At the moment, we have two functions that create and look at TOC references:
create_TOC_reference (global function)
use_toc_relative_ref (static function in rs6000.c)
Since I am adding pc-relative support that will be used instead of TOC support,
this patch renames these two functions to be:
create_data_reference
use_toc_or_pc_relative_ref
and it adds some of the foundation for adding pc-relative support. Note, it
will need future patches to completely flesh out the pc-relative support. As
per a previous private discussion, I kept the old create_TOC_reference and
added a gcc assert if it is called when pc-relative addressing is used. There
is currently one place that still calls create_TOC_reference (in a section
using TLS addresses).
I have done a bootstrap on a power8 little endian Linux system with no
regressions. Can I check this into the trunk?
2019-06-28 Michael Meissner <meiss...@linux.ibm.com>
* config/rs6000/rs6000-logue.c (create_TOC_reference): Move debug
statements to create_data_reference. Add gcc_assert to make sure
we are using TOCs and not pc-relative addressing.
(create_data_reference): New function, create either a TOC style
reference or a pc-relative reference to local symbols.
* config/rs6000/rs6000-protos.h (create_data_reference): Add
declaration.
* config/rs6000/rs6000.c (rs6000_legitimize_address): Call
create_data_reference instead of create_TOC_reference.
(use_toc_or_pc_relative_ref): Rename from use_toc_relative_ref and
add support for pc-relative addressing.
(rs6000_emit_move): Call use_toc_or_pc_relative_ref and
create_data_reference instead of use_toc_relative_ref and
create_TOC_reference.
* config/rs6000/rs6000.md (cmp<mode>_internal2): Call
create_data_reference instead of create_TOC_reference.
Index: gcc/config/rs6000/rs6000-logue.c
===================================================================
--- gcc/config/rs6000/rs6000-logue.c (revision 272714)
+++ gcc/config/rs6000/rs6000-logue.c (working copy)
@@ -1406,23 +1406,13 @@ uses_TOC (void)
}
#endif
+/* Create a TOC style reference for a symbol. */
rtx
create_TOC_reference (rtx symbol, rtx largetoc_reg)
{
rtx tocrel, tocreg, hi;
- if (TARGET_DEBUG_ADDR)
- {
- if (SYMBOL_REF_P (symbol))
- fprintf (stderr, "\ncreate_TOC_reference, (symbol_ref %s)\n",
- XSTR (symbol, 0));
- else
- {
- fprintf (stderr, "\ncreate_TOC_reference, code %s:\n",
- GET_RTX_NAME (GET_CODE (symbol)));
- debug_rtx (symbol);
- }
- }
+ gcc_assert (TARGET_TOC && !TARGET_PCREL);
if (!can_create_pseudo_p ())
df_set_regs_ever_live (TOC_REGISTER, true);
@@ -1441,6 +1431,39 @@ create_TOC_reference (rtx symbol, rtx la
return gen_rtx_LO_SUM (Pmode, hi, tocrel);
}
+/* Create either a TOC reference to a locally defined item or a pc-relative
+ reference, depending on the ABI. */
+rtx
+create_data_reference (rtx symbol, rtx largetoc_reg)
+{
+ if (TARGET_DEBUG_ADDR)
+ {
+ const char *toc_or_pcrel = (TARGET_PCREL) ? "pc-relative" : "TOC";
+
+ if (SYMBOL_REF_P (symbol))
+ fprintf (stderr, "\ncreate_data_reference, abi %s, (symbol_ref %s)\n",
+ toc_or_pcrel, XSTR (symbol, 0));
+ else
+ {
+ fprintf (stderr, "\ncreate_data_reference, abi %s, code %s:\n",
+ toc_or_pcrel, GET_RTX_NAME (GET_CODE (symbol)));
+ debug_rtx (symbol);
+ }
+ }
+
+ /* We don't have to do anything special for pc-relative references. The
+ SYMBOL_REF bits sayss whether the label is local where we can use
+ pc-relative addressing, or if we have to load the address from the GOT
+ section to use it on external addresses. */
+ if (TARGET_PCREL)
+ {
+ gcc_assert (TARGET_CMODEL == CMODEL_MEDIUM);
+ return symbol;
+ }
+
+ return create_TOC_reference (symbol, largetoc_reg);
+}
+
/* Issue assembly directives that create a reference to the given DWARF
FRAME_TABLE_LABEL from the current function section. */
void
Index: gcc/config/rs6000/rs6000-protos.h
===================================================================
--- gcc/config/rs6000/rs6000-protos.h (revision 272714)
+++ gcc/config/rs6000/rs6000-protos.h (working copy)
@@ -131,6 +131,7 @@ extern void rs6000_emit_swdiv (rtx, rtx,
extern void rs6000_emit_swsqrt (rtx, rtx, bool);
extern void output_toc (FILE *, rtx, int, machine_mode);
extern void rs6000_fatal_bad_address (rtx);
+extern rtx create_data_reference (rtx, rtx);
extern rtx create_TOC_reference (rtx, rtx);
extern void rs6000_split_multireg_move (rtx, rtx);
extern void rs6000_emit_le_vsx_permute (rtx, rtx, machine_mode);
Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c (revision 272766)
+++ gcc/config/rs6000/rs6000.c (working copy)
@@ -8084,7 +8084,7 @@ rs6000_legitimize_address (rtx x, rtx ol
&& SYMBOL_REF_P (x)
&& constant_pool_expr_p (x)
&& ASM_OUTPUT_SPECIAL_POOL_ENTRY_P (get_pool_constant (x), Pmode))
- return create_TOC_reference (x, NULL_RTX);
+ return create_data_reference (x, NULL_RTX);
else
return x;
}
@@ -8696,19 +8696,21 @@ rs6000_cannot_force_const_mem (machine_m
return TARGET_ELF && tls_referenced_p (x);
}
-/* Return true iff the given SYMBOL_REF refers to a constant pool entry
- that we have put in the TOC, or for cmodel=medium, if the SYMBOL_REF
- can be addressed relative to the toc pointer. */
+/* Return true iff the given SYMBOL_REF refers to a constant pool entry that we
+ have put in the TOC or is referenced via a pc-relative reference. In
+ addition, for cmodel=medium, if the SYMBOL_REF can be addressed relative to
+ the either toc pointer or via a pc-relative reference. */
static bool
-use_toc_relative_ref (rtx sym, machine_mode mode)
+use_toc_or_pc_relative_ref (rtx sym, machine_mode mode)
{
return ((constant_pool_expr_p (sym)
&& ASM_OUTPUT_SPECIAL_POOL_ENTRY_P (get_pool_constant (sym),
get_pool_mode (sym)))
|| (TARGET_CMODEL == CMODEL_MEDIUM
&& SYMBOL_REF_LOCAL_P (sym)
- && GET_MODE_SIZE (mode) <= POWERPC64_TOC_POINTER_ALIGNMENT));
+ && (TARGET_PCREL
+ || GET_MODE_SIZE (mode) <= POWERPC64_TOC_POINTER_ALIGNMENT)));
}
/* TARGET_LEGITIMATE_ADDRESS_P recognizes an RTL expression
@@ -9810,8 +9812,8 @@ rs6000_emit_move (rtx dest, rtx source,
reference to it. */
if (TARGET_TOC
&& SYMBOL_REF_P (operands[1])
- && use_toc_relative_ref (operands[1], mode))
- operands[1] = create_TOC_reference (operands[1], operands[0]);
+ && use_toc_or_pc_relative_ref (operands[1], mode))
+ operands[1] = create_data_reference (operands[1], operands[0]);
else if (mode == Pmode
&& CONSTANT_P (operands[1])
&& GET_CODE (operands[1]) != HIGH
@@ -9864,11 +9866,11 @@ rs6000_emit_move (rtx dest, rtx source,
if (TARGET_TOC
&& SYMBOL_REF_P (XEXP (operands[1], 0))
- && use_toc_relative_ref (XEXP (operands[1], 0), mode))
+ && use_toc_or_pc_relative_ref (XEXP (operands[1], 0), mode))
{
- rtx tocref = create_TOC_reference (XEXP (operands[1], 0),
- operands[0]);
- operands[1] = gen_const_mem (mode, tocref);
+ rtx dataref = create_data_reference (XEXP (operands[1], 0),
+ operands[0]);
+ operands[1] = gen_const_mem (mode, dataref);
set_mem_alias_set (operands[1], get_TOC_alias_set ());
}
}
Index: gcc/config/rs6000/rs6000.md
===================================================================
--- gcc/config/rs6000/rs6000.md (revision 272757)
+++ gcc/config/rs6000/rs6000.md (working copy)
@@ -11666,9 +11666,9 @@ (define_insn_and_split "*cmp<mode>_inter
if (TARGET_TOC)
{
rtx tocref;
- tocref = create_TOC_reference (XEXP (operands[14], 0), operands[11]);
+ tocref = create_data_reference (XEXP (operands[14], 0), operands[11]);
operands[14] = gen_const_mem (DFmode, tocref);
- tocref = create_TOC_reference (XEXP (operands[15], 0), operands[11]);
+ tocref = create_data_reference (XEXP (operands[15], 0), operands[11]);
operands[15] = gen_const_mem (DFmode, tocref);
set_mem_alias_set (operands[14], get_TOC_alias_set ());
set_mem_alias_set (operands[15], get_TOC_alias_set ());
--
Michael Meissner, IBM
IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA
email: meiss...@linux.ibm.com, phone: +1 (978) 899-4797
