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[RS6000] Make -msingle-pic-base remove the ELFv2 global entry code
- From: Alan Modra <amodra at gmail dot com>
- To: gcc-patches at gcc dot gnu dot org
- Cc: David Edelsohn <dje dot gcc at gmail dot com>
- Date: Wed, 30 Sep 2015 15:41:35 +0930
- Subject: [RS6000] Make -msingle-pic-base remove the ELFv2 global entry code
- Authentication-results: sourceware.org; auth=none
For other ABIs, -msingle-pic-base makes gcc omit loading of the PIC
register in function prologues. This patch makes the option affect
ELFv2 too.
I wrote a patch like this during the initial ELFv2 effort, but there
were many more important patches to push and this one somehow got
dropped. Dusted off and retested at the request of powerpc64 kernel
people who'd like an option to disable ELFv2 global entry code for
the kernel. OK mainline?
* config/rs6000/rs6000.c (rs6000_emit_prologue): Don't set
r2_setup_needed when TARGET_SINGLE_PIC_BASE.
(rs6000_output_mi_thunk): Likewise.
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index ae456ff..023f622 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -24118,13 +24118,13 @@ rs6000_emit_prologue (void)
#define NOT_INUSE(R) do {} while (0)
#endif
- if (DEFAULT_ABI == ABI_ELFv2)
+ if (DEFAULT_ABI == ABI_ELFv2
+ && !TARGET_SINGLE_PIC_BASE)
{
cfun->machine->r2_setup_needed = df_regs_ever_live_p (TOC_REGNUM);
/* With -mminimal-toc we may generate an extra use of r2 below. */
- if (!TARGET_SINGLE_PIC_BASE
- && TARGET_TOC && TARGET_MINIMAL_TOC && get_pool_size () != 0)
+ if (TARGET_TOC && TARGET_MINIMAL_TOC && get_pool_size () != 0)
cfun->machine->r2_setup_needed = true;
}
@@ -26800,7 +26800,8 @@ rs6000_output_mi_thunk (FILE *file, tree thunk_fndecl ATTRIBUTE_UNUSED,
/* Ensure we have a global entry point for the thunk. ??? We could
avoid that if the target routine doesn't need a global entry point,
but we do not know whether this is the case at this point. */
- if (DEFAULT_ABI == ABI_ELFv2)
+ if (DEFAULT_ABI == ABI_ELFv2
+ && !TARGET_SINGLE_PIC_BASE)
cfun->machine->r2_setup_needed = true;
/* Run just enough of rest_of_compilation to get the insns emitted.
--
Alan Modra
Australia Development Lab, IBM