Hi,
This patch adds basic infrastructure support to enable PC-relative addressing.
It adds the -mpcrel / -mno-pcrel option (defaulted on for -mcpu=future,
otherwise
off), and provides a couple of interfaces to determine whether PC-relative
addressing should be used when generating a single function.
Bootstrapped and tested on powerpc64le-unknown-linux-gnu with no regressions.
Is this okay for trunk?
Thanks,
Bill
2019-05-22 Bill Schmidt <wschm...@linux.ibm.com>
Michael Meissner <meiss...@linux.ibm.com>
Segher Boessenkool <seg...@kernel.crashing.org>
* config/rs6000/rs6000-cpus.def (ISA_FUTURE_MASKS_SERVER): Add
OPTION_MASK_PCREL.
(OTHER_FUTURE_MASKS): New #define.
(OTHER_P9_VECTOR_MASKS): Add OTHER_FUTURE_MASKS.
(POWERPC_MASKS): Add OPTION_MASK_PCREL.
* config/rs6000/rs6000-protos.h (rs6000_pcrel_p): New prototype.
(rs6000_fndecl_pcrel_p): Likewise.
* config/rs6000/rs6000.c (rs6000_option_override_internal): Report
error if -mpcrel is requested without -mcpu=future.
(rs6000_fndecl_pcrel_p): New function.
(rs6000_pcrel_p): Likewise.
* config/rs6000/rs6000.opt (mpcrel): New option.
* doc/invoke.texi: Document -mpcrel and -mno-pcrel.
diff --git a/gcc/config/rs6000/rs6000-cpus.def
b/gcc/config/rs6000/rs6000-cpus.def
index f32da25930d..a4e1d1a01d8 100644
--- a/gcc/config/rs6000/rs6000-cpus.def
+++ b/gcc/config/rs6000/rs6000-cpus.def
@@ -74,10 +74,15 @@
/* Support for a future processor's features. */
#define ISA_FUTURE_MASKS_SERVER (ISA_3_0_MASKS_SERVER
\
- | OPTION_MASK_FUTURE)
+ | OPTION_MASK_FUTURE \
+ | OPTION_MASK_PCREL)
+
+/* Flags that need to be turned off if -mno-future. */
+#define OTHER_FUTURE_MASKS (OPTION_MASK_PCREL)
/* Flags that need to be turned off if -mno-power9-vector. */
-#define OTHER_P9_VECTOR_MASKS (OPTION_MASK_FLOAT128_HW \
+#define OTHER_P9_VECTOR_MASKS (OTHER_FUTURE_MASKS \
+ | OPTION_MASK_FLOAT128_HW \
| OPTION_MASK_FUTURE \
| OPTION_MASK_P9_MINMAX)
@@ -129,6 +134,7 @@
| OPTION_MASK_P9_MINMAX \
| OPTION_MASK_P9_MISC \
| OPTION_MASK_P9_VECTOR \
+ | OPTION_MASK_PCREL \
| OPTION_MASK_POPCNTB \
| OPTION_MASK_POPCNTD \
| OPTION_MASK_POWERPC64 \
diff --git a/gcc/config/rs6000/rs6000-protos.h
b/gcc/config/rs6000/rs6000-protos.h
index 9718adaa2b9..18ece005a96 100644
--- a/gcc/config/rs6000/rs6000-protos.h
+++ b/gcc/config/rs6000/rs6000-protos.h
@@ -152,6 +152,8 @@ extern rtx rs6000_machopic_legitimize_pic_address (rtx,
machine_mode,
extern rtx rs6000_allocate_stack_temp (machine_mode, bool, bool);
extern align_flags rs6000_loop_align (rtx);
extern void rs6000_split_logical (rtx [], enum rtx_code, bool, bool, bool);
+extern bool rs6000_pcrel_p (struct function *);
+extern bool rs6000_fndecl_pcrel_p (const_tree);
#endif /* RTX_CODE */
#ifdef TREE_CODE
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 57c9eae8208..68abc81c354 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -4296,6 +4296,15 @@ rs6000_option_override_internal (bool global_init_p)
rs6000_isa_flags &= ~OPTION_MASK_FLOAT128_HW;
}
+ /* -mpcrel requires the prefixed load/store support on FUTURE systems. */
+ if (!TARGET_FUTURE && TARGET_PCREL)
+ {
+ if ((rs6000_isa_flags_explicit & OPTION_MASK_PCREL) != 0)
+ error ("%qs requires %qs", "-mpcrel", "-mcpu=future");
+
+ rs6000_isa_flags &= ~OPTION_MASK_PCREL;
+ }
+
/* Print the options after updating the defaults. */
if (TARGET_DEBUG_REG || TARGET_DEBUG_TARGET)
rs6000_print_isa_options (stderr, 0, "after defaults", rs6000_isa_flags);
@@ -38112,6 +38121,34 @@ rs6000_save_toc_in_prologue_p (void)
return (cfun && cfun->machine && cfun->machine->save_toc_in_prologue);
}
+/* Return whether we should generate PC-relative code for FNDECL. */
+bool
+rs6000_fndecl_pcrel_p (const_tree fndecl)
+{
+ if (DEFAULT_ABI != ABI_ELFv2)
+ return false;
+
+ struct cl_target_option *opts = target_opts_for_fn (fndecl);
+
+ return ((opts->x_rs6000_isa_flags & OPTION_MASK_PCREL) != 0
+ && TARGET_CMODEL == CMODEL_MEDIUM);
+}
+
+/* Return whether we should generate PC-relative code for *FN. */
+bool
+rs6000_pcrel_p (struct function *fn)
+{
+ if (DEFAULT_ABI != ABI_ELFv2)
+ return false;
+
+ /* Optimize usual case. */
+ if (fn == cfun)
+ return ((rs6000_isa_flags & OPTION_MASK_PCREL) != 0
+ && TARGET_CMODEL == CMODEL_MEDIUM);
+
+ return rs6000_fndecl_pcrel_p (fn->decl);
+}
+
#ifdef HAVE_GAS_HIDDEN
# define USE_HIDDEN_LINKONCE 1
#else
diff --git a/gcc/config/rs6000/rs6000.opt b/gcc/config/rs6000/rs6000.opt
index 196e75d7009..43b04834746 100644
--- a/gcc/config/rs6000/rs6000.opt
+++ b/gcc/config/rs6000/rs6000.opt
@@ -573,3 +573,7 @@ Target Undocumented Var(rs6000_speculate_indirect_jumps)
Init(1) Save
mfuture
Target Report Mask(FUTURE) Var(rs6000_isa_flags)
Use instructions for a future architecture.
+
+mpcrel
+Target Report Mask(PCREL) Var(rs6000_isa_flags)
+Generate (do not generate) pc-relative memory addressing.
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index fbbc4f829b7..c6ca0c7216a 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -1121,7 +1121,7 @@ See RS/6000 and PowerPC Options.
-mfloat128 -mno-float128 -mfloat128-hardware -mno-float128-hardware @gol
-mgnu-attribute -mno-gnu-attribute @gol
-mstack-protector-guard=@var{guard} -mstack-protector-guard-reg=@var{reg} @gol
--mstack-protector-guard-offset=@var{offset}}
+-mstack-protector-guard-offset=@var{offset} -mpcrel -mno-pcrel}
@emph{RX Options}
@gccoptlist{-m64bit-doubles -m32bit-doubles -fpu -nofpu@gol
@@ -25084,6 +25084,13 @@ which register to use as base register for reading the
canary, and from what
offset from that base register. The default for those is as specified in the
relevant ABI. @option{-mstack-protector-guard-symbol=@var{symbol}} overrides
the offset with a symbol reference to a canary in the TLS block.
+
+@item -mpcrel
+@itemx -mno-pcrel
+@opindex mpcrel
+@opindex mno-pcrel
+Generate (do not generate) pc-relative addressing when the option
+@option{-mcpu=future} is used.
@end table
@node RX Options
