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Diffstat (limited to 'runtime/x86_32/i64_umulh.S')
| -rw-r--r-- | runtime/x86_32/i64_umulh.S | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/runtime/x86_32/i64_umulh.S b/runtime/x86_32/i64_umulh.S new file mode 100644 index 00000000..449a0f8b --- /dev/null +++ b/runtime/x86_32/i64_umulh.S @@ -0,0 +1,74 @@ +// ***************************************************************** +// +// 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. IA32 version. + +#include "sysdeps.h" + +// Multiply-high unsigned + +#define XL 12(%esp) +#define XH 16(%esp) +#define YL 20(%esp) +#define YH 24(%esp) + +// X * Y = 2^64 XH.YH + 2^32 (XH.YL + XL.YH) + XL.YL + +FUNCTION(__i64_umulh) + pushl %esi + pushl %edi + movl XL, %eax + mull YL // EDX:EAX = 64-bit product XL.YL + movl %edx, %ecx + xorl %esi, %esi + xorl %edi, %edi // EDI:ESI:ECX accumulate bits 127:32 of result + movl XH, %eax + mull YL // EDX:EAX = 64-bit product XH.YL + addl %eax, %ecx + adcl %edx, %esi + adcl $0, %edi + movl YH, %eax + mull XL // EDX:EAX = 64-bit product YH.XL + addl %eax, %ecx + adcl %edx, %esi + adcl $0, %edi + movl XH, %eax + mull YH // EDX:EAX = 64-bit product XH.YH + addl %esi, %eax + adcl %edi, %edx + popl %edi + popl %esi + ret +ENDFUNCTION(__i64_umulh) + |