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[PATCHv2] PowerPC: Add msingle-pic-base option.
- From: Joakim Tjernlund <Joakim dot Tjernlund at transmode dot se>
- To: gcc-patches at gcc dot gnu dot org, Michael Meissner <meissner at linux dot vnet dot ibm dot com>, Alan Modra <amodra at gmail dot com>, David Edelsohn <dje dot gcc at gmail dot com>, Dave Korn <dave dot korn dot cygwin at gmail dot com>
- Cc: Joakim Tjernlund <Joakim dot Tjernlund at transmode dot se>
- Date: Tue, 23 Nov 2010 16:36:49 +0100
- Subject: [PATCHv2] 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>
---
- Use Var instead of Mask and add some docs per
Michael Meissner <meissner@linux.vnet.ibm.com>
gcc/config/rs6000/rs6000.c | 7 ++++++-
gcc/config/rs6000/rs6000.opt | 4 ++++
gcc/doc/invoke.texi | 9 ++++++++-
3 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 63f8ef9..bf5b5d3 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_TOC && TARGET_MINIMAL_TOC)))
+ && TARGET_TOC && TARGET_MINIMAL_TOC
+ && !TARGET_SINGLE_PIC_BASE)))
|| (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