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[arm] New option for PIC offset unfixed

Message ID 000101cee08a$ba5b5720$2f120560$@arm.com
State New
Headers show

Commit Message

Joey Ye Nov. 13, 2013, 4:09 p.m. UTC 
This patch address all comments.

Thanks,
Joey

> -----Original Message-----
> From: Richard Earnshaw
> Sent: Wednesday, November 13, 2013 19:07
> To: Joey Ye
> Cc: gcc-patches@gcc.gnu.org
> Subject: Re: [patch] [arm] New option for PIC offset unfixed
> 
> On 13/11/13 10:20, Joey Ye wrote:
> >>> +@item -mpic-data-is-text-relative
> >>> > > +@opindex mpic-data-is-text-relative Assume that each data
> >>> > > +segments are relative to text segment at load
> > time.
> >> >
> >>> > > +Therefore, prevent PC relative and GOTOFF style relocations to
> >>> > > +reference data.
> >> >
> >> > I think the sense of this sentence is now backwards.  I'd also try
> >> > to
> > avoid
> >> > GOTOFF in the user part of the manual.
> > How about
> > "Therefore, prevent addressing data with relocation types that doesn't
> > apply in such circumstance."
> >
> >> >
> 
> No, that's still backwards.  Remember, the option is now pic-data-is-text-
> relative, so the option /permits/ addressing data using PC-relative
operations.
> 
> R.
diff mbox

Patch

diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 7757e86..5a95399 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -2504,6 +2504,11 @@  arm_option_override (void)
 	arm_pic_register = pic_register;
     }
 
+  if (arm_pic_data_is_text_relative < 0 && TARGET_VXWORKS_RTP)
+    arm_pic_data_is_text_relative = 0;
+  else
+    arm_pic_data_is_text_relative = 1;
+
   /* Enable -mfix-cortex-m3-ldrd by default for Cortex-M3 cores.  */
   if (fix_cm3_ldrd == 2)
     {
@@ -6020,7 +6025,7 @@  legitimize_pic_address (rtx orig, enum machine_mode mode, rtx reg)
 	   || (GET_CODE (orig) == SYMBOL_REF &&
 	       SYMBOL_REF_LOCAL_P (orig)))
 	  && NEED_GOT_RELOC
-	  && !TARGET_VXWORKS_RTP)
+	  && arm_pic_data_is_text_relative)
 	insn = arm_pic_static_addr (orig, reg);
       else
 	{
@@ -21498,7 +21503,7 @@  arm_assemble_integer (rtx x, unsigned int size, int aligned_p)
 	{
 	  /* See legitimize_pic_address for an explanation of the
 	     TARGET_VXWORKS_RTP check.  */
-	  if (TARGET_VXWORKS_RTP
+	  if (!arm_pic_data_is_text_relative
 	      || (GET_CODE (x) == SYMBOL_REF && !SYMBOL_REF_LOCAL_P (x)))
 	    fputs ("(GOT)", asm_out_file);
 	  else
diff --git a/gcc/config/arm/arm.opt b/gcc/config/arm/arm.opt
index 9b74038..adac749 100644
--- a/gcc/config/arm/arm.opt
+++ b/gcc/config/arm/arm.opt
@@ -158,6 +158,10 @@  mlong-calls
 Target Report Mask(LONG_CALLS)
 Generate call insns as indirect calls, if necessary
 
+mpic-data-is-text-relative
+Target Report Var(arm_pic_data_is_text_relative) Init(-1)
+Assume data segments are relative to text segment.
+
 mpic-register=
 Target RejectNegative Joined Var(arm_pic_register_string)
 Specify the register to be used for PIC addressing
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 863e518..fbe77e6 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -12120,6 +12120,12 @@  before execution begins.
 Specify the register to be used for PIC addressing.  The default is R10
 unless stack-checking is enabled, when R9 is used.
 
+@item -mpic-data-is-text-relative
+@opindex mpic-data-is-text-relative
+Assume that each data segments are relative to text segment at load time.
+Therefore, it permits addressing data using PC-relative operations.
+This option is on by default for targets other than VxWorks RTP.
+
 @item -mpoke-function-name
 @opindex mpoke-function-name
 Write the name of each function into the text section, directly