ext: Include libfputils

This changeset includes libfputils from revision bbf0d61d75. This
library can be used to convert to and from 80-bit floats and query the
type of an 80-bit float, which is needed to support the x87 FPU.

1 files changed, 95 insertions, 0 deletions

diff --git a/ext/fputils/fpbits.h b/ext/fputils/fpbits.h
new file mode 100644
index 000000000..9fb934843
--- /dev/null
+++ b/ext/fputils/fpbits.h
@@ -0,0 +1,95 @@
+/*
+ * Copyright (c) 2013, Andreas Sandberg
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above
+ *    copyright notice, this list of conditions and the following
+ *    disclaimer in the documentation and/or other materials provided
+ *    with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _FPBITS_H
+#define _FPBITS_H
+
+#include <stdint.h>
+
+#define FP80_FRAC_BITS 63
+#define FP80_INT_BIT  0x8000000000000000ULL
+#define FP80_QNAN_BIT  0x4000000000000000ULL
+#define FP80_FRAC_MASK  0x7fffffffffffffffULL
+#define FP80_EXP_MASK 0x7fff
+#define FP80_SIGN_BIT 0x8000
+#define FP80_EXP_BIAS 0x3fff
+
+#define FP80_EXP_SPECIAL 0x7fff
+#define FP80_FRAC_SNAN  0x3fffffffffffffffULL
+#define FP80_FRAC_QNAN  0x7fffffffffffffffULL
+#define FP80_FRAC_QNANI 0x4000000000000000ULL
+
+
+#define FP64_EXP_SHIFT 52
+#define FP64_FRAC_BITS 52
+#define FP64_SIGN_BIT  0x8000000000000000ULL
+#define FP64_EXP_MASK  0x7ff0000000000000ULL
+#define FP64_FRAC_MASK 0x000fffffffffffffULL
+#define FP64_EXP_BIAS 0x3ff
+
+#define FP64_EXP_SPECIAL 0x7ff
+#define FP64_FRAC_SNAN  0x0007ffffffffffffULL
+#define FP64_FRAC_QNAN  0x000fffffffffffffULL
+#define FP64_FRAC_QNANI 0x0008000000000000ULL
+
+#define BUILD_IFP64(sign, frac, exp)                            \
+    ((sign) ? FP64_SIGN_BIT : 0) |                              \
+    (((uint64_t)(exp) << FP64_EXP_SHIFT) & FP64_EXP_MASK) |     \
+    ((frac) & FP64_FRAC_MASK)
+
+#define BUILD_FP64(sign, frac, exp)                             \
+    { .bits = BUILD_IFP64(sign, frac, exp) }
+
+#define BUILD_FP80_SE(sign, exp)                                \
+    ((sign) ? FP80_SIGN_BIT : 0) |                              \
+    ((exp) & FP80_EXP_MASK)
+
+#define BUILD_FP80_FI(frac, exp)                                \
+    ((exp) ? FP80_INT_BIT : 0) |                                \
+    ((frac) & FP80_FRAC_MASK)
+
+#define BUILD_FP80(sign, frac, exp)                             \
+    {                                                           \
+        .u.repr.se = BUILD_FP80_SE(sign, exp),                  \
+        .u.repr.fi = BUILD_FP80_FI(frac, exp)                   \
+    }
+
+#define FP80_FRAC(fp80)                                         \
+    (fp80.u.repr.fi & FP80_FRAC_MASK)
+
+#define FP80_EXP(fp80)                                          \
+    (fp80.u.repr.se & FP80_EXP_MASK)
+
+#define FP64_FRAC(fp64)                                         \
+    (fp64.bits & FP64_FRAC_MASK)
+
+#define FP64_EXP(fp80)                                          \
+    ((fp64.bits & FP64_EXP_MASK) >> FP64_EXP_SHIFT)
+
+#endif