aboutsummaryrefslogtreecommitdiff
path: root/lib/builtins/fp_fixint_impl.inc
diff options
context:
space:
mode:
Diffstat (limited to 'lib/builtins/fp_fixint_impl.inc')
-rw-r--r--lib/builtins/fp_fixint_impl.inc41
1 files changed, 41 insertions, 0 deletions
diff --git a/lib/builtins/fp_fixint_impl.inc b/lib/builtins/fp_fixint_impl.inc
new file mode 100644
index 000000000000..035e87ca10e0
--- /dev/null
+++ b/lib/builtins/fp_fixint_impl.inc
@@ -0,0 +1,41 @@
+//===-- lib/fixdfsi.c - Double-precision -> integer conversion ----*- C -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements float to integer conversion for the
+// compiler-rt library.
+//
+//===----------------------------------------------------------------------===//
+
+#include "fp_lib.h"
+
+static inline fixint_t __fixint(fp_t a) {
+ const fixint_t fixint_max = (fixint_t)((~(fixuint_t)0) / 2);
+ const fixint_t fixint_min = -fixint_max - 1;
+ // Break a into sign, exponent, significand
+ const rep_t aRep = toRep(a);
+ const rep_t aAbs = aRep & absMask;
+ const fixint_t sign = aRep & signBit ? -1 : 1;
+ const int exponent = (aAbs >> significandBits) - exponentBias;
+ const rep_t significand = (aAbs & significandMask) | implicitBit;
+
+ // If exponent is negative, the result is zero.
+ if (exponent < 0)
+ return 0;
+
+ // If the value is too large for the integer type, saturate.
+ if ((unsigned)exponent >= sizeof(fixint_t) * CHAR_BIT)
+ return sign == 1 ? fixint_max : fixint_min;
+
+ // If 0 <= exponent < significandBits, right shift to get the result.
+ // Otherwise, shift left.
+ if (exponent < significandBits)
+ return sign * (significand >> (significandBits - exponent));
+ else
+ return sign * ((fixint_t)significand << (exponent - significandBits));
+}