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Re: [PATCHv2] PowerPC: Add msingle-pic-base option.
David Edelsohn <dje.gcc@gmail.com> wrote on 2010/11/29 01:24:22:
>
> This patch is okay, but would you please make the order consistent in
> the first hunk so both are
>
> (reg == RS6000_PIC_OFFSET_TABLE_REGNUM
> && !TARGET_SINGLE_PIC_BASE
>
> Thanks, David
Sure, like this?
>From a9321d3549b5d29024c4bb011bf6e75903aef4e9 Mon Sep 17 00:00:00 2001
From: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
Date: Sat, 9 Oct 2010 12:45:39 +0200
Subject: [PATCHv3] PowerPC: Add msingle-pic-base option.
Do not generate fPIC/fpic prologue nor save
and restore PIC register.
Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
---
v2: Use Var instead of Mask and add some docs per
Michael Meissner <meissner@linux.vnet.ibm.com>
v3: Make order in if statement consistent.
gcc/config/rs6000/rs6000.c | 5 +++++
gcc/config/rs6000/rs6000.opt | 4 ++++
gcc/doc/invoke.texi | 9 ++++++++-
3 files changed, 17 insertions(+), 1 deletions(-)
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 63f8ef9..310d28b 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -16036,8 +16036,10 @@ rs6000_reg_live_or_pic_offset_p (int reg)
return ((df_regs_ever_live_p (reg)
&& (!call_used_regs[reg]
|| (reg == RS6000_PIC_OFFSET_TABLE_REGNUM
+ && !TARGET_SINGLE_PIC_BASE
&& TARGET_TOC && TARGET_MINIMAL_TOC)))
|| (reg == RS6000_PIC_OFFSET_TABLE_REGNUM
+ && !TARGET_SINGLE_PIC_BASE
&& ((DEFAULT_ABI == ABI_V4 && flag_pic != 0)
|| (DEFAULT_ABI == ABI_DARWIN && flag_pic))));
}
@@ -16737,6 +16739,9 @@ rs6000_emit_prologue (void)
insn = emit_insn (generate_set_vrsave (reg, info, 0));
}
+ if (TARGET_SINGLE_PIC_BASE)
+ return; /* Do not set PIC register */
+
/* If we are using RS6000_PIC_OFFSET_TABLE_REGNUM, we need to set it up. */
if ((TARGET_TOC && TARGET_MINIMAL_TOC && get_pool_size () != 0)
|| (DEFAULT_ABI == ABI_V4
diff --git a/gcc/config/rs6000/rs6000.opt b/gcc/config/rs6000/rs6000.opt
index 8a62352..2adb6dd 100644
--- a/gcc/config/rs6000/rs6000.opt
+++ b/gcc/config/rs6000/rs6000.opt
@@ -119,6 +119,10 @@ mupdate
Target Report RejectNegative InverseMask(NO_UPDATE, UPDATE)
Generate load/store with update instructions
+msingle-pic-base
+Target Report Var(TARGET_SINGLE_PIC_BASE) Init(0)
+Do not load the PIC register in function prologues
+
mavoid-indexed-addresses
Target Report Var(TARGET_AVOID_XFORM) Init(-1)
Avoid generation of indexed load/store instructions when possible
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 393e418..fc30537 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -728,7 +728,7 @@ See RS/6000 and PowerPC Options.
-mstrict-align -mno-strict-align -mrelocatable @gol
-mno-relocatable -mrelocatable-lib -mno-relocatable-lib @gol
-mtoc -mno-toc -mlittle -mlittle-endian -mbig -mbig-endian @gol
--mdynamic-no-pic -maltivec -mswdiv @gol
+-mdynamic-no-pic -maltivec -mswdiv -msingle-pic-base @gol
-mprioritize-restricted-insns=@var{priority} @gol
-msched-costly-dep=@var{dependence_type} @gol
-minsert-sched-nops=@var{scheme} @gol
@@ -14129,6 +14129,13 @@ relocatable, but that its external references are relocatable. The
resulting code is suitable for applications, but not shared
libraries.
+@item -msingle-pic-base
+@opindex msingle-pic-base
+Treat the register used for PIC addressing as read-only, rather than
+loading it in the prologue for each function. The run-time system is
+responsible for initializing this register with an appropriate value
+before execution begins.
+
@item -mprioritize-restricted-insns=@var{priority}
@opindex mprioritize-restricted-insns
This option controls the priority that is assigned to
--
1.7.2.2