From: IainS <idsandoe@googlemail.com>
To: gcc-patches List <gcc-patches@gcc.gnu.org>
Cc: mrs@gcc.gnu.org, Uros Bizjak <ubizjak@gmail.com>,
David Edelsohn <dje.gcc@gmail.com>,
Richard Henderson <rth@redhat.com>
Subject: Re: [Patch, darwin] do not generate branch islands when the linker can do it.
Date: Sat, 17 Jul 2010 18:10:00 -0000 [thread overview]
Message-ID: <C4754598-6935-43D4-8E47-E9416071E21D@sandoe-acoustics.co.uk> (raw)
In-Reply-To: <A06FF40A-AF29-4E56-8993-8241125599BF@sandoe-acoustics.co.uk>
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On 15 Jul 2010, at 20:34, IainS wrote:
> On 15 Jul 2010, at 19:44, Richard Henderson wrote:
>
>> On 07/15/2010 11:27 AM, IainS wrote:
>>> +#ifndef TARGET_MACHO_BRANCH_ISLANDS
>>> +# define TARGET_MACHO_BRANCH_ISLANDS 0
>>> +#endif
>>
>> This could go next to the TARGET_MACHO definition in i386.h, for
>> consistency.
>>
>> From a i386 maintainer perspective, I think this is ok. I'll defer
>> for ppc and darwin knowledge.
>
> FWIW: At your suggestion,
> since then I've built powerpc-unknown-linux-gnu (crossed from i6868-
> darwin9) and proved it can compile a trivial source file.
>
> (of course, the patch was already tested on powerpc-apple-darwin9
> as well)
consolidated patch with the amendments suggested by Richard, ...
... still needs rs6000 and darwin reviews.
thanks,
Iain
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Index: gcc/config/i386/darwin.h
===================================================================
--- gcc/config/i386/darwin.h (revision 162275)
+++ gcc/config/i386/darwin.h (working copy)
@@ -60,6 +60,12 @@ along with GCC; see the file COPYING3. If not see
#undef WCHAR_TYPE_SIZE
#define WCHAR_TYPE_SIZE 32
+/* Generate branch islands stubs if this is true. */
+extern int darwin_emit_branch_islands;
+
+#undef TARGET_MACHO_BRANCH_ISLANDS
+#define TARGET_MACHO_BRANCH_ISLANDS darwin_emit_branch_islands
+
#undef MAX_BITS_PER_WORD
#define MAX_BITS_PER_WORD 64
@@ -225,7 +231,7 @@ along with GCC; see the file COPYING3. If not see
#undef FUNCTION_PROFILER
#define FUNCTION_PROFILER(FILE, LABELNO) \
do { \
- if (MACHOPIC_INDIRECT && !TARGET_64BIT) \
+ if (TARGET_MACHO_BRANCH_ISLANDS && MACHOPIC_INDIRECT && !TARGET_64BIT) \
{ \
const char *name = machopic_mcount_stub_name (); \
fprintf (FILE, "\tcall %s\n", name+1); /* skip '&' */ \
Index: gcc/config/i386/i386.c
===================================================================
--- gcc/config/i386/i386.c (revision 162275)
+++ gcc/config/i386/i386.c (working copy)
@@ -11513,7 +11513,7 @@ output_pic_addr_const (FILE *file, rtx x, int code
break;
case SYMBOL_REF:
- if (! TARGET_MACHO || TARGET_64BIT)
+ if (TARGET_64BIT || ! TARGET_MACHO_BRANCH_ISLANDS)
output_addr_const (file, x);
else
{
@@ -27233,10 +27233,11 @@ x86_output_mi_thunk (FILE *file,
if (TARGET_MACHO)
{
rtx sym_ref = XEXP (DECL_RTL (function), 0);
- tmp = (gen_rtx_SYMBOL_REF
+ if (TARGET_MACHO_BRANCH_ISLANDS)
+ sym_ref = (gen_rtx_SYMBOL_REF
(Pmode,
machopic_indirection_name (sym_ref, /*stub_p=*/true)));
- tmp = gen_rtx_MEM (QImode, tmp);
+ tmp = gen_rtx_MEM (QImode, sym_ref);
xops[0] = tmp;
output_asm_insn ("jmp\t%0", xops);
}
Index: gcc/config/i386/i386.h
===================================================================
--- gcc/config/i386/i386.h (revision 162275)
+++ gcc/config/i386/i386.h (working copy)
@@ -477,6 +477,11 @@ extern tree x86_mfence;
redefines this to 1. */
#define TARGET_MACHO 0
+/* This is a options flag on darwin systems. */
+#ifndef TARGET_MACHO_BRANCH_ISLANDS
+#define TARGET_MACHO_BRANCH_ISLANDS 0
+#endif
+
/* Likewise, for the Windows 64-bit ABI. */
#define TARGET_64BIT_MS_ABI (TARGET_64BIT && ix86_cfun_abi () == MS_ABI)
Index: gcc/config/rs6000/darwin.h
===================================================================
--- gcc/config/rs6000/darwin.h (revision 162275)
+++ gcc/config/rs6000/darwin.h (working copy)
@@ -65,6 +65,9 @@
} \
while (0)
+/* Generate branch islands stubs if this is true. */
+extern int darwin_emit_branch_islands;
+
#define SUBTARGET_OVERRIDE_OPTIONS darwin_rs6000_override_options ()
#define C_COMMON_OVERRIDE_OPTIONS do { \
@@ -385,8 +388,6 @@
#define BLOCK_REG_PADDING(MODE, TYPE, FIRST) \
(!(FIRST) ? upward : FUNCTION_ARG_PADDING (MODE, TYPE))
-/* XXX: Darwin supports neither .quad, or .llong, but it also doesn't
- support 64 bit PowerPC either, so this just keeps things happy. */
#define DOUBLE_INT_ASM_OP "\t.quad\t"
/* For binary compatibility with 2.95; Darwin C APIs use bool from
Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c (revision 162275)
+++ gcc/config/rs6000/rs6000.c (working copy)
@@ -15392,7 +15392,8 @@ print_operand (FILE *file, rtx x, int code)
{
const char *name = XSTR (x, 0);
#if TARGET_MACHO
- if (MACHOPIC_INDIRECT
+ if (darwin_emit_branch_islands
+ && MACHOPIC_INDIRECT
&& machopic_classify_symbol (x) == MACHOPIC_UNDEFINED_FUNCTION)
name = machopic_indirection_name (x, /*stub_p=*/true);
#endif
@@ -24482,14 +24483,6 @@ get_prev_label (tree function_name)
return 0;
}
-#ifndef DARWIN_LINKER_GENERATES_ISLANDS
-#define DARWIN_LINKER_GENERATES_ISLANDS 0
-#endif
-
-/* KEXTs still need branch islands. */
-#define DARWIN_GENERATE_ISLANDS (!DARWIN_LINKER_GENERATES_ISLANDS \
- || flag_mkernel || flag_apple_kext)
-
/* INSN is either a function call or a millicode call. It may have an
unconditional jump in its delay slot.
@@ -24500,7 +24493,7 @@ output_call (rtx insn, rtx *operands, int dest_ope
int cookie_operand_number)
{
static char buf[256];
- if (DARWIN_GENERATE_ISLANDS
+ if (darwin_emit_branch_islands
&& GET_CODE (operands[dest_operand_number]) == SYMBOL_REF
&& (INTVAL (operands[cookie_operand_number]) & CALL_LONG))
{
Index: gcc/config/darwin.c
===================================================================
--- gcc/config/darwin.c (revision 162275)
+++ gcc/config/darwin.c (working copy)
@@ -79,6 +79,12 @@ along with GCC; see the file COPYING3. If not see
of MACHO_SYMBOL_STATIC for the code that handles @code{static}
symbol indirection. */
+/* For darwin >= 9 (OSX 10.5) the linker is capable of making the necessary
+ branch islands and we no longer need to emit darwin stubs.
+ However, if we are generating code for earlier systems (or for use in the
+ kernel) the stubs might still be required, and this will be set true. */
+int darwin_emit_branch_islands = false;
+
/* Section names. */
section * darwin_sections[NUM_DARWIN_SECTIONS];
@@ -625,6 +631,9 @@ machopic_indirect_data_reference (rtx orig, rtx re
rtx
machopic_indirect_call_target (rtx target)
{
+ if (! darwin_emit_branch_islands)
+ return target;
+
if (GET_CODE (target) != MEM)
return target;
@@ -1888,12 +1897,19 @@ darwin_override_options (void)
flag_exceptions = 0;
/* No -fnon-call-exceptions data in kexts. */
flag_non_call_exceptions = 0;
+ /* We still need to emit branch islands for kernel context. */
+ darwin_emit_branch_islands = true;
}
if (flag_var_tracking
&& strverscmp (darwin_macosx_version_min, "10.5") >= 0
&& debug_info_level >= DINFO_LEVEL_NORMAL
&& debug_hooks->var_location != do_nothing_debug_hooks.var_location)
flag_var_tracking_uninit = 1;
+
+ /* It is assumed that branch island stubs are needed for earlier systems. */
+ if (darwin_macosx_version_min
+ && strverscmp (darwin_macosx_version_min, "10.5") < 0)
+ darwin_emit_branch_islands = true;
}
/* Add $LDBL128 suffix to long double builtins. */
Index: gcc/config/darwin9.h
===================================================================
--- gcc/config/darwin9.h (revision 162275)
+++ gcc/config/darwin9.h (working copy)
@@ -44,9 +44,6 @@ along with GCC; see the file COPYING3. If not see
/* libSystem contains unwind information for signal frames. */
#define DARWIN_LIBSYSTEM_HAS_UNWIND
-/* The linker can generate branch islands. */
-#define DARWIN_LINKER_GENERATES_ISLANDS 1
-
#undef ASM_OUTPUT_ALIGNED_COMMON
#define ASM_OUTPUT_ALIGNED_COMMON(FILE, NAME, SIZE, ALIGN) \
do { \
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next prev parent reply other threads:[~2010-07-17 18:10 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-15 17:10 IainS
2010-07-15 17:38 ` Richard Henderson
2010-07-15 18:27 ` IainS
2010-07-15 18:44 ` Richard Henderson
2010-07-15 19:34 ` IainS
2010-07-17 18:10 ` IainS [this message]
2010-07-18 13:08 ` David Edelsohn
2010-07-18 13:20 ` Iain Sandoe
2010-07-18 18:18 ` Mike Stump
2010-07-19 9:13 ` IainS
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