From 697dfd2cb2acd640324565ec3298645b6f6bd4c5 Mon Sep 17 00:00:00 2001
From: bonzini <bonzini@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Thu, 29 Apr 2004 07:40:05 +0000
Subject: 2004-04-28  Paolo Bonzini  <bonzini@gnu.org>

        * config/acx.m4: Fix fastcompare support for new-bootstrap.
        * configure: Regenerate.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@81281 138bc75d-0d04-0410-961f-82ee72b054a4
---
 config/acx.m4 | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

(limited to 'config')

diff --git a/config/acx.m4 b/config/acx.m4
index 9b40d4f0771..3652836bb8d 100644
--- a/config/acx.m4
+++ b/config/acx.m4
@@ -193,3 +193,34 @@ else
   have_gnat=no
 fi
 ])
+
+dnl 'make compare' can be significantly faster, if cmp itself can
+dnl skip bytes instead of using tail.  The test being performed is
+dnl "if cmp --ignore-initial=2 t1 t2 && ! cmp --ignore-initial=1 t1 t2"
+dnl but we need to sink errors and handle broken shells.  We also test
+dnl for the parameter format "cmp file1 file2 skip1 skip2" which is
+dnl accepted by cmp on some systems.
+AC_DEFUN([ACX_PROG_CMP_IGNORE_INITIAL],
+[AC_CACHE_CHECK([how to compare bootstrapped objects], gcc_cv_prog_cmp_skip,
+[ echo abfoo >t1
+  echo cdfoo >t2
+  gcc_cv_prog_cmp_skip='tail +16c $$f1 > tmp-foo1; tail +16c $$f2 > tmp-foo2; cmp tmp-foo1 tmp-foo2'
+  if cmp t1 t2 2 2 > /dev/null 2>&1; then
+    if cmp t1 t2 1 1 > /dev/null 2>&1; then
+      :
+    else
+      gcc_cv_prog_cmp_skip='cmp $$f1 $$f2 16 16'
+    fi
+  fi
+  if cmp --ignore-initial=2 t1 t2 > /dev/null 2>&1; then
+    if cmp --ignore-initial=1 t1 t2 > /dev/null 2>&1; then
+      :
+    else
+      gcc_cv_prog_cmp_skip='cmp --ignore-initial=16 $$f1 $$f2'
+    fi
+  fi
+  rm t1 t2
+])
+do_compare="$gcc_cv_prog_cmp_skip"
+AC_SUBST(do_compare)
+])
-- 
cgit v1.2.1