summaryrefslogtreecommitdiffstats
path: root/arch/mips/math-emu/dp_rint.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--arch/mips/math-emu/dp_rint.c78
1 files changed, 78 insertions, 0 deletions
diff --git a/arch/mips/math-emu/dp_rint.c b/arch/mips/math-emu/dp_rint.c
new file mode 100644
index 000000000..7f30b7a30
--- /dev/null
+++ b/arch/mips/math-emu/dp_rint.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* IEEE754 floating point arithmetic
+ * double precision: common utilities
+ */
+/*
+ * MIPS floating point support
+ * Copyright (C) 1994-2000 Algorithmics Ltd.
+ * Copyright (C) 2017 Imagination Technologies, Ltd.
+ * Author: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
+ */
+
+#include "ieee754dp.h"
+
+union ieee754dp ieee754dp_rint(union ieee754dp x)
+{
+ union ieee754dp ret;
+ u64 residue;
+ int sticky;
+ int round;
+ int odd;
+
+ COMPXDP;
+
+ ieee754_clearcx();
+
+ EXPLODEXDP;
+ FLUSHXDP;
+
+ if (xc == IEEE754_CLASS_SNAN)
+ return ieee754dp_nanxcpt(x);
+
+ if ((xc == IEEE754_CLASS_QNAN) ||
+ (xc == IEEE754_CLASS_INF) ||
+ (xc == IEEE754_CLASS_ZERO))
+ return x;
+
+ if (xe >= DP_FBITS)
+ return x;
+
+ if (xe < -1) {
+ residue = xm;
+ round = 0;
+ sticky = residue != 0;
+ xm = 0;
+ } else {
+ residue = xm << (64 - DP_FBITS + xe);
+ round = (residue >> 63) != 0;
+ sticky = (residue << 1) != 0;
+ xm >>= DP_FBITS - xe;
+ }
+
+ odd = (xm & 0x1) != 0x0;
+
+ switch (ieee754_csr.rm) {
+ case FPU_CSR_RN: /* toward nearest */
+ if (round && (sticky || odd))
+ xm++;
+ break;
+ case FPU_CSR_RZ: /* toward zero */
+ break;
+ case FPU_CSR_RU: /* toward +infinity */
+ if ((round || sticky) && !xs)
+ xm++;
+ break;
+ case FPU_CSR_RD: /* toward -infinity */
+ if ((round || sticky) && xs)
+ xm++;
+ break;
+ }
+
+ if (round || sticky)
+ ieee754_setcx(IEEE754_INEXACT);
+
+ ret = ieee754dp_flong(xm);
+ DPSIGN(ret) = xs;
+
+ return ret;
+}