forked from pool/gcc13
202 lines
8.3 KiB
Diff
202 lines
8.3 KiB
Diff
|
From 1807ab6f3a5028ef0b7b30a37e947ea2c9d2bb18 Mon Sep 17 00:00:00 2001
|
|||
|
|
From: Richard Biener <rguenther@suse.de>
|
|||
|
|
Date: Wed, 13 Nov 2024 16:04:06 +0100
|
|||
|
|
Subject: [PATCH] rs6000: Add -msplit-patch-nops (PR112980)
|
|||
|
|
To: gcc-patches@gcc.gnu.org
|
|||
|
|
|
|||
|
|
From: Michael Matz <matz@suse.de>
|
|||
|
|
|
|||
|
|
as the bug report details some uses of -fpatchable-function-entry
|
|||
|
|
aren't happy with the "before" NOPs being inserted between global and
|
|||
|
|
local entry point on powerpc. We want the before NOPs be in front
|
|||
|
|
of the global entry point. That means that the patching NOPs aren't
|
|||
|
|
consecutive for dual entry point functions, but for these usecases
|
|||
|
|
that's not the problem. But let us support both under the control
|
|||
|
|
of a new target option: -msplit-patch-nops.
|
|||
|
|
|
|||
|
|
gcc/
|
|||
|
|
|
|||
|
|
PR target/112980
|
|||
|
|
* config/rs6000/rs6000.opt (msplit-patch-nops): New option.
|
|||
|
|
* doc/invoke.texi (RS/6000 and PowerPC Options): Document it.
|
|||
|
|
* config/rs6000/rs6000.h (machine_function.stop_patch_area_print):
|
|||
|
|
New member.
|
|||
|
|
* config/rs6000/rs6000.cc (rs6000_print_patchable_function_entry):
|
|||
|
|
Emit split nops under control of that one.
|
|||
|
|
* config/rs6000/rs6000-logue.cc (rs6000_output_function_prologue):
|
|||
|
|
Add handling of split patch nops.
|
|||
|
|
---
|
|||
|
|
gcc/config/rs6000/rs6000-logue.cc | 15 +++++++++------
|
|||
|
|
gcc/config/rs6000/rs6000.cc | 27 +++++++++++++++++++++++----
|
|||
|
|
gcc/config/rs6000/rs6000.h | 6 ++++++
|
|||
|
|
gcc/config/rs6000/rs6000.opt | 4 ++++
|
|||
|
|
gcc/doc/invoke.texi | 17 +++++++++++++++--
|
|||
|
|
5 files changed, 57 insertions(+), 12 deletions(-)
|
|||
|
|
|
|||
|
|
diff --git a/gcc/config/rs6000/rs6000-logue.cc b/gcc/config/rs6000/rs6000-logue.cc
|
|||
|
|
index 208404e6864..0c3425fdd9a 100644
|
|||
|
|
--- a/gcc/config/rs6000/rs6000-logue.cc
|
|||
|
|
+++ b/gcc/config/rs6000/rs6000-logue.cc
|
|||
|
|
@@ -4003,8 +4003,8 @@ rs6000_output_function_prologue (FILE *file)
|
|||
|
|
|
|||
|
|
unsigned short patch_area_size = crtl->patch_area_size;
|
|||
|
|
unsigned short patch_area_entry = crtl->patch_area_entry;
|
|||
|
|
- /* Need to emit the patching area. */
|
|||
|
|
- if (patch_area_size > 0)
|
|||
|
|
+ /* Emit non-split patching area now. */
|
|||
|
|
+ if (!TARGET_SPLIT_PATCH_NOPS && patch_area_size > 0)
|
|||
|
|
{
|
|||
|
|
cfun->machine->global_entry_emitted = true;
|
|||
|
|
/* As ELFv2 ABI shows, the allowable bytes between the global
|
|||
|
|
@@ -4025,7 +4025,6 @@ rs6000_output_function_prologue (FILE *file)
|
|||
|
|
patch_area_entry);
|
|||
|
|
rs6000_print_patchable_function_entry (file, patch_area_entry,
|
|||
|
|
true);
|
|||
|
|
- patch_area_size -= patch_area_entry;
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
@@ -4035,9 +4034,13 @@ rs6000_output_function_prologue (FILE *file)
|
|||
|
|
assemble_name (file, name);
|
|||
|
|
fputs ("\n", file);
|
|||
|
|
/* Emit the nops after local entry. */
|
|||
|
|
- if (patch_area_size > 0)
|
|||
|
|
- rs6000_print_patchable_function_entry (file, patch_area_size,
|
|||
|
|
- patch_area_entry == 0);
|
|||
|
|
+ if (patch_area_size > patch_area_entry)
|
|||
|
|
+ {
|
|||
|
|
+ patch_area_size -= patch_area_entry;
|
|||
|
|
+ cfun->machine->stop_patch_area_print = false;
|
|||
|
|
+ rs6000_print_patchable_function_entry (file, patch_area_size,
|
|||
|
|
+ patch_area_entry == 0);
|
|||
|
|
+ }
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
else if (rs6000_pcrel_p ())
|
|||
|
|
diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
|
|||
|
|
index 2b876c90e6f..e6fbfe76e19 100644
|
|||
|
|
--- a/gcc/config/rs6000/rs6000.cc
|
|||
|
|
+++ b/gcc/config/rs6000/rs6000.cc
|
|||
|
|
@@ -14937,11 +14937,25 @@ rs6000_print_patchable_function_entry (FILE *file,
|
|||
|
|
{
|
|||
|
|
bool global_entry_needed_p = rs6000_global_entry_point_prologue_needed_p ();
|
|||
|
|
/* For a function which needs global entry point, we will emit the
|
|||
|
|
- patchable area before and after local entry point under the control of
|
|||
|
|
- cfun->machine->global_entry_emitted, see the handling in function
|
|||
|
|
- rs6000_output_function_prologue. */
|
|||
|
|
- if (!global_entry_needed_p || cfun->machine->global_entry_emitted)
|
|||
|
|
+ patchable area when it isn't split before and after local entry point
|
|||
|
|
+ under the control of cfun->machine->global_entry_emitted, see the
|
|||
|
|
+ handling in function rs6000_output_function_prologue. */
|
|||
|
|
+ if (!TARGET_SPLIT_PATCH_NOPS
|
|||
|
|
+ && (!global_entry_needed_p || cfun->machine->global_entry_emitted))
|
|||
|
|
default_print_patchable_function_entry (file, patch_area_size, record_p);
|
|||
|
|
+
|
|||
|
|
+ /* For split patch nops we emit the before nops (from generic code)
|
|||
|
|
+ in front of the global entry point and after the local entry point,
|
|||
|
|
+ under the control of cfun->machine->stop_patch_area_print, see
|
|||
|
|
+ rs6000_output_function_prologue and rs6000_elf_declare_function_name. */
|
|||
|
|
+ if (TARGET_SPLIT_PATCH_NOPS)
|
|||
|
|
+ {
|
|||
|
|
+ if (!cfun->machine->stop_patch_area_print)
|
|||
|
|
+ default_print_patchable_function_entry (file, patch_area_size,
|
|||
|
|
+ record_p);
|
|||
|
|
+ else
|
|||
|
|
+ gcc_assert (global_entry_needed_p);
|
|||
|
|
+ }
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
enum rtx_code
|
|||
|
|
@@ -21115,6 +21129,11 @@ rs6000_elf_declare_function_name (FILE *file, const char *name, tree decl)
|
|||
|
|
fprintf (file, "\t.previous\n");
|
|||
|
|
}
|
|||
|
|
ASM_OUTPUT_LABEL (file, name);
|
|||
|
|
+ /* At this time, the "before" NOPs have been already emitted.
|
|||
|
|
+ For split nops stop generic code from printing the "after" NOPs and
|
|||
|
|
+ emit them just after local entry ourself later. */
|
|||
|
|
+ if (rs6000_global_entry_point_prologue_needed_p ())
|
|||
|
|
+ cfun->machine->stop_patch_area_print = true;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
static void rs6000_elf_file_end (void) ATTRIBUTE_UNUSED;
|
|||
|
|
diff --git a/gcc/config/rs6000/rs6000.h b/gcc/config/rs6000/rs6000.h
|
|||
|
|
index b8edba43d53..b5dae276420 100644
|
|||
|
|
--- a/gcc/config/rs6000/rs6000.h
|
|||
|
|
+++ b/gcc/config/rs6000/rs6000.h
|
|||
|
|
@@ -2443,6 +2443,12 @@ typedef struct GTY(()) machine_function
|
|||
|
|
global entry. It helps to control the patchable area before and after
|
|||
|
|
local entry. */
|
|||
|
|
bool global_entry_emitted;
|
|||
|
|
+ /* With ELFv2 ABI dual entry points being adopted, generic framework
|
|||
|
|
+ targetm.asm_out.print_patchable_function_entry would generate "after"
|
|||
|
|
+ NOPs before local entry, which is wrong. This flag is to stop it from
|
|||
|
|
+ printing patch area before local entry, it is only useful when the
|
|||
|
|
+ function requires dual entry points. */
|
|||
|
|
+ bool stop_patch_area_print;
|
|||
|
|
} machine_function;
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
diff --git a/gcc/config/rs6000/rs6000.opt b/gcc/config/rs6000/rs6000.opt
|
|||
|
|
index 52507956a4d..6acd8c3c5ff 100644
|
|||
|
|
--- a/gcc/config/rs6000/rs6000.opt
|
|||
|
|
+++ b/gcc/config/rs6000/rs6000.opt
|
|||
|
|
@@ -300,6 +300,10 @@ mfull-toc
|
|||
|
|
Target
|
|||
|
|
Put everything in the regular TOC.
|
|||
|
|
|
|||
|
|
+msplit-patch-nops
|
|||
|
|
+Target Var(TARGET_SPLIT_PATCH_NOPS) Init(0)
|
|||
|
|
+Emit NOPs before global and after local entry point for -fpatchable-function-entry.
|
|||
|
|
+
|
|||
|
|
mvrsave
|
|||
|
|
Target Var(TARGET_ALTIVEC_VRSAVE) Save
|
|||
|
|
Generate VRSAVE instructions when generating AltiVec code.
|
|||
|
|
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
|
|||
|
|
index 89d4b24dd74..1b0cd6c8e26 100644
|
|||
|
|
--- a/gcc/doc/invoke.texi
|
|||
|
|
+++ b/gcc/doc/invoke.texi
|
|||
|
|
@@ -1265,6 +1265,7 @@ See RS/6000 and PowerPC Options.
|
|||
|
|
-mtraceback=@var{traceback_type}
|
|||
|
|
-maix-struct-return -msvr4-struct-return
|
|||
|
|
-mabi=@var{abi-type} -msecure-plt -mbss-plt
|
|||
|
|
+-msplit-patch-nops
|
|||
|
|
-mlongcall -mno-longcall -mpltseq -mno-pltseq
|
|||
|
|
-mblock-move-inline-limit=@var{num}
|
|||
|
|
-mblock-compare-inline-limit=@var{num}
|
|||
|
|
@@ -17449,11 +17450,12 @@ If @code{N=0}, no pad location is recorded.
|
|||
|
|
The NOP instructions are inserted at---and maybe before, depending on
|
|||
|
|
@var{M}---the function entry address, even before the prologue. On
|
|||
|
|
PowerPC with the ELFv2 ABI, for a function with dual entry points,
|
|||
|
|
-the local entry point is this function entry address.
|
|||
|
|
+the local entry point is this function entry address by default. See
|
|||
|
|
+the @option{-msplit-patch-nops} option to change this.
|
|||
|
|
|
|||
|
|
The maximum value of @var{N} and @var{M} is 65535. On PowerPC with the
|
|||
|
|
ELFv2 ABI, for a function with dual entry points, the supported values
|
|||
|
|
-for @var{M} are 0, 2, 6 and 14.
|
|||
|
|
+for @var{M} are 0, 2, 6 and 14 when not using @option{-msplit-patch-nops}.
|
|||
|
|
@end table
|
|||
|
|
|
|||
|
|
|
|||
|
|
@@ -29486,6 +29488,17 @@ requires @code{.plt} and @code{.got}
|
|||
|
|
sections that are both writable and executable.
|
|||
|
|
This is a PowerPC 32-bit SYSV ABI option.
|
|||
|
|
|
|||
|
|
+@opindex msplit-patch-nops
|
|||
|
|
+@item -msplit-patch-nops
|
|||
|
|
+When adding NOPs for a patchable area via the
|
|||
|
|
+@option{-fpatchable-function-entry} option emit the ``before'' NOPs in front
|
|||
|
|
+of the global entry point and the ``after'' NOPs after the local entry point.
|
|||
|
|
+This makes the sequence of NOPs not consecutive when a global entry point
|
|||
|
|
+is generated. Without this option the NOPs are emitted directly before and
|
|||
|
|
+after the local entry point, making them consecutive but moving global and
|
|||
|
|
+local entry point further apart. If only a single entry point is generated
|
|||
|
|
+this option has no effect.
|
|||
|
|
+
|
|||
|
|
@opindex misel
|
|||
|
|
@opindex mno-isel
|
|||
|
|
@item -misel
|
|||
|
|
--
|
|||
|
|
2.43.0
|
|||
|
|
|