Refactor extendsfdf2.

Patch by: GuanHong Liu
Differential Revision: http://reviews.llvm.org/D3887


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@209781 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 76 insertions, 0 deletions

diff --git a/lib/builtins/fp_extend.h b/lib/builtins/fp_extend.h
new file mode 100644
index 000000000..fff676eec
--- /dev/null
+++ b/lib/builtins/fp_extend.h
@@ -0,0 +1,76 @@
+//===-lib/fp_extend.h - low precision -> high precision 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.
+//
+//===----------------------------------------------------------------------===//
+//
+// Set source and destination setting
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef FP_EXTEND_HEADER
+#define FP_EXTEND_HEADER
+
+#include "int_lib.h"
+
+#if defined SRC_SINGLE
+typedef float src_t;
+typedef uint32_t src_rep_t;
+#define SRC_REP_C UINT32_C
+static const int srcSigBits = 23;
+#define src_rep_t_clz __builtin_clz
+
+#elif defined SRC_DOUBLE
+typedef double src_t;
+typedef uint64_t src_rep_t;
+#define SRC_REP_C UINT64_C
+static const int srcSigBits = 52;
+static inline int src_rep_t_clz(src_rep_t a) {
+#if defined __LP64__
+    return __builtin_clzl(a);
+#else
+    if (a & REP_C(0xffffffff00000000))
+        return __builtin_clz(a >> 32);
+    else
+        return 32 + __builtin_clz(a & REP_C(0xffffffff));
+#endif
+}
+
+#else
+#error Source should be single precision or double precision!
+#endif //end source precision
+
+#if defined DST_DOUBLE
+typedef double dst_t;
+typedef uint64_t dst_rep_t;
+#define DST_REP_C UINT64_C
+static const int dstSigBits = 52;
+
+#elif defined DST_QUAD
+typedef long double dst_t;
+typedef __uint128_t dst_rep_t;
+#define DST_REP_C (__uint128_t)
+static const int dstSigBits = 112;
+
+#else
+#error Destination should be double precision or quad precision!
+#endif //end destination precision
+
+// End of specialization parameters.  Two helper routines for conversion to and
+// from the representation of floating-point data as integer values follow.
+
+static inline src_rep_t srcToRep(src_t x) {
+    const union { src_t f; src_rep_t i; } rep = {.f = x};
+    return rep.i;
+}
+
+static inline dst_t dstFromRep(dst_rep_t x) {
+    const union { dst_t f; dst_rep_t i; } rep = {.i = x};
+    return rep.f;
+}
+// End helper routines.  Conversion implementation follows.
+
+#endif //FP_EXTEND_HEADER