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[6/6, committed] RTP PIC support for MIPS VxWorks
- From: Richard Sandiford <richard at codesourcery dot com>
- To: gcc-patches at gcc dot gnu dot org
- Date: Thu, 12 Apr 2007 19:00:38 +0100
- Subject: [6/6, committed] RTP PIC support for MIPS VxWorks
- References: <87mz1dtt4y.fsf@firetop.home>
And here is the RTP patch itself. insn-emit.c neds to call
get_hard_reg_initial_val, so I've also added integrate.h to
the list of files that it includes. That falls outside the
MIPS backend, but I thought it counted as obvious.
I hope the comments adequately explain what the new code is doing.
Tested on mips64-linux-gnu and mips-wrs-vxworks. Applied to trunk.
Richard
gcc/
* Makefile.in (insn-emit.o): Depend on $(INTEGRATE_H).
* genemit.c (main): Emit #include "integrate.h".
* config/mips/mips-protos.h (SYMBOL_HALF): New mips_symbol_type.
(LOADGP_RTP): New mips_loadgp_style.
* config/mips/mips.h: Include config/vxworks-dummy.h.
(TARGET_RTP_PIC): New macro.
(TARGET_USE_GOT): Return true for TARGET_RTP_PIC.
(TARGET_USE_PIC_FN_ADDR_REG): Return true for TARGET_VXWORKS_RTP.
(ASM_OUTPUT_ADDR_DIFF_ELT): Emit function-relative case tables
for TARGET_RTP_PIC.
* config/mips/vxworks.h (SUBTARGET_ASM_SPEC): Define. Pass down
-mvxworks-pic when using -mrtp and a PIC option.
* config/mips/mips.c (mips_classify_symbol): Return SYMBOL_GOT_DISP
for RTP PIC.
(mips_symbolic_constant_p, mips_symbolic_address_p)
(mips_symbol_insns): Handle SYMBOL_HALF.
(override_options): Warn about -G and -mrtp being used together.
Initialize mips_lo_relocs[SYMBOL_HALF].
(mips_current_loadgp_style): Return LOADGP_RTP for RTP PIC.
(mips_emit_loadgp): Handle LOADGP_RTP.
(mips_in_small_data_p): Return false for TARGET_VXWORKS_RTP.
* config/mips/mips.md (loadgp_rtp): New insn and splitter.
(tablejump): Handle function-relative case table entries if
TARGET_RTP_PIC.
* config/mips/predicates.md (symbol_ref_operand): New predicate.
Index: gcc/Makefile.in
===================================================================
--- gcc/Makefile.in 2007-04-02 14:29:16.000000000 +0100
+++ gcc/Makefile.in 2007-04-12 09:56:42.000000000 +0100
@@ -2847,7 +2847,7 @@ insn-automata.o : insn-automata.c $(CONF
insn-emit.o : insn-emit.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) \
$(RTL_H) $(EXPR_H) $(REAL_H) output.h insn-config.h $(OPTABS_H) \
reload.h $(RECOG_H) toplev.h $(FUNCTION_H) $(FLAGS_H) hard-reg-set.h \
- $(RESOURCE_H) $(TM_P_H) $(BASIC_BLOCK_H) tm-constrs.h
+ $(RESOURCE_H) $(TM_P_H) $(BASIC_BLOCK_H) $(INTEGRATE_H) tm-constrs.h
insn-extract.o : insn-extract.c $(CONFIG_H) $(SYSTEM_H) coretypes.h \
$(TM_H) $(RTL_H) toplev.h insn-config.h $(RECOG_H)
insn-modes.o : insn-modes.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) \
Index: gcc/config/mips/mips-protos.h
===================================================================
--- gcc/config/mips/mips-protos.h 2007-04-12 09:54:35.000000000 +0100
+++ gcc/config/mips/mips-protos.h 2007-04-12 09:56:42.000000000 +0100
@@ -82,7 +82,11 @@ #define GCC_MIPS_PROTOS_H
SYMBOL_64_LOW
For a 64-bit symbolic address X, this is the value of
- (%hi(X) << 16) + %lo(X). */
+ (%hi(X) << 16) + %lo(X).
+
+ SYMBOL_HALF
+ An UNSPEC wrapper around any kind of address. It represents the
+ low 16 bits of that address. */
enum mips_symbol_type {
SYMBOL_GENERAL,
SYMBOL_SMALL_DATA,
@@ -101,9 +105,10 @@ enum mips_symbol_type {
SYMBOL_TPREL,
SYMBOL_64_HIGH,
SYMBOL_64_MID,
- SYMBOL_64_LOW
+ SYMBOL_64_LOW,
+ SYMBOL_HALF
};
-#define NUM_SYMBOL_TYPES (SYMBOL_64_LOW + 1)
+#define NUM_SYMBOL_TYPES (SYMBOL_HALF + 1)
/* Identifiers a style of $gp initialization sequence.
@@ -119,12 +124,16 @@ #define NUM_SYMBOL_TYPES (SYMBOL_64_LOW
by .cpsetup).
LOADGP_ABSOLUTE
- The GNU absolute sequence, as generated by loadgp_absolute. */
+ The GNU absolute sequence, as generated by loadgp_absolute.
+
+ LOADGP_RTP
+ The VxWorks RTP PIC sequence, as generated by loadgp_rtp. */
enum mips_loadgp_style {
LOADGP_NONE,
LOADGP_OLDABI,
LOADGP_NEWABI,
- LOADGP_ABSOLUTE
+ LOADGP_ABSOLUTE,
+ LOADGP_RTP
};
extern bool mips_symbolic_constant_p (rtx, enum mips_symbol_type *);
Index: gcc/config/mips/mips.c
===================================================================
--- gcc/config/mips/mips.c 2007-04-12 09:54:35.000000000 +0100
+++ gcc/config/mips/mips.c 2007-04-12 09:56:42.000000000 +0100
@@ -1245,6 +1245,9 @@ mips_symbol_binds_local_p (rtx x)
static enum mips_symbol_type
mips_classify_symbol (rtx x)
{
+ if (TARGET_RTP_PIC)
+ return SYMBOL_GOT_DISP;
+
if (GET_CODE (x) == LABEL_REF)
{
if (TARGET_MIPS16)
@@ -1385,6 +1388,7 @@ mips_symbolic_constant_p (rtx x, enum mi
case SYMBOL_TPREL:
case SYMBOL_GOTTPREL:
case SYMBOL_TLS:
+ case SYMBOL_HALF:
return false;
}
gcc_unreachable ();
@@ -1484,6 +1488,7 @@ mips_symbolic_address_p (enum mips_symbo
case SYMBOL_64_HIGH:
case SYMBOL_64_MID:
case SYMBOL_64_LOW:
+ case SYMBOL_HALF:
return true;
}
gcc_unreachable ();
@@ -1630,6 +1635,7 @@ mips_symbol_insns (enum mips_symbol_type
return (ABI_HAS_64BIT_SYMBOLS ? 6 : 2);
case SYMBOL_SMALL_DATA:
+ case SYMBOL_HALF:
return 1;
case SYMBOL_CONSTANT_POOL:
@@ -4886,6 +4892,9 @@ override_options (void)
warning (0, "%<-G%> is incompatible with %<-mabicalls%>");
}
+ if (TARGET_VXWORKS_RTP && mips_section_threshold > 0)
+ warning (0, "-G and -mrtp are incompatible");
+
/* mips_split_addresses is a half-way house between explicit
relocations and the traditional assembler macros. It can
split absolute 32-bit symbolic constants into a high/lo_sum
@@ -5192,6 +5201,8 @@ override_options (void)
mips_hi_relocs[SYMBOL_TPREL] = "%tprel_hi(";
mips_lo_relocs[SYMBOL_TPREL] = "%tprel_lo(";
+ mips_lo_relocs[SYMBOL_HALF] = "%half(";
+
/* We don't have a thread pointer access instruction on MIPS16, or
appropriate TLS relocations. */
if (TARGET_MIPS16)
@@ -6573,6 +6584,9 @@ mips_current_loadgp_style (void)
if (!TARGET_USE_GOT || cfun->machine->global_pointer == 0)
return LOADGP_NONE;
+ if (TARGET_RTP_PIC)
+ return LOADGP_RTP;
+
if (TARGET_ABSOLUTE_ABICALLS)
return LOADGP_ABSOLUTE;
@@ -6589,7 +6603,7 @@ static GTY(()) rtx mips_gnu_local_gp;
static void
mips_emit_loadgp (void)
{
- rtx addr, offset, incoming_address;
+ rtx addr, offset, incoming_address, base, index;
switch (mips_current_loadgp_style ())
{
@@ -6611,6 +6625,14 @@ mips_emit_loadgp (void)
emit_insn (gen_loadgp_blockage ());
break;
+ case LOADGP_RTP:
+ base = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (VXWORKS_GOTT_BASE));
+ index = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (VXWORKS_GOTT_INDEX));
+ emit_insn (gen_loadgp_rtp (base, index));
+ if (!TARGET_EXPLICIT_RELOCS)
+ emit_insn (gen_loadgp_blockage ());
+ break;
+
default:
break;
}
@@ -7313,9 +7335,9 @@ mips_in_small_data_p (tree decl)
if (TREE_CODE (decl) == STRING_CST || TREE_CODE (decl) == FUNCTION_DECL)
return false;
- /* We don't yet generate small-data references for -mabicalls. See related
- -G handling in override_options. */
- if (TARGET_ABICALLS)
+ /* We don't yet generate small-data references for -mabicalls or
+ VxWorks RTP code. See the related -G handling in override_options. */
+ if (TARGET_ABICALLS || TARGET_VXWORKS_RTP)
return false;
if (TREE_CODE (decl) == VAR_DECL && DECL_SECTION_NAME (decl) != 0)
Index: gcc/config/mips/mips.h
===================================================================
--- gcc/config/mips/mips.h 2007-04-12 09:54:19.000000000 +0100
+++ gcc/config/mips/mips.h 2007-04-12 09:56:42.000000000 +0100
@@ -24,6 +24,8 @@ the Free Software Foundation; either ver
Boston, MA 02110-1301, USA. */
+#include "config/vxworks-dummy.h"
+
/* MIPS external variables defined in mips.c. */
/* Which processor to schedule for. Since there is no difference between
@@ -143,6 +145,9 @@ #define BITMASK_LOWER16 ((unsigned long)
/* Run-time compilation parameters selecting different hardware subsets. */
+/* True if we are generating position-independent VxWorks RTP code. */
+#define TARGET_RTP_PIC (TARGET_VXWORKS_RTP && flag_pic)
+
/* True if the call patterns should be split into a jalr followed by
an instruction to restore $gp. It is only safe to split the load
from the call when every use of $gp is explicit. */
@@ -178,7 +183,7 @@ #define TARGET_SIBCALLS \
(!TARGET_MIPS16 && (!TARGET_USE_GOT || TARGET_EXPLICIT_RELOCS))
/* True if we need to use a global offset table to access some symbols. */
-#define TARGET_USE_GOT TARGET_ABICALLS
+#define TARGET_USE_GOT (TARGET_ABICALLS || TARGET_RTP_PIC)
/* True if TARGET_USE_GOT and if $gp is a call-clobbered register. */
#define TARGET_CALL_CLOBBERED_GP (TARGET_ABICALLS && TARGET_OLDABI)
@@ -186,8 +191,9 @@ #define TARGET_CALL_CLOBBERED_GP (TARGET
/* True if TARGET_USE_GOT and if $gp is a call-saved register. */
#define TARGET_CALL_SAVED_GP (TARGET_USE_GOT && !TARGET_CALL_CLOBBERED_GP)
-/* True if indirect calls must use register class PIC_FN_ADDR_REG. */
-#define TARGET_USE_PIC_FN_ADDR_REG TARGET_ABICALLS
+/* True if indirect calls must use register class PIC_FN_ADDR_REG.
+ This is true for both the PIC and non-PIC VxWorks RTP modes. */
+#define TARGET_USE_PIC_FN_ADDR_REG (TARGET_ABICALLS || TARGET_VXWORKS_RTP)
/* True if .gpword or .gpdword should be used for switch tables.
@@ -2578,6 +2584,16 @@ #define ASM_OUTPUT_ADDR_DIFF_ELT(STREAM,
fprintf (STREAM, "\t%s\t%sL%d\n", \
ptr_mode == DImode ? ".gpdword" : ".gpword", \
LOCAL_LABEL_PREFIX, VALUE); \
+ else if (TARGET_RTP_PIC) \
+ { \
+ /* Make the entry relative to the start of the function. */ \
+ rtx fnsym = XEXP (DECL_RTL (current_function_decl), 0); \
+ fprintf (STREAM, "\t%s\t%sL%d-", \
+ Pmode == DImode ? ".dword" : ".word", \
+ LOCAL_LABEL_PREFIX, VALUE); \
+ assemble_name (STREAM, XSTR (fnsym, 0)); \
+ fprintf (STREAM, "\n"); \
+ } \
else \
fprintf (STREAM, "\t%s\t%sL%d\n", \
ptr_mode == DImode ? ".dword" : ".word", \
Index: gcc/config/mips/mips.md
===================================================================
--- gcc/config/mips/mips.md 2007-04-12 09:56:04.000000000 +0100
+++ gcc/config/mips/mips.md 2007-04-12 09:56:42.000000000 +0100
@@ -4125,6 +4125,30 @@ (define_insn "loadgp_blockage"
(set_attr "mode" "none")
(set_attr "length" "0")])
+;; Initialize $gp for RTP PIC. Operand 0 is the __GOTT_BASE__ symbol
+;; and operand 1 is the __GOTT_INDEX__ symbol.
+(define_insn "loadgp_rtp"
+ [(unspec_volatile [(match_operand 0 "symbol_ref_operand")
+ (match_operand 1 "symbol_ref_operand")] UNSPEC_LOADGP)]
+ "mips_current_loadgp_style () == LOADGP_RTP"
+ "#"
+ [(set_attr "length" "12")])
+
+(define_split
+ [(unspec_volatile [(match_operand:P 0 "symbol_ref_operand")
+ (match_operand:P 1 "symbol_ref_operand")] UNSPEC_LOADGP)]
+ "mips_current_loadgp_style () == LOADGP_RTP"
+ [(set (match_dup 2) (high:P (match_dup 3)))
+ (set (match_dup 2) (unspec:P [(match_dup 2)
+ (match_dup 3)] UNSPEC_LOAD_GOT))
+ (set (match_dup 2) (unspec:P [(match_dup 2)
+ (match_dup 4)] UNSPEC_LOAD_GOT))]
+{
+ operands[2] = pic_offset_table_rtx;
+ operands[3] = mips_unspec_address (operands[0], SYMBOL_GENERAL);
+ operands[4] = mips_unspec_address (operands[1], SYMBOL_HALF);
+})
+
;; Emit a .cprestore directive, which normally expands to a single store
;; instruction. Note that we continue to use .cprestore for explicit reloc
;; code so that jals inside inline asms will work correctly.
@@ -4931,6 +4955,15 @@ (define_expand "tablejump"
else if (TARGET_GPWORD)
operands[0] = expand_binop (Pmode, add_optab, operands[0],
pic_offset_table_rtx, 0, 0, OPTAB_WIDEN);
+ else if (TARGET_RTP_PIC)
+ {
+ /* When generating RTP PIC, we use case table entries that are relative
+ to the start of the function. Add the function's address to the
+ value we loaded. */
+ rtx start = get_hard_reg_initial_val (Pmode, PIC_FUNCTION_ADDR_REGNUM);
+ operands[0] = expand_binop (ptr_mode, add_optab, operands[0],
+ start, 0, 0, OPTAB_WIDEN);
+ }
if (Pmode == SImode)
emit_jump_insn (gen_tablejumpsi (operands[0], operands[1]));
Index: gcc/config/mips/predicates.md
===================================================================
--- gcc/config/mips/predicates.md 2007-04-12 09:54:20.000000000 +0100
+++ gcc/config/mips/predicates.md 2007-04-12 09:56:42.000000000 +0100
@@ -251,6 +251,9 @@ (define_predicate "got_page_ofst_operand
return mips_symbolic_constant_p (op, &type) && type == SYMBOL_GOT_PAGE_OFST;
})
+(define_predicate "symbol_ref_operand"
+ (match_code "symbol_ref"))
+
(define_predicate "stack_operand"
(and (match_code "mem")
(match_test "mips_stack_address_p (XEXP (op, 0), GET_MODE (op))")))
Index: gcc/config/mips/vxworks.h
===================================================================
--- gcc/config/mips/vxworks.h 2007-04-03 10:17:11.000000000 +0100
+++ gcc/config/mips/vxworks.h 2007-04-12 09:56:42.000000000 +0100
@@ -86,3 +86,6 @@ #define MIPS_DEFAULT_GVALUE 0
/* No _mcount profiling on VxWorks. */
#undef FUNCTION_PROFILER
#define FUNCTION_PROFILER VXWORKS_FUNCTION_PROFILER
+
+#undef SUBTARGET_ASM_SPEC
+#define SUBTARGET_ASM_SPEC "%{mrtp:%{fPIC|fpic:-mvxworks-pic}}"
Index: gcc/genemit.c
===================================================================
--- gcc/genemit.c 2007-03-20 09:38:16.000000000 +0000
+++ gcc/genemit.c 2007-04-12 09:56:42.000000000 +0100
@@ -857,6 +857,7 @@ main (int argc, char **argv)
printf ("#include \"tm-constrs.h\"\n");
printf ("#include \"ggc.h\"\n\n");
printf ("#include \"basic-block.h\"\n\n");
+ printf ("#include \"integrate.h\"\n\n");
printf ("#define FAIL return (end_sequence (), _val)\n");
printf ("#define DONE return (_val = get_insns (), end_sequence (), _val)\n\n");