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Diffstat (limited to 'runtime/x86_64/i64_utof.S')
| -rw-r--r-- | runtime/x86_64/i64_utof.S | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/runtime/x86_64/i64_utof.S b/runtime/x86_64/i64_utof.S new file mode 100644 index 00000000..d0935341 --- /dev/null +++ b/runtime/x86_64/i64_utof.S @@ -0,0 +1,56 @@ +// ***************************************************************** +// +// The Compcert verified compiler +// +// Xavier Leroy, INRIA Paris +// +// Copyright (c) 2016 Institut National de Recherche en Informatique et +// en Automatique. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are met: +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * 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. +// * Neither the name of the <organization> nor the +// names of its contributors may be used to endorse or promote products +// derived from this software without specific prior written permission. +// +// 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 <COPYRIGHT +// HOLDER> 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. +// +// ********************************************************************* + +// Helper functions for 64-bit integer arithmetic. x86_64 version. + +#include "sysdeps.h" + +// Conversion unsigned long -> single-precision float + +FUNCTION(__i64_utof) + testq %rdi, %rdi + js 1f + pxor %xmm0, %xmm0 // if < 2^63, + cvtsi2ssq %rdi, %xmm0 // convert as if signed + ret +1: // if >= 2^63, use round-to-odd trick + movq %rdi, %rax + shrq %rax + andq $1, %rdi + orq %rdi, %rax // (arg >> 1) | (arg & 1) + pxor %xmm0, %xmm0 + cvtsi2ssq %rax, %xmm0 // convert as if signed + addss %xmm0, %xmm0 // multiply result by 2.0 + ret +ENDFUNCTION(__i64_utof) |