
+ ieee754_clearcx();
+
+ FLUSHXDP;
+
+ switch (xc) {
+ case IEEE754_CLASS_SNAN:
+ x = ieee754dp_nanxcpt(x);
+ EXPLODEXDP;
+ fallthrough;
+ case IEEE754_CLASS_QNAN:
+ y = ieee754sp_nan_fdp(xs, xm);
+ if (!ieee754_csr.nan2008) {
+ EXPLODEYSP;
+ if (!ieee754_class_nan(yc))
+ y = ieee754sp_indef();
+ }
+ return y;
+
+ case IEEE754_CLASS_INF:
+ return ieee754sp_inf(xs);
+
+ case IEEE754_CLASS_ZERO:
+ return ieee754sp_zero(xs);
+
+ case IEEE754_CLASS_DNORM:
+ /* can't possibly be sp representable */
+ ieee754_setcx(IEEE754_UNDERFLOW);
+ ieee754_setcx(IEEE754_INEXACT);
+ if ((ieee754_csr.rm == FPU_CSR_RU && !xs) ||
+ (ieee754_csr.rm == FPU_CSR_RD && xs))
+ return ieee754sp_mind(xs);
+ return ieee754sp_zero(xs);
+
+ case IEEE754_CLASS_NORM:
+ break;
+ }
+
+ /*
+ * Convert from DP_FBITS to SP_FBITS+3 with sticky right shift.
+ */
+ rm = (xm >> (DP_FBITS - (SP_FBITS + 3))) |
+ ((xm << (64 - (DP_FBITS - (SP_FBITS + 3)))) != 0);
+
+ return ieee754sp_format(xs, xe, rm);
+}