invoke.texi (xtensa options): Add -mforce-no-pic.

2010-05-27 Sterling Augustine <sterling@tensilica.com>

        * doc/invoke.texi (xtensa options): Add -mforce-no-pic.
        * config/xtensa/xtensa.c (override_options): Check
          TARGET_FORCE_NO_PIC and set flag_pic.
        * config/xtensa/xtensa.opt: Document -mforce-no-pic

From-SVN: r159950

gcc/config/xtensa/xtensa.c

@@ -2109,6 +2109,8 @@ override_options (void)
   if (flag_pic && TARGET_CONST16)
     error ("-f%s is not supported with CONST16 instructions",
 	   (flag_pic > 1 ? "PIC" : "pic"));
+  else if (TARGET_FORCE_NO_PIC)
+    flag_pic = 0;
   else if (XTENSA_ALWAYS_PIC)
     {
       if (TARGET_CONST16)

gcc/config/xtensa/xtensa.opt

@@ -26,6 +26,10 @@ mfused-madd
 Target Report Mask(FUSED_MADD)
 Enable fused multiply/add and multiply/subtract FP instructions
 
+mforce-no-pic
+Target Report Mask(FORCE_NO_PIC)
+Disable position-independent code (PIC) for use in OS kernel code
+
 mlongcalls
 Target
 Use indirect CALLXn instructions for large programs

gcc/doc/invoke.texi

@@ -889,6 +889,7 @@ See i386 and x86-64 Options.
 @emph{Xtensa Options}
 @gccoptlist{-mconst16 -mno-const16 @gol
 -mfused-madd  -mno-fused-madd @gol
+-mforce-no-pic @gol
 -mserialize-volatile  -mno-serialize-volatile @gol
 -mtext-section-literals  -mno-text-section-literals @gol
 -mtarget-align  -mno-target-align @gol
@@ -17082,6 +17083,12 @@ When this option is enabled, GCC inserts @code{MEMW} instructions before
 The default is @option{-mserialize-volatile}.  Use
 @option{-mno-serialize-volatile} to omit the @code{MEMW} instructions.
 
+@item -mforce-no-pic
+@opindex mforce-no-pic
+For targets, like GNU/Linux, where all user-mode Xtensa code must be
+position-independent code (PIC), this option disables PIC for compiling
+kernel code.
+
 @item -mtext-section-literals
 @itemx -mno-text-section-literals
 @opindex mtext-section-literals