On Mon, 2013-07-15 at 22:35 +0200, Jakub Jelinek wrote:
> On Mon, Jul 15, 2013 at 02:46:56PM -0500, Peter Bergner wrote:
> > > I'd say something like (but, untested and can't test it right now (and no
> > > access to power8 anyway)):
> >
> > Do we also need to update DWARF_REG_TO_UNWIND_COLUMN similarly, which
> > also uses FIRST_PSEUDO_REGISTER when the dwarf reg is an SPE synthetic
> > register?
>
> Looks like it. Guess that "- 1" in there:
> #define DWARF_REG_TO_UNWIND_COLUMN(r) \
> ((r) > 1200 ? ((r) - 1200 + FIRST_PSEUDO_REGISTER - 1) : (r))
> stands for the sfp register and thus it would be "- 4".
>
> > Or should we just break the dependence on FIRST_PSEUDO_REGISTER
> > altogether so this type of thing doesn't happen again? Otherwise, we
> > should place a comment at the definition of FIRST_PSEUDO_REGISTER
> > warning of it's use in DWARF_FRAME_REGISTER.
>
> That is surely an option too. Or use (DWARF_FRAME_REGISTERS - 32)
> in the DWARF_REG_TO_UNWIND_COLUMN definition instead of the current
> FIRST_PSEUDO_REGISTER - 1, and perhaps make DWARF_FRAME_REGISTERS
> just a number (independent on FIRST_PSEUDO_REGISTER).
> Guess this depends on what David prefers.
I like the idea of removing FIRST_PSEUDO_REGISTER from the definition
of DWARF_REG_TO_UNWIND_COLUMN. I'll still let David decide whether
he wants DWARF_FRAME_REGISTERS to be just a number of computed off
of FIRST_PSEUDO_REGISTER. In the meantime, I'll bootstrap and
regtest your patch along with the DWARF_REG_TO_UNWIND_COLUMN
change.
Peter
* config/rs6000/rs6000.h (FIRST_PSEUDO_REGISTERS): Mention HTM
registers in the comment.
(DWARF_FRAME_REGISTERS): Subtract also the 3 HTM registers.
(DWARF_REG_TO_UNWIND_COLUMN): Use DWARF_FRAME_REGISTERS
rather than FIRST_PSEUDO_REGISTERS.
Index: gcc/config/rs6000/rs6000.h
===================================================================
--- gcc/config/rs6000/rs6000.h (revision 200985)
+++ gcc/config/rs6000/rs6000.h (working copy)
@@ -892,15 +892,17 @@ enum data_align { align_abi, align_opt,
in inline functions.
Another pseudo (not included in DWARF_FRAME_REGISTERS) is soft frame
- pointer, which is eventually eliminated in favor of SP or FP. */
+ pointer, which is eventually eliminated in favor of SP or FP.
+ The 3 HTM registers aren't also included in DWARF_FRAME_REGISTERS. */
+
#define FIRST_PSEUDO_REGISTER 117
/* This must be included for pre gcc 3.0 glibc compatibility. */
#define PRE_GCC3_DWARF_FRAME_REGISTERS 77
/* Add 32 dwarf columns for synthetic SPE registers. */
-#define DWARF_FRAME_REGISTERS ((FIRST_PSEUDO_REGISTER - 1) + 32)
+#define DWARF_FRAME_REGISTERS ((FIRST_PSEUDO_REGISTER - 4) + 32)
/* The SPE has an additional 32 synthetic registers, with DWARF debug
info numbering for these registers starting at 1200. While eh_frame
@@ -916,7 +918,7 @@ enum data_align { align_abi, align_opt,
We must map them here to avoid huge unwinder tables mostly consisting
of unused space. */
#define DWARF_REG_TO_UNWIND_COLUMN(r) \
- ((r) > 1200 ? ((r) - 1200 + FIRST_PSEUDO_REGISTER - 1) : (r))
+ ((r) > 1200 ? ((r) - 1200 + (DWARF_FRAME_REGISTERS - 32)) : (r))
/* Use standard DWARF numbering for DWARF debugging information. */
#define DBX_REGISTER_NUMBER(REGNO) rs6000_dbx_register_number (REGNO)
