summaryrefslogtreecommitdiffstats
path: root/arch/mips/math-emu/sp_div.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/mips/math-emu/sp_div.c')
-rw-r--r--arch/mips/math-emu/sp_div.c142
1 files changed, 142 insertions, 0 deletions
diff --git a/arch/mips/math-emu/sp_div.c b/arch/mips/math-emu/sp_div.c
new file mode 100644
index 0000000000..2bfa266fdc
--- /dev/null
+++ b/arch/mips/math-emu/sp_div.c
@@ -0,0 +1,142 @@
+// 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"
+
+union ieee754sp ieee754sp_div(union ieee754sp x, union ieee754sp y)
+{
+ unsigned int rm;
+ int re;
+ unsigned int bm;
+
+ COMPXSP;
+ COMPYSP;
+
+ EXPLODEXSP;
+ EXPLODEYSP;
+
+ ieee754_clearcx();
+
+ FLUSHXSP;
+ FLUSHYSP;
+
+ 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 ieee754sp_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 ieee754sp_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_INF):
+ ieee754_setcx(IEEE754_INVALID_OPERATION);
+ return ieee754sp_indef();
+
+ case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_INF):
+ case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_INF):
+ case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_INF):
+ return ieee754sp_zero(xs ^ ys);
+
+ case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_ZERO):
+ case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_NORM):
+ case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_DNORM):
+ return ieee754sp_inf(xs ^ ys);
+
+ /*
+ * Zero handling
+ */
+ case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO):
+ ieee754_setcx(IEEE754_INVALID_OPERATION);
+ return ieee754sp_indef();
+
+ case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_ZERO):
+ case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_ZERO):
+ ieee754_setcx(IEEE754_ZERO_DIVIDE);
+ return ieee754sp_inf(xs ^ ys);
+
+ case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_NORM):
+ case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_DNORM):
+ return ieee754sp_zero(xs == ys ? 0 : 1);
+
+ case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
+ SPDNORMX;
+ fallthrough;
+ case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
+ SPDNORMY;
+ break;
+
+ case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_NORM):
+ SPDNORMX;
+ break;
+
+ case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_NORM):
+ break;
+ }
+ assert(xm & SP_HIDDEN_BIT);
+ assert(ym & SP_HIDDEN_BIT);
+
+ /* provide rounding space */
+ xm <<= 3;
+ ym <<= 3;
+
+ /* now the dirty work */
+
+ rm = 0;
+ re = xe - ye;
+
+ for (bm = SP_MBIT(SP_FBITS + 2); bm; bm >>= 1) {
+ if (xm >= ym) {
+ xm -= ym;
+ rm |= bm;
+ if (xm == 0)
+ break;
+ }
+ xm <<= 1;
+ }
+
+ rm <<= 1;
+ if (xm)
+ rm |= 1; /* have remainder, set sticky */
+
+ assert(rm);
+
+ /* normalise rm to rounding precision ?
+ */
+ while ((rm >> (SP_FBITS + 3)) == 0) {
+ rm <<= 1;
+ re--;
+ }
+
+ return ieee754sp_format(xs == ys ? 0 : 1, re, rm);
+}