Ticket #11920: sympow-1.018.1.p10-p11.diff

sympow-1.018.1.

@@ -46 +46 @@
 
 == Changelog ==
 
-=== sympow-1.018.1.p10 (Jeroen Demeyer, 19 Oct 2011) ===
+=== sympow-1.018.1.p11 (Jeroen Demeyer, 19 Jan 2012) ===
  * #11920: Remove -fno-expensive-optimizations workaround, instead try
    various flags which might force 53-bit precision doubles.
  * Find out the actual FPU precision with config/fpubits1.c and
    config/fpubits2.c.
  * Move all x86 extended precision FPU-control word stuff from
    src/Configure to spkg-install
- * Generate binary datafiles when installing sympow. This ensures that
+ * Generate binary datafiles when installing SYMPOW. This ensures that
    all users (not only the one which installed Sage) can use the standard
    datafiles.
  * execlp.patch: Use execlp() instead of execl() to execute "sh".  This
    is needed for the -new_data option to work (which surely could never
    have worked before).
  * Use `patch` instead of `cp` for patching.
+ * Lots of small fixes in spkg-install.
  * Remove dist/debian directory.
 
 === sympow-1.018.1.p9 (Jeroen Demeyer, 2 May 2011) ===

config/fpubits1.c

@@ -8 +8 @@
 
 #include <stdio.h>
 
-double mul_and_add(double, double, double);
+double mul_and_add(double, double, double);  /* config/fpubits2.c */
+void fpu_53bits();  /* src/fpu.c */
 
 int main(int argc, char** argv)
 {
+        /* If x86 is defined, set the FPU to 53 bits */
+#ifdef x86
+        fpu_53bits();
+#endif
+
         /* Let a = 1 + x,
          *     b = 1 + y,
          * and compute

sympow-1.018.1.

@@ -1 +1 @@
 #!/usr/bin/env bash
 
 if [ "$SAGE_LOCAL" = "" ]; then
-   echo "SAGE_LOCAL undefined ... exiting";
-   echo "Maybe run 'sage -sh'?"
+   echo >&2 "SAGE_LOCAL undefined ... exiting"
+   echo >&2 "Maybe run 'sage -sh'?"
    exit 1
 fi
 
@@ -14 +14 @@
 
 # If SAGE64 is "yes", build 64-bit. 
 if [ "x$SAGE64" = xyes ] ; then 
-   echo "Building Sympow 64-bit"             
+   echo "Building SYMPOW 64-bit"
    CFLAGS="$CFLAGS $CFLAG64"
    LDFLAGS="$LDFLAGS $CFLAG64"
    export CFLAGS
@@ -39 +39 @@
 
 
 #######################################################################
-# Check FPU precision
+# Fix FPU precision
 #######################################################################
-# Try adding various flags to CFLAGS to ensure that doubles are really
-# IEEE doubles with 53 bits of precision.
-# In particular, we need to avoid 80 bits extended precision on x86 and
-# we need to avoid fused multiply-and-instructions (e.g. on ia64).
-# To check whether a flag is supported, compile and run a program
-# compiled with that flag.
-for FLAG in '-ffp-contract=on' '-mno-fused-madd' '-mfpmath=sse' '-mpc64'; do
+# SYMPOW really needs doubles to have *exactly* 53 bits precision,
+# they need to be true IEEE-754 double precision numbers.
+# In particular, we need to avoid 80 bits extended precision on i386
+# and we need to avoid fused multiply-add instructions (e.g. on ia64).
+# We might need to add various flags to CFLAGS to ensure this.
+# See Trac tickets #9703, #9734, #9166, #11226, #11920.
+
+# Usage: try_add_CFLAG $FLAG
+# Try adding $FLAG to $CFLAGS, compile and run the fpubits program.
+# If it compiles and running it doesn't crash it (with an Illegal
+# Instruction for example), then we add $FLAG to $CFLAGS.
+# Return 0 if we added $FLAG and the FPU correctly used 53 bits,
+# return 1 if we added $FLAG but the FPU doesn't use 53 bits,
+# return 2 if we did not add $FLAG.
+try_add_CFLAG()
+{
     # We use -O3 here to really force generation of fused
-    # multiply-and-add instructions and to keep floats as much as
+    # multiply-add instructions and to keep floats as much as
     # possible in registers.
-    if $CC $CFLAGS $FLAG -O3 -o config/fpubits config/fpubits1.c config/fpubits2.c 2>/dev/null; then
+    # We compile in the (already patched!) src/fpu.c which only does
+    # something if the macro x86 is defined.
+    if $CC -O3 $CFLAGS $FLAG config/fpubits1.c config/fpubits2.c src/fpu.c -o config/fpubits 2>/dev/null; then
         # Compiled successfully, now run it
         config/fpubits >/dev/null 2>/dev/null
-        if [ $? -le 1 ]; then
+        status=$?
+        if [ $status -le 1 ]; then
             # The program ran successfully.  For now, we don't need
             # the exit status to be zero (indicating exactly 53 bits),
             # we simply need the program not to crash (which would
             # give an exit status > 128).
             CFLAGS="$CFLAGS $FLAG"
+            return $status
         fi
     fi
+    return 2
+}
+
+# These flags never hurt, so add them if possible
+for FLAG in '-fno-fast-math' '-mfpmath=sse' '-Dx86'; do
+    try_add_CFLAG $FLAG
+done
+
+# Add at most one flag of the following to avoid gcc warnings:
+# gcc versions which support -ffp-contract deprecate -mno-fused-madd
+for FLAG in '-ffp-contract=on' '-mno-fused-madd'; do
+    try_add_CFLAG $FLAG && break
+done
+
+# Some flags to try as last resort.  These hurt performance, so only add
+# them if needed.
+for FLAG in '' '-ffloat-store' '-O0'; do
+    # Stop the loop if the FPU precision already is 53 bits
+    try_add_CFLAG $FLAG && break
 done
 
 
 # Check the actual FPU precision with our new flags.
-# As before, we use -O3 for "worst case" behaviour.
-$CC $CFLAGS -O3 -o config/fpubits config/fpubits1.c config/fpubits2.c
+$CC -O3 $CFLAGS config/fpubits1.c config/fpubits2.c src/fpu.c -o config/fpubits
 if [ $? -ne 0 ]; then
-    echo "The command below failed:"
-    echo "$CC $CFLAGS -O3 -o config/fpubits config/fpubits1.c config/fpubits2.c"
+    echo >&2 "Error: the command below failed:"
+    echo >&2 "$CC -O3 $CFLAGS config/fpubits1.c config/fpubits2.c src/fpu.c -o config/fpubits"
     exit 1
 fi
+export CFLAGS
+
+echo "CFLAGS for SYMPOW:$CFLAGS"
 
 config/fpubits
 status=$?
 if [ $status -eq 1 ]; then
-    echo "The Quad Double library used by SYMPOW assumes IEEE-754 double precision"
-    echo "numbers with exactly 53 bits in the mantissa (64 bits in total)."
-    echo ""
-
-    # Check whether src/fpu.c (already patched!) compiles with -Dx86.
-    # If it does, we are almost surely on a x86 system. There is no need to
-    # run anything, we only need to see whether the asm instructions are
-    # recognized.
-    if $CC $CFLAGS -Dx86 -c -o config/srcfpu.o src/fpu.c >/dev/null 2>/dev/null; then
-        echo "It looks like you are running an x86 system. The default mode of"
-        echo "operation of the FPU in the x86 chips (first introduced in the 8087) is"
-        echo "to use extended precision, with 64 bits in the mantissa (and 80 bits in"
-        echo "total). We will add code to set the CPU's control word to disable this"
-        echo "extended precision. This is critical and was the cause of several"
-        echo "annoying Sage bugs - see"
-        echo "http://trac.sagemath.org/sage_trac/ticket/9703 (Solaris x86)"
-        echo "http://trac.sagemath.org/sage_trac/ticket/9734 (Solaris x86)"
-        echo "http://trac.sagemath.org/sage_trac/ticket/9166 (Cygwin)"
-        CFLAGS="$CFLAGS -Dx86"
-    else
-        echo "Unfortunately, we currently have no workaround for your system."
-        echo "Running SYMPOW will almost certainly fail on some inputs."
-        echo "Please report this problem to"
-        echo "sage-devel (http://groups.google.com/group/sage-devel),"
-        echo "mentioning in particular your operating system, processor type"
-        echo "and compiler version (run $CC --version)."
-        exit 1
-    fi
+cat >&2 <<EOF
+Error: the Quad Double library used by SYMPOW assumes IEEE-754 double
+precision numbers with exactly 53 bits in the mantissa (64 bits in
+total).  Unfortunately, this is not the case on your system and we
+currently have no workaround for your system.  Running SYMPOW will
+almost certainly fail on some inputs.
+
+Please report this problem to sage-devel
+(http://groups.google.com/group/sage-devel), mentioning in particular
+your operating system, processor type and compiler version
+(run $CC --version).
+EOF
 elif [ $status -ne 0 ]; then
-    echo "Something very bad happened while checking the precision of your FPU."
-    echo "Please report this problem (mentioning any error messages above) to"
-    echo "sage-devel (http://groups.google.com/group/sage-devel)."
-    echo "Mention in particular your operating system and compiler version"
-    echo "(run $CC --version)."
-    exit 1
+cat >&2 <<EOF
+Error: something very bad happened while checking the precision of your
+FPU.  Please report this problem (mentioning any error messages above)
+to sage-devel (http://groups.google.com/group/sage-devel).
+Mention in particular your operating system and compiler version
+(run $CC --version).
+EOF
+exit 1
 fi
 
-export CFLAGS
-
 #######################################################################
 # Configure
 #######################################################################
 cd src/
 bash ./Configure  # Force bash as shell
 if [ $? -ne 0 ]; then
-   echo "Error configuring sympow"
+   echo >&2 "Error configuring SYMPOW"
    exit 1
 fi
 
@@ -131 +149 @@
 # Build
 #######################################################################
 $MAKE
-
 if [ $? -ne 0 ]; then
-   echo "Error building sympow"
-   exit 1
-fi
-
-if [ ! -f sympow ]; then
-   echo "sympow executable missing"
+   echo >&2 "Error building SYMPOW"
    exit 1
 fi
 
@@ -147 +159 @@
 #######################################################################
 TARGET="$SAGE_LOCAL/lib/sympow"
 
-if [ -d "$TARGET" ]; then
-    rm -rf "$TARGET"
-fi
+rm -rf "$TARGET"
 mkdir "$TARGET"
 
 cp sympow *.gp new_data "$TARGET/"
-
-if [ ! -f "$TARGET/sympow" ]; then
-   echo "sympow executable didn't copy correctly"
+if [ $? -ne 0 ]; then
+   echo >&2 "Error copying SYMPOW files"
    exit 1
 fi
 
 # Copy datafiles
 mv datafiles "$TARGET/"
 if [ ! -d "$TARGET/datafiles" ]; then
-   echo "Error installing sympow datafiles."
+   echo >&2 "Error installing SYMPOW datafiles"
    exit 1
 fi
 
@@ -172 +181 @@
     NUM=`grep -c AT $file`
     ../sympow -txt2bin "$NUM" <$file ${file/%txt/bin}
     if [ $? -ne 0 ]; then
-        echo "Running sympow failed"
+        echo >&2 "Error running SYMPOW"
         exit 1
     fi
 done
@@ -180 +189 @@
 # Create sympow script in $SAGE_ROOT/local/bin
 SCRIPT="$SAGE_LOCAL/bin/sympow"
 
-cat >$SCRIPT <<'EOF'
+cat >"$SCRIPT" <<'EOF'
 #!/usr/bin/env bash
 
 cd "$SAGE_LOCAL/lib/sympow"
 exec ./sympow "$@"
 EOF
 
-chmod +x $SCRIPT
-
-exit 0
+chmod +x "$SCRIPT"