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-rw-r--r--arch/mips/math-emu/dp_mul.c159
1 files changed, 159 insertions, 0 deletions
diff --git a/arch/mips/math-emu/dp_mul.c b/arch/mips/math-emu/dp_mul.c
new file mode 100644
index 000000000..8a671bb7a
--- /dev/null
+++ b/arch/mips/math-emu/dp_mul.c
@@ -0,0 +1,159 @@
+// 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.
+ */
+
+#include "ieee754dp.h"
+
+union ieee754dp ieee754dp_mul(union ieee754dp x, union ieee754dp y)
+{
+ int re;
+ int rs;
+ u64 rm;
+ unsigned int lxm;
+ unsigned int hxm;
+ unsigned int lym;
+ unsigned int hym;
+ u64 lrm;
+ u64 hrm;
+ u64 t;
+ u64 at;
+
+ COMPXDP;
+ COMPYDP;
+
+ EXPLODEXDP;
+ EXPLODEYDP;
+
+ ieee754_clearcx();
+
+ FLUSHXDP;
+ FLUSHYDP;
+
+ switch (CLPAIR(xc, yc)) {
+ case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_SNAN):
+ case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_SNAN):
+ case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_SNAN):
+ case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_SNAN):
+ case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_SNAN):
+ return ieee754dp_nanxcpt(y);
+
+ case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_SNAN):
+ case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_QNAN):
+ case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_ZERO):
+ case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_NORM):
+ case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_DNORM):
+ case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_INF):
+ return ieee754dp_nanxcpt(x);
+
+ case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_QNAN):
+ case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_QNAN):
+ case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_QNAN):
+ case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_QNAN):
+ return y;
+
+ case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN):
+ case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_ZERO):
+ case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_NORM):
+ case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_DNORM):
+ case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_INF):
+ return x;
+
+
+ /*
+ * Infinity handling
+ */
+ case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_ZERO):
+ case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_INF):
+ ieee754_setcx(IEEE754_INVALID_OPERATION);
+ return ieee754dp_indef();
+
+ case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_INF):
+ case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_INF):
+ case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_NORM):
+ case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_DNORM):
+ case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_INF):
+ return ieee754dp_inf(xs ^ ys);
+
+ case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO):
+ case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_NORM):
+ case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_DNORM):
+ case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_ZERO):
+ case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_ZERO):
+ return ieee754dp_zero(xs ^ ys);
+
+
+ case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
+ DPDNORMX;
+ fallthrough;
+ case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
+ DPDNORMY;
+ break;
+
+ case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_NORM):
+ DPDNORMX;
+ break;
+
+ case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_NORM):
+ break;
+ }
+ /* rm = xm * ym, re = xe+ye basically */
+ assert(xm & DP_HIDDEN_BIT);
+ assert(ym & DP_HIDDEN_BIT);
+
+ re = xe + ye;
+ rs = xs ^ ys;
+
+ /* shunt to top of word */
+ xm <<= 64 - (DP_FBITS + 1);
+ ym <<= 64 - (DP_FBITS + 1);
+
+ /*
+ * Multiply 64 bits xm, ym to give high 64 bits rm with stickness.
+ */
+
+ lxm = xm;
+ hxm = xm >> 32;
+ lym = ym;
+ hym = ym >> 32;
+
+ lrm = DPXMULT(lxm, lym);
+ hrm = DPXMULT(hxm, hym);
+
+ t = DPXMULT(lxm, hym);
+
+ at = lrm + (t << 32);
+ hrm += at < lrm;
+ lrm = at;
+
+ hrm = hrm + (t >> 32);
+
+ t = DPXMULT(hxm, lym);
+
+ at = lrm + (t << 32);
+ hrm += at < lrm;
+ lrm = at;
+
+ hrm = hrm + (t >> 32);
+
+ rm = hrm | (lrm != 0);
+
+ /*
+ * Sticky shift down to normal rounding precision.
+ */
+ if ((s64) rm < 0) {
+ rm = (rm >> (64 - (DP_FBITS + 1 + 3))) |
+ ((rm << (DP_FBITS + 1 + 3)) != 0);
+ re++;
+ } else {
+ rm = (rm >> (64 - (DP_FBITS + 1 + 3 + 1))) |
+ ((rm << (DP_FBITS + 1 + 3 + 1)) != 0);
+ }
+ assert(rm & (DP_HIDDEN_BIT << 3));
+
+ return ieee754dp_format(rs, re, rm);
+}