Make ia32/ code more portable across systems.

git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2214 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e

1 files changed, 60 insertions, 0 deletions

diff --git a/runtime/ia32/i64_sar.S b/runtime/ia32/i64_sar.S
new file mode 100644
index 0000000..cf2233b
--- /dev/null
+++ b/runtime/ia32/i64_sar.S
@@ -0,0 +1,60 @@
+// *****************************************************************
+//
+//               The Compcert verified compiler
+//
+//           Xavier Leroy, INRIA Paris-Rocquencourt
+//
+// Copyright (c) 2013 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"
+
+// Shift right signed
+
+// Note: IA32 shift instructions treat their amount (in %cl) modulo 32
+
+FUNCTION(__i64_sar)
+        movl 12(%esp), %ecx             // ecx = shift amount, treated mod 64
+        testb $32, %cl
+        jne 1f
+  // shift amount < 32
+        movl 4(%esp), %eax
+        movl 8(%esp), %edx
+        shrdl %cl, %edx, %eax           // eax = low(XH:XL >> amount)
+        sarl %cl, %edx                  // edx = XH >> amount (signed)
+        ret
+  // shift amount >= 32
+1:      movl 8(%esp), %eax
+        movl %eax, %edx
+        sarl %cl, %eax                  // eax = XH >> (amount - 32)
+        sarl $31, %edx                  // edx = sign of X
+        ret
+ENDFUNCTION(__i64_sar)
+