vendor/compiler-rt/compiler-rt-r224034

1 files changed, 50 insertions, 0 deletions

diff --git a/lib/builtins/floatunsisf.c b/lib/builtins/floatunsisf.c
new file mode 100644
index 0000000000000..ea6f161adc02e
--- /dev/null
+++ b/lib/builtins/floatunsisf.c
@@ -0,0 +1,50 @@
+//===-- lib/floatunsisf.c - uint -> single-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.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements unsigned integer to single-precision conversion for the
+// compiler-rt library in the IEEE-754 default round-to-nearest, ties-to-even
+// mode.
+//
+//===----------------------------------------------------------------------===//
+
+#define SINGLE_PRECISION
+#include "fp_lib.h"
+
+#include "int_lib.h"
+
+ARM_EABI_FNALIAS(ui2f, floatunsisf)
+
+COMPILER_RT_ABI fp_t
+__floatunsisf(unsigned int a) {
+    
+    const int aWidth = sizeof a * CHAR_BIT;
+    
+    // Handle zero as a special case to protect clz
+    if (a == 0) return fromRep(0);
+    
+    // Exponent of (fp_t)a is the width of abs(a).
+    const int exponent = (aWidth - 1) - __builtin_clz(a);
+    rep_t result;
+    
+    // Shift a into the significand field, rounding if it is a right-shift
+    if (exponent <= significandBits) {
+        const int shift = significandBits - exponent;
+        result = (rep_t)a << shift ^ implicitBit;
+    } else {
+        const int shift = exponent - significandBits;
+        result = (rep_t)a >> shift ^ implicitBit;
+        rep_t round = (rep_t)a << (typeWidth - shift);
+        if (round > signBit) result++;
+        if (round == signBit) result += result & 1;
+    }
+    
+    // Insert the exponent
+    result += (rep_t)(exponent + exponentBias) << significandBits;
+    return fromRep(result);
+}