Imported gcc-4.4.3

[msp430-gcc.git] / libgcc / config / libbid / bid64_scalb.c

diff --git a/libgcc/config/libbid/bid64_scalb.c b/libgcc/config/libbid/bid64_scalb.c
new file mode 100644 (file)
index 0000000..a565d65
--- /dev/null
+++ b/libgcc/config/libbid/bid64_scalb.c
@@ -0,0 +1,105 @@
+/* Copyright (C) 2007, 2009  Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+<http://www.gnu.org/licenses/>.  */
+
+#include "bid_internal.h"
+
+#define MAX_FORMAT_DIGITS     16
+#define DECIMAL_EXPONENT_BIAS 398
+#define MAX_DECIMAL_EXPONENT  767
+
+#if DECIMAL_CALL_BY_REFERENCE
+
+void
+bid64_scalb (UINT64 * pres, UINT64 * px,
+            int *pn _RND_MODE_PARAM _EXC_FLAGS_PARAM _EXC_MASKS_PARAM
+            _EXC_INFO_PARAM) {
+  UINT64 x;
+  int n;
+#else
+
+UINT64
+bid64_scalb (UINT64 x,
+            int n _RND_MODE_PARAM _EXC_FLAGS_PARAM _EXC_MASKS_PARAM
+            _EXC_INFO_PARAM) {
+#endif
+  UINT64 sign_x, coefficient_x, res;
+  SINT64 exp64;
+  int exponent_x, rmode;
+
+#if DECIMAL_CALL_BY_REFERENCE
+#if !DECIMAL_GLOBAL_ROUNDING
+  _IDEC_round rnd_mode = *prnd_mode;
+#endif
+  x = *px;
+  n = *pn;
+#endif
+
+  // unpack arguments, check for NaN or Infinity
+  if (!unpack_BID64 (&sign_x, &exponent_x, &coefficient_x, x)) {
+    // x is Inf. or NaN or 0
+#ifdef SET_STATUS_FLAGS
+    if ((x & SNAN_MASK64) == SNAN_MASK64)      // y is sNaN
+      __set_status_flags (pfpsf, INVALID_EXCEPTION);
+#endif
+    if (coefficient_x)
+      res = coefficient_x & QUIET_MASK64;
+       else {
+       exp64 = (SINT64) exponent_x + (SINT64) n;
+          if(exp64<0) exp64=0;
+          if(exp64>MAX_DECIMAL_EXPONENT) exp64=MAX_DECIMAL_EXPONENT;
+       exponent_x = exp64;
+      res = very_fast_get_BID64 (sign_x, exponent_x, coefficient_x);   // 0
+       }
+    BID_RETURN (res);
+  }
+
+  exp64 = (SINT64) exponent_x + (SINT64) n;
+  exponent_x = exp64;
+
+  if ((UINT32) exponent_x <= MAX_DECIMAL_EXPONENT) {
+    res = very_fast_get_BID64 (sign_x, exponent_x, coefficient_x);
+    BID_RETURN (res);
+  }
+  // check for overflow
+  if (exp64 > MAX_DECIMAL_EXPONENT) {
+    // try to normalize coefficient
+    while ((coefficient_x < 1000000000000000ull)
+          && (exp64 > MAX_DECIMAL_EXPONENT)) {
+      // coefficient_x < 10^15, scale by 10
+      coefficient_x = (coefficient_x << 1) + (coefficient_x << 3);
+      exponent_x--;
+      exp64--;
+    }
+    if (exp64 <= MAX_DECIMAL_EXPONENT) {
+      res = very_fast_get_BID64 (sign_x, exponent_x, coefficient_x);
+      BID_RETURN (res);
+    } else
+      exponent_x = 0x7fffffff; // overflow
+  }
+  // exponent < 0
+  // the BID pack routine will round the coefficient
+  rmode = rnd_mode;
+  res = get_BID64 (sign_x, exponent_x, coefficient_x, rmode, pfpsf);
+  BID_RETURN (res);
+
+}